Impact of the impurity concentration on modulating charge state occupation in silicon

This paper discusses the impact of the concentration of an impurity/defect on charge state distributions due to its ability to act as a dopant. A model using Sah-Shockley statistics is developed using an iterative process to include this behavior and is essential to consider when the impurity concentration approaches or exceeds the inherent background doping concentration. We highlight the importance of this effect for negative-U defect systems such as interstitial boron, hydrogen and the boron-oxygen defect. For hydrogen, this behavior can lead to an `auto-generation' of the highly mobile neutral charge species, or even convert a p-type wafer to an n-type wafer.