| 摘要 |
The disclosure relates to a system for pumping down pressurized gas residing after shut-off in the piping used to provide a gas flow for backside wafer heating/cooling during the processing of the semiconductor wafer (20). The system includes a valve selectable secondary piping line (70) for equalizing on shut-off any pressure differential occurring in the primary gas flow line (50) between the process chamber (12) and the backside heating element (30). The secondary line runs from an opening (76) in the process chamber wall to a tee-joint (72) installed in the primary flow line immediately downstream of the final isolation valve (42) in the primary line. A valve (78) is installed in the secondary line and is operationally interlocked (80), in an inverse manner, with the isolation valve in the primary line such that when one valve is open the other valve is closed and vice versa. <IMAGE> |
