Stress-dependent transformation of interstitial oxygen in processed Ge-doped Cz-Si

Abstract

The effect of stress induced by enhanced hydrostatic pressure (HP, up to 1.2GPa) applied at processing at up to 1400K, on the transformation of interstitial oxygen (Oi) in Ge-doped Czochralski silicon (Cz-Si:Ge, cGe=7×1017cm−3) was investigated by spectroscopic, X-ray and electrical methods.While the presence of Ge results in reduced generation of thermal donors (TDs) in Cz-Si:Ge annealed under 105Pa, the same processing under HP at 675–750K produces TDs in a concentration up to about 1015cm−3. The treatment under HP at 1270–1400K stimulates agglomeration of interstitial oxygen; the HP-dependent generation of different oxygen-containing defects is observed. The effect of HP on transformation of oxygen in Ge-doped Cz-Si is related, among others, to stress-induced activation of germanium to act as a component of nuclei for precipitation of Oi’s.