I-V CHARACTERISTICS OF COPLANAR METAL-SEMICONDUCTOR-METAL NANOJUNCTIONS

Planar metal/semiconductor/metal (PMSM) junctions buried in a SiO2 lay er are fabricated using electron beam lithography on a silicon sample. A technique of jump of pixels is used to obtain different sizes of ju nctions, the smallest having an inter-electrode distance of 5 nm. The current-voltage characteristics and the variation of the junction cond uctance with the temperature down to 8 K have been studied. At all siz es and for both polarities, the I-V curves correspond to the reverse c haracteristic of a metal/semiconductor contact. At low bias voltage, t he influence of a thin insulator interfacial layer between the metal a nd the semiconductor has been pointed out. For these junctions, a non- linear low voltage I-V characteristics is observed before the large vo ltage thermionic emission regime. For the smallest junctions obtained without interfacial oxide layer, a linear I-V characteristic is recove red at low voltage. Their conductance can be lowered by decreasing the temperature.