DLTS Study of RIE-Induced Deep Levels in Si Using p+n Diode Arrays

Publisher Website
Google Scholar
Abstract
Deep levels in Si induced by reactive ion etching (RIE) of SiO2 film have been studied by DLTS. In order to detect the RIE-induced damage existing near the surface region, special device structures consisting of p+n diode arrays are used. It is found that the dominant deep levels produced by RIE are four hole traps. One level at E v+0.40 eV exhibits the Poole-Frenkel effect, from which it is identified as an acceptor. Another level at E v+0.46 eV is deduced to be an interstitial iron level from the emission rate. There is a strong decrease in the deep level concentrations upon annealing above 500°C. However, the deep levels do not completely disappear upon annealing at high temperatures. The deep level concentrations correlate well with the current-voltage characteristics of the devices.