CN101894750A

CN101894750A - Method for carrying out dry etching on TaN electrode

Info

Publication number: CN101894750A
Application number: CN2010101875407A
Authority: CN
Inventors: 李全波; 姜利军
Original assignee: ZHEJIANG DALI TECHNOLOGY Co Ltd; Shanghai Integrated Circuit Research and Development Center Co Ltd
Current assignee: ZHEJIANG DALI TECHNOLOGY Co Ltd; Shanghai IC R&D Center Co Ltd
Priority date: 2010-05-28
Filing date: 2010-05-28
Publication date: 2010-11-24

Abstract

The invention provides a method for carrying out dry etching on a TaN electrode. In the method, the F-containing gases are adopted to carry out dry etching on the TaN electrode and include CF4, CHF3 and Ar. CF4 and CHF3 serve as the sources of the F free radical with chemical function of plasma etching and Ar has the functions of diluting and bombarding. The conditions meeting the actual production requirements can be obtained by refining the process parameters. The method has the following advantages: the pressure and temperature limitation and gas selection range for etching TaN are broken through; the gases for etching are expanded from Cl gases to the gases with F as the major part under low temperature; and the types of equipment capable of etching the TaN electrode are increased.

Description

The method of carrying out dry etching on TaN electrode

Technical field

The present invention relates to field of IC technique, specially refer to TaN electrode dry method (plasma) lithographic method under the capacitance coupling plasma etching apparatus low-pressure low-temperature degree.

Background technology

Continuous development along with ic manufacturing technology, the TaN material is used also more and more wider, mainly contains three aspects: the first, and copper-connection material barrier layer, copper interconnection layer mainly is made of the TaN/Ta/Cu layer, and the TaN layer has good copper diffusion barrier effect and preferable dielectric layer contact performance; Second is the application of TaN metal gate, and especially for 65nm and following technology generation thereof, owing to have good thermal stability and good with high K value (high-k) match materials, TaN often is used as the grid metal material; The 3rd, the micro-electromechanical system (MEMS) electrode material.For copper barrier layer material TaN,, do not need to remove TaN, so to the no requirement (NR) of TaN etching owing to take big horse scholar mosaic texture.And,, then unwanted TaN must be removed promptly and etch away because will form electrode to electrode material.Because plasma (dry method) etching phase, almost is being in the ascendance aspect the transfer of TaN fine pattern because have anisotropy for wet etching.Plasma main etching gas is halogen-containing gas, is mainly F, Cl, and Br etc. are because the halide of Ta has lower volatility, so the challenge of etching difficulty is bigger.

Etching apparatus at present commonly used mainly contains two kinds of capacitive coupling and inductance coupling high.Wherein capacitive coupling is middle density plasma, generally do not have the top (on) power source, inductance coupling high then generally possesses two of source power (source power) and bias powers (bias power) at least, controls plasma density and energy respectively, can meticulousr control adjusting process parameter.Capacitance coupling plasma CCP is mainly used in dielectric etch, and inductively coupled plasma ICP metal and the use of silicon etching aspect are more.The TaN etching is generally carried out on ICP.

The inductively coupled plasma ICP etching apparatus that is mainly that the carrying out dry etching on TaN technology of the present comparative maturity in actual production field adopts contains the Cl plasma, and this technology can reach technological requirement, by volume production.But must be on the equipment that possesses Cl gas, just can use or higher temperatures environment (＞45 ℃) etching.And, then also do not have the mature technique scheme for the capacitive coupling plasma CCP equipment (main etching gas is for containing the F class) that does not contain Cl gas under the low temperature.Etching apparatus all has the independent gas of wearing (to be mainly the F class, the Cl class, Br class gas), wherein equipment component does not carry the gas source that contains Cl, only possess gas and other complementary gases of containing F, the general etching cavity temperature of this kind equipment is less than 20 ℃, and this is dry-etched in application on it with regard to restricted T aN.

Summary of the invention

The objective of the invention is to develop the method for a kind of new carrying out dry etching on TaN under the capacitance coupling plasma equipment low-pressure low-temperature degree.This method mainly contains the gas of F, no longer contains Cl class gas, by the process for refining parameter, draws the condition that satisfies the production actual demand.

In order to achieve the above object, the present invention proposes a kind of method of carrying out dry etching on TaN electrode, and this method employing contains F gas described TaN electrode is carried out dry etching, and the described F of containing gas comprises CF4, three kinds of gases of CHF3 and Ar.

Further, this method adopts the capacitive coupling plasma etching equipment, wherein, and this capacitive coupling plasma etching equipment using plasma.

Further, the etch chamber body wall of described capacitive coupling plasma etching equipment and bottom electrode temperature are 10 ℃-25 ℃.

Further, described plasma generation mode is a capacitive coupling, and the source power of described plasma and bias power are same power source.

Further, the etching cavity internal pressure of described capacitive coupling plasma etching equipment is 10-30mt.

Further, the power of described plasma is 200w-400w.

Further, the flow of described CF4 is 50-100sccm, and the flow of described CHF3 is 10-40sccm, and the flow of described Ar is 200-400sccm.

The present invention proposes the method for a kind of new carrying out dry etching on TaN under a kind of capacitance coupling plasma equipment low-pressure low-temperature degree, and its advantage is that the present invention passes through the process for refining parameter, can draw the condition that satisfies the production actual demand.Break through pressure and temp restriction and the gas range of choice of etching TaN, etching gas expands to gas based on F from the Cl class under the low temperature, but the device type of increase TaN electrode etching.

Description of drawings

Figure 1 shows that the schematic diagram behind film layer structure and the lithographic definition pattern;

Figure 2 shows that the schematic diagram after the anti-reflecting layer etching is finished;

Figure 3 shows that the schematic diagram after the TaN etching;

Figure 4 shows that the schematic diagram after photoresistance is removed.

Embodiment

In order more to understand technology contents of the present invention, especially exemplified by specific embodiment and cooperate appended graphic being described as follows.

Please refer to Fig. 1, Figure 1 shows that the schematic diagram behind film layer structure and the lithographic definition pattern.Deposit TaN layer 2 successively on chip substrates 1, anti-reflecting layer 3, photoresistance 4, and lithographic definition goes out to need the pattern that shifts.Then the chip that photoetching is good imports etching cavity into, is positioned on the bottom electrode.Anti-reflecting layer 3 on the carrying out dry etching on TaN layer 2 then.Be exactly to carry out carrying out dry etching on TaN layer 2 afterwards, contain the optional CF4 of gas and two kinds of gases of CHF3 of F, complementary gas then is Ar.Gas CF4 and CHF3 be as the source of plasma etching chemical action F free radical, and Ar is then as Portability gas and the cation of physical bombardment effect is provided in plasma.Etching apparatus need contain CF4, CHF3 and Ar gas, typical etch rate be 400A/min to 800A/min, etch period is decided according to thickness.Remove light at last and rent 4, take out chip.

The method of the carrying out dry etching on TaN electrode that the present invention proposes, this method employing contains F gas described TaN electrode is carried out dry etching, and the described F of containing gas comprises CF4, three kinds of gases of CHF3 and Ar.

Further, the flow of described CF4 is 50-100sccm, and the flow of described CHF3 is 10-40sccm, and the flow of described Ar is 200-400sccm.This method adopts the capacitive coupling plasma etching equipment, wherein, and this capacitive coupling plasma etching equipment using plasma.Described plasma generation mode is a capacitive coupling, and the source power of described plasma and bias power are same power source.

Further, the etching cavity internal pressure of described capacitive coupling plasma etching equipment is 10-30mt.The etch chamber body wall of described capacitive coupling plasma etching equipment and bottom electrode temperature are 10 ℃-25 ℃.The power of described plasma is 200w-400w, utilizes the preferable volatility etching TaN layer 2 of product under these process conditions.

Through experiment, capacitive coupling plasma etching equipment (as AMAT EMAX) is gone up 500A TaN dry etching, cavity wall and bottom electrode temperature are set 15 ℃ for, can choose the CF4 flow is 70sccm, the CHF3 flow is 20sccm, and the Ar flow is 250sccm, etching cavity internal pressure 35mt, plasma power 350w, the about 90s of etch period.Through test, experimental result meets the integrated technique requirement.

In sum, the present invention can draw the condition that satisfies the production actual demand by the process for refining parameter.Advantage is to break through pressure and temp restriction and the gas range of choice of etching TaN, and etching gas expands to gas based on F from the C1 class under the low temperature, but the device type of increase TaN electrode etching.

Though the present invention discloses as above with preferred embodiment, so it is not in order to limit the present invention.The persond having ordinary knowledge in the technical field of the present invention, without departing from the spirit and scope of the present invention, when being used for a variety of modifications and variations.Therefore, protection scope of the present invention is as the criterion when looking claims person of defining.

Claims

1. the method for a carrying out dry etching on TaN electrode is characterized in that, this method employing contains F gas described TaN electrode is carried out dry etching, and the described F of containing gas comprises CF4, three kinds of gases of CHF3 and Ar.

2. the method for carrying out dry etching on TaN electrode according to claim 1 is characterized in that, this method adopts the capacitive coupling plasma etching equipment, wherein, and this capacitive coupling plasma etching equipment using plasma.

3. the method for carrying out dry etching on TaN electrode according to claim 2 is characterized in that, the etch chamber body wall of described capacitive coupling plasma etching equipment and bottom electrode temperature are 10 ℃-25 ℃.

4. the method for carrying out dry etching on TaN electrode according to claim 2 is characterized in that, described plasma generation mode is a capacitive coupling, and the source power of described plasma and bias power are same power source.

5. the method for carrying out dry etching on TaN electrode according to claim 2 is characterized in that, the etching cavity internal pressure of described capacitive coupling plasma etching equipment is 10-30mt.

6. the method for carrying out dry etching on TaN electrode according to claim 2 is characterized in that, the power of described plasma is 200w-400w.

7. the method for carrying out dry etching on TaN electrode according to claim 1 is characterized in that, the flow of described CF4 is 50-100sccm, and the flow of described CHF3 is 10-40sccm, and the flow of described Ar is 200-400sccm.