Synthesis of silicon dioxide by ion implantation

Abstract

The first pioneering and primitive attempts at synthesis of SiO 2 by implantation of oxygen into single crystal silicon were in the late 1960s. The early layers, assessed mainly be infrared absorption and electrical measurements, were poor in quality. The prognosis for their use in microelectronics was pessimistic. Undeterred by this a second wave of experimenters continued to study these layers and Rutherford backscattering analysis (RBS) was brought into use. Lately buried oxide layers have been used to create silicon on insulator structures for high speed CMOS [complimentary metal-oxide-semiconductor (transistors)] integrated circuits. Progress has been rapid in the last six years and results from analysis of buried layers by RBS, TEM, SIMS, AES and XPS(TEM: transmission electron microscopy; SIMS: secondary ion mass spectrometry; AES: Auger electron spectroscopy; XPS: X-ray photoelectron spectroscopy) enable optimization of implant and annealing procedures for fabrication of device structures. However, many questions remain unanswered with regard to the microstructure of the various layers, particularly the near surface regions. Mass transport during implantation and annealing is not fully understood. Recent results in the areas of radiation damage and the behaviour of oxygen in silicon and SiO 2 shed light into some of these areas.