Lam Research Corporation
Moment cancelling pad raising mechanism in wafer positioning pedestal for semiconductor processing

Abstract:

An assembly used in a process chamber for depositing a film on a wafer including a pedestal assembly having a pedestal movably mounted to a main frame. A lift pad rests upon the pedestal and moves with the pedestal. A raising mechanism separates the pad from the pedestal, and includes a hard stop fixed to the main frame, a roller attached to the pedestal assembly, a slide moveably attached to the pedestal assembly, a lift pad bracket interconnected to the slide and a pad shaft extending from the lift pad, a lever rotatably attached to lift pad bracket, a ferroseal assembly surrounding the pad shaft, and a yoke assembly offsetting a moment to the ferroseal assembly when the lever rotates. When the pedestal assembly moves upwards, the lever rotates when engaging with the upper hard stop and roller, and separates the pad from the pedestal by a process rotation displacement.