An improved fabrication technique for porous silicon

Abstract

An improved technique for fabrication of porous silicon is described. Silicon wafers of any size and shape can be anodized with this very versatile apparatus. Also, this technique is shown to be safer due to reduced HF acid handling. Overall, this equipment allows more efficient fabrication of uniform and good quality porous silicon safely on silicon wafers of variable sizes and shapes.

Methods to Evaluate Spatial Uniformity in Porous Silicon

“…The uniformity of the current density at smaller spatial scales can be affected by the hydrogen gas bubbles that are evolved during the etching process, especially if they adhere to the porous silicon surface or are trapped by the counter electrode. While there are strategies to reduce all these experimental variables, they can require large-volume cells (with the concomitant need for large volumes of hydrofluoric acid) (Diaz et al 1993;Semai et al 2009), active pumping of hydrofluoric acid-containing electrolyte, programmed current-voltage control (James et al 2009;Salem et al 2007), or other special cell design (Berge et al 2006;Gautier et al 2015;James et al 2007;Tobail et al 2008).…”