STRUCTURAL CHARACTERIZATION OF INGAAS INALAS QUANTUM-WELLS GROWN ON (111)-INP SUBSTRATES/

Recent studies on HEMT structures according to their growth orientatio n have attracted much interest from the viewpoint of physics and novel device applications. However, the optimization of their properties ne eds a high degree of crystalline quality. In this work, the structural characteristics of the layers present on InGaAs/InAlAs HEMT structure s grown on (111)-InP substrates have been analyzed by atomic force and transmission electron microscopies. The presence of a strained quantu m well induces a defect structure and surface morphology quite differe nt from those observed in similar samples without the quamtum well. Th ese results show that an accurate control of the growth conditions is necessary to obtain acceptable structural quality for (111) devices. ( C) 1997 Elsevier Science Ltd.