The effects of RTA processes on flow pattern defects in Czochralski silicon

Abstract

The changes of flow pattern defects (FPDs), one kind of grown-in defects in CZ-Si, in RTA annealed wafers were investigated in this paper. The wafers were rapid thermal annealed in N/sub 2/, N/sub 2//O/sub 2/ and Ar atmosphere respectively under RTA processes. A void was found on the apex of the parabola outline of FPDs by AFM and optical microscopy. It's shown that the hole on the tip of FPDs became shallower in depth and larger in width obviously when annealed above 1100/spl deg/C, esp. annealed in Ar atmosphere 1200/spl deg/C. Furthermore, it's also shown that the density of FPDs to reduce when annealed above 1100/spl deg/C, and most of FPDs in CZ-Si would disappear during RTA process in Ar atmosphere above 1200/spl deg/C.