Influence of metallic catalyst and doping level on the metal assisted chemical etching of silicon

The presented work shows a study of the boundary condition between metal and silicon, in metal assisted chemical etching. This is achieved by varying silicon doping type and concentration as well as metal type and oxidation agent concentration. First, the etch rate dependence of silver particles, on n- and on p-doped samples is investigated revealing different etch rates depending on doping concentration. Additional experiments using an etch solution containing no oxidation agent show an impact of the metal–semiconductor combination on the etch process. In this case the higher work function of Pt particles compared to Ag leads to an etching independent of silicon doping.

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