Scanning-tunneling-microscopy study of InP(001) surfaces prepared by UHV decapping of metal-organic vapor-phase-epitaxy-grown samples

In this study we report on an investigation of the microscopic structure of InP(001) surfaces grown by metal-organic vapor-phase epitaxy (MOVPE). InP(001) homoepitaxial layers were grown in a MOVPE reactor and capped in situ with a P/As sandwich layer by photodecomposition of the phosphine and arsine precursors in the gas phase. The passivated samples were transferred through atmosphere into a separate UHV system. After thermal desorption of the capping layers, a clear (2X4) LEED pattern was achieved. STM images show large, flat surface areas. Images with atomic resolution reveal a (2X4) surface structure corresponding to an In-rich surface. The microscopic surface structure is discussed in the light of recently proposed structure models.