WO2003079107A1

WO2003079107A1 - Semiconductor device manufacturing method, semiconductor device, and liquid crystal display

Info

Publication number: WO2003079107A1
Application number: PCT/JP2003/003381
Authority: WO
Inventors: Hideo Tanaka; Yoshihisa Hatta
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2002-03-19
Filing date: 2003-03-19
Publication date: 2003-09-25
Also published as: TW200402756A; AU2003221122A1

Abstract

A semiconductor device having a reflection electrode and its manufacturing method are disclosed. A passivation film (8) is etched by using an underlying film (9) on a substrate as an etching mask to make a hole (8a) in the passivation film (8). A hole (9a) in the underlying film (9) is made to communicate with the hole (8a) in the passivation film to form a reflection electrode (10) connected to a drain electrode (7). Thus, the man-hours and cost of the manufacture are reduced. The invention can be applied to semi-transparent liquid crystal displays and reflection liquid crystal displays.

Description

Description: Semiconductor device manufacturing method, semiconductor device, and liquid crystal display device

The present invention relates to a method for manufacturing a semiconductor device having a reflective electrode, a semiconductor device, and a liquid crystal display device. Background art

Conventionally, liquid crystal display devices, such as reflective liquid crystal display devices and transflective liquid crystal display devices, which display images by reflecting external light, are provided with a reflective electrode for reflecting external light for each pixel. I have. Such a liquid crystal display device has a large number of concave portions or convex portions on the surface of the reflective electrode for the purpose of improving light use efficiency. Further, the reflective electrode is connected to the TFT so as to serve to apply a voltage supplied from the TFT to the liquid crystal layer. Such a reflective electrode is formed, for example, through the following steps.

First, a TFT having a gate electrode, a source electrode, and a drain electrode is formed on a substrate, and an insulating film covering the TFT is formed. Next, the insulating film is patterned by a photolithography process so that a contact hole for connecting the TFT drain electrode and the reflective electrode is formed in the insulating film. Thereafter, a photosensitive resin, which is a material of a base film of the reflective electrode, is applied to the surface of the insulating film, and the applied photosensitive resin is patterned to form a base film of the reflective electrode. On the surface of the base film thus formed, a reflection electrode connected to the drain electrode is formed via a contact hole formed in the insulating film.

In the above method, it is necessary to perform exposure and development each time the insulating film patterning step and the photosensitive resin patterning step are performed, and there is a problem that the number of manufacturing steps and the manufacturing cost increase. Disclosure of the invention

In view of the above circumstances, an object of the present invention is to provide a method in which the number of manufacturing steps and manufacturing cost are reduced, and an apparatus to which the method is applied.

A method of manufacturing a semiconductor device according to the present invention, which achieves the above object, comprises: manufacturing a semiconductor device including, on a substrate, a transistor having a gate electrode, a source electrode, and a drain electrode; A method comprising: forming the source electrode and the drain electrode on the substrate; forming a first insulating film on the substrate on which the source electrode and the drain electrode are formed; On the substrate on which the first insulating film is formed, a base film of the reflective electrode, a first hole at a position corresponding to the drain electrode, and a plurality of concave or convex portions on the surface. Forming a ground film, and etching the base film so that a first communication hole continuously following the first hole is formed at a position of the first insulating film corresponding to the drain electrode. trout A step of etching the first insulating film, and a reflective electrode covering a part of the surface of the base film on the substrate having the first insulating film in which the first communication hole is formed. Forming the reflective electrode connected to the drain electrode through the first hole and the first communication hole.

The base film of the reflective electrode has a plurality of concave portions or convex portions on its surface. Therefore, by forming a reflective electrode on the base film, the reflective electrode can have a plurality of concave portions or convex portions according to the shape of the surface of the underlying film. Further, the base film is also used as an etching mask for forming a first communication hole in the first insulating film. Therefore, after forming the first insulating film and before forming the base film, a special photoresist process for forming the first communication hole in the first insulating film becomes unnecessary, and the number of manufacturing steps is reduced. As a result, production costs can be reduced.

Here, in the method of manufacturing a semiconductor device according to the present invention, the etching step may be configured such that an inner wall surface of the first communication hole of the first insulating film is inclined with respect to the substrate. 03 03381

Third, it is preferable to perform a step of taper etching the first insulating film.

By performing the taper etching, the step coverage in the first communication hole of the reflection electrode can be easily improved.

Here, in the method of manufacturing a semiconductor device according to the present invention, the step of performing the taper etching includes the step of using the first gas using a mixed gas containing an etching gas containing a hydrocarbon-based gas having fluorine and a carrier gas. It is preferable to taper-etch the insulating film.

By including a hydrocarbon-based gas having fluorine in the etching gas, the taper angle of the inner wall surface of the first communication hole formed in the first insulating film can be easily controlled. Further, by mixing the carrier gas into the mixed gas, the etching rate of the base film can be made sufficiently lower than the etching rate of the first insulating film. Therefore, deformation of the shape of the surface of the base film is minimized, and it is possible to make the reflective electrode have good reflection characteristics.

Further, the method of manufacturing a semiconductor device of the present invention may include a step of forming the gate electrode on the substrate before the step of forming the source electrode and the drain electrode. After the step of forming the insulating film, before the step of forming the base film, a step of forming the gate electrode on the substrate on which the first insulating film is formed may be provided.

With the above steps, a bottom-gate or top-gate transistor can be manufactured.

Further, in the method for manufacturing a semiconductor device according to the present invention, before the step of forming the source electrode and the drain electrode, a conductive light-shielding film having conductivity on the substrate corresponds to the gate electrode. Forming a conductive light-shielding film having a first portion and a second portion connected to the first portion; and forming the conductive light-shielding film; and forming the source electrode and the drain. Before the step of forming the electrodes, after the step of forming a second insulating film on the substrate on which the conductive light-shielding film is formed, and the step of forming the first insulating film, the base film is removed. Before the forming step, Forming a gate line connected to the good electrode and the good electrode on the substrate on which the insulating film is formed, wherein the step of forming the base film comprises: Forming a second hole at a position corresponding to the second portion of the conductive light-shielding film, and forming a third hole at a position of the base film corresponding to the gut line; In the etching step, a second communication hole continuous with the second hole is formed at a position of the first insulating film corresponding to the second portion of the conductive light-shielding film, Etching the base film so that a third communication hole continuous with the second communication hole is formed at a position of the insulating film corresponding to the second portion of the conductive light-shielding film. Further comprising a step of etching the first and second insulating films as an etching mask, The step of forming the reflective electrode includes connecting the conductive light-shielding film and the gate line through the third hole, the second hole, the second communication hole, and the third communication hole. It is preferable that the method further includes a step of forming a conductive portion.

With the above steps, a double-gate transistor can be manufactured.

Another method for manufacturing a semiconductor device of the present invention includes a transistor having a gate electrode, a source electrode, and a drain electrode on a substrate; a conductive light-transmitting film connected to the drain electrode and having conductivity. A method of manufacturing a semiconductor device comprising: a reflective electrode connected to the conductive light transmitting film; and a step of forming the source electrode and the drain electrode on the substrate; A conductive light-transmitting film connected to the drain electrode on a substrate on which an electrode is formed, the first part being connected to the drain electrode; and the drain being connected to the first part and being connected to the drain. Forming the conductive light-transmitting film having an electrode and a second portion extending to a region other than the region corresponding to the source electrode; and a substrate having the conductive light-transmitting film formed thereon. Forming a third insulating film on the substrate, and forming a base film of the reflective electrode on the substrate on which the third insulating film is formed, the base film corresponding to the second portion of the conductive light transmitting film. Fourth hole in position and multiple recesses in surface Forming a base film having a concave portion or a convex portion; and forming a third film continuously following the fourth hole at a position of the third insulating film corresponding to the second portion of the conductive light transmitting film. Etching the third insulating film using the base film as an etching mask so that the fourth communication hole is formed, and forming the fourth insulating film on the substrate having the fourth communication hole. characterized by comprising a step of forming the reflective electrode connected to the conductive light transmissive film through the underlying film partially covering and the ^fourth hole and the fourth through hole of the surface of the .

According to this method, after forming the insulating film and before forming the base film, a dedicated photoresist process for forming the first communication hole in the insulating film becomes unnecessary, and the number of manufacturing steps and the manufacturing cost are reduced. Is reduced.

Further, a semiconductor device of the present invention is manufactured by using the method of manufacturing a semiconductor device according to any one of claims 1 to 7.

Furthermore, a liquid crystal display device of the present invention is characterized by being configured using the semiconductor device according to claim 8. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a partial cross-sectional view of a reflective liquid crystal display device manufactured by using the first embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 2 is a cross-sectional view of the glass substrate 1 on which TFT 50 is formed.

FIG. 3 is a cross-sectional view of the substrate on which the passivation film 8 is formed.

FIG. 4 is a cross-sectional view of the substrate on which the base film 9 is formed.

FIG. 5 is a cross-sectional view of the substrate after the passivation film 8 has been etched. FIG. 6 is a cross-sectional view showing the substrate on which the reflective electrode 10 is formed.

FIG. 7 is a partial cross-sectional view of a transflective liquid crystal display device manufactured by using the second embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 8 is a cross-sectional view showing the substrate on which the ITO film 21 has been formed.

FIG. 9 is a cross-sectional view showing the substrate on which the passivation film 22 is formed. FIG. 10 is a cross-sectional view of the substrate on which the base film 23 is formed.

FIG. 11 is a cross-sectional view of the substrate after the passivation film 22 has been etched.

FIG. 12 is a partial cross-sectional view of a top gate type liquid crystal display device manufactured using the third embodiment of the method for manufacturing a semiconductor device of the present invention.

FIG. 13 is a cross-sectional view showing the substrate on which the source electrode 61, the drain electrode 62, the semiconductor film 63, and the SiN film 64 are formed.

FIG. 14 is a cross-sectional view of the substrate on which the insulating film 65 is formed.

FIG. 15 is a cross-sectional view of the substrate on which the gate electrode 66 is formed.

FIG. 16 is a cross-sectional view of the substrate on which the base film 67 is formed.

FIG. 17 is a cross-sectional view of the substrate after the insulating film 65 has been etched.

FIG. 18 is a cross-sectional view showing the substrate on which the reflective electrode 68 is formed.

FIG. 19 is a plot showing the reflection characteristics of the TFT substrate 600 and the conventional TFT substrate.

FIG. 20 is a plan view of a TFT substrate 100 having a double gate structure. FIG. 21 is a cross-sectional view taken along line AA of FIG.

FIG. 22 is a cross-sectional view taken along line BB of FIG.

FIG. 23 is a plan view showing the substrate 1 on which the light shielding film 101 is formed.

FIG. 24 is a cross-sectional view taken along line CC of FIG.

FIG. 25 is a cross-sectional view showing the substrate on which the SiO ₂ film 102 is formed.

FIG. 26 is a plan view showing the substrate on which the source electrode 103, the source line 104, and the drain electrode 105 are formed.

FIG. 27 is a sectional view taken along line DD in FIG.

FIG. 28 is a plan view showing the substrate on which the gate electrode 109 is formed.

FIG. 29 is a cross-sectional view taken along the line EE of FIG.

FIG. 30 is a plan view showing the substrate on which the base film 112 is formed.

FIG. 31 is a sectional view taken along line FF of FIG. FIG. 32 is a sectional view taken along line GG of FIG.

FIG. 33 is a cross-sectional view corresponding to FIG.

FIG. 34 is a cross-sectional view corresponding to FIG. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described.

This liquid crystal display device has a TFT substrate 51 on which a TFT 50 and a reflective electrode 10 are formed, and a color filter substrate 52 on which a color filter and the like are formed. A large number of concave portions 10a and convex portions 1Ob are provided on the surface of the reflective electrode 10. Since the structure of the color filter substrate 52 is irrelevant to the features of the present embodiment, it is shown in a simplified manner in FIG. A liquid crystal layer 53 exists between the TFT substrate 51 and the color filter substrate 52. Hereinafter, a method of manufacturing the TFT substrate 51 having the features of the present embodiment will be described.

First, a TFT 50 is formed on a glass substrate 1 (see FIG. 2).

FIG. 2 is a sectional view of the glass substrate 1 on which the TFT 50 is formed.

The TFT 50 includes, for example, a gate electrode 2, a gate insulating film 3, a semiconductor film 4 such as a-Si: H or a—Si: F, a ohmic contact layer 5, and a source electrode 6 on a glass substrate 1. And the drain electrode 7 is formed. Although a gate line and a source line are also formed on the glass substrate 1, these lines are not shown.

After manufacturing the TFT 50, a passivation film is formed so as to cover the TFT 50 (see FIG. 3).

In the present embodiment, a silicon nitride film is used as the passivation film 8 (corresponding to the first insulating film in the present invention). Since the drain electrode 7 existing under the passivation film 8 needs to be connected to a reflective electrode 10 (see FIG. 6) described later, the passivation film 8 includes the drain electrode 7 and the reflective electrode 10. It is necessary to form a hole for connecting However, in the present embodiment, before forming a hole in the passivation film 8, a base film for providing a large number of concave portions 10 a and convex portions 10 b (see FIG. 6) on the surface of the reflective electrode 10 is formed. Form first (see Figure 4).

The base film 9 has a hole 9 a (corresponding to the first hole according to the present invention) at a position corresponding to the drain electrode 7. A portion 9b and a convex portion 9c are provided. In order to form such a base film 9, for example, a photosensitive resin is applied to the surface of the passivation film 8, a portion corresponding to the hole 9a of the applied photosensitive resin, a portion corresponding to the concave portion 9b, The applied photosensitive resin is exposed such that the portions corresponding to the projections 9c absorb different exposure energies. By developing and baking the photosensitive resin thus exposed, the base film 9 having the holes 9a, the concave portions 9b, and the convex portions 9c can be formed as shown in FIG. Since a large number of concave portions 9 b and convex portions 9 c are provided on the surface of the base film 9, the inclination angle of the surface of the base film 9 changes continuously. The reflection electrode 10 (see FIG. 6), which will be described later, is formed on the surface of the base film 9 where the inclination angle (¾ continuously changes), so that the reflection characteristics of the reflection electrode 10 are as follows. It largely depends on the inclination angle α of the surface of the ground film 9. Therefore, by changing the inclination angle α of the base film 9, it becomes possible to change the reflection characteristics of the reflective electrode 10. The inclination angle α For example, change the exposure energy absorbed in the portion corresponding to the concave portion 9b of the applied photosensitive resin and / or the exposure energy absorbed in the portion corresponding to the convex portion 9c of the applied photosensitive resin. In order for the reflective electrode 10 to have good reflection characteristics, the inclination angle α of the base film 9 should be within a range of 0 ° and 15 ° as much as possible. Therefore, in the present embodiment, the inclination of the base film 9 is preferred. Catching only 0 Doc can Kakuhi The base film 9 is formed so as to be included in the range of 15 degrees.

The method of forming the base film 9 having a large number of the concave portions 9 b and the convex portions 9 c is not limited to the above-described method. For example, before the photosensitive resin that is the material of the base film 9 is applied. Alternatively, a number of protrusions may be formed first, and a photosensitive resin as a material of the base film 9 may be applied so as to cover the number of protrusions. By forming a large number of projections first, a photosensitive resin as a material of the base film 9 is applied so as to follow the shape of these projections, and as a result, a large number of depressions and projections are formed on the surface. It is possible to form an underlying film having the following.

After forming the base film 9, the passivation film 8 is etched (see FIG. 5). FIG. 5 is a cross-sectional view of the substrate after the passivation film 8 has been etched. Since the holes 9a are formed in the base film 9, the passivation film 8 is etched using the base film 9 as an etching mask, so that the passivation film 8 is continuous with the holes 9a of the base film 9. A continuous hole 8a (corresponding to the first communication hole in the present invention) is formed. By forming the holes 8 a in the passivation film 8, the drain electrodes 7 are exposed. In the present embodiment, 3 ₆ and. The passivation film 8 is etched by a dry etching apparatus using a mixed gas of an etching gas containing HF ₃ and a carrier gas such as He (SF ₆ : CHF ₃ : He = 12.5: 12.5: 75). ing. By etching the passivation film 8 using not only SF ₆ but also CHF ₃ as an etching gas, it is possible to easily perform taper etching so that the inner wall surface 8 b of the hole 8 a is inclined with respect to the surface of the substrate 1. Can be. As the dry etching apparatus, for example, a reactive ion etching (RIE) apparatus, an inductively coupled plasma etching (ICP) apparatus, a high-density plasma etching apparatus, or the like can be used. In this embodiment, the {taper angle of the wall surface 8b} is about 70 degrees. By performing the taper etching, the step coverage in the hole 8a of the later-described reflective electrode 10 (see FIG. 6) can be improved. The taper angle 0 can be changed, for example, by changing the mixing amount of CH ₃ gas. Also, the real 1

10 In the embodiment, the CHF ₃ gas is used in order to easily perform the taper etching of the passivation film 8, but for example, a C ₂ HF ₅ gas may be used instead of the CHF ₃ gas. it can.

As described above, the base film 9 plays a role as an etching mask for the passivation film 8, but this base film 9 is good not only for the role of the etching mask but also for the reflective electrode 10 (see FIG. 6) described later. It is also necessary to play a role as a base film for providing high reflection characteristics. However, if the underlying film 9 is also etched while the passivation film 8 is being etched, the shape of the surface of the underlying film 9 is deformed, and the surface of the underlying film 9 after the etching of the passivation film 8 is performed. (See FIG. 4) may greatly deviate from the range of the inclination angle α of the surface of the base film 9 before the passivation film 8 is etched. When the range of the inclination angle α of the surface of the base film 9 shifts as described above, even if a reflective electrode 10 (see FIG. 6) described later is formed on the surface of the base film 9, the reflection of the reflective electrode 10 does not occur. It is preferable that the underlying film 9 is not etched as much as possible because there is a possibility that the characteristics deviate significantly from the desired characteristics. Thus, in the present embodiment, the passivation film 8 is etched using a mixed gas of an etching gas and a carrier gas. By including the carrier gas in the mixed gas, the etching rate of the base film 9 can be sufficiently reduced with respect to the etching rate of the passivation film 8, and the surface of the base film 9 after the etching of the passivation film 8 is completed. Can be kept substantially the same as the shape of the surface of the base film 9 before the passivation film 8 is etched. Therefore, even when the passivation film 8 is etched, the deformation of the surface of the base film 9 is minimized, and the base film 9 serves as a base film for giving the reflective electrode good reflection characteristics. Can also be fulfilled. Although He is used as the carrier gas in the present embodiment, Ar may be used instead of He, for example.

After etching the passivation film 8 as described above, the reflective electrode is formed. (See Figure 6).

FIG. 6 is a cross-sectional view showing the substrate on which the reflective electrode 10 is formed.

The reflective electrode 10 is formed by forming a conductive film having a high reflectivity such as an A1 film and patterning the conductive film. Since a large number of concave portions 9 b and convex portions 9 c are formed on the surface of the base film 9 of the reflective electrode 10 (see FIG. 5), the shape of the surface of the base film 9 is also formed on the reflective electrode 10. Thus, a large number of concave portions 10a and convex portions 10b are formed, and as a result, it is possible to obtain a reflective electrode 10 having good reflection characteristics 1 ". In this manner, the TFT substrate 5 1 (see FIG. 1) In this embodiment, the base film 9 of the reflective electrode 10 has a large number of concave portions 9b and convex portions 9c on its surface, so that the reflective electrode 10 has In addition to serving to provide good reflection characteristics, it also serves as an etching mask for forming the holes 8a (see FIG. 5) in the passivation film 8. Therefore, after forming the passivation film 8, Before forming the base film 9, a hole 8 a is formed in the passivation film 8. According to the conventional method, after the passivation film 8 is formed and before the base film 9 is formed, a dedicated photolithography process for forming the holes 8a in the passivation film 8 is not required. Although it is necessary, according to the present embodiment, the photolithography step is not required, so that the number of manufacturing steps and the manufacturing cost can be reduced.

Next, a TFT substrate manufactured by using the second embodiment of the method for manufacturing a semiconductor device of the present invention will be described.

This liquid crystal display device has a TFT substrate 510 on which a TFT 550 and a reflective electrode 224 are formed, and a color filter substrate 520 on which a color filter and the like are formed. A large number of concave portions 24 b and convex portions 24 c are provided on the surface of the reflective electrode 24. The structure of the color filter substrate 520 is described in a simplified manner as in FIG. Liquid between the TFT substrate 5 10 and the color filter substrate 5 20 A crystal layer 530 is present. A backlight BL is provided on the rear surface of the TFT substrate 510. Hereinafter, a method for manufacturing the TFT substrate 5100 having the features of the second embodiment will be described with reference to FIG. 7 and FIGS. First, the gate electrode 2, the gate insulating film 3, the semiconductor film 4, the ohmic contact layer 5, the source electrode 6, and the like are formed on the glass substrate 1 in the same manner as described with reference to FIG. After the formation of the drain electrode 7, an ITO film connected to the drain electrode 7 is formed (see FIG. 8).

The ITO film 21 (corresponding to the conductive light transmitting film according to the present invention) includes a first portion 21 a connected to the drain electrode, and the first portion 21 a on the gate insulating film 3. And a second portion 21b extending to After forming the ITO film 21, a passivation film is formed on the substrate on which the ITO film 21 has been formed.

FIG. 9 is a cross-sectional view showing the substrate on which the passivation film 22 is formed. The ITO film 21 existing under the passivation film 22 (corresponding to the third insulating film in the present invention) needs to be connected to a later-described reflective electrode 24 (see FIG. 7). In this passivation film 8, it is necessary to form a hole for connecting the ITO film 21 and the reflection electrode 24. However, in the second embodiment, before forming a hole in the passivation film 22, the surface of the reflective electrode 24 is provided with a large number of concave portions 24 b and convex portions 24 c (see FIG. 7). A base film is formed first (see FIG. 10).

FIG. 10 is a cross-sectional view of the substrate on which the base film 23 is formed.

The base film 23 has a hole 23a (corresponding to the fourth hole according to the present invention) at a position corresponding to the second portion 21b of the ITO film 21. On the surface of the base film 23, a large number of concave portions 23b and convex portions 23c are provided. Such a base film 23 can be formed using a method similar to the method described with reference to FIG. After forming the base film 23, the passivation film 22 is etched (see FIG. 11). FIG. 11 is a cross-sectional view of the substrate after etching the passivation film 22.

Since the holes 23 a are formed in the base film 23, the passivation film 22 is etched by using the base film 23 as an etching mask, thereby forming the base film 23 with the passivation film 22. A hole 22a (corresponding to the fourth communication hole according to the present invention) that continuously follows the hole 23a is formed. The etching of the passivation film 22 can be performed using the same method as described with reference to FIG. By forming the hole 22 a in the passivation film 22, the second portion 21 b of the ITO film 21 is exposed. After etching the passivation film 22, a reflective electrode 24 is formed as shown in FIG. 7 to manufacture the TFT substrate 510. The reflective electrode 24 has a hole 24a for transmitting light from the backlight BL (see FIG. 7). In this manner, by providing the hole 24a in the reflective electrode 24, the TFT substrate 5100 can be used for a transflective liquid crystal display device having both a reflective type and a transmissive type. You.

In the second embodiment, the base film 23 of the reflective electrode 24 has a large number of four parts 23 b and convex parts 23 c on its surface, so that the reflective electrode 24 has good reflection characteristics. And also serves as an etching mask for forming holes 22a (see FIG. 11) in the passivation film 22. Therefore, after forming the passivation film 22 and before forming the base film 23, a dedicated photolithography process for forming the hole 22a in the passivation film 22 becomes unnecessary, and the number of manufacturing steps and Manufacturing costs can be reduced.

In the first and second embodiments described above, the method of manufacturing the bottom gate type TFT substrates 51 and 50 has been described. However, the present invention is also applicable to the manufacture of top gate type TFT substrates. can do. An example in which the present invention is applied to the manufacture of a top gate type TFT substrate will be described below.

FIG. 12 shows a semiconductor device manufactured using the third embodiment of the manufacturing method of the present invention. FIG. 2 is a partial cross-sectional view of a top gate type liquid crystal display device.

This liquid crystal display device has a TFT substrate 601 on which a TFT 600 and a reflective electrode 68 are formed, and a color filter substrate 602 on which a color filter and the like are formed. The TFT substrate 601 has a reflective electrode 68, and a large number of concave portions and convex portions are provided on the surface of the reflective electrode 68. The structure of the color filter substrate 602 is described in a simplified manner. A liquid crystal layer 603 exists between the TFT substrate 601 and the color filter substrate 602. A back light BL is provided on the rear surface of the TFT substrate 601. Hereinafter, a method of manufacturing the TFT substrate 601 will be described with reference to FIGS. First, as shown in FIG. 13, on the S I_〇 ₂ film glass base plate 60 (not shown) is formed, a source electrode 61 and drain electrode 62, the semiconductor film 63, S i N film 64 . Here, the source electrode 61 and the drain electrode 62 are formed of a two-layer film of the ITO film F1 and the metal film F2, but may be formed of a single-layer film or a laminated film of three or more layers. Can also. As the metal film F2, for example, a metal film containing molybdenum (Mo) to which a small amount of chromium (Cr) is added as a main component can be used. After the formation of the 3 1 ^ 1 film 64, an insulating film is formed so as to cover the SiN film 64 (see FIG. 14).

As the insulating film 65 (corresponding to the first insulating film in the present invention), for example, a SiN film can be used. After forming the insulating film 65, a gate electrode is formed (see FIG. 15).

The gate electrode 66 can be formed, for example, by forming a metal film such as an A1 film and patterning this metal film. When the metal film is patterned, a gate line connected to the gate electrode 66 is also formed in addition to the gate electrode 66, but the gate line is not shown in FIG. The drain electrode 62 under the insulating film 65 is a reflective electrode 68 described later. (See Figures 12 and 18). Therefore, it is necessary to form a hole in the insulating film 65 for connecting the drain electrode 62 and the reflective electrode 68, but in the third embodiment, after forming the gate electrode 66, Before forming a hole in the insulating film 65, a base film for forming a plurality of concave portions and convex portions in the reflective electrode 68 described later is formed first.

The base film 67 can be formed by a method similar to the method described with reference to FIG. The base film 67 has a hole 67 a (corresponding to the first hole referred to in this book) at a portion corresponding to the drain electrode 62, and further has a surface on the base film 67. Has a large number of concave portions 67 b and convex portions 67 c. After forming such a base film 67, the insulating film 65 is etched (see FIG. 17).

The insulating film 65 is dry-etched using the base film 67 as an etching mask in the same manner as the method described with reference to FIG. Due to this dry etching, the inner wall surface 65b of the hole 65a of the insulating film 65 (corresponding to the first communication hole in the present invention) has the same taper angle as the inner wall surface 8b of FIG. Can be provided. After etching the insulating film 65, a reflective electrode is formed (see FIG. 18). FIG. 18 is a cross-sectional view showing the substrate on which the reflective electrode 68 is formed.

The reflective electrode 68 can be formed, for example, by forming an A1 film and etching the A1 film. The reflective electrode 68 has a hole 68a for transmitting light from the backlight BL (see FIG. 12). However, in FIG. 18, since the ITO film F 1 of the drain electrode 62 is covered with the metal film F 2, the backlight BL cannot be obtained simply by providing the hole 68 a in the reflection electrode 68. Light cannot pass through hole 68a. Therefore, after forming the reflective electrode 68 having the hole 68a, the portion of the metal film F2 corresponding to the hole 68a is etched. As a result of this etching, as shown in FIG. 12, one I-type film of the drain electrode 62 is exposed (see FIG. 12), and the light of the backlight BL passes through the hole 68 a of the reflective electrode 68. You can have. As described above, the TFT substrate 600 is manufactured. In the third embodiment, the base film 67, which is the base film of the reflective electrode 68, has a large number of concave portions 67b and convex portions 67c on its surface. Reflection characteristics 1 "In addition to playing a role in giving life, it also plays a role as an etching mask for forming holes 65a (see Fig. 17) in the insulating film 65. Therefore, the insulating film After the formation of the base film 67 and before the formation of the base film 67, a special photolithography process for forming the hole 65a in the insulating film 65 is unnecessary. After the formation of the base film 67 and before the formation of the base film 67, a dedicated photolithography step for forming the hole 65a in the insulating film 65 is required. According to the present embodiment, this dedicated photolithography step is performed. Since no process is required, the number of manufacturing steps and manufacturing cost can be reduced.

Hereinafter, the reflection characteristics of the TFT substrate 61 manufactured by the method of the third embodiment and the insulating film using a dedicated photolithography process after forming the insulating film 65 and before forming the base film 67 will be described. A comparison is made with the reflection characteristics of a conventional TFT substrate manufactured using the conventional method of forming a hole 65a in 65.

FIG. 19 is a plot showing the reflection characteristics of the TFT substrate 61 and the conventional TFT substrate.

This plot shows the reflection characteristics when the TFT substrate was irradiated with external light from the 130 ° direction. The horizontal axis shows the viewing angle, and the vertical axis shows the reflectance. In the plots, the symbol 〇 indicates the reflection characteristic of the TFT substrate according to the third embodiment, and the symbol X indicates the reflection characteristic of the TFT substrate manufactured by using the conventional method.

From FIG. 19, it can be seen that in the third embodiment, the reflection characteristics almost the same as the reflection characteristics by the conventional method are maintained. Therefore, it is understood that the number of manufacturing steps and manufacturing cost can be reduced by adopting the method of the third embodiment as compared with the conventional method while maintaining the reflection characteristics.

Note that the present invention can also be applied to the manufacture of a TFT substrate having a double gate structure. Hereinafter, the semiconductor device manufacturing method according to the fourth embodiment of the present invention will be described. An example of manufacturing a TFT substrate having a double gate structure will be described.

FIG. 20 is a partial plan view of a TF substrate 100 having a double-gut structure, FIG. 21 is a cross-sectional view taken along the line A—Α of FIG. 20, and FIG. 22 is a line B—B of FIG. FIG. On the TFT substrate 100, a reflective electrode 113 having a hole 113a and a connection conductive portion 114 (corresponding to the conductive portion according to the present invention) are formed. The reflection electrode 113 is connected to the drain electrode 105. The connection conductive portion 114 is a conductive portion for electrically connecting the light shielding film 101 and the gate line 110 as shown in FIG. Hereinafter, a method of manufacturing the TFT substrate 100 shown in FIGS. 20 to 22 will be described with reference to FIGS.

FIG. 23 is a plan view showing the substrate 1 on which the light-shielding film 101 is formed, and FIG. 24 is a cross-sectional view taken along line CC of FIG.

On the substrate 1, a conductive light-shielding film 101 having conductivity is formed. As the conductive light-shielding film 101, for example, a metal film mainly composed of molybdenum (Mo) to which a trace amount of chromium (Cr) is added is formed, and this metal film is formed into a shape shown in FIG. It can be formed by patterning. The conductive light-shielding film 101 shown in FIG. 23 has a substantially L-shape, but the shape of the conductive light-shielding film 101 can be appropriately changed. This conductive light-shielding film 101 has a first portion 101 a corresponding to a gate electrode 109 described later (see FIG. 29) and a first portion 101 extending from the first portion 101. 2 portion 101b. After forming the light shielding film 101, a SiO ₂ film is formed (see FIG. 25). FIG. 25 is a cross-sectional view showing the substrate on which the SiO ₂ film 102 is formed.

S i 0 ₂ film 1 0 2 (corresponding to the second insulating film in the present invention) is formed so as to cover the conductive light shielding film 1 0 1. Since the light-shielding film 1 0 1 underlying the S i 0 ₂ film 1 0 2 need to be connected to the connection conductive portions 1 1 4 (see FIG. 2 2) to be formed later, the S i 0 _{In the second} film 102, it is necessary to form a hole for connecting the light-shielding film 101 and the connection conductive portion 114. However, here, before you form holes for connecting the S I_〇 ₂ film 1 0 2 in the light shielding film 1 0 1 and the connecting conductive portion 1 1 4, the source electrode, the source line and the drain electrode (Figure 26 and See Figure 27).

FIG. 26 is a plan view showing a substrate on which the source electrode 103, the source line 104, and the drain electrode 105 are formed, and FIG. 27 is a cross-sectional view taken along line DD of FIG. . The source electrode 103 is connected to a source line 104 extending in the y direction, and a drain electrode 105 is formed on the right side of the source line 104. Here, the source electrode 103, the source line 104, and the drain electrode 105 have a two-layer structure including the ITO film F1 and the metal film F2. In addition, it may have a single-layer structure or a multilayer structure of three or more layers. After forming the source electrode 103, the source line 104 and the drain electrode 105, a semiconductor film, a SiN film, an insulating film, a gut electrode, etc. are formed (FIGS. 28 and 29). reference).

FIG. 28 is a plan view showing a substrate on which the gate electrode 109 and the like are formed, and FIG. 29 is a cross-sectional view taken along line EE of FIG.

After forming the source electrode 103, the source line 104 and the drain electrode 105 (see FIGS. 26 and 27), a semiconductor film 106 and a SiN film 107 are formed. An insulating film 108 (corresponding to the first insulating film according to the present invention) is formed. After forming the insulating film 108, a gate electrode 109 and a gate line 110 are formed on the insulating film 108. As the insulating film 108, for example, a SiN film can be used. The gate electrode 109 is formed right above the first portion 101 a of the light-shielding film 101 (see FIG. 29), and is connected to the gate line 110 extending in the X direction. (See Figure 28). The gate electrode 109 and the gate line 110 can be formed by forming a metal film such as an A1 film on the entire surface of the insulating film 108 and patterning the metal film. Here, when the metal film is buttered, a Cs line 111 is also formed in addition to the gate electrode 109 and the gate line 110. Although the Cs line 111 is not always necessary, the storage capacitor can be easily formed by forming the Cs line 111. The drain electrode 105 covered with the insulating film 108 is a reflective electrode described later.

1 1 3 (see FIG. 21), and the light-shielding film 101 under the insulating film 108 via the 310 ₂ film 102 is formed later. Connection conductive part

It must be connected to 1 1 4 (see Figure 22). Therefore, this insulating film 108 has a hole for connecting the drain electrode 105 and the reflective electrode 113, and a light-shielding film 1

It is necessary to form a hole for connecting 0 1 and the connection conductive portion 1 14. However, here, before forming these holes in the insulating film 108, a base film for forming a large number of concaves and convexes on the surface of the reflective electrode 113 (see FIG. 21). Is formed first (see FIGS. 30 and 31).

FIG. 30 is a plan view showing the substrate on which the base film 112 is formed, FIG. 31 is a cross-sectional view taken along the line FF of FIG. 30, and FIG. 32 is a line GG of FIG. FIG.

The base film 112 has a large number of concave portions 112d and convex portions 112e. Such a base film 112 can be formed by a method similar to the method described with reference to FIG. In FIGS. 30 to 32, the base film 112 is shown by oblique lines. The base film 112 includes a hole 112 a formed at a position corresponding to the drain electrode 105 (corresponding to the first hole according to the present invention) and a second hole of the light shielding film 101. Hole 112b (corresponding to the second hole according to the present invention) formed at a position corresponding to the portion 1101b, and a hole 111 formed at a portion corresponding to the gate line 110. 2 c (corresponding to the third hole in the present invention). Such holes 1 1 2 a, 1 1 underlayer 1 1 2 an etching mask having a 2 b及Pi 1 1 2 c, etching the insulating film 1 0 8及Pi S i 0 ₂ film 1 0 2 ( See Figures 33 and 34). FIGS. 33 and 34 are cross-sectional views of the substrate immediately after the insulating film 108 and the SiO ₂ film 102 are etched. FIG. 33 is a sectional view corresponding to FIG. 31, and FIG. 34 is a sectional view corresponding to FIG.

Using the base film 112 as an etching mask, the insulating film 108 is dry-etched by the same method as described with reference to FIG. By this dry etching, the holes 111a and 112b of the insulating film 108 and the base film 112 are respectively formed. 1

20 A continuous hole 108a (corresponding to the first communication hole according to the present invention) and a hole 108b (corresponding to the second communication hole according to the present invention) are formed. Once these holes 10 8 a and 108 b are formed continuously performed continuously dry etching of S i 0 ₂ film 102. By this dry etching, a hole 102a (corresponding to a third communication hole according to the present invention) is formed in the SiO ₂ film 102 continuously following the hole 108b of the insulating film 108. By performing the dry etching in this manner, the taper angle 同様 similar to that of the inner wall surface 8 b of FIG. 5 can be provided on the inner wall surface 108 c of the hole 108 a of the insulating film 108, and Si 0 ₂ The inner wall surface 102b of the hole 102a of the film 102 can also be provided with a taper angle 0 '. When the dry etching is completed, as shown in FIGS. 20 to 22, the reflective electrode 113 having the hole 113a and the connection conductive portion 114 are formed, whereby the TFT substrate 100 is manufactured. The reflective electrode 113 and the connection conductive portion 114 can be formed by, for example, forming an A1 film and etching the A1 film. After etching the A1 film, the metal film F2 is also etched until the ITO film F1 is exposed as shown in FIG. By exposing the ITO film F1, light from a backlight (not shown) can pass through the hole 113a of the reflective electrode 113, and the TFT substrate 100 can be divided into a reflective type and a transmissive type. Can be used for both. The connection conductive part 114 is a conductive part for connecting the gate line 110 and the light shielding film 101. The signal from the gate line can be transmitted to the light shielding film 101 by the connection conductive portion 114. As a result, the light-shielding film 101 can function in the same manner as the gate electrode 109, and the TFT substrate 100 having a double gut structure can be manufactured.

In the fourth embodiment, the base film 112 of the reflective electrode 113 serves to provide the reflective electrode 113 with good reflection characteristics, and forms the holes 108a and 108b in the insulating film 108. It also plays a role as an etching mask. Therefore, after forming the insulating film 108 and before forming the base film 112, a dedicated photoresist for forming the holes 108 a and 108 b in the insulating film 108 is formed. The need for a dying process is eliminated, and the number of manufacturing steps and manufacturing costs can be reduced. Furthermore, in the fourth embodiment, the insulating film 1 is used with the base film 112 as an etching mask.

After etching 08, the SiO ₂ film 102 is also etched. Accordance connexion, dedicated photoresist process for forming a hole 1 0 2 a to S i 0 ₂ film 1 0 2 becomes unnecessary, it is achieved further reduction in the number of manufacturing steps and manufacturing cost. In the first to fourth embodiments, the method of manufacturing a substrate used in a liquid crystal display device has been described. However, the present invention is not limited to a liquid crystal display device as long as it does not depart from the gist of the present invention. It is also applicable to devices. Industrial applicability

According to the present invention, there are provided a method in which the number of manufacturing steps and manufacturing cost are reduced, and an apparatus to which the method is applied.

Claims

The scope of the claims

1. A method for manufacturing a semiconductor device, comprising: a transistor having a gate electrode, a source electrode, and a drain electrode on a substrate; and a reflective electrode connected to the drain electrode.

Forming the source electrode and the drain electrode on the substrate; forming a first insulating film on the substrate on which the source electrode and the drain electrode are formed;

On the substrate on which the first insulating film is formed, a base film of the reflective electrode, a first hole at a position corresponding to the drain electrode, and a plurality of concave portions or convex portions on the surface. Forming a base film having

The first insulating film is used as an etching mask so that a first communication hole continuous with the first hole is formed at a position corresponding to the drain electrode in the first insulating film. Etching an insulating film;

A reflective electrode covering a part of the surface of the base film on the substrate having the first insulating film in which the first communication hole is formed, wherein the first hole and the first Forming the reflective electrode connected to the drain electrode through a communication hole;

A method for manufacturing a semiconductor device, comprising:

2. The etching step is a step of taper-etching the first insulating film so that an inner wall surface of the first communication hole of the first insulating film is inclined with respect to the substrate. The method for manufacturing a semiconductor device according to claim 1, wherein:

3. The step of performing the taper etching is characterized in that the first insulating film is taper-etched using a mixed gas containing an etching gas containing a hydrocarbon-based gas having fluorine and a carrier gas. The semiconductor according to claim 2 Manufacturing method of body device.

4. The method according to any one of claims 1 to 3, further comprising, before the step of forming the source electrode and the drain electrode, a step of forming the good electrode on the substrate. Of manufacturing a semiconductor device.

5. After the step of forming the first insulating film and before the step of forming the base film, a step of forming the gate electrode on the substrate on which the first insulating film is formed is provided. The method for manufacturing a semiconductor device according to any one of claims 1 to 3, wherein:

6. Prior to the step of forming the source electrode and the drain electrode, a first portion corresponding to the gate electrode, wherein the first portion is a conductive light-shielding film having conductivity on the substrate; Forming a conductive light-shielding film having a second portion connected to

Forming a second insulating film on the substrate on which the conductive light-shielding film is formed, after the step of forming the conductive light-shielding film, and before the step of forming the source electrode and the drain electrode; ,

After the step of forming the first insulating film, and before the step of forming the base film, on the substrate on which the first insulating film is formed, a gate connected to the gut electrode and the gut electrode Forming a line,

The step of forming the base film includes forming a second hole in the base film at a position corresponding to a second portion of the conductive light-shielding film, and forming a second hole in the base film corresponding to the goose line of the base film. Forming a third hole at the position,

In the etching step, a second communication hole continuous with the second hole is formed at a position of the first insulating film corresponding to a second portion of the conductive light-shielding film, A second insulating film, at a position corresponding to a second portion of the conductive light-shielding film, Etching the first and second insulating films using the base film as an etching mask so that a third communication hole continuously following the second communication hole is formed;

The step of forming the reflective electrode includes connecting the conductive light-shielding film and the gut line through the third hole, the second hole, the second communication hole, and the third communication hole. 4. The method of manufacturing a semiconductor device according to claim 1, further comprising a step of forming a conductive portion.

7. A substrate having a gate electrode, a source electrode, and a drain electrode on a substrate, a conductive light transmitting film connected to the drain electrode and having conductivity, and a reflective electrode connected to the conductive light transmitting film. A method for manufacturing a semiconductor device comprising:

Forming the source electrode and the drain electrode on the substrate, and the conductive light transmitting film connected to the drain electrode on the substrate on which the source electrode and the drain electrode are formed; A conductive portion having a first portion connected to the drain electrode and a second portion connected to the first portion and extending to a region other than a region corresponding to the drain electrode and the source electrode; Forming an electrically conductive light transmitting film;

Forming a third insulating film on the substrate on which the conductive light transmitting film is formed, and forming a base film of the reflective electrode on the substrate on which the third insulating film is formed, Forming a base film having a fourth hole at a position corresponding to the second portion of the conductive light transmitting film and having a plurality of concave portions or convex portions on the surface;

The base film such that a fourth communication hole continuous with the fourth hole is formed at a position of the third insulating film corresponding to the second portion of the conductive light transmitting film. Etching the third insulating film using an etching mask,

On the substrate having the insulating film in which the fourth communication hole is formed, a part of the surface of the base film is covered and the fourth communication hole is formed through the fourth communication hole and the fourth communication hole. Forming the reflective electrode connected to the conductive light-transmitting film.

8. A semiconductor device manufactured using the method for manufacturing a semiconductor device according to claim 1.

9. A liquid crystal display device comprising the semiconductor device according to claim 8.