Low-Defect, High-Quality Simox Produced By Multiple Oxygen Implantation with Substoichiometric Total Dose

Abstract

ABSTRACTThis work addresses the formation of Separation by IMplantation of OXygen (SIMOX) structures by multiple oxygen implantation into silicon and high temperature annealing. We observed no threading dislocation defects in the several plane view TEM and XTEM micro graphs of each of the samples implanted with a single dose of up to 8 × 1017 0+/cm2. We also demonstrated that with a multiple low-dose (3 to 4 × 1017 0+/cm2) oxygen implantation and high temperature annealing process, we are able to produce continuous and uniform buried SiO2 layers with a total dose of 1.1 × 1018 0+/cm2 (about 60% of the total dose for standard SIMOX). The density of defects is about 105/cm2. There are no silicon islands in the buried layer, no SiO2 precipitates in the silicon top layer, and the Si-SiO2 interfaces are sharp and smooth. SIMOX material with a high-quality Si top layer and a continuous buried layer has been produced with a total dose of 7 × 1017 0+/cm2 (40% of the total dose for standard SIMOX) and a two-step process. However, in this case there are a few Si islands present in the buried SiO2 layer.