Control of Lifetime in Silicon by Implantation of Iron
SourceThe hole lifetime in n-type silicon could be reduced by the implantation of iron in a well-controlled manner. By choosing a suitable dose and annealing temperature, a nearly temperature-independent hole lifetime was obtained. The temperature dependence of the hole lifetime was analyzed by the Shockley-Read-Hall theory, and we found that two types of recombination centers,—that is, a process-induced center and an iron-implanted center,—were responsible for the recombination. The energy level, the capture cross section, and the charge state of these centers were determined by deep-level transient spectroscopy (DLTS) and by compensation effect. We applied the method of iron implantation to fast-switching diodes and gate-controlled switches (GCSs) and demonstrated that iron offered improved high-temperature properties when applied to switching devices.