Title:
PROCESS FOR PREPARING LOW DEFECT DENSITY SILICON USING HIGH GROWTH RATES
Document Type and Number:
WIPO Patent Application WO2002075025
Kind Code:
A3
Abstract:
The present invention relates to a process for growing a single crystal silicon ingot which contains an axially symmetric region which is substantially free of agglomerated intrinsic point defects. The process comprises (i) forming a region within the constant diameter portion in which vacancies are the predominant intrinsic point defect; (ii) heating the lateral surface of the ingot to cause a thermally induced inward flux of silicon self interstitial atoms into the region from the heated surface which reduces the concentration of vacancies in the region; and (iii) maintaining the temperature of the region in excess of the temperature, TA, at which agglomeration of vacancy point defects into agglomerated defects occurs during the period of time between the formation of the region and the reduction of the concentration of vacancies in the region.
Inventors:
FALSTER ROBERT J
VORONKOV VLADIMIR
VORONKOV VLADIMIR
Application Number:
PCT/US2001/043044
Publication Date:
March 20, 2003
Filing Date:
October 22, 2001
Export Citation:
Assignee:
MEMC ELECTRONIC MATERIALS (US)
International Classes:
C30B29/06; A61K31/427; A61K31/513; A61K31/675; A61K31/7008; A61K31/704; C30B15/00; C30B15/14; C30B15/20; (IPC1-7): C30B29/06; C30B15/00; C30B15/14
Domestic Patent References:
| WO2000000675A1 | 2000-01-06 | |||
| WO1998045509A1 | 1998-10-15 |
Foreign References:
| EP0990718A1 | 2000-04-05 | |||
| EP0890662A1 | 1999-01-13 | |||
| US5919302A | 1999-07-06 |
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