[16a-W8E_307-1~10] 15.7 Crystal characterization, impurities and crystal defects

11:00 AM - 11:15 AM JST(2:00 AM - 2:15 AM UTC)

[16a-W8E_307-8] Quality of silicon substrate and point defects: Renaissance (15) Effect of internal thermal stress on point defects (2)

〇Naohisa Inoue¹, Shuichi Kawamata¹, Shuichi Okuda¹ (1.Osaka Metropolitan Univ. Radiation Research center)

Keywords:

silicon crystal,point defects,internal thermal stress

Abe showed the stress effect on the point defect type by doping with different atomic radius. He suggested the increase of vacancy type defects in large diameter crystal. In 1999, we calculated the equilibrium point defect increase. There were analyses on the pressure and internal stress effect. The vacancy concentration increase was given by the following equation. Ce(σ)/Ce(0) = exp (σV_r/k_BT), where Vr is the relaxation volume. By calculation using the parameters known before, the increase was 0.006 %, much smaller than 0.1-1% in case of doping. However, novel data were given till 2001, several orders of magnitude larger than those we used. By using the newer data, the expected increase is about 0.5%, enough in large diameter crystal. In 2014, it was experimentally confirmed as the break of Voronkov criterion in large diameter crystal. It also showed the Abe’s stress model is not valid in small diameter crystal. Now it is indispensable in growing modern large diameter crystal.