High selectivity patterned substrate epitaxy of InxGa1-xAs/GaAs(0 &le × &le 1) by conventional LPOMVPE

A study of InxGa1-xAs/GaAs (0 &le × &le 1) selective epitaxy by conventional low-pressure organometallic vapor phase epitaxy (LPOMVPE) was performed using a variety of masking materials. Very low or zero nucleation of polycrystalline (poly) GaAs, In0.7Ga0.3As, and InAs was observed on the 300°C chemical vapor deposition (CVD) SiO2, sputtered SiO2, and plasma enhanced CVD (PECVD) Si3Nx masking materials over a wide range of typical growth parameters. Dense polycrystalline nucleation was observed on TiW masks. The degree of selectivity achieved vs. mask material and InGaAs composition at relatively low LPOMVPE reaction temperatures was examined. It was repeatedly observed that during selective epitaxy, zero polycrystalline GaAs and InAs nucleation occurred on the dielectric masks using conventional LPOMVPE. High selectivity in mask areas as large as 500 μm × 500 μm was achieved without specifically using a chloride precurser, or extremely low pressure, or SiNx masks.