In-situ dry etching of InP using phosphorus trichloride inside a chemical beam epitaxial growth chamber

The authors have extended the capability of a chemical beam epitaxial (CBE) system by demonstrating reactive chemical beam etching (RCBE) of InP using phosphorus tri-chloride (PCl₃) as the gaseous etching beam injected directly into the growth chamber. This permits instant switching from etching to growth in the same run. RCBE of InP was investigated at various substrate temperatures under different PCl₃ fluences, and etching conditions. Excellent surface morphology was obtained at high temperatures and under an etching rate of 1A/sec during RCBE a dramatic improvement in surface morphology was obtained. The surface morphology obtained under such conditions is indistinguishable from that of the original substrate surface. Using SiO₂ as a mask, selective-area etching and etching followed immediately by regrowth having excellent etched and regrown morphologies were obtained