AVS 46th International Symposium
    Electronic Materials and Processing Division Wednesday Sessions
       Session EM+NS-WeM

Paper EM+NS-WeM1
Homoepitaxy on AlSb(001): Novel Reconstructions and Their Implications for Nucleation and Growth

Wednesday, October 27, 1999, 8:20 am, Room 6C

Session: Nano-characterization of Molecules, Materials, and Devices
Presenter: W. Barvosa-Carter, HRL Laboratories
Authors: W. Barvosa-Carter, HRL Laboratories
A.S. Bracker, Naval Research Laboratory
J.C. Culbertson, Naval Research Laboratory
B.V. Shanabrook, Naval Research Laboratory
B.R. Bennett, Naval Research Laboratory
L.J. Whitman, Naval Research Laboratory
N. Modine, Sandia National Laboratories
H. Kim, Harvard University
E. Kaxiras, Harvard University
Correspondent: Click to Email
Strained-layer heterostructures involving the 6.1 Å family of III-V semiconductors (InAs, GaSb, and AlSb) are being investigated for use in a growing number of high-frequency and infrared devices. The structure of the interfaces in these heterostructures can be critical to device performance, and device optimization will ultimately require precise and reproducible control over surface morphology during growth. To accomplish this level of morphological control, models are being developed which relate process parameters to surface roughness. These models require a detailed understanding of the relevant surface reconstructions and the mechanisms by which epitaxy proceeds. Using MBE, RHEED, and STM (performed at NRL), combined with first-principles theoretical calculations, we have discovered a novel (4x3) reconstruction on the nominally "(1x3)" AlSb(001) growth surface. This new reconstruction is different than those previously proposed for this surface and, surprisingly, includes mixed III-V dimers in the top layer of the reconstruction. The presence of surface Al atoms close to their natural lattice sites leads to nucleation and growth mechanisms that are fundamentally different than for III-As systems. We have also studied AlSb homoepitaxy as a function of coverage. The relationship between the observed reconstructions, island structure, island distributions, and possible growth modes will be discussed.