Patent ID: 7422655

Claim:
An apparatus for performing a semiconductor process on a target substrate, comprising: a process container configured to accommodate the target substrate; a gas supply system configured to supply a process gas into the process container; a worktable disposed in the process container, the worktable having an upper surface on which the target substrate is placed, and a lower surface which is exposed inside the process container; and a lifting mechanism configured to assist transfer of the target substrate with respect to the upper surface of the worktable, wherein the lifting mechanism comprises a lifter pin configured to support the target substrate, a driving unit configured to move the lifter pin up and down, and a guide hole configured to guide the lifter pin being moved up and down, the guide hole comprising a main hole portion which extends from the upper surface to the lower surface through the worktable, and an extended hole portion which extends into an extension sleeve which projects downward from the lower surface of the worktable to correspond to the main hole portion, wherein a groove portion is formed in an outer surface of the lifter pin and extends in a longitudinal direction of the lifter pin such that, when the lifter pin is set by the driving unit in a predetermined state where the lifter pin protrudes above the upper surface of the worktable, an upper side of the groove portion is exposed above the upper surface of the worktable while a lower side of the groove portion is present below the upper surface of the worktable.