Visible luminescence from silicon wafers subjected to stain etches

Abstract

Etching of Si in a variety of solutions is known to cause staining. These stain layers consist of porous material similar to that produced by anodic etching of Si in HF solutions. We have observed photoluminescence peaked in the red from stain-etched Si wafers of different dopant types, concentrations, and orientations produced in solutions of HF:HNO3:H2O. Luminescence is also observed in stain films produced in solutions of NaNO2 in HF, but not in stain films produced in solutions of CrO3 in HF. The luminescence spectra are similar to those reported recently for porous Si films produced by anodic etching in HF solutions. However, stain films are much easier to produce, requiring no special equipment.

Synthesis of ammonium silicon fluoride cryptocrystals on silicon by dry etching

“…The fluoride cryptocrystals were formed when Si surface was exposed to the vapors of a mixture of hydrofluoric acid (HF) and nitric acid (HNO 3 ). The HF: HNO 3 mixture is known as stain-etching solution in the porous silicon formation process [9,10]. The volume ratio of the solutions of HF:HNO 3 mixture was between 7:1 -7:3.6 for the sample preparation.…”

Влияние типа и степени легирования на морфологию por-Si, полученного гальваническим травлением

“…Более производительными и простыми с точки зрения аппаратурного исполнения при груп-повой обработке не только пластин, но и порошков, являются методы, не требующие применения внешнего источника тока. К ним относятся stain etching [8][9][10], локальное химическое травление кремния с использова-нием металла (Ag [11], Au [12], Pt [13] и т. д.)…”

Optical Biosensing and Bioimaging With Porous Silicon and Silicon Quantum Dots (Invited Review)

“…Anodization of silicon in hydrofluoric acid solution is considered the best technique to form homogeneous porous structures reproducibly, although other methods have also been reported, such as stain etching [15], galvanic etching [16], metal-assisted chemical etching [17,18], and contactless electrochemical etching [19]. In the anodization process, semiconductor silicon with defect electrons (e − ) or holes (h + ) is dissolved to form pores orthogonal to the Si surface ( Figure 1) [20].…”