Deep traps in very thin SIMOX MOSFET by current DLTS

Summary form only given. The study of deep levels in thin SIMOX (separation by implanted oxygen) films present difficulties due to the series resistance present when standard capacitance deep-level transient spectroscopy (DLTS) is used. The authors have developed a theory of current DLTS appropriate for the study of enhancement MOSFETs, for the case of both fully depleted and not fully depleted transistors. They have found that careful biasing of the device during measurement and a prudent choice of rate windows can effectively suppress the current overshoot, which if present leads to erroneous DLTS spectra. They have also found that in fully depleted structures, bulk and back interface traps are easily distinguished by applying various substrate biases. The authors have applied this technique to study the effect of various postimplantation annealing treatments on the deep levels in both n-channel and p-channel transistors and have observed a number of traps, including the Pb center and one due to iron (0.45 eV above the valence band edge)