WO2005036140A1

WO2005036140A1 - Device for absorbing and/or emitting radiation, method for the production of such a device, and method for analyzing fluids

Info

Publication number: WO2005036140A1
Application number: PCT/EP2004/005789
Authority: WO
Inventors: Joachim Nurnus; Christa KÜNZEL; Armin Lambrecht
Original assignee: Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.
Priority date: 2003-09-16
Filing date: 2004-05-28
Publication date: 2005-04-21
Also published as: DE10342800A1

Abstract

The invention relates to a method for producing a component that is used for absorbing and/or emitting radiation. Said method comprises the following steps: the thickness of a substrate is reduced; and an absorbing and/or emitting element is produced in the zone having a reduced thickness, said absorbing and/or emitting element (3) being produced by carving a material (4, 9) of the substrate (4, 7, 8, 9). The invention further relates to a device (1) for absorbing and/or emitting radiation, comprising an absorbing and/or emitting element (3) that is disposed in a zone (2) of a substrate (4, 7, 8, 9), which has a reduced thickness, and is provided with the same material (4, 9) as the material (4, 9) of the substrate. Also disclosed is a method for analyzing fluids, according to which radiation is emitted by means of an emitting element, said radiation penetrates an area that can be filled with a fluid, and the radiation is absorbed, the radiation being emitted and/or absorbed by said device (1) or a device which is produced according to the inventive method.

Description

Device for absorbing and / or emitting radiation, method for producing such a device and method for analyzing fluids

The invention relates to a device for absorption and / or emission of radiation with an absorption and / or emission element arranged in a thinned area of a substrate, a method for producing such a device and a method for analyzing fluids.

Such devices are used in the infrared spectral range as emitters or detectors. Here, an efficient conversion of radiation energy into heat (detector) or the efficient conversion of heat into radiation (emitter) is important. It is important here that the absorption / emission element is thermally decoupled from the rest of the component, since this results in a high sensitivity of the detector or, in the case of the emitters, a lower energy consumption with simultaneous rapid heating, i.e. enable quicker operational readiness.

The detectors include e.g. the thermoelectric, pyroelectric or bolometric radiation detectors.

It is state of the art to thin a substrate for the production of such detectors or emitters in order to achieve the thermal insulation and then to separate the absorption or emission layer. For this purpose, for example, metal clusters are generated which are deposited on the substrate. With such layers, absorption in the range of 99% can be achieved.

It is also known from the prior art to etch a silicon surface or to expose it to laser radiation under certain ambient gases and thus to produce a fine cone-like structure on the silicon, as a result of which the absorption is increased (BSI, Black Sjlicon).

A disadvantage of the known detectors is that the metal clusters have poor adhesion to the substrate and that a coating can only be achieved using a shadow mask technique, which therefore does not permit use in microstructure technology. Another disadvantage is that due to the different thermal expansion coefficients of the different materials, stresses build up when the temperature changes, which can lead to destruction in the thinnest possible membranes that arise in the area of thinning.

The object of the present invention is to provide a device for absorbing or emitting radiation which is simple and reproducible to produce, and furthermore it is an object, a corresponding method for producing such a device and a method for analyzing fluids with such To provide devices or devices so produced.

This object is achieved by a method having the steps of claim 1 and by an apparatus having the features of claim 13 and a method for analyzing fluids according to claim 23.

In the manufacturing method, an absorption or emission element is not produced by applying a material with a high absorption, but rather the absorption and / or emission element is produced by working out of a material of the substrate. It is thus possible to also produce the absorption and / or emission element using the same or a similar process, process step or method as is used for thinning the substrate.

It is advantageous here if a silicon substrate is used, since a highly developed process technology is available for silicon substrates.

The absorption and / or emission element is preferably produced by etching the substrate, this etching being possible under certain environmental conditions by dry etching or laser processing. It is either possible to produce BSI ("Black Silicon") (see FIG. 12 and the description thereof), or it is also possible to produce regions which are as fine and deeply structured as possible (for example pores or the like) with good absorption. A method configuration in which the thinning and the production of the absorption and / or emission element take place simultaneously is particularly advantageous. Two properties (thinning, absorption and / or emission element) can be achieved simultaneously in one process step.

An absorption and / or emission element structured in this way is advantageously passivated, this being possible with various methods. This prevents aging and contamination of the absorption and / or emission element. Furthermore, the optical properties such as transmission or reflectivity can be tailored or optimized by an aftertreatment. For example, it is possible to minimize the transparency of the material in the relevant spectral range or to increase the absorption. Gold vapor deposition can significantly reduce transparency.

Here, a method is advantageous in which, when the substrate is thinned, it is thinned to such an extent that a material thickness remains which is sufficient for producing the absorption and / or emission element. The thickness can be checked, for example, by time-controlled etching.

Also particularly advantageous is a method with which the thinning is carried out down to an etching stop layer and then the etching stop layer is removed and the absorption and / or emission element is subsequently produced thereon. With such a method, the thinning can be achieved very precisely and homogeneously over a large area of a wafer.

For this purpose, an etching stop layer is advantageously provided which is surrounded by a semiconductor material, which means that there is semiconductor material on both sides of the etching stop layer.

Furthermore, a method is advantageous in which a superstructure mask is provided adjacent to the stop layer for producing the absorption and / or emission element. After the etching stop layer has been removed, the superstructure mask remains, so that it can subsequently serve as a superstructure mask in the production of the absorption or emission element. This makes it possible to To produce sorption and / or emission element, which consists not only of a single part, but of several independent areas.

In the device for absorption and / or emission of radiation, an absorption and / or emission element is therefore provided which comprises the same material as a material of the substrate.

This material is preferably silicon, although other semiconductor materials or materials other than semiconductors are also possible.

Because the absorption and / or emission element comprises the same material as the material of the substrate, it can be produced using the same processes and methods that are available for processing the substrate (for example thinning).

It is preferred here that the absorption and / or emission element comprises or consists of BSI. BSI has a very high absorption and can be produced using the same process as thinning. It is also possible, similar to BSI, to provide silicon with a large surface area which is as fine and deeply structured as possible and which has a good absorption or emission effect.

The device for absorption and / or emission of radiation can be only the processed substrate itself or any product in which a processed substrate is installed, such as a fully assembled detector.

The device advantageously has further optical elements, such as mirror or focusing devices, with which the optical properties of the device can be influenced in a targeted manner. Mirroring or focusing devices make it possible to collect or emit radiation from or in a large area even with a small absorption and / or emission element.

If the device also has thermoelectric and / or pyroelectric materials and / or resistance layers for heating or for temperature detection, these are preferably on the other side of the substrate, such as the absorption and / or emission element is provided and can thus be applied, structured, processed and / or manufactured independently of the absorption and / or emission element. However, they can also be provided on the same side. Such further materials can be used to detect the temperature change caused by absorption of radiation in the absorption element or to achieve the temperature required for the emission of the emission element.

A device which has an emission and an absorption element and in which at least one cavity for a fluid (gas, liquid) is provided on the path through which the radiation passes between the emission and the absorption element is particularly advantageous. With such a device it is possible to determine various properties, such as the density, composition, etc., of the fluid.

Advantageous embodiments of the present invention will be explained with reference to the accompanying figures. It shows:

1 is a schematic sectional drawing of an embodiment of the device,

2 shows a schematic sectional drawing of a further embodiment of the device,

3 shows a schematic sectional drawing of a further embodiment of the device,

4 shows a schematic sectional drawing of a further embodiment of the device,

5 shows a schematic sectional drawing of an absorption and / or emission element,

6 shows a schematic, three-dimensional representation of an advantageous embodiment of the device (detector element, emitter element), 7 shows a schematic sectional drawing of a further embodiment of the device,

8 shows various schematically represented states when an embodiment of the method is carried out,

9 shows various schematically represented states when carrying out a further embodiment of the method,

10 shows various schematically represented states when carrying out a further embodiment of the method;

11 shows various schematically represented states when carrying out a further embodiment of the method,

Fig. 12 is a greatly enlarged schematic plan view of an absorption and / or emission element.

1 shows a device 1 for the absorption and / or emission of radiation. A substrate 4 is thinned in a region 2. An absorption and / or emission element 3 is arranged in the thinned area 2. The thinner 2 serves to thermally decouple the absorption and / or emission element from the substrate 4. Because the absorption and / or emission element 3 is only connected to the substrate 4 via the regions 5a, 5b and the substrate is greatly thinned in the regions 5a, 5b, the thermal decoupling or thermal insulation between the absorption and / or given emission element 3 and the substrate 4.

The absorption and / or emission element 3 is shown hatched, but comprises the same material as the substrate 4. This is due to the fact that the absorption and / or emission element 3 has been worked out of the material of the substrate 4. Even if it is in principle irrelevant from which side the substrate is thinned and on which side the absorption and / or emission element is arranged, the specific arrangement as shown in FIG. 1 has the thinning and absorption and / or emission element 3 are arranged on the same side, certain advantages. The fact that the absorption and / or emission element 3 is arranged in areas of the thinning 2 and thus sits in a recess means that it is somewhat protected against mechanical unwanted action and destruction. Furthermore, the flanks of the thinner 2 can be used to direct radiation in the direction of the absorption and / or emission element or away from it, in that the flanks are, for example, specular.

Even if the flanks of the thinning are shown obliquely in FIG. 1, the flanks can also be oriented approximately perpendicular to the substrate. This can be achieved, for example, by trenching or the like.

In the embodiment in FIG. 2, an insulation layer 7 is provided on the side of the substrate that faces away from the absorption and / or emission element 3. This can consist, for example, of silicon oxide, silicon nitride or combinations and mixtures thereof. For example, the layer 7 can be composed of different individual layers, so that an adaptation of the properties of the insulation layer 7 with respect to, for example, electrical insulation capacity, thermal conductivity, mechanical stresses etc. is possible. The insulation layer 7 is used for electrical insulation and not so much for thermal insulation. It should be as thin as possible so that a good heat exchange between the absorption and / or emission element and the contact point 10 (see below) is made possible.

Two materials 6a and 6b are arranged on the insulation layer 7 and are in contact with one another in a region 10. The area 10 is brought as close as possible to the absorption and / or emission element 3. If the materials 6a and 6b are different (for example p- and n-conducting thermoelectric materials; Si-Si / Ge superlattice structures), when the element 3 is heated relative to the substrate 4 at the contact point 10, a thermal voltage arises which can be registered, whereby on the temperature of the contact point 10 and thus on the temperature of element 3 can be closed. In this function, element 3 would act as an absorption element or as an emission element, the temperature of which is to be controlled.

Material 6a and 6b can also be used for heating or cooling. For this purpose, a current is passed through the contact point 10, so that heating or cooling occurs depending on the direction of the current. The target temperature can be set particularly quickly here. Also, instead of a single contact point 10, a special material (Ag, Au, Pt, etc.) for heating by means of an electrical resistance can be arranged between or instead of material 6a and 6b, with which the absorption and / or emission element 3 can be heated.

Highly doped silicon can be used as the etch stop layer (see below). This can be arranged on or under an insulation layer. If it is still crystallographically oriented, it can serve as the basis for epitaxial superlattice materials with which it is possible to produce very efficient thermoelectric materials (Si-Si / Ge superlattice structures).

3 shows a further embodiment of the device for absorption and / or emission of radiation, in which the absorption and / or emission element 3 is arranged directly on the insulation layer 7, that is to say that the thinner 2 extends through the entire substrate 4 extends to the insulation layer 7. This embodiment is characterized by a particularly good thermal decoupling between the absorption and / or emission element 3 and the substrate 4, since no material remains for the thermal coupling from the substrate 4 itself.

In this embodiment too, the absorption and / or emission element 3 is worked out from the material of the substrate 4 and consists of or thus comprises the same material and is therefore identical to the substrate.

FIG. 4 shows an embodiment in which a substrate is assumed, which on the one hand comprises an original substrate 4, but the substrate still has an etching stop layer 8 and a further material layer 9. The insulation layer 7 can also already be part of the substrate. With regard to the materials 6a, 6b and the contact point 10, reference is made to the description of the function thereof for FIG. 2.

The embodiment shown in FIG. 4 is particularly advantageous with respect to the manufacturing process that will be discussed below.

While the absorption and / or emission element 3 is shown as a coherent element in FIGS. 1 to 4, it can also consist of individual elements 3a to 3e in each of these figures, as shown in FIG. 5. 5 shows a superstructure of the absorption and / or emission element 3. Such superstructures have the advantage that the surface of the absorption element 3, which is available for absorbing the radiation, can be increased further, so that there is still an improved absorption effect.

FIG. 6 shows a three-dimensional schematic representation of a device for absorption and / or emission of radiation, which corresponds to a combination of the device shown in FIG. 3 with the version of the absorption and / or emission element 3 from FIG. 5. Instead of the multi-segment absorption and / or emission element 3, a one-segment one can also be provided.

With reference to FIG. 6, it should be mentioned in particular how, in order to increase, for example, the thermal voltage that can be generated in such a device, a plurality of thermal voltage sources are connected in series. The materials labeled 11 are each of the same type, as are the materials labeled 12 and 13, respectively. The material 11 could be a p-type semiconductor, the material 12 an n-type semiconductor and the material 13 a metallization or the like. As can be seen, there are several contact points 10 in the area of the absorption and / or emission element 3 on the opposite side of the insulation layer 7, but in the direction of the materials 11, 12 and 13 applied in the form of a serpentine line there is a transition from one material 11 to one material 12, so that the different thermal voltages generated at the contact points 10 add up. Different materials 13 can be interposed between the materials 11 and 12. However, since these contact points between the materials 12 and 13 and between the materials 13 and 11 are in the area of the thick substrate 4, these different contact points are each at the same temperature, so that no disruptive thermal stresses can arise here.

While only four contact points 10 are shown in FIG. 6, several tens, hundreds or thousands or even more contact points 10 can be connected in series in such a manner by means of the microstructuring. However, the arrangement of only a single contact point 10 is also possible.

The same applies in the event that thermal voltages are not to be registered at the contact point 10, but instead Peltier cooling or heating or resistance heating is to take place here.

A particularly advantageous embodiment of the invention is shown in FIG. 7. Two thinnings are provided in a substrate 4. An emission element 3a is provided in one thinning and an absorption element 3b in the other thinning. The emission element 3a can be heated with a local heater 16. The temperature of the absorption element 3b can be detected. In FIG. 7, this is achieved, for example, by two different materials 6a and 6b which are in contact with one another at a contact point 10, the contact point 10 being in thermal interaction with the absorption element 3b, so that the temperature of the contact point 10 is substantially the same as that Temperature of the absorption element 3b will be. An insulation layer 7 is provided for the electrical insulation of the various electrical devices. This is common to both thinnings, but can also consist of two or more individual layer areas for the respective thinning.

A further substrate 17 is arranged adjacent to the substrate 4 and here has only one thinner 19. With a suitable shaping of the substrate 4 or 17, however, thinning 19 may also be dispensed with. Here, for example, the area between the two thinnings of the substrate 4, which is not thinned in FIG. 7, is also to be thinned, so that the absorption element 3b and the emissive element tion element 3a can be in radiation contact with one another through the space 18.

The flanks and inner sides of the space 18 created by the various thinnings are provided with a reflective layer 15. This can be, for example, gold vapor deposition or the like, which suitably reflects infrared radiation or the type of radiation used in each case. The gold vapor deposition can also be applied to the absorption and / or emission element at the same time, because here. the large surface area increases the absorption instead of increasing the reflectivity.

The radiation generated by the emission element 3a must pass through the cavity 18 in order to reach the absorption element 3b. In order to make the path through the cavity 18 as long as possible, no direct beam path between the emission element 3a and the absorption element 3b is possible in FIG. 7. Depending on the arrangement of different recesses in the substrates 4 and 17, the path can also be configured longer than shown in FIG. 7.

It is also possible, for example, for the absorption and / or emission element not to be provided in the same substrate (in FIG. 7, the substrate 4), but for them to be arranged on different substrates. For example, it is possible to provide the absorption element 3b directly opposite the emission element 3a, but on the other substrate 17. Then the substrate 4 need only have a thinning and the size of the thinning 19 corresponds to the size of the thinning of the substrate 4.

Fluids can be introduced into the cavity 18 via suitable external micromechanical or other devices. The concentration, nature or composition of the fluids can be determined by a device as shown in Fig. 7, e.g. Spectroscopy by emission of radiation by the emission element 3a and absorption of the radiation by the absorption element 3b can be detected.

Another embodiment of the invention comprises a window or a filter in front of the absorption and / or emission element (3). A window can be made from a rial (e.g. diamond, sapphire, CaF ₂ , BaF ₂ ), which allows the emitted or absorbed radiation to pass through. With the window it is possible to protect the absorption and / or emission element (3) from environmental influences. It can also be prevented that a gas z. B. to be examined, is heated or cooled by the absorption and / or emission element (3). This can prevent a "thermal short circuit".

A filter can pass certain spectral ranges, or absorb / reflect and thus filter the radiation. A specific Spactral range can be selected with this.

The window or the filter can be provided in the thinning or can also cover this thinning. The window or the filter can also be provided at a distance from the substrate.

Another embodiment relates to the possibility of providing a plurality of absorption elements for one emission element. It is possible, for example, to provide the absorption elements at different distances from the emission element. As a result, even with different absorption levels of the emitted radiation on the way to the absorption element 3, there can always be one that receives enough radiation to be meaningfully evaluated (see below). The dynamic range can thus be increased.

It is also possible to arrange the absorption elements at equal distances from the emission element 3. This enables redundancy, which is helpful if an element fails.

It is also possible to design the detection characteristics of the individual absorption elements differently by means of different aftertreatment, different filters, different sizes, etc. In this way, for example, intensities can be determined simultaneously for different spectral ranges.

The procedure for the analysis of a fluid (gas, liquid) will be explained with reference to FIG. 7. Such a method can be used to determine whether a certain fluid, several specific fluids or the like are present at all, and if so, in what concentration. So this is about the quantitative as well as the qualitative analysis of fluids. For example, the partial pressure of gases, and thus the pressure at all, can thus be determined.

A fluid is admitted into cavity 18 in FIG. 7. Then or before that, the heater 16 is put into operation so that the emission element 3a begins to emit infrared radiation. The emitted radiation is reflected by the coating 15 and thus finally passes through the cavity 18 to the absorption element 3b. The absorption element 3b heats up due to the absorption of the infrared radiation, so that the contact point 10 is heated and a thermal voltage is thus generated between the material 6a and 6b.

An absorption of the emitted radiation by the fluid in the cavity 18 results in a corresponding temperature of the absorption element 3b at a certain temperature of the emission element 3a, so that from the temperature to the composition, the presence, the concentration, the density, pressure, etc ., Can be closed by fluids in the region of the cavity 18. The longer the interaction of the radiation with the fluid lasts, the smaller the noise in the measured signal, since there is more absorption by the fluid. Therefore, a long way between emission and absorption source is advantageous for high sensitivity. However, if the absorption of the fluid is so strong that no more measurable radiation arrives at the absorption element, a shorter beam path would be advantageous. As mentioned above, several absorption elements 3 can increase the measuring range at different distances.

Furthermore, it is possible to shift the wavelength of the peak intensity by varying the temperature of the emission element 3a. This makes it possible to determine the absorption of the fluid in the cavity 18 spectroscopically at different wavelengths if the corresponding temperature of the absorption element 3b is detected at the respective temperature. Infrared spectroscopy is useful for identifying certain fluids or for determining their concentration, since different fluids have very characteristic absorption bands. The method and the device can be used, for example, in air conditioning systems, in chemistry, pharmacy or also for controlling exhaust gases from power plants, engines or the like.

If several absorption elements 3 are provided, these can be matched to the respective spectral range with filters and the composition of the fluid with regard to several fluid components can be examined simultaneously.

8 shows various process states in the manufacture of a device for the absorption and / or emission of radiation. 8A shows a substrate 4 with an insulation layer 7. The insulation layer 7 can also be understood as a component of the substrate 4.

Materials 6a, 6b are arranged on the insulation layer 7 and are used to form thermoelectric elements, Peltier elements, heating elements, etc.

Subsequently, as shown in FIG. 8B, a thinning in the region 2 is formed on the side of the substrate 4 opposite the materials 6a and 6b. The thinner 2 initially does not completely thin the substrate 4 down to the insulation layer 7. Rather, part of the material of the substrate 4 remains. This can be done for example by time control of the etching process or similar control mechanisms of the etching.

In the next step, the absorption and / or emission element 3 is formed from the remaining material of the substrate 4. Various approaches are conceivable for this.

On the one hand, the area of the future absorption and / or emission element 3 can be heavily doped. This is particularly possible in the case where the substrate 4 is a semiconductor material. It is also advantageous that the semiconductor material is silicon, so that such doping processes are already very well developed in terms of process technology. An etching selectivity can be achieved by the doping in the area of the future absorption and / or emission element 3. A mask or the like can be used to control the area in which the doping takes place.

In the subsequent etching, the areas to the side of the future absorption and / or emission element 3 are etched away as far as the insulation layer 7. The material for the absorption and / or emission element thus remains. If the material for the absorption and / or emission element is also slightly etched, then this must be taken into account in the previous etching step (see FIG. 8b), so that an absorption and / or emission element of a suitable thickness then remains. In a final step, this can be processed, for example, in such a way that its absorption or emission capacity is increased. This is done by increasing the surface area of the absorption and / or emission element, as is the case, for example, in the production of BSI (black silicon).

Because the absorption and / or emission element 3 consists of the same material as the substrate 4, it can be produced using the same types of processes.

It is also possible, by suitable choice of the etching method, to simultaneously etch away the areas on the side of the absorption and / or emission element 3 and to form the BSI in a single process step. Such a method step can be optimized in each case with regard to the formation of the absorption and / or emission element 3, since this element can be etched down to the side on an insulation layer 7 which acts as an etching stop layer.

Instead of doping in order to achieve an etching selectivity, the desired structure can also be worked out with a mask (metal, lacquer, polymer, etc., mask).

Another procedure is to be explained with reference to FIG. 9. FIG. 9A shows a substrate which consists of an original substrate 4, an etch stop layer 8, a further material layer 9 and an insulation layer 7. The ur The original substrate 4 can, for example, be silicon, the etch stop layer 8, any suitable etch stop layer and the material layers 9 again a silicon layer.

The materials 6a, 6b are applied to such a layered substrate as described with reference to FIG. 8.

As shown in FIG. 9B, thinning 2 is then carried out. However, this thinning takes place down to the etching stop layer 8.

In the subsequent step, the etch stop layer 8, which is exposed in the area of the thinner 2, is removed using suitable methods (see FIG. 9C). As a result, the material layer 9 of the substrate is exposed. From this, the absorption and / or emission element 3 can now be suitably worked out, as described with reference to FIG. 8 (see FIG. 9D).

The advantage of this method is that the thickness of the material from which the absorption and / or emission element 3 is worked out is independent of the etching process. Rather, the thickness is predetermined by the thickness of the layer 9. This improves the process accuracy compared to a method in which the thickness of the material for the absorption and / or emission element 3 is determined by a time control of the etching, which is somewhat imprecise and possibly not homogeneous across the substrate.

10 shows a further procedure for producing a device for absorption and / or emission of radiation. FIG. 10A shows a substrate 4 in which a special doping is present in a region of the future absorption and / or emission element 3. It would also be conceivable that in the area of the future absorption and / or emission element 3 a suitable material is introduced into a previously made trench of the substrate 4, which thus becomes part of the substrate 4.

The substrate 4 is provided with an insulation layer 7. It is also possible for the substrate to consist of an original substrate 4 and the insulation layer 7 and for doping to take place in the region of the future absorption and / or emission element 3 through the insulation layer 7.

In the area of the future absorption and / or emission element 3, thinning is carried out from the opposite side of the substrate 4. By doping the area of the future absorption and / or emission element 3, an etching selectivity with respect to the undoped material can be produced, so that, as shown in FIG. 10B, the absorption and / or emission element 3 can be obtained.

FIG. 11 shows a special embodiment of a method for producing a device for the absorption and / or emission of radiation. Starting from an original substrate 4, an etch stop layer 8 is arranged thereon. A superstructure mask 20 is arranged on the etch stop layer 8 by means of microstructuring, which overgrown with a further material layer 9. After a planarization, the insulation layer 7 is possibly applied to this further material layer 9 and the finished substrate is thus obtained. In the area in which the superstructure mask 20 is formed, the contact point between the material 6a and 6b or a corresponding heating material or the like is arranged on the insulation layer 7.

After the original substrate 4 has been thinned and the etching stop layer 8 has been removed, the further material layer 9 and the superstructure mask 20 are exposed.

In a further process step, the further material layer 9 can then be etched away as far as the insulation layer 7, certain regions of the further material layer 9 not being etched away by the superstructure mask 20 (see FIG. 11B). An absorption and / or emission element 3 with a superstructure can then be obtained from these.

For further processing, the superstructure mask 20 can be removed by a suitable selective measure and then removed from the remaining constituents. len of the material layers 9, the absorption and / or emission element 3 are produced (see also FIG. 5).

Instead of the superstructure mask, a mask without a superstructure could also be used, so that an absorption and / or emission element 3 with only one part is obtained

After the absorption and / or emission element 3 has been produced using the various methods, the same can be passivated. The passivation can take place, for example, by oxidation of the surface, coating of the surface or the like. The passivation serves to increase the life of the absorption and / or emission element. This could be restricted, for example, by aging processes, pollution or the like.

A greatly enlarged top view of the surface of BSI is shown in FIG. Machining the surface creates pyramid-like very fine structures. Such a surface has a very high absorption or emission capacity.

Claims

claims

1. A method for producing a component for absorption and / or emission of radiation with the steps

thinning a substrate and

the manufacture of an absorption and / or emission element in the area of thinning

characterized in that

the absorption and / or emission element (3) is produced by working out of a material (4,9) of the substrate (4,7,8,9).

2. The method according to claim 1, characterized in that the substrate (4,7,8,9) a semiconductor substrate preferably comprises or is a silicon substrate.

3. The method according to any one of claims 1 or 2, characterized in that the Absoφtions- and / or emission element (3) by structuring, preferably by etching, such as dry etching and / or laser processing, from the material (4,9) of the substrate (4,7,8,9) is produced.

4. The method according to any one of claims 1 to 3, characterized in that the absorption and / or emission element (3) comprises BSI.

5. The method according to any one of claims 1 to 4, characterized in that the thinning and the manufacture of an absorption and / or emission element (3) is carried out simultaneously.

6. The method according to any one of claims 1 to 5, characterized by the step of forming at least one further optical element (15) such as egg Nem mirror (15) and / or a focusing element (14) and / or a window and / or a filter.

7. The method according to any one of claims 1 to 6, characterized by the step of passivation and / or post-treatment of the absorption and / or emission element (3), for example by coating and / or oxidizing and / or chemical surface treatment.

8. The method according to any one of claims 1 to 7, characterized by the step of arranging thermoelectric and / or pyroelectric materials (6a, 6b, 11, 12, 13) and / or resistance layers (16) for heating / cooling or for detecting one Temperature which is preferably on the other side of the substrate than on the side on which the absorption and / or emission element (3) is or will be produced and which are preferably electrically insulated from the substrate (4,7,8,9) ,

9. The method according to any one of claims 1 to 8, characterized by the step of thinning down to an etch stop layer (8), which is preferably an epitaxial and preferably highly doped Si layer.

10. The method according to claim 9, characterized in that the etching stop layer (8) is adjacent to a superstructure mask (20) of the manufacture of the absorption and / or emission element (3).

11. The method according to any one of claims 1 to 8, characterized in that before the manufacture of the absorption and / or emission element (3) by ion implantation highly doped areas are created, which in an etching process as an absorption and / or emission element (3) or as Superstructure mask for the production of the absorption and / or emission element (3) remain.

12. Device (1) for absorption and / or emission of radiation, with an absorption and / or emission element (3) arranged in a thinned area (2) of a substrate (4,7,8,9)

characterized in that

the absorption and / or emission element (3) comprises the same material (4,9) as a material (4,9) of the substrate (4,7,8,9).

13. The apparatus according to claim 12, characterized in that the substrate (4,7,8,9) a semiconductor substrate preferably comprises or is a silicon substrate.

14. Device according to one of claims 12 or 13, characterized in that the thinning (2) is provided so that it can serve for sufficient thermal insulation of the absorption and / or emission element (3).

15. Device according to one of claims 12 to 14, characterized in that the absorption and / or emission element (3) comprises a structured semiconductor material which is preferably produced by etching, such as dry etching and / or laser processing.

16. Device according to one of claims 12 to 15, characterized in that the absorption and / or emission element (3) comprises BSI.

17. Device according to one of claims 12 to 16, characterized in that the device (1) comprises further optical elements such as mirrors (15) and / or focusing devices (14).

18. Device according to one of claims 12 to 17, characterized in that the absorption and / or emission element (3) is passivated, for example by coating, oxidizing, or a chemical surface treatment.

19. Device according to one of claims 12 to 18, characterized in that the device thermoelectric and / or pyroelectric materials (6a, 6b, 11, 12, 13) and / or resistance layers (16) for heating or for temperature detection, which are preferably on the other side of the substrate like the absorption and / or emission element (3).

20. Device according to one of claims 12 to 19, characterized in that the device (1) at least one emission element (3a) and at least one Ab¬

Sorption element (3b), wherein at least one cavity (18) for a fluid is provided on the radiation path between the emission element and the absorption element.

21. The apparatus according to claim 20, characterized in that the emission element (3a) and absorption element (3b) on the same substrate (4,7,8,9) or on two different substrates (4,7,8,9, preferably arranged opposite one another) 17) are arranged.

22. The device according to one of claims 12 to 21, characterized in that a window and / or filter is arranged in front of the absorption and / or emission element (3), which comprises, for example, diamond, sapphire, CaF ₂ or BaF ₂ .

23. The device according to claim 22 as far as referred back to claim 20 or 21, characterized in that the window and / or the filter spatially separates the cavity and the absorption and / or emission element (3).

24. Device according to one of claims 12 to 23, characterized in that a plurality of absorption elements (3) are assigned to one emission element (3), each of which preferably has different detection characteristics.

25. Device according to one of claims 12 to 24, characterized in that a plurality of absorption elements (3) are assigned to one emission element (3), each of which has different distances from the emission element.

26. Method for the analysis of fluids by emission of radiation, passage of the radiation through an area which can be filled with a fluid, and absorption of the radiation,

characterized in that

the emission and / or absorption of the radiation is carried out with a device (1) according to one of claims 12 to 25 or a device produced according to a method of claims 1 to 11.