Reflection high-energy electron diffraction and scanning tunneling microscopy study of InP(001) surface reconstructions

TL;DR

This study investigates InP(001) surface reconstructions using RHEED and STM, revealing five reconstructions with only two showing long-range order and challenging the universality of the (4x2) reconstruction in III-V surfaces.

Contribution

The paper provides detailed in situ analysis of InP(001) surface reconstructions, highlighting the absence of the expected (4x2) structure and identifying new reconstruction patterns.

Findings

Five reconstructions observed with RHEED.

Only two reconstructions show long-range periodicity.

InP(001) does not form the (4x2) reconstruction.

Abstract

The reconstructions of the InP(001) surface prepared by molecular beam epitaxy have been studied with in situ reflection high-energy electron diffraction (RHEED) and scanning tunneling microscopy (STM). The growth chamber contains a highly accurate temperature measurement system and uses a solid-source, cracked phosphorus, valved effusion cell. Five InP(001) reconstructions are observed with RHEED by analyzing patterns in three principal directions. Under a fixed P2 flux, decreasing the substrate temperature gives the following reconstructions: c(2x8), (2x4), (2x1), (2x2), and c(4x4). In situ STM images reveal that only two of these reconstructions yields long-range periodicity in real space. InP(001) does not form the metal rich (4x2) reconstruction, which is surprising because the (4x2) reconstruction has been coined the universal surface reconstruction since all III-V(001) surfaces were thought to favor its formation.