Engineered Stresses for a Functional Si Light Emitter at Bandgap: An Overview

Abstract

Interfacing various materials results in stresses and strains that typically alter the properties of either or both interfaced surfaces. In this work, we focus on enhanced light emission properties at the bandgap for silicon interfaced with silica or layers of silica and silicon nitride. This discovery is corroborated by several evidences of engineered stresses and strains at the bulk or interface such as implantation and/or diffusion of dopants in silicon and rough silicon surfaces formed by wafer cutting or etching and patterning. Silicon light emitters are being eagerly sought, and upon achieving reasonable efficiencies, they may be at hand soon. The significant investment in Si-photonics by dominant semiconductor players implies that such devices will be welcomed particularly in applications such as optical emitters for next-generation integrated optical circuits and interconnects; all-Si transceivers and cross connects for integrated circuit chips; light-wave components and high-power discrete and array emitters. Engineered stresses and strains modulate the indirect Si bandgap, resulting in enhanced radiative electron–hole recombination, which competes more effectively with non-radiative recombination.