Fabrication of Device-grade Separation-by-implantation-of-oxygen Materials by Optimizing Dose-energy Match

Abstract

In this article, we report formation of separation-by-implantation-of-oxygen (SIMOX) silicon-on-insulator (SOI) materials with doses ranging from (2.5 to 13.5) × 1017 cm−2 at acceleration energies of 70–160 keV and subsequent annealing at temperatures over 1300 °C in oxygen + argon atmosphere for 5 h. The microstructure evolution of SIMOX wafers was characterized by Rutherford backscattering spectroscopy, cross-sectional transmission electron microscopy, high-resolution transmission electron microscopy, Secco, and Cu-plating. This study revealed a series of good matches of dose-energy combination at acceleration energies of 70–160 keV with doses of (2.5–5.5) × 1017 cm−2, in which SIMOX wafers had good crystallinity of the top silicon, sharp Si/SiO2 interfaces, high-integrity buried oxide layers with low pinhole density, and low detectable silicon islands. Furthermore, the higher the oxygen dose, the higher the implanted energy required for the formation of a buried oxide free from Si islands. The mechanism of the optimum dose-energy match is discussed.