Atomistic Mechanisms for the Thermal Relaxation of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Au</mml:mi></mml:math>-hyperdoped <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"><mml:mi>Si</mml:mi></mml:math>

Abstract

Implanting gold ions in silicon at concentrations far higher than the equilibrium solubility limit promotes sub-band-gap optical absorption, and thus has been explored in the context of Si-based near-infrared photodetectors. This absorption enhancement decreases after annealing, though, according to the structural relaxation of the material. In this article, the evolution of composition and structure of Au-hyperdoped Si after thermal relaxation is investigated in detail. The results provide crucial information for fabricating devices using Au-hyperdoped Si, and may also pertain to other hyperdoped impurities.