In this paper, an

, added during dry oxidation and annealing m Si( 111) is clarified effect ive to suppress or remove defects. Annealing effects in

and

ambient are estimated with dry

and

oxidation(

added in dry

oxidation) method. C;em'rated defects in dry

oxidation are lengthened according to oxidation time. but any defects in

oxidation are not found. Dry oxidation, after

oxidation as an initial oxidation. lias the defect -removing effect at the interface of Si -

. After dry or

. oxidation. the annealmg 7.5%

ambient brings out gettering effect of OSF. The annealing in 7.5%

ambient for NI L oxidation method decreaSE,s

length of OSF about 20 % compared with dry oxidation method. Tlw feature of OSF is pit type, the gettering is directed to (011) plane for (111) plane. and OSFs are etched following to 110) directIon.