Kenneth Torres

US Patent:

20010001953, May 31, 2001

Filed:

Jul 10, 1997

Appl. No.:

08/891304

Inventors:

STEWART K. GRIFFITHS - DANVILLE CA, US
ROBERT H. NILSON - CARDIFF CA, US
KENNETH J. TORRES - AUSTIN TX, US

International Classification:

C23C016/00

US Classification:

118/728000, 118/500000

Abstract:

A support apparatus for minimizing gravitational stress in semiconductor wafers, and particularly silicon wafers, during thermal processing. The support apparatus comprises two concentric circular support structures disposed on a common support fixture. The two concentric circular support structures, located generally at between 10 and 70% and 70 and 100% and preferably at 35 and 82.3% of the semiconductor wafer radius, can be either solid rings or a plurality of spaced support points spaced apart from each other in a substantially uniform manner. Further, the support structures can have segments removed to facilitate wafer loading and unloading. In order to withstand the elevated temperatures encountered during semiconductor wafer processing, the support apparatus, including the concentric circular support structures and support fixture can be fabricated from refractory materials, such as silicon carbide, quartz and graphite. The claimed wafer support apparatus can be readily adapted for use in either batch or single-wafer processors.