Compositional Inhomogeneity at the Epitaxial Layer and Substrate Interface ofAlGaAs/GaAs Heterostructures

摘要

Carrier concentration spikes at the epilayer/substrate interface were observed insome two-dimensional electron gas AlGaAs/GaAs structures grown by low pressure organometallic vapor phase epitaxy. Using secondary ion mass spectroscopy, the carrier spikes were correlated with indium. Under certain growth conditions an anomalous interfacial layer, which is compositionally inhomogeneous, is formed producing an enhanced carrier density. Procedures are described which reduce the presence of indium at the epilayer/substrate interface and eliminate the carrier spike. jg p.3.