KLA Corporation
Dual Vacuum Seal

Abstract:

A vacuum system includes a wall of a vacuum chamber, a flange of the vacuum chamber, an outer seal disposed between the wall and the flange, and an inner seal disposed between the wall and the flange. The outer seal includes a first material; the inner seal includes a second material distinct from the first material. The inner seal is closer to the interior of the vacuum chamber than the outer seal and is separated from the outer seal by a gap. The outer seal may be capable of providing tighter vacuum sealing between the wall and the flange than the inner seal. The inner seal may be more resistant than the outer seal to a gas to be used to clean the interior of the vacuum chamber. The vacuum system also includes a path to couple the gap to a first vacuum pump, to evacuate the gap.