Organometallic vapor-phase homoepitaxy of gallium arsenide assisted by a downstream hydrogen afterglow plasma in the growth region

Abstract

In situ generated arsenic hydrides are reacted downstream with trimethylgallium (TMGa), both in the presence of and in the absence of a downstream hydrogen afterglow plasma. The homoepitaxial activation energy dramatically changes from 62 kcal/mol for the pure thermal to 21 kcal/mol for the plasma-assisted growth. The carbon incorporation mechanism for the plasma-assisted growth at temperatures less than 400 °C has a distinct activation energy for carbon incorporation of 23 kcal/mol, independent of V-III ratios. At temperatures above 400 °C, the level of carbon incorporated in the films reaches a level that appears to be dependent on the gas-phase precursor V-III ratio. The activation energy of the low-temperature region is consistent with the surface decomposition of arsenic hydrides.