Ballistic-electron emission microscopy on the Au/ n -Si(111)7×7 interface

Abstract

Ballistic-electron emission microscopy (BEEM), performed under ultrahigh vacuum conditions at the room-temperature-grown Au/n-Si(111)7×7 interface, allows a measurement of the BEEM current for tip biases up to ≊ 8 V without a noticeable change in ballistic transmissivity. The differences of the present results to previous reports, where either no BEEM current was observed or the transmissivity was modified when applying high tip voltages, can be explained by the absence of intermixing at the Au/Si interface. Scanning tunneling microscope images of ≊40-Å-thick Au films reveal a characteristic topography of the metal surface with ≊2.5 Å high circular terraces stacked in up to four stages.