Passivation Mechanisms of Atomic Layer-deposited AlOx Films and AlOx/SiOx Stack

Abstract

A new passivation layer of AlOx/SiOx were prepared, in which 80 nm SiOx was prepared by spin-coating perhydropolysilazane (PHPS) and annealed at 450°C. In order to compare the passivation effect of single AlOx layers and the SiOx/AlOx stack on silicon surface, the fixed charge (Qf) in the passivated layers and chemical passivation effect were obtained by corona charge method. Fourier transform infrared spectroscopy (FTIR) and Time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to investigate the Si-H, Si-O bonds and the hydrogen profile in the passivation layer, respectively. The result reveals that the single layer of AlOx provides good field effect with a large amount of negative Qf. Furthermore, SiOx capping on AlOx have more excellent chemical passivation because of amount of H saturate the dangling bonds on the silicon surface.