Epitaxial growth device, production method for epitaxial wafer, and lift pin for epitaxial growth device
An epitaxial growth device includes; a chamber; a susceptor; a supporting shaft, having a main column located coaxially with the center of the susceptor and supporting arms; and a lift pin, at least the surface layer region of the lift pin is made of a material having a hardness lower than the susceptor, the lift pin has a straight trunk part upper region configured to pass through the through-hole of the susceptor and having a surface roughness of from not less than 0.1 μm to not more than 0.3 μm, and the lift pin has a straight trunk part lower region configured to pass through the through-hole of the supporting arm and having a surface roughness of from not less than 1 μm to not more than 10 μm.
1. An epitaxial growth device comprising:
a chamber;
a susceptor for placing a silicon wafer thereon within the chamber;
a supporting shaft for supporting the susceptor from below, having a main column located coaxially with a center of the susceptor and supporting arms radially extending from the main column; and
lift pins configured to be inserted through both through-holes provided in the susceptor and through-holes provided in the supporting arms, and arranged movably in a vertical direction so that the silicon wafer is attached and detached on the susceptor by ascending and descending the lift pins, each of the lift pins having a rod-shaped straight trunk part and a head part having a diameter larger than the straight trunk part and the through-hole of the susceptor, wherein
a straight trunk part lower region has a surface roughness larger than a surface roughness of a straight trunk part upper region,
at least a surface layer region of each of the lift pins is made of glassy carbon having a hardness lower than a hardness of the susceptor,
the straight trunk part of each of the lift pins comprises the straight trunk part upper region configured to pass through the through-hole of the susceptor and having the surface roughness of from not less than 0.1 um to not more than 0.3 um, and
the straight trunk part of each of the lift pins comprises the straight trunk part lower region configured to pass through the through-hole of the supporting arm and having the surface roughness of from not less than 1 um to not more than 10 um.
2. The epitaxial growth device according to claim 1 , wherein at least the surface layer region of each of the lift pins is made of glassy carbon, at least a surface layer region of the susceptor is made of silicon carbide, and the supporting arm is made of quartz.
3. The epitaxial growth device according to claim 1 or 2 , wherein each of the lift pins comprises a rounded lower end part.
4. The epitaxial growth device according to claim 1 , wherein the straight trunk part upper region has a surface roughness of 0.15 um to 0.3 um.
5. The epitaxial growth device according to claim 1 , wherein the straight trunk part lower region has a surface roughness of 1 μm to 2 μm.