Lift pin, and epitaxial growth apparatus and method of producing silicon epitaxial wafer using the lift pin
Provided is a lift pin for an epitaxial growth apparatus, which can prevent the back surface of a silicon wafer from being damaged by the lift pin, reduce emission of dust due to the rubbing of the lift pin against the wall surface of a through hole in a susceptor, and prevent peeling of glassy carbon. The lift pin has a straight trunk part to be inserted through the through hole; a head part to be made to abut a silicon wafer; and a cover part covering at least a top of the head part. The straight trunk part and the head part are made of a porous body, the cover part is made of a carbon-based covering material, and at least part of voids of the porous body of the head part is filled with the cover part.
1. A lift pin which is inserted through a through hole of a susceptor placed in an epitaxial growth apparatus so that the lift pin is movable in directions in which the through hole extends, and moves a silicon wafer placed on the susceptor up and down with respect to the susceptor while supporting the silicon water, comprising:
a straight trunk part inserted through the through hole;
a head part abutting the silicon wafer; and
a cover part covering at least a top of the head part,
wherein:
the straight trunk part and the head part are made of a porous body,
the porous body is made of porous SiC,
a porosity of the porous body is 15% or more and 85% or less,
the cover part is made of a carbon-based covering material, and
at least part of voids of the porous body of the head part is filled with the cover part.
2. The lift pin according to claim 1 , wherein the straight trunk part is coated with an SiC coating material.
3. The lift pin according to claim 1 , wherein the carbon-based covering material of the cover part is made of glassy carbon or pyrolytic carbon.
4. An epitaxial growth apparatus having the lift pin according to claim 1 .