PURPOSE: To provide a method for producing a quarty glass product for semiconductor, especially wafer boat, in which a final product comes within an accurate tolerance.
CONSTITUTION: Virtual temperature (FT1) of a quartz glass material is detected prior to heat treatment. When a virtual temperature (FT2) is set for a final product after finishing all heat treatments, machining is conducted between a plurality of points at a rate represented by following formula while taking account of the distance or the pitch error between the plurality of points. R= L×{1/[1+x×(FT1-FT2)]}; where, R is the distance or the pitch (mm) between a plurality of points in which elongation/contraction due to FT is corrected, x is the elongation/contraction coefficient of quartz glass due to variation of FT (1×10-7-5×10-6) (°C-1), and L is the distance or pitch (mm) between the plurality of points required for the final product.
FUJINOKI AKIRA
INAGI KYOICHI
YOKOTA TORU
SHINETSU QUARTZ PROD