Patent ID: 7866341
Filing Date: 2011-01-11
Classification: H01L,Y10T

Abstract:
1. A vacuum pumping system comprising: an exhaust line connected to a chamber; a booster pump and a dry pump sequentially connected to the exhaust line; a bypass line detouring the booster pump, wherein one end of the bypass line is connected to the exhaust line between the booster pump and the dry pump, and the other end of the bypass line is connected to the exhaust line ahead of the booster pump; and a first three-way valve between the booster pump and the dry pump and a second three-way valve ahead of the booster pump, wherein the one end and the other end of the bypass line are connected to the first and second three-way valves, respectively, wherein a valve is disposed between the second three-way valve and the booster pump and a slow pumping line is connected to the second three-way valve and the bypass line, and wherein the slow pumping line has a smaller diameter than the bypass line.