Rapid cooling dual slot load locks for liquid crystal display

Rapid cooling of 680X880 mm glass substrates was demonstrated in the dual-s lot load locks [S. Kurita, W. Blonigan, and A. Hosokawa, U.S. Patent pendin g No. 7828.7017 (December 1999)] of an AKT 5500 chemical vapor deposition s ystem. Two complimentary techniques are used to cool a substrate from 400 t o 60 degreesC within 33 s while maintaining a temperature uniformity of +/- 5 degreesC. Helium equivalent to a partial pressure of 9 Torr is injected at the initial stage of venting. Cooling plates are located as close as 8 m m above and below the substrate while cooling. Rapid-cool dual-slot load lo cks reduce cost by eliminating large vacuum pumps and machine components. U niform cooling eliminated undesirable thermal stress during cooling and thu s enabled reliable substrate handling. (C) 2001 American Vacuum Society.