Fabrication of radiation hardened SOI with embedded Si nanocrystal by ion-cut technique

Abstract

The ion-cut technique has been proposed to improve the top Si crystalline quality of the radiation hardened silicon-on-insulator (SOI). Si ion implantation prior to wafer bonding and splitting is performed to reduce the lattice damage induced by direct Si implantation through top Si film. Atomic-resolution transmission electron microscopy studies reveal that the top Si film possesses nearly perfect crystalline quality. Photoluminescence spectroscopy, x-ray photoelectron spectroscopy, and high-resolution transmission electron microscopy have corroborated the existence of the embedded Si nanocrystals. The pseudo-MOS transistors are fabricated on the hardened and unhardened SOI wafers for a quick and effective evaluation on the electrical properties of SOI wafers. The results indicate that the improvement in the total ionizing dose tolerance of the hardened SOI wafer can be attributed to the generation of deep electron and proton traps which reduce the positive charge build-up defects in the buried oxides.