Electrical transport across oxygen-doped-silicon buried layers by substoichiometric oxygen ion implantation in silicon

The electrical and physical property changes of c-Si after substoichiometric oxygen ion implantation have been investigated using I-V, spreading resistance, secondary ion mass spectroscopy, spectroscopic ellipsometry and Fourier transform infrared spectroscopy. A key observation is the presence of donors in the vicinity of the implanted region, resulting in extensive counterdoping of p-type c-Si. Redistribution of the oxygen atoms during the high-temperature anneal results in sharp interfaces aiding the formation of a heterojunction. Mesa-type diodes on the implanted sample exhibit excellent rectification with a diode ideality factor n of 1.2 and a reverse saturation current density of 1×10^-8 A/cm². The near-surface region is shown to be crucial for achieving the high rectification behavior.