Effects of As$_4$ flux on morphology of InGaAs quantum dots and the critical thickness

POSTER

Abstract

We present a comprehensive in-situ scanning tunneling microscopy (STM) study of InGaAs quantum dots (QDs) on GaAs (001) substrates as a function of arsenic flux using molecular beam epitaxy (MBE). At 500$^{\circ}$C and with all other MBE growth parameters fixed, changes in arsenic flux result in changes in the morphology of InGaAs QDs. Increasing arsenic flux results in decreasing numbers of InGaAs QDs. Reflection high energy electron diffraction patterns taken before the InGaAs deposition show that the surface reconstruction changes as a function of arsenic flux. The arsenic fluxes were kept the same during the subsequent In$_{.4}Ga$_{.6}$As deposition. After the deposition, the MBE grown samples were cooled down to room temperature by turning the growth stage heater off. The samples were then taken into the STM chamber via ultra-high vacuum port. STM images of InGaAs deposition show no dots with high As4 flux, and very high density of dots with low As4 flux. Effects of arsenic flux on the changes in surface reconstruction surface morphology and density of QDs, and the critical thickness to form the self-assembled QDs will be discussed.

Authors

  • Stanley C. Solomon

    University of California and Lawrence Berkeley National Laboratory, Rutgers University, Utah State University, Brigham Young University, University of Utah, NASA, Duke University, FMA Research, Colorado State University, Dartmouth University, Idaho State University, Physics Department, Idaho State University, Physics Department, Utah State University, Los Alamos National Laboratory, Department of Physics, Nanjing University, China, University of California at Riverside, Physics Department, Colorado School of Mines, Physics Department, University of Utah, University of Nebraska - Lincoln, USU, Society of Physics Students, Arizona State University, Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan, LANSCE-LC, Los Alamos National Laboratory, Van der Waals-Zeeman Institute, University of Amsterdam, Chemistry and Physics Dept., Virginia State University, University of Saskatchewan, Canada, Chalk River Laboratories, Physics Dept, Oxford University, Physics Dept, Utah State University, Sandia National Laboratories, National Renewable Energy Laboratory, DOE Center for Integrated Nanotechnologies, Sandia National Laboratories, National Center for Atmospheric Research

  • Stanley C. Solomon

    University of California and Lawrence Berkeley National Laboratory, Rutgers University, Utah State University, Brigham Young University, University of Utah, NASA, Duke University, FMA Research, Colorado State University, Dartmouth University, Idaho State University, Physics Department, Idaho State University, Physics Department, Utah State University, Los Alamos National Laboratory, Department of Physics, Nanjing University, China, University of California at Riverside, Physics Department, Colorado School of Mines, Physics Department, University of Utah, University of Nebraska - Lincoln, USU, Society of Physics Students, Arizona State University, Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan, LANSCE-LC, Los Alamos National Laboratory, Van der Waals-Zeeman Institute, University of Amsterdam, Chemistry and Physics Dept., Virginia State University, University of Saskatchewan, Canada, Chalk River Laboratories, Physics Dept, Oxford University, Physics Dept, Utah State University, Sandia National Laboratories, National Renewable Energy Laboratory, DOE Center for Integrated Nanotechnologies, Sandia National Laboratories, National Center for Atmospheric Research

  • Stanley C. Solomon

    University of California and Lawrence Berkeley National Laboratory, Rutgers University, Utah State University, Brigham Young University, University of Utah, NASA, Duke University, FMA Research, Colorado State University, Dartmouth University, Idaho State University, Physics Department, Idaho State University, Physics Department, Utah State University, Los Alamos National Laboratory, Department of Physics, Nanjing University, China, University of California at Riverside, Physics Department, Colorado School of Mines, Physics Department, University of Utah, University of Nebraska - Lincoln, USU, Society of Physics Students, Arizona State University, Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan, LANSCE-LC, Los Alamos National Laboratory, Van der Waals-Zeeman Institute, University of Amsterdam, Chemistry and Physics Dept., Virginia State University, University of Saskatchewan, Canada, Chalk River Laboratories, Physics Dept, Oxford University, Physics Dept, Utah State University, Sandia National Laboratories, National Renewable Energy Laboratory, DOE Center for Integrated Nanotechnologies, Sandia National Laboratories, National Center for Atmospheric Research

  • Stanley C. Solomon

    University of California and Lawrence Berkeley National Laboratory, Rutgers University, Utah State University, Brigham Young University, University of Utah, NASA, Duke University, FMA Research, Colorado State University, Dartmouth University, Idaho State University, Physics Department, Idaho State University, Physics Department, Utah State University, Los Alamos National Laboratory, Department of Physics, Nanjing University, China, University of California at Riverside, Physics Department, Colorado School of Mines, Physics Department, University of Utah, University of Nebraska - Lincoln, USU, Society of Physics Students, Arizona State University, Institute for Materials Science (NIMS), Namiki 1-1, Tsukuba, Ibaraki 305-0044, Japan, LANSCE-LC, Los Alamos National Laboratory, Van der Waals-Zeeman Institute, University of Amsterdam, Chemistry and Physics Dept., Virginia State University, University of Saskatchewan, Canada, Chalk River Laboratories, Physics Dept, Oxford University, Physics Dept, Utah State University, Sandia National Laboratories, National Renewable Energy Laboratory, DOE Center for Integrated Nanotechnologies, Sandia National Laboratories, National Center for Atmospheric Research