Behavior of InP growth by gas source molecular beam epitaxy on singular and vicinal substrates

Abstract

Based on the vast data concerning molecular beam epitaxial (MBE) growth of GaAs, it is usually assumed that the growth rate in III-V MBE is limited by supply of the group-III flux as long as sufficient group-V flux is provided. It is also assumed that the growth rate can be calibrated by the period of reflection high-energy electron diffraction (RHEED) oscillation. Presently, these two basic assumptions form the basis of the standard procedure for predetermination of the growth rate in MBE growth of III-V compounds and their related heterostructures and quantum wells. The purpose of this paper is to clarify the behavior of the growth rate during gas source MBE growth of InP on singular and vicinal substrates. RHEED oscillations during growths with various growth conditions were investigated and compared with the real growth rates obtained from direct measurements of the layer thicknesses. Furthermore, effects of both growth conditions and substrate misorientation on the layers' properties were examined by Hall effect measurements and photoluminescence (PL) measurements. It is shown that the above two assumptions based on GaAs MBE experiences are not necessarily true in gas source MBE growth of InP. Namely, the growth rate shows a marked dependence on phosphorus pressure, and the RHEED oscillation is very sensitive to the substrate misorientation. It is also shown that use of the vicinal substrates has significant effects on incorporation process of the adatoms into the grown layers.<>