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EP0504837A2
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Method and apparatus for producing silicon single crystal
Assignee: Shin-Etsu Handotai Co Ltd
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Filing: 1992-03-18
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Granted: —
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Expires: 2012-03-18
Abstract
Abstract A method of producing a Czochralski-grown silicon single crystal stably and efficiently with high production yield, which comprises the steps of setting pulling conditions such that at least a portion of a growing silicon single crystal (28) having a temperature in excess of 1150°C is spaced upwardly from a surface of silicon melt (14) by a distance greater than 280 mm; and pulling the growing silicon single crystal (28) upward while maintaining the pulling conditions. The silicon single crystal produced by this method has an excellent oxide film dielectric breakdown strength. An apparatus (2) for carrying out the method is also disclosed.
Inventors
- 👤 Tetsuhiro Oda
- 👤 Izumi Fusegawa
- 👤 Hirotoshi Yamagishi
- 👤 Atsushi Iwasaki
- 👤 Akiho Maeda
- 👤 Shinobu Takeyasu
- 👤 Nobuyoshi Fujimaki
- 👤 Yukio Karasawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 16:40
CPC Classifications
C; C30; C30B; C30B29/00; C30B29/02; C30B29/06; C30B15/00; C30B15/14; Y; Y10; Y10S; Y10S117/00; Y10S117/90; Y10T; Y10T117/00; Y10T117/10; Y10T117/1024; Y10T117/1032; Y10T117/1068
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
68 words
A method of producing a silicon single crystal grown by Czochralski method, characterized by: setting pulling conditions such that at least a portion of a growing silicon single crystal (28) having a temperature in excess of 1150°C is spaced upwardly from the surface of silicon melt (14) by a distance greater than 280 mm; and pulling the growing silicon single crystal (28) upward while maintaining said pulling conditions.
Claim 2
Dependent Claim
27 words
A method according to claim 1, wherein the growing silicon single crystal (28) is pulled at a pulling rate in the range of 0.8 - 2 mm/min.
Claim 3
Dependent Claim
196 words
An apparatus for carrying out the method of claim 1, including: a main chamber (6) having a side wall (6a) and an upper wall (6b) disposed on an upper end of said side wall (6a), said upper wall (6b) having an open central portion extending upwardly so as to form a neck portion (4) at an upper end of said main chamber (6); a quartz crucible (12) disposed in said main chamber (6), with a heater (16) and a thermal shield (18) disposed between said quartz crucible (12) and said side wall (6a) of said main chamber (6) in the order named; and a gate valve (8), a pull chamber and a crystal lift mechanism that are disposed above said neck portion (4) of said main chamber (6) in the order named for pulling a growing silicon single crystal (28) upward from a silicon melt (14) retained in said quartz crucible (12), characterized in that a heat insulator (30) is disposed in said main chamber (6) for keeping the temperature of an upper part of a hot zone (H) defined by and between an upper portion of said side wall (6a) and said upper wall (6b).
Claim 4
Dependent Claim
180 words
An apparatus for carrying out the method of claim 1, including: a main chamber (6) having a side wall (6a) and an upper wall (6b) disposed on an upper end of said side wall (6a), said upper wall (6b) having an open central portion extending upwardly so as to form a neck portion (4) at an upper end of said main chamber (6); a quartz crucible (12) disposed in said main chamber (6), with a heater (16) and a thermal shield (18) disposed between said quartz crucible (12) and said side wall (6a) of said main chamber (6) in the order named; and a gate valve (8), a pull chamber and a crystal lift mechanism that are disposed above said neck portion (4) of said main chamber (6) in the order named for pulling a growing silicon single crystal (28) upward from a silicon melt (14) retained in said quartz crucible (12), characterized in that a lower end of said neck portion (4) and an upper end (18a) of said thermal shield (18) are connected by a heat insulator (30).
Claim 5
Dependent Claim
17 words
An apparatus according to claim 3 or 4, wherein said heat insulator (30) has a dome-like shape.
Claim 6
Independent Claim
44 words
An apparatus according to any one of the preceding claims 3 - 5, wherein said heat insulator (30) has a composite structure composed of a graphite (32) and a heat-insulating material (34), said graphite (32) forming an inner lining of said heat-insulating material (34).
Claim 7
Dependent Claim
174 words
An apparatus for carrying out the method of claim 1, including: a main chamber (6) having a side wall (6a) and an upper wall (6b) disposed on an upper end of said side wall (6a), said upper wall (6b) having an open central portion extending upwardly so as to form a neck portion (4) at an upper end of said main chamber (6); a quartz crucible (12) disposed in said main chamber (6), with a heater (16) and a thermal shield (18) disposed between said quartz crucible (12) and said side wall (6a) of said main chamber (6) in the order named; and a gate valve (8), a pull chamber and a crystal lift mechanism that are disposed above said neck portion (4) of said main chamber (6) in the order named for pulling a growing silicon single crystal (28) upward from a silicon melt (14) retained in said quartz crucible (12), characterized in that a second heater (38) is disposed above said first heater (16) for heating the growing silicon single crystal (28).
Claim 8
Independent Claim
51 words
An apparatus according to any one of the preceding claims 3 - 7, further including a purge tube (40) depending from a lower end of the neck portion (6) for increasing the temperature gradient of only a portion of the growing silicon single crystal (28) located near said silicon melt surface.
References Cited (Backward Citations)
No citation records indexed.
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