MOS C-t Evaluation of Reactive Ion Etched Silicon Substrate

Abstract

The distribution and electrical activity of damage in Si substrates created by reactive ion etching(RIE) in CF4+H2 using a metal contamination free chamber was studied by MOS C-t measurement. RIE damage is divided into primary and secondary damage. Primary damage is caused by the penetration of carbon generated in the decomposition of reactive gas, and restricted to the region from the top surface to a depth of 3000 Å. Secondary damage is extended to more than a few µm in depth, although its intensity is lower than primary damage. It is also shown that electrical activity of secondary damage is affected by the original defects in the Si substrate.