Deep-level transient spectroscopy of detector-grade high-resistivity float-zone silicon

In this paper, the application of standard capacitance DLTS to high-resistivity (HR) silicon is investigated both theoretically and experimentally. As will be demonstrated, typical artefacts occur, which are related to the low doping density of the material (order of a few times 10¹¹ to 10¹² cm^-3). The high series resistance of a HR-Si diode gives rise to the so-called Q-effect, yielding a reduction of the DLTS peak amplitude, which is particularly pronounced at room temperature and for p-type material. A second effect is the occurrence of non-negligible re-emission during the filling pulse, which causes the Arrhenius plot to deviate from a straight line and is particularly important for repulsive trapping centres. Methods will be discussed to reduce or correct for these phenomena. They will be illustrated by the practical example of the interstitial Fe donor-level in p-type HR-Si.