Roland M Wanser, Age 87Waterbury, VT

5407349, Apr 18, 1995

Jan 22, 1993

8/007699

Richard R. Hansotte - Richmond VT
Dieter K. Neff - Cambridge VT
Dennis A. Rock - St. Albans VT
Jeffrey A. Walker - Hyde Park VT
Roland M. Wanser - Bolton VT

International Business Machines Corporation - Armonk NY

F27D 312

432241

An exhaust system for use with a high temperature furnace used to perform oxidation and/or annealing operations of the type used in semiconductor fabrication. The exhaust system is designed to permit the furnace to be used with a controlled environment chamber surrounding the entry to the process chamber of the furnace. The exhaust system allows a relatively high velocity flow of exhaust gas from the process chamber through the exhaust system to occur when a positive pressure (e. g. , annealing) operations are performed. Such high velocity flow prevents (a) backstreaming and (b) the accumulation of non-uniform concentrations of exhaust gases in the exhaust system, thereby permitting the accurate monitoring of the concentration of a selected gas in the exhaust system. Based on such monitoring, the opening of the door to the process chamber of the furnace may be prevented when the concentration of the selected gas exceeds a predetermined level. Preferably, all portions of the exhaust system potentially exposed to process chamber gases are made from quartz.

5752819, May 19, 1998

Aug 26, 1996

8/703240

Richard Rene Hansotte - Richmond VT
Dieter Klaus Neff - Cambridge VT
Dennis Arthur Rock - St. Albans VT
Jeffrey Alan Walker - Hyde Park VT
Roland Michael Wanser - Bolton VT

International Business Machines Corporation - Armonk NY

F27D 312

432241

An exhaust system for use with a high temperature furnace used to perform oxidation and/or annealing operations of the type used in semiconductor fabrication. The exhaust system is designed to permit the furnace to be used with a controlled environment chamber surrounding the entry to the process chamber of the furnace. The exhaust system allows a relatively high velocity flow of exhaust gas from the process chamber through the exhaust system to occur when a positive pressure (e. g. , annealing) operations are performed. Such high velocity flow prevents (a) backstreaming and (b) the accumulation of non-uniform concentrations of exhaust gases in the exhaust system, thereby permitting the accurate monitoring of the concentration of a selected gas in the exhaust system. Based on such monitoring, the opening of the door to the process chamber of the furnace may be prevented when the concentration of the selected gas exceeds a predetermined level. Preferably, all portions of the exhaust system potentially exposed to process chamber gases are made from quartz.

5567149, Oct 22, 1996

Dec 14, 1994

8/355571

Richard R. Hansotte - Richmond VT
Dieter K. Neff - Cambridge VT
Dennis A. Rock - St. Albans VT
Jeffrey A. Walker - Hyde Park VT
Roland M. Wanser - Bolton VT

International Business Corporation - Armonk NY

F27D 500

432 6

An exhaust system for use with a high temperature furnace used to perform oxidation and/or annealing operations of the type used in semiconductor fabrication. The exhaust system is designed to permit the furnace to be used with a controlled environment chamber surrounding the entry to the process chamber of the furnace. The exhaust system allows a relatively high velocity flow of exhaust gas from the process chamber through the exhaust system to occur when a positive pressure (e. g. , annealing) operations are performed. Such high velocity flow prevents (a) backstreaming and (b) the accumulation of non-uniform concentrations of exhaust gases in the exhaust system, thereby permitting the accurate monitoring of the concentration of a selected gas in the exhaust system. Based on such monitoring, the opening of the door to the process chamber of the furnace may be prevented when the concentration of the selected gas exceeds a predetermined level. Preferably, all portions of the exhaust system potentially exposed to process chamber gases are made from quartz.