JPH02229473A - Manufacture of patterned photoconductor element - Google Patents

Abstract

PURPOSE:To enable fine patterns to be formed easily and at a high aspect ratio by forming a photosensitive layer on the whole surface of a conductive substrate and masking the photosensitive layer in desired patterns with a transparent metal and heating the substrate under a vacuum for reevaporating the non-masked part of the photosensitive layer to pattern the photosensitive layer. CONSTITUTION:A photosensitive layer 2 is formed by vapor depositing a photoconductive material on the whole surface of a conductive substrate 1. The photosensitive layer 2 is then masked in desired patterns of a transparent electrode 3 by application, vapor deposition or the like of the transparent electrode. Subsequently, the substrate is heated under a vacuum whereby the non- masked part of the photosensitive layer is reevaporated while the masked part is not. As a result, the photosensitive layer is patterned in the desired patterns. Finally, a protecting layer 4 if required is formed by application or vapor deposition of a transparent protecting material, The transparent electrode material used as the patterned mask should be a material not evaporated in the reevaporation process, and such material may be a metal such as Al or Au or a transparent conductive material such as SnO2, InO3, ITO or TiO2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a photoconductor element having a patterned photosensitive layer. [Prior Art] Conventionally, the method for manufacturing a photoconductor element in which a photoconductive layer of an alloy such as Ss-As or Sa=S is patterned is as follows: 1) Masking a desired pattern by printing or the like on a conductive substrate. After that, the photoconductive material is deposited on the entire surface of the conductive substrate by a method such as vapor deposition to form a photosensitive layer, and then the mask is removed using a solvent or the like.2) The photoconductive material is deposited on the entire surface of the conductive substrate by a method such as vapor deposition. After depositing and forming a photosensitive layer, masking the top with a desired pattern (transparent metal is used), remove the unmasked areas of the photosensitive layer by wet etching using an etching solution, dry etching using reverse sputtering, etc. There are known methods to do this. However, method l) has the drawback that the aspect ratio cannot be increased due to the thickness of the mask during vapor deposition, and that it cannot be patterned, especially when the pattern is fine. In addition, in method 2), in the case of wet etching, the etching solution penetrates into the mask part during etching, so as in case 1),
In addition to not increasing the aspect ratio, there are problems such as controlling the etching temperature, time, etc., and processing waste etching liquid (chalcogenide photosensitive layers are etched with alkaline solution or aqua regia, but these etching liquids make up the substrate. The etching temperature, time, etc. must be strictly controlled because the metal may be etched and there is a risk of generating highly toxic gases such as hydrogen selenide and arsine due to the reaction between the activated metal and moisture. In addition, the dry etching method has drawbacks such as low production efficiency due to equipment limitations, and the mask part is also easily heated and deformed. [Problems to be Solved by the Invention] The purpose of the present invention is to easily form fine patterns with a high aspect ratio using conventional vacuum evaporation equipment, and to do so without requiring special processing or equipment such as recovery of etching waste liquid. The purpose of the present invention is to provide a method for manufacturing a patterned photoconductor element that does not require a patterned photoconductor element. [Structure/Operation of the Invention] The method for producing a patterned photoconductor element of the present invention involves depositing a photoconductive substance on the entire surface of a conductive substrate to form a photosensitive layer, and masking the top with a desired transparent metal pattern. After that, the photosensitive layer in the non-masked areas is reevaporated and patterned by heating in a vacuum. The method of the present invention will be explained with reference to FIG. 1. First, a photoconductive material is deposited on the entire surface of a conductive substrate 1 to form a photosensitive layer 2 [FIG. 1(a)]. Next, this photosensitive layer is masked with a desired transparent electrode pattern 3 by a method such as coating or vapor deposition [FIG. 1(b)]. When this substrate is subsequently heated in a vacuum, the photosensitive layer in the non-masked areas is re-evaporated, while the masked areas remain, so that the photosensitive layer is patterned into a desired pattern [FIG. 1(c)]. Finally, if necessary, a transparent protective material is applied to the entire surface by coating, vapor deposition, etc. to form a protective layer 4. The heating temperature during reevaporation may vary depending on the type of photoconductive material, but is generally in the range of 200 to 450°C. In the case of a photoconductive material with a saturated vapor pressure of 10-5 Torr or more in the range of 200 to 450°C, it can be reevaporated sufficiently in the above temperature range, but the higher the temperature, the more intense the reevaporation becomes and the side surfaces tend to become rough. Furthermore, high temperatures may cause deterioration of the substrate and masking pattern. For these reasons, the upper limit of the heating temperature is approximately 450°C. The photoconductive material used in the method of the present invention has a saturated vapor pressure in the range of 200 to 450°C. 10-'Torr or more is suitable, such as Se, As''S alloy, As~
Se alloy. Se=As alloy, Se”Te alloy, Te
Examples include As alloys.The saturated vapor pressure is 200℃.
If the temperature exceeds 10-'Torr at 450°C, the re-evaporation rate is slow and takes time, and if the temperature exceeds 10-'Torr at 450°C, there is a risk of deteriorating the substrate or masking pattern. The transparent electrode material used for the masking pattern must not evaporate during the re-evaporation process. Such materials include metals such as tQ and Au (used in thin film form).
; SnO, , Ink, , ITO, Tie,
Transparent conductive materials such as

Generally, metal plates such as AFI, stainless steel, and brass, drums, belts, etc. are used as conductive substrates, but for special applications such as irradiation from the substrate side, a transparent conductive film such as the one described above may be applied to a glass plate. You can also use the one provided. In addition to conductive materials, non-conductive materials such as glass can also be used. The present invention will be explained below using examples. Example 1 Figure 2 (In the figure, 5 is a vacuum chamber, 6 is a substrate holder 7 is a substrate,
8 is a base mask, 9 is an evaporation source, and 10 is an evaporation material).
A photosensitive layer was formed by depositing the As alloy to a thickness of 6 μm over the entire surface of the AQ substrate in an atmosphere with a vacuum degree of 10-' Torr and a substrate temperature of 200° C. and an evaporation source temperature of 400° C. Next, a negative pattern mask was set on this photosensitive layer, the evaporation substance was changed to Au, and the vacuum degree was 1.
After evaporating Au to a thickness of 1000 nm in an atmosphere of 0-sTorr, substrate temperature 20°C, and evaporation source temperature 1000°C, a transparent electrode pattern was formed by removing the negative pattern mask. Furthermore, in the same vacuum chamber, heating was performed for 5 minutes from the substrate side under the vapor deposition conditions of the above alloy to re-evaporate it. When this substrate was taken out and observed, it was found that the non-mask portion of the photosensitive layer had been peeled off so well that the base of the substrate was clearly visible. Finally, the evaporation substance was changed to Sin, and the vacuum degree was 10" in the same vacuum chamber.
'Torr atmosphere, substrate temperature 20℃, evaporation source temperature 12
A protective layer was provided by depositing sio to a thickness of 1 μm over the entire surface of the substrate at 00°C. When the photoconductive properties of the patterned photoconductive device thus obtained were investigated, the results were comparable to those of devices fabricated using conventional wet or dry etching methods. Example 2 S~A with As content of 40 mol% instead of Se-As alloy
Same method as Example 1 except that s alloy was used. A well-patterned photoconductive device was fabricated. The photoconductive properties of this product were as good as in Example 1. [Operations and Effects of the Invention] Since the method of the present invention forms a pattern by re-evaporating the photosensitive layer, fine patterns can be easily formed with a high aspect ratio using a conventional vacuum evaporation device, and moreover, it uses less etching waste liquid. It has the advantage of not requiring special processing or equipment such as collection.

[Brief explanation of the drawing]

FIG. 1 is a manufacturing process diagram of an example of a patterned photoconductive element of the present invention, and FIG. 2 is a cross-sectional view of a vacuum evaporation apparatus used in the example. l... Conductive substrate 2... Photosensitive layer 3... Masking pattern or transparent electrode pattern 4... Protective layer 5... Vacuum chamber 7... Conductive substrate
9...Evaporation source 10...Substance for evaporation

Claims (1)

[Claims] 1. A photoconductive material is deposited on the entire surface of a conductive substrate to form a photosensitive layer, the top thereof is masked with a desired transparent metal pattern, and then heated in vacuum to form a photosensitive layer on the non-masked area. A method for producing a patterned photoconductor element, comprising reevaporating and patterning a photosensitive layer. 2. Each photoconductive substance contains As with an As content of 50 mol% or less
2. The manufacturing method according to claim 1, wherein the alloy is a ~S alloy or an As~Se alloy. 3. The manufacturing method according to claim 1 or 2, wherein the heating temperature is in the range of 200 to 450°C.