Impurity removal by chemical beam etching of GaAs

The effectiveness of the chemical beam etching process to remove dopant impurities from GaAs is investigated. Structures containing Si and Be δ-doped as well as uniformly Si-doped layers were subjected to etching and the dopant distributions were monitored by secondary ion mass spectrometry. While Be is shown to be promptly removed from GaAs by this technique, Si is shown to chemically react much less effectively to the etching process