Atomic layer epitaxy of GaMnAs on GaAs(001)

A self-limiting mechanism in atomic layer epitaxy (ALE) has been investigated for the heterogrowth of GaMnAs on GaAs(001) substrate. In the ALE, trimethylgallium, bismethylcyclopentadienylmanganese and trisdimethylaminoarsine were used as source materials of gallium, manganese and arsenic atoms, respectively. Although the growth of GaMnAs was carried out at a high growth temperature of 500 degrees C, a distinct self-limiting mechanism was observed for the manganese alloy composition up to 6% and the epitaxial layer had no indications of including MnAs phase. The layer showed an atomically flat surface morphology reflecting the self-limiting growth. The self-limiting mechanism was largely affected by the lattice mismatch between GaMnAs epitaxial layer and GaAs substrate. When the manganese alloy composition exceeded 7%, the self-limiting mechanism was broken and MnAs precipitates were observed in the epitaxial layer. (c) 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.