Patent ID: 9032741
Filing Date: 2015-05-19
Classification: F04B

Abstract:
1. A cryopump comprising: a first cryopanel comprising a radiation shield having an opening and a baffle arranged in the opening; a second cryopanel surrounded by the first cryopanel; and a refrigerator configured to cool the first cryopanel to a first cooling temperature and to cool the second cryopanel to a second cooling temperature lower than the first cooling temperature, wherein the baffle includes an exterior surface having a first surface roughness and a second surface roughness being smaller than the first surface roughness and wherein a first center-line average roughness of the first surface roughness is within a range of 0.5 μm to 100 μm and a second center-line average roughness of the second surface roughness is within a range of 1 nm to 400 nm.