Temperature-dependent tunneling through thermally grown SiO2 on n-type 4H-and 6H-SiC

The temperature dependence of field emission through thermally grown silicon dioxide (SiO2) on n-type 4H and 6H silicon carbide (SiC) substrates is reported. Room-temperature SiO2/SiC barrier heights, Phi(B), of 1.92 and 2.12 V are extracted for the 4H- and 6H-SiC samples, respectively, using a Fowler-Nordheim analysis. Barrier heights of 2.2 and 2.4 V along with a linear temperature-dependent barrier height lowering, Delta Phi(B)/Delta T, of 2.4 and 2.0 mV/K for 4H- and 6H-SiC are extracted using an alternative analytical expression for tunneling from semiconducting substrates derived previously. In both analyses, the temperature-dependent flatband voltage, using the measured room-temperature value, was included. (C) 2000 American Institute of Physics. [S0003-6951(00)03808-0].