# US 5,344,796 A · Method for making polycrystalline silicon thin film > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,344,796 A - Document ID: US5344796A - Status: Granted - Kind: A - Application number: 07/998,665 - Filed: 1992-12-30 - Granted: 1994-09-06 - Earliest claimed: 1992-10-19 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Jong Y. Shin; Suk B. Ma - Web page: https://patentgrep.com/patent/US5344796A ## CPC - H10P 14/24: using chemical vapour deposition [CVD] - C23C 16/02: Pretreatment of the material to be coated (C23C16/04 takes precedence) - C23C 16/24: Deposition of silicon only - C23C 16/56: After-treatment - C30B 1/023: {from solids with amorphous structure} - C30B 29/06: Silicon - H10P 14/274: {using seed materials} - H10P 14/2922: {being non-crystalline insulating materials, e.g. glass or polymers} - H10P 14/3211: {Silicon, silicon germanium or germanium} - H10P 14/3411: {Silicon, silicon germanium or germanium} - H10P 14/3802: {Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth} - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR ## Abstract A method for making a polycrystalline silicon thin film by crystallizing an amorphous silicon thin film at a low temperature of 500.degree. C. to 600.degree. C. Over a glass substrate is deposited a microcrystalline silicon seed layer having a thickness of 100 .ANG. to 500 .ANG., using the chemical vapor deposition method. Over the microcrystalline silicon seed layer, a hydrogen-containing amorphous silicon layer is formed by chemical vapor deposition, at a temperature of 180.degree. C. to 270.degree. C., which is then crystallized to form a polycrystalline silicon thin film. A hydrogen-containing amorphous silicon layer having a thickness of 300 .ANG. to 500 .ANG. may be formed over the glass substrate. In this case, the hydrogen-containing amorphous silicon layer is crystallized at a temperature of 600.degree. C., to form a polycrystaline seed layer. Over the polycrystalline silicon seed layer, another hydrogen-containing amorphous silicon layer is formed which is then crystallized by a heat treatment, to form a polycrystalline thin film. The heat treatment is carried out at a temperature of 580.degree. C. to 600.degree. C. for a period of 20 hours to 50 hours. ## Claims ### Claim 1 A method of making a polycrystalline silicon thin film comprising the steps of: preparing a glass substrate; forming a microcrystalline silicon layer as a seed layer over the glass substrate; forming a hydrogen-containing amorphous silicon layer over the microcrystalline silicon seed layer by chemical vapor deposition at a temperature in the range of 180.degree. C. to 270.degree. C.; and heat treating the hydrogen-containing amorphous silicon layer, to form a polycrystalline silicon thin film. ### Claim 2 (depends on 1) A method in accordance with claim 1, wherein the microcrystalline silicon seed layer formed over the glass substrate has a thickness of 100 .ANG. to 500 .ANG.. ### Claim 3 (depends on 1) A method in accordance with claim 1, wherein the hydrogen-containing amorphous silicon layer has a thickness of not more than 1,000 .ANG. and is crystallized at a temperature of 580.degree. C. to 600.degree. C. for a period of 20 hours to 50 hours at a heat treating step thereof, to form the polycrystalline silicon thin film. ### Claim 4 A method for making a polycrystalline silicon thin film comprising the steps of: preparing a glass substrate; forming a hydrogen-containing amorphous silicon layer over the glass substrate; heat treating the hydrogen-containing amorphous silicon layer, to form a polycrystalline silicon layer as a seed layer; forming another hydrogen-containing amorphous silicon layer over the polycrystalline silicon seed layer by chemical vapor deposition at a temperature in the range of 180.degree. C. to 270.degree. C.; and heat treating said other hydrogen-containing amorphous silicon layer, to form a polycrystalline silicon thin film. ### Claim 5 (depends on 4) A method in accordance with claim 4, wherein the hydrogen-containing amorphous silicon layer formed over the glass substrate has a thickness of 300 .ANG. to 600 .ANG. and is crystallized at a temperature of 600.degree. C. at the heat treating step thereof, to form the polycrystalline silicon seed layer. ### Claim 6 (depends on 1) A method in accordance with claim 1, wherein the another hydrogen-containing amorphous silicon layer has a thickness of not more than 1,000 .ANG. and is crystallized at a temperature of 580.degree. C. to 600.degree. C. for a period of 20 hours to 50 hours at the heat treating step thereof, to form the polycrystalline silicon thin film.