Realhyphen;time study of the reflection high energy electron diffraction specular beam intensity during atomic layer epitaxy of GaAs

摘要

The intensity behavior of the specular beam in reflection high energy electron diffraction (RHEED) from GaAs (001) is investigated during the exposure of trimethylgallium (TMGa) and tertiarybutylarsine (TBAs) in atomic layer epitaxy (ALE) of GaAs. The temporal behavior of RHEED specular beam intensity corresponding to the transient behavior of the reflectance difference (RD) at 632.8 nm reveals several phases of surface reactions in ALE using TMGa and TBAs. RHEED specular beam intensity relaxation after short exposure to TMGa shows a longer time constant than that observed by RD, suggesting that it is the result of the overall changes in the surface atomic arrangements and morphology whereas the latter is responding to the formation/annihilation of Ga dimers.