The formation of porous silicon by chemical stain etches

Silicon Porosification: State of the Art

“…[212][213][214] Turner 204 proposed that stain etching is actually electrochemical in its action, that is, there are anodic and cathodic sites on the surface of the semiconductor with local cell currents flowing between them. This assertion is supported by structural studies, such as those of Beale et al 215 and Schoisswohl et al, 216 in which it was reported that the structure of anodically and stain etched PSi is similar and, therefore, their formation mechanisms must share much in common. Si goes into solution at the anodic sites while the oxidant is reduced at the cathodic areas.…”

Nanocrystalline Porous Silicon

“…Chemical etching of silicon using chemical solutions of HF, HNO 3 and water (Vasquez et al, 1992), NaNO 2 and HF or CrO 3 and HF (Beale et al, 1986;Zubko et al 1999) are employed for PS formation. However, the most widely used method is the electrochemical etching of silicon crystal in an electrolyte solution of HF and ethanol or methanol (Saha et al, 1998;Kanungo et al, 2006) or HF and water or HF and N, N dimethyl formamide (DMF) (Archer et al, 2005) by passing current for a fixed duration of time.…”

Luminescent Properties of Porous Silicon

“…Turner (1960) suggested that stain etching is actually electrochemical in its action; that is, there are anodic and cathodic sites on the surface of the semiconductor with local cell currents flowing between them. This assertion is supported by structural studies, such as those of Beale et al (1986) and Schoisswohl et al (1995), in which it was reported that the structure of anodically and stain-etched PSi is similar and, therefore, their formation mechanisms must share much in common. Si goes into solution at the anodic sites while the oxidant is reduced at the cathodic areas.…”