SURFACE-MORPHOLOGY AND GROWTH-RATE VARIATION OF INP ON PATTERNED SUBSTRATES USING TERTIARYBUTYLPHOSPHINE

The surface morphology and growth rate variation of InP on patterned s ubstrates were investigated. InP substrates were patterned with ridges parallel to the [1 1 0] direction by reactive ion etching. The ridges were overgrown by metal organic vapor phase epitaxy (MOVPE) using ter tiarybutylphosphine (TBP) as the phosphor source. The morphology of th e overgrown ridges was dependent on the substrate temperature and V/II I ratio. Sidewall facets overgrown at a substrate temperature of 550 d egrees C were smooth. A small step was formed in front of the ridge at 570 degrees C, and the (0 0 1) surface became concave near the ridge. The lateral growth rate varied remarkably with the substrate temperat ure. The lower the substrate temperature, the higher the lateral growt h rate. A step flow growth mode was proposed to explain the enhancemen t of lateral growth rates on patterned substrates. The results of TBP are similar to that of PH3, but TBP can be used at a lower substrate t emperature with a higher utilization efficiency. (C) 1998 Elsevier Sci ence B.V. All rights reserved.