Enhanced iron gettering with black silicon

Description

Nanostructured silicon, also known as black-silicon, is a promising method for completely eliminating surface reflectance in silicon-based optoelectronic devices. It has recently been shown that despite the increased surface area, these surfaces can be effectively passivated, resulting in high-performing optoelectronic devices, such as solar cells and photodiodes. This work investigates a thus-far neglected benefit of black silicon: the increased surface area provides an opportunity for enhanced gettering of deleterious metal impurities.

Here, we perform a benchmark study to quantitatively investigate the gettering performance of iron, the most deleterious metal impurity in p-type silicon processing in highly-doped black-silicon structures. We use IC-grade Cz-Si wafers intentionally contaminated with iron at specific concentrations. We manufacture high-quality black silicon on these wafers and subject these wafers to different kind of doping processes. We quantify the resulting gettering efficiency and discuss the dominant gettering mechanisms.

Period	3 Oct 2017
Event title	Conference on Gettering and Defect Engineering in Semiconductor Technology
Event type	Conference
Conference number	17
Location	Telavi, Georgia
Degree of Recognition	International