Etching SiC‐slurry and diamond wire‐sawn silicon wafers with HF‐HCl‐Cl2 mixtures - Parameter influences on etch rates and surface structures
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2017-06-07 |
| Journal | physica status solidi (a) |
| Authors | André Stapf, Peter Nattrodt, Christoph Gondek, Edwin Kroke |
| Institutions | TU Bergakademie Freiberg |
| Citations | 5 |
Abstract
Section titled “Abstract”Solutions for the wet chemical treatment of silicon wafer surfaces were investigated using mixtures which are based on hydrofluoric acid (HF), hydrochloric acid (HCl), and chlorine (Cl 2 ). We used a DoE‐test plan (Design of Experiments) to evaluate the effects of five selected parameters: concentrations of HF and HCl, gas flow rate of Cl 2 , stirring, and saw type of the wafer material. High etch rates of up to 0.63 μm min −1 were observed at room temperature, which are comparable to the etch rates of KOH‐IPA solutions. The silicon surface was investigated by reflectivity measurements and scanning electron microscopy (SEM), indicating pyramidal textured and polished surfaces for diamond wire‐ and SiC‐slurry‐sawn wafers. Using an optimized parameter set, random inverted pyramidal surface structures are formed. These random inverted structures show a significant increase in light absorption compared to standard random upright pyramid textures, for example produced by KOH‐IPA solutions.