Patent ID: 7955511

Claim:
A process for forming fine grooves on at least an outer surface of a wall part of a silica glass crucible used for pulling silicon single crystal, wherein the silica glass crucible has a wall part, an open diameter, an inner surface, and the outer surface; and a graphite susceptor adhered to the outer surface of the silica glass crucible, comprising carrying out a sand-blast treatment and a hydrofluoric acid etching on the said surface; wherein after the sand blast treatment and the hydrofluoric acid etching at least the outer surface of the wall part of the crucible is covered with fine grooves having a length of from 10 μm, to 200 μm, a width of from 10 μm to 30 μm and a depth of from more than 3 μm to less than 30 μm; and wherein a sliding frictional coefficient of the outer surface of the crucible to the graphite susceptor at 1500° C. is more than 0.6, and wherein a number of projections having a height of 0.1 mm or more is an average of less than 5/mm 2 per unit area on the outer surface of the crucible.