Insertion Effect of the Monolayr of Column II Elements at GaAs/Si Interface

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We propose charge-balance heteroepitaxy, where the GaAs/Si interface is neutralized by inserting one monolayr of column II elements in place of the Ga atoms at GaAs/Si interface. We have constructed this structure using Be atoms, and have investigated the initial stages of GaAs molecular beam epitaxy growth on this charg-balanced structure by high-energy electron diffraction (RHEEED), and ultraviolet and X-ray photoemission spectroscopy (UPS,XPS).After Si (111) substrates which are treated under UV light, are heated at 900ﾟC,the sharp (7x7) RHEED pattern is obtained. As lone-pair states on Si (1x1) -As surfaces gradually decreases as depositing both Be and As at 450ﾟC.After one onolayr deposition of BeAs, this peak completely disappears. After one monolayr GaAs growth on this charge-balanced structure at 450ﾟC,GaAs-like UPS spectrum is obtained. Furthermore, a broad streaked (1x1) RHEED pattern remains till several monolayr GaAs deposition. The Si 2p XPS measurements also support that accumulation of nuclear charge at the interface is extinguished.These measurements reveal that the charge-balanced structure neutralizeds the GaAs/Si interface, and the GaAs growth mode proceeds in a Stranski-Krastanow mode.