| 摘要 |
PROBLEM TO BE SOLVED: To provide single crystal silicon, in ingot or wafer form, which contains an axially symmetric region which is free of agglomerated intrinsic point defects, and a method for producing it. SOLUTION: The method comprises controlling growth conditions, such as growth velocity v, instantaneous axial temperature gradient G<SB>o</SB>, and the cooling rate, within a range of temperatures at which silicon self-interstitials are mobile, in order to prevent the formation of the agglomerated defects. In ingot form, the axially symmetric region has a width, as measured from the circumferential edge of the ingot radially toward the central axis, which is at least about 30% the length of the radius of the ingot. The axially symmetric region additionally has a length, as measured along the central axis, which is at least about 20% the length of the constant diameter portion of the ingot. COPYRIGHT: (C)2006,JPO&NCIPI |
