Enhanced iron gettering with black silicon

Pasanen, T. (Contributor), Hannu Laine (Contributor), Vähänissi, V. (Contributor), Jonas Schön (Contributor), Savin, H. (Invited speaker)

Activity: Talk or presentation typesPublic or invited talk

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.
Period3 Oct 2017
Event titleConference on Gettering and Defect Engineering in Semiconductor Technology
Event typeConference
Conference number17
LocationTelavi, Georgia
Degree of RecognitionInternational

Keywords

  • black silicon
  • nanostructured silicon
  • gettering
  • iron