Hydride vapor phase epitaxial growth of AlGaN

The growth of AlGaN layers on GaN and AlN templates by hydride vapor phase epitaxy (HVPE) was experimentally investigated in detail. Linear control of the Al solid fraction with respect to that of the gas phase was established under conditions with a relatively low H2 partial pressure. Severe surface deterioration caused by microcrystal inclusion and hillock formation were effectively removed through the use of HVPE conditions that enhanced an etching effect and suppressed parasitic reactions. As a result, AlGaN layers with good surface and crystal qualities were successfully prepared within almost the entire Al-fraction range by the HVPE method.