BALLISTIC-ELECTRON-EMISSION MICROSCOPY ON THE AU N-SI(111)7X7 INTERFACE/

Ballistic-electron emission microscopy (BEEM), performed under ultrahi gh vacuum conditions at the room-temperature-grown Au/n-Si(111)7X7 int erface, allows a measurement of the BEEM current for tip biases up to almost-equal-to 8 V without a noticeable change in ballistic transmiss ivity. The differences of the present results to previous reports, whe re either no BEEM current was observed or the transmissivity was modif ied when applying high tip voltages, can be explained by the absence o f intermixing at the Au/Si interface. Scanning tunneling microscope im ages of almost-equal-to 40-angstrom-thick Au films reveal a characteri stic topography of the metal surface with almost-equal-to 2.5 angstrom high circular terraces stacked in up to four stages.