Titanium gettering in silicon: Investigation by deep level transient spectroscopy and secondary ion mass spectroscopy

Abstract

Extrinsic gettering of titanium in float-zone silicon was investigated. After heat treatments under various atmospheres the titanium concentration was determined in the bulk by deep level transient spectroscopy and in the surface region by secondary ion mass spectroscopy. The gettering is limited by the slow diffusion coefficient and by the ability of the surface to act as a sink. We show that an oxide layer, a phosphorous glass layer, and a surface damage zone are efficient sinks. A free surface, however, shows a very limited gettering action for titanium.