US Patent 11282738 Lift pin module

A lift pin module includes a lift pin which includes a head portion disposed at a first end of the lift pin, and a connecting portion disposed at a second end of the lift pin opposite to the first end, the head portion connected to a stage disposed inside a semiconductor process chamber, and the head portion extending in a first direction; an upper weight which includes a side surface with an opening extending in the first direction, the opening configured to receive the lift pin therein, and the upper weight surrounding the connecting portion of the lift pin; and a lower weight screwed to the upper weight, the lower weight disposed below the upper weight.