Chemical Beam Epitaxy of GaAsN Thin Films with Monomethylhydrazine as N Source

Abstract

GaAsN thin films were grown by chemical beam epitaxy (CBE) with monomethylhydrazine (MMHy) as a N source. Processes that determine the N composition in the GaAsN thin films were investigated in the growth temperature range from 340 to 480 °C. When growth temperature is low (340–390 °C), N composition is mainly determined by the supply of N species generated from MMHy and growth rate, since the desorption rate of N species from the growing surface is low. The effect of the desorption of N species on N composition is enhanced by increasing growth temperature (390–445 °C). When growth temperature is high (445–480 °C), the degree of N atom segregation from the grown layer increases, resulting in a marked decrease in N composition. Thus, N composition is determined by the balance of supply and desorption of N species, and growth rate.