JP3252626B2 - Forming method of infrared absorption layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm structure in which a semiconductor having a fine processing technology established by photolithography is used as a base and an infrared absorption layer having good infrared absorption efficiency is thermally separated from the semiconductor base. And a method for forming an infrared absorbing layer.

[0002]

2. Description of the Related Art There are two types of infrared detectors, a quantum type that requires cooling and a thermal type that does not require cooling. There are a pyroelectric type, a thermopile type, and a bolometer type as a thermal infrared detecting element for detecting incident infrared light. In addition, in order to make effective use of incident infrared rays, a heat separation structure, that is,
A diaphragm structure thermally separated from the semiconductor substrate is used. As a material with excellent infrared absorption efficiency,
There is a metal black film, particularly a gold black film. A metal black film having a high infrared absorption efficiency is formed by a thin film forming technique under a low degree of vacuum, and the features are as follows. (A) The state is microscopically dendritic. (B) Very good infrared absorption. (C) Good step coverage. (D) Poor adhesion to the substrate. (E) The film strength is weak. (F) The film density is low. To ensure the infrared absorption function of the metal black film having these features, a certain thickness is required. For example, in the case of a gold black film, a thickness of about 3 μm or more is necessary to obtain an infrared absorption efficiency of 90% or more.

As a conventional method of forming an infrared absorbing layer, in the case of the metal black film, a patterning method using a metal mask is used.
In the case of an r film (a metal film having ordinary characteristics) and the like, a technique of patterning by a photolithography technique using a known photosensitive resin film (hereinafter, referred to as a photoresist) is used. FIG. 8 shows a conventional process of the lift-off method as an example of the photolithography technique in the latter case. As shown in FIG. 1A, an oxide film (for example, SiO ₂
A film 81 or a photoresist 81 is applied on the semiconductor substrate 1 on which the silicon nitride film 80 is formed, as shown in FIG. A photoresist opening 82 is formed. Next, as shown in FIG.
An iCr film 83 is formed on the entire surface by a thin film forming technique such as a vacuum evaporation method, and the photoresist pattern is removed with a photoresist stripper as shown in FIG.

However, in the method of forming the pattern of the infrared absorbing layer by the lift-off method as described above, as shown in FIG. 1D, the thickness of the NiCr film 83 is smaller than the thickness of the photoresist film 81, and the photo-resist at the step portion. It is necessary that there be an opening 84 through which a resist stripping solution (etching solution) can penetrate into the resist film. For example, in the case of a NiCr film, its infrared absorptance is about 70% at a thickness of 60 nm or less,
Above 60 nm, the reflection increases and becomes as low as about 50%, so that infrared absorption is possible with a thin film, and the difference between the thickness of the infrared absorption layer and the thickness of the photoresist is remarkably different. enable. In addition to the above, there is a method of patterning an infrared absorbing layer in which a metal film is etched and removed using a photoresist pattern.

However, the ordinary metal film has a large infrared reflection on the surface as described above and has a high infrared absorption efficiency as compared with a metal black film having a high infrared absorptivity (for example, 90% or more in the case of a gold black film). Is low. For this reason, it is important to form a pattern of a metal black film (for example, a gold black film) excellent in infrared absorption as an infrared absorption layer, but conventionally, only a pattern formation method using a metal mask has been used. . However, in this method, it is difficult to secure accuracy, and it is difficult to form a fine pattern of the infrared absorbing layer.

[0006]

The conventional method for forming an infrared absorbing layer has the following problems. (A) In the case of a black metal film having normal strength and density, such as a NiCr film, the surface condition is smooth, the infrared reflection on the surface is large, and the infrared absorption efficiency can be about 70% or more. Can not. (B) When a metal black film having the highest infrared absorption efficiency, such as a gold black film, is used as the infrared absorption layer, it is difficult to secure a required film thickness due to restrictions on exposure conditions and the like. It is difficult to form a pattern of the infrared absorbing layer. (C) The conventional method of patterning a metal black film using a metal mask makes it difficult to secure accuracy and miniaturize. From these facts, it has been technically difficult to form a pattern of a metal black film having excellent infrared absorption efficiency, for example, a gold black film according to the prior art.

The present invention solves the above-mentioned conventional problems and provides a method for forming an infrared absorbing layer having a good infrared absorbing efficiency, such as a metal black film, in a desired pattern shape with high accuracy. The task is to provide

[0008]

In order to solve the above-mentioned problems, according to the present invention, a sacrificial layer is formed on the entire main surface of a semiconductor substrate directly or through an underlayer, and then the sacrificial layer is partially formed. After forming the removed portion into a desired pattern shape, the opening portion of the sacrificial layer faces the opening portion of the sacrificial layer with an infrared absorbing layer that is microscopically dendritic and easily penetrates the etching solution downward.
That side also is coated on the entire surface, including, then further directly or down on one major surface an infrared absorption layer of the semiconductor substrate in the desired pattern by lift-off removal of the sacrificial layer by the infrared-absorbing layer of the bottom by a wet etching The coating was left over through the ground film.

[0009]

According to the above means, even if the thickness of the infrared absorbing layer is larger than the pattern forming step of the sacrificial layer,
If the infrared absorbing layer is a normal metal film, for example, a NiCr film, the etchant penetrates from the step around the opening to the sacrificial layer under the infrared absorbing layer in a portion outside the desired pattern of the infrared absorbing layer. Even in difficult cases, since the infrared absorbing layer according to the present invention is microscopically dendritic porous, according to the present invention, the infrared absorbing layer itself is etched by penetrating the etching solution to the lower sacrificial layer. Is performed to peel off the sacrificial layer from the lower semiconductor substrate or the underlying film formed thereon, and the sacrificial layer together with the infrared absorption layer formed thereon is lifted off and removed. As described above, the infrared absorbing layer according to the present invention is microscopically dendritic porous and hardly reflects infrared light, so that infrared absorbing efficiency is extremely good, and as described above, the infrared absorbing film itself moves the etching solution downward. Since the infrared absorption layer other than the desired pattern portion is removed by the lift-off method utilizing the property of being easily penetrated, the infrared absorption layer is made sufficiently thick so that the infrared absorption efficiency is increased. Even if the thickness is greater than the thickness of the sacrificial layer,
An infrared absorbing layer having an accurate pattern shape can be formed by wet etching. As described above, according to the present invention, an infrared absorption layer having extremely good infrared absorption efficiency can be formed in a desired pattern shape with high accuracy, which contributes to improvement in sensitivity of an infrared detection element. it can.

[0010]

FIG. 1 is a view for explaining the procedure of the first embodiment of the present invention. As shown in FIG. 1A, an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film is formed as a base film 2 on the entire main surface of the semiconductor substrate 1 by a thin film forming technique. Unnecessary regions of the base film 2 may be removed by etching using a photolithography technique. Next, a sacrificial layer 3 having a thickness of about 2 μm is formed as shown in FIG. As the sacrificial layer, for example, a photoresist film, a polysilicon film, or a phosphor silicate glass (PSG) film containing high concentration of P ₂ O ₃ is used.
The appropriate thickness of the sacrificial layer is related to the selectivity of the rate at which the sacrificial layer etchant etches the underlayer of the sacrificial layer and the infrared absorbing layer, and is taken into account from the sacrificial layer etching removal time. For example, in the case of a combination of a PSG film containing a high concentration of P ₂ O ₃ of 7.6 mol% and a silicon nitride film formed by a plasma CVD method, NH ₄ F: CH ₃ COOH: H ₂ O = 1: When an etching solution mixed at a volume ratio of 1: 1 is used, the selectivity of the etching rate between the PSG film and the silicon nitride film is about 80. If the thickness of the PSG film is increased, the time required for removal by etching becomes longer, which hinders the pattern formation of the infrared absorbing layer. In the case of this combination, the thickness of the PSG film is 2 μm.
m is used.

Next, an opening 4 is provided in the sacrificial layer by photolithography and etching, as shown in FIG. On the entire surface of the semiconductor substrate 1, as shown in FIG.
An infrared absorbing layer 5, for example, a gold black film, into which the sacrificial layer etching solution easily penetrates, is formed by a vacuum evaporation method as shown in FIG. When forming a gold black film, the degree of vacuum is 1.2 to 3.0 T
When a film is formed in an inert gas having a low vacuum of about orr, for example, in a nitrogen atmosphere, a film having a good infrared absorptance can be obtained. At a degree of vacuum of about 2 Torr, the weight is 2 per square centimeter.
It is preferable to use an infrared absorbing layer having a thickness of at least 00 μg, for example, a gold black film. Next, immerse in the sacrificial layer etching solution,
The etchant penetrates to the lower portion of the infrared absorbing layer, is uniformly etched from the upper surface of the sacrificial layer, etches away the infrared absorbing layer in unnecessary regions, and forms a pattern of the infrared absorbing layer as shown in FIG.

Here, the mechanism of pattern formation of the infrared absorbing layer will be described. FIG. 2A is a diagram showing an SEM (scanning electron microscope) photograph of the surface of the gold black film used as an example of the infrared absorbing layer, and FIG. 2B is a diagram showing a SEM photograph of the cross section of the gold black film as a binary image. is there. The gold black film in this case was formed by a vacuum evaporation method in a nitrogen atmosphere at a degree of vacuum of 2 Torr, and both photographs were taken at a magnification of 10,000 times. Looking at the surface photo, you can see that there are 1
It is formed at intervals of about μm, and has a structure in which the sacrificial layer etching solution can penetrate through the gaps between the gold tree branches. In addition, it can be seen from the cross-sectional photograph that the gold-black tree branches have grown above the semiconductor substrate, and have a three-dimensional structure with many gaps. As described above, the gold black film is shaped so that the sacrificial layer etchant can penetrate to the lower part everywhere. For this reason, the sacrificial layer etching is better than starting from the opening side.
The process is started uniformly from the upper surface of the entire sacrificial layer, and enables the pattern formation of the infrared absorbing layer having a structure like a gold black film.
Even when the thickness of the infrared absorption layer is larger than the thickness of the sacrificial layer, the sacrificial layer can be removed by etching. Although gold black has been described as an example of the material of the infrared absorbing layer, the sacrificial layer is etched by a film having a good infrared absorbing efficiency, such as Bi black, Ni black, NiP black, or Pt black, having a microscopic dendritic shape. Any material that is resistant to the liquid may be used.

FIG. 3 is a view showing a procedure of a second embodiment of the present invention. As shown in FIG. 3A, an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film is formed on the entire main surface of the semiconductor substrate 1 by a thin film forming technique. Unnecessary regions of the base film 2 may be removed by etching using a photolithography technique. Next, a sacrificial layer having a thickness of 1 μm or less is formed on the entire surface by a thin film forming technique. Next, the sacrifice layer other than the vicinity of the peripheral edge where the infrared absorption layer is formed in a desired pattern is removed by etching using photolithography technology, and a sacrifice layer 30 is formed as shown in FIG. As the sacrifice layer 30, for example, when the base film 2 is a silicon oxide film, a silicon nitride film, or a metal film, an amorphous silicon film, a polysilicon film, or a metal film (for example, an aluminum film) is used. In the case of a polysilicon film, a metal film, for example, an aluminum film is used.

Next, the sacrificial layer 3 having a thickness of about 2 μm of the first embodiment is formed, and an opening is formed by photolithography and etching as shown in FIG. 3C. Next, the sacrificial layer 30 is removed by wet etching, and the vicinity of the opening of the sacrificial layer 30 is formed into an overhang shape 31.
Next, as shown in FIG.
An infrared absorbing layer 5 is formed on the entire surface of the semiconductor substrate on which the sacrificial layer 3 is formed by a thin film forming technique. Finally, the substrate is immersed in a sacrificial layer etching solution, and as shown in FIG. 3E, the upper surface of the sacrificial layer 3 is uniformly etched to form a pattern of the infrared absorbing layer.

FIG. 4 is a view showing a procedure of a third embodiment of the present invention. As shown in FIG. 1A, an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film is formed on one main surface of the semiconductor substrate 1 as a base film 2 by a thin film forming technique. Unnecessary regions of the base film 2 such as an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film may be removed by photolithography and etching. Next, as shown in FIG. 4B, a sacrifice layer 40 with a high removal rate and a sacrifice layer 41 with a low removal rate are formed with a sacrifice layer etchant to form a plurality of sacrifice layers with different etching rates. I do.
Next, the sacrificial layer is removed by photolithography and etching to provide an opening. When the sacrifice layer is removed by etching, the lower sacrifice layer is etched faster and the upper sacrifice layer is etched slower, so that the region where the infrared absorption layer is formed, that is, the step of the opening of the sacrifice layer as shown in FIG. The shape can be overhang 42. Further, an infrared absorbing layer 5, for example, a gold black film is formed on the entire surface by a vacuum evaporation method as shown in FIG. Finally, the substrate is immersed in a sacrificial layer etching solution to uniformly start etching from the upper surface of the sacrificial layer as shown in FIG. By thus forming the sacrifice layer into a plurality of layers, the disconnection of the infrared absorption layer 5 at the opening of the sacrifice layer for forming a pattern is improved.

For example, when the sacrificial layer is a polysilicon film,
When the lower sacrifice layer is a non-doped or doped polysilicon film, and the upper sacrifice layer is a sacrifice layer composed of a combination of a polysilicon film doped with high-concentration boron. ,
As a sacrificial layer that combines thin film such as PSG film or non-doped silicate glass (NSG) film or a boron phosphosilicate Las silicate glass (BPSG) film containing P ₂ O ₃ of high concentration in the lower sacrificial layer, silicate film etchant e.g. P-etch solution or NH ₄ F: CH ₃ CO mixed at a volume ratio of HF: HNO ₃ : H ₂ O = 3: 2: 60
It is immersed in an etching solution mixed at a volume ratio of OH: H ₂ O = 1: 1: 1 to remove by etching, and the step shape of the opening of the sacrificial layer is overhanged.

FIG. 5 is a view showing a procedure of a fourth embodiment of the present invention. In the first to third embodiments, in the step of forming the infrared absorbing layer base film 50 made of an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film, holes or holes are partially formed in the base film. A step of providing a groove is added. The steps will be described. First, a base film 50 formed on one main surface of the semiconductor substrate 1 is partially opened by a photolithography technique and etching to form a hole or a groove 51 as shown in FIG. Next, a sacrifice layer 40 having a high removal rate and a sacrifice layer 41 having a low removal rate are formed by a sacrifice layer etchant, and as shown in FIG. Layers. Next, the opening of the sacrificial layer is removed by photolithography and etching, and a sacrificial layer having a stepped overhang 42 as shown in FIG. 5C is provided. Further, an infrared absorbing layer 5, for example, a gold black film is formed on the entire surface by a vacuum deposition method as shown in FIG. Finally, the substrate is immersed in a sacrificial layer etching solution to uniformly etch the sacrificial layer from the upper surface, and a pattern of an infrared absorbing layer is formed as shown in FIG.

FIG. 6 is a view showing a procedure of a fifth embodiment of the present invention. In the step of forming an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film under the infrared absorption layer of the first to fourth embodiments, the sacrificial layer etching solution used in the fourth embodiment removes the film. To form a fast layer 60, and then
A base film 61 made of an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film is formed, and this film is partially removed by photolithography and etching to form a hole or a groove 62. .

The steps will be described. First, a layer 60 with a high removal rate by a sacrificial layer etchant is formed on one main surface of the semiconductor substrate 1, and then an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal is formed on this layer. A base film 61 made of a film is formed. The base film 61 is partially removed by photolithography and etching to form a plurality of holes or a plurality of grooves 62 as shown in FIG. next,
As shown in the fourth embodiment, a sacrifice layer 40 having a high removal rate with the sacrifice layer removing liquid and a sacrifice layer 41 having a low removal rate with the sacrifice layer removal liquid are formed. As shown, a sacrificial layer composed of a plurality of layers having different etching rates is formed. Next, as shown in FIG. 6C, the opening of the sacrificial layer is removed by photolithography and etching, and the step 42 of the sacrificial layer and an amorphous silicon film, a polysilicon film, a silicon oxide film, or a silicon nitride film are formed. Alternatively, holes or grooves 6 in a base film 61 made of a metal film
The lower step of No. 2 is overhang 62. Further FIG.
As shown in (d), an infrared absorbing layer 5, for example, a gold black film is formed on the entire surface by a vacuum evaporation method. Finally, the substrate is immersed in a sacrificial layer etching solution, and as shown in FIG. 6E, the sacrificial layers 40 and 41 are uniformly formed from the upper surface, and an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film. The layer below the underlying film 61 is etched away, and the pattern of the infrared absorbing layer 5 is formed.

FIG. 7 is a view for explaining a method of etching and removing the sacrificial layer for patterning the infrared absorbing layer. The semiconductor substrate 71 having the structure of Examples 1 to 5 in which an infrared absorbing layer is formed on the entire surface is immersed in a slow flow 73 of a sacrificial layer etching solution to form a pattern of the infrared absorbing layer. In FIG. 7, reference numeral 70 denotes an etching tank;
Reference numeral 2 denotes a sacrificial layer etching solution. The flow rate of the sacrificial layer etchant is, for example, 3 minutes per minute when using a stirrer.
It is a flow speed of about 00 rotations. Even if the sacrificial layer etchant is stationary, the infrared absorbing layer pattern can be formed, but the removal of the sacrificial layer etchant is easier when the sacrificial layer etchant flows. However, if the flow is too fast, the infrared absorption layer in the region to be left is also removed.

[0021]

As described above, according to the present invention, an infrared absorbing layer having characteristics such as microscopic dendritic, very good infrared absorption, poor adhesion, low density and low strength. The pattern formation of the gold black film is performed by penetrating the sacrificial layer etchant from the infrared absorbing layer to the lower part using the microscopically dendritic porous structure, and uniformly etching and removing the entire surface of the sacrificial layer. Therefore, an accurate pattern can be formed even if the thickness of the infrared absorbing layer is larger than the thickness of the sacrificial layer. When an amorphous silicon film, a polysilicon film, a silicon nitride film, or a metal film is used as a base of the infrared absorption layer, a selectivity of an etching rate with respect to the sacrificial layer can be secured. Further, in the case of a metal film, the adhesion to the infrared absorbing layer can be improved. When such an infrared absorbing layer is used, the sensitivity of the infrared detecting element can be significantly improved.

An advantage peculiar to the second embodiment is that the size of the overhang portion of the sacrificial layer can be increased. For this reason,
It is possible to reduce the wraparound of vapor when forming a metal black film by a vacuum deposition method, to improve the cutting of the infrared absorption layer for forming a pattern, to improve the precision of the pattern, and to facilitate the pattern formation.

The effect peculiar to the third embodiment is that the step shape of the opening of the sacrificial layer can be made overhang, the step of the infrared absorbing layer can be improved in forming the pattern, the precision of the pattern can be improved, and the formation can be facilitated. To When a plurality of sacrificial layers having different etching rates, that is, a sacrificial layer in which the etching rate of the lower sacrificial layer is higher than the etching rate of the upper sacrificial layer is used, the pattern formation of the sacrificial layer becomes one.
In this case, the step of the opening of the sacrificial layer can be made to have a reverse taper, the cutting of the infrared absorbing layer for forming the pattern can be improved, and the pattern can be easily formed. When used together with the second embodiment, the effect is further improved.

The effect peculiar to the fourth embodiment is that a plurality of partial holes or a plurality of grooves are formed in an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film underlying the infrared absorption layer. By forming the infrared absorbing layer, the mechanical adhesion of the infrared absorbing layer is improved, and the yield of the pattern forming step of the infrared absorbing layer can be increased.

The effect peculiar to the fifth embodiment is that, in addition to the effect peculiar to the fourth embodiment, a plurality of layers provided on the amorphous silicon film, the polysilicon film, the silicon oxide film, the silicon nitride film, or the metal film underlying the infrared absorbing layer. By etching and removing the lower part of the partial hole or the plurality of grooves, the mechanical adhesion of the infrared absorbing layer is further improved by overhanging the step there, preventing mechanical peeling,
The yield of the pattern formation step of the infrared absorbing layer can be further increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a procedure in a first embodiment of the present invention.

FIG. 2A is a diagram illustrating an electron micrograph of the surface of a gold black film used as an infrared absorbing layer, and FIG. 2B is a diagram illustrating an electron micrograph of a cross section of the gold black film as a binary image.

FIG. 3 is a cross-sectional view for explaining a procedure in a second embodiment of the present invention.

FIG. 4 is a cross-sectional view for explaining a procedure in a third embodiment of the present invention.

FIG. 5 is a cross-sectional view for explaining a procedure in a fourth embodiment of the present invention.

FIG. 6 is a cross-sectional view for explaining a procedure in a fifth embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an etching method according to the present invention for etching and removing a sacrificial layer in a flow of an etchant for patterning an infrared absorbing layer.

FIG. 8 is a cross-sectional view for explaining a conventional process procedure for patterning a thin NiCr film or the like having relatively good infrared absorption by a lift-off method of a photolithography technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Semiconductor substrate 2 ... Amorphous silicon film, silicon nitride film, silicon oxide film, silicon nitride film, or metal film 3 ... Sacrificial layer 4 ... Sacrifice layer opening 5 ... Microscopically dendritic porous Infrared absorbing layer 30 sacrifice layer 31 sacrifice layer overhang 40 sacrifice layer with high etching removal speed 41 sacrifice layer with low etching removal speed 42 step overhang of sacrifice layer opening 50 amorphous silicon A base film made of a film, a silicon nitride film, a silicon oxide film, a silicon nitride film, or a metal film 51... A plurality of base films formed on an amorphous silicon film, a silicon nitride film, a silicon oxide film, a silicon nitride film, or a metal film Hole or groove 60... Sacrificial layer 61 having a high etching removal speed 61 ... A base film made of an amorphous silicon film, a silicon nitride film, a silicon oxide film, a silicon nitride film, or a metal film 62... A stepped overhang at the opening of the sacrificial layer 70... An etching tank 71. Flow of sacrificial layer etchant 80: amorphous silicon film or silicon nitride film or silicon oxide film or silicon nitride film 81: photoresist 82: photoresist pattern or photoresist opening 83: NiCr film for infrared absorption 84: photoresist and NiCr Opening step with membrane

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-183563 (JP, A) JP-A-4-132259 (JP, A) JP-A-5-206432 (JP, A) JP-A-5-206432 129568 (JP, A) JP-A-63-182820 (JP, A) Journal of the Infrared Society of Japan, Vol. 9, No. 1 (1999), p. 28-33 Materials from the Society of Infrared Society of Japan, No. IR-99-1 / 6 (1999), pp. 139-163. 13-23 (58) Fields surveyed (Int. Cl. ⁷ , DB name) H01L 27/14 G01J 1/02 G01J 5/02 H01L 37/02 JICST file (JOIS)

Claims (9)

(57) [Claims] The method according to claim 1 semi conductor for fabricating an infrared sensing element according to the substrate to form a sacrificial layer directly or via an underlying film on the entire surface of one main surface of the semiconductor substrate, then the sacrificial layer is partially After forming the removed opening into a desired pattern shape,
Side surface facing the opening of the sacrificial layer with an infrared absorbing layer that is microscopically dendritic and easily penetrates the etching solution downward
Also to coat the entire surface, including, after further an infrared absorbing layer is directly on a principal surface of the semiconductor substrate in the desired pattern shape or the base film by lifting off removing the sacrificial layer by the infrared-absorbing layer of the bottom by a wet etching A method of forming an infrared absorbing layer, wherein the method further comprises: 2. The method according to claim 1, wherein at least the upper surface of the underlayer is made of an amorphous silicon film, a polysilicon film, a silicon oxide film, a silicon nitride film, or a metal film. 3. The method for forming an infrared absorbing layer according to claim 1, wherein the periphery of the opening of the sacrificial layer is overhang. 4. The method for forming an infrared absorbing layer according to claim 2, wherein the base film in the opening formed in the sacrificial layer is partially removed. 5. The semiconductor device according to claim 1, wherein the sacrifice layer is sequentially arranged upward from the semiconductor substrate side.
Rate is removed by wet etching, and fast layers the slow layer, the method of forming the infrared absorption layer as claimed in any one of claims 1 to 4, wherein the ing a plurality of layers. 6. A phosphor silicate glass according to claim 1, wherein
Film, non-doped silicate glass film or boron film
The method for forming an infrared absorbing layer according to any one of claims 1 to 5, wherein the infrared absorbing layer is any one of a silicate glass film and a silicate glass film . 7. The infrared absorbing device according to claim 1, wherein the sacrificial layer is wet-etched while flowing an etching solution to form an infrared absorbing layer having a desired pattern shape. The method of forming the layer. 8. The method for forming an infrared absorbing layer according to claim 1, wherein the infrared absorbing layer is a gold black film. 9. The method of claim 1, wherein the gold black film of the infrared absorbing layer has a degree of vacuum of 1.2 to 3.
The method for forming an infrared absorbing layer according to any one of claims 1 to 8, wherein the infrared absorbing layer is formed by a vacuum evaporation method in an inert gas atmosphere of 0 Torr.