Vacancies and Self‐Interstitials in Silicon: Generation and Interaction in Diffusion

Abstract

Overwhelming evidence has been accumulated since 1974 that diffusion in silicon takes place via a dual vacancy‐interstitialcy mechanism. Most of the ensuing discoveries of new phenomena and the further sophistication of the dual vacancy‐interstitialcy diffusion model are related to nonequilibrium point defects. Many sources of excess silicon interstitials and excess vacancies have been discovered; but the mechanisms of defect generation, particularly by surface sources, have remained unresolved issues. We discuss in some detail two areas that are very important in diffusion modeling, but have not been well understood; the relationship between the concentrations of vacancies and interstitials under nonequilibrium conditions, and the chemical pump and the vacancy wind phenomena. We also discuss the interactions between point defects and oxygen precipitation and their implications.

Diffusion of Ge in Si1-xGex/Si single quantum wells in inert and oxidizing ambients

“…It is generally accepted that thermal oxidation of the silicon surface injects excess interstitials into the bulk material. 6,7 The proportional dependence of a material's selfdiffusion mechanism or dopant's diffusion mechanism on these defects can be determined by monitoring any enhancement or retardation of the diffusion with the addition of these defects. Thermal processing of Si/Si 0.85 Ge 0.15 /Si material in both inert and oxidizing ambients over the same temperature range has allowed estimation of the enhancement factor of interdiffusion under interstitial injection and equilibrium defect concentration conditions.…”

Recombination mechanisms in crystalline silicon: bulk and surface contributions

“…1. Oxygen related defects: thermal donors and new thermal donors, oxygen clusters and precipitates, 2. metal impurities and their complexes: fast diffusing metal atoms, acceptor-metal complexes, precipitates, 3. extended defects: dislocations and slip lines, stacking faults.…”

“…After the growth any process involving thermal treatments will induce various stage of precipitation and phase segregation of superasaturated oxygen, giving rise to different defects, both neutral and electrically active. Their influence on lifetime has been extensively investigated for their role in impurity gettering during device processing [3].…”

ZnO Thin Film, Device, and Circuit Fabrication using Low-Temperature PECVD Processes

“…[1][2][3] Doped ZnO is both highly transparent to visible light and electrically conductive, allowing it to be employed as the transparent electrodes in photovoltaic device and flat-panel displays. 4 We reported highly conducting boron-doped ZnO thin films grown at low temperature (200°C) by plasma chemical vapor deposition (PECVD) using lowtoxicity triethylboron (TEB) as the dopant. 5 The minimum resistivity was <4 · 10 -4 X cm with excellent optical transmission (>85% for visible spectrum).…”