DETERMINATION OF MAIN ELECTRICAL PARAMETERS OF Au–4H-n-SiC (MS) AND Au–Al2O3–4H-n-SiC (MIS) DEVICES

In this study, Au–4H-n-SiC metal–semiconductor (MS) and Au–Al2O3–4H-n-SiC metal–insulator–semiconductor (MIS) devices were fabricated to examine the effects on the performance of electronic devices of interfacial insulating materials. In order to determine the dielectric properties, capacitance/conductance–voltage (C/G–V) measurements were realized in a wide range of voltages (−3.0 V)–(11.0 V). Current–voltage (I–V) measurements to obtain the electric properties were realized at ±2.5V. Moreover, both the energy distributions of surface states (Nss) and series resistance (Rs) were obtained from the C/G–V data. Obtained results provided that series resistance originating from interfacial layer (Al2O3) was more effective on the I–V and C/G–V characteristics which must be taken into account in the calculation of main electrical parameters. The rectification ratio (RR) and shunt resistance (Rsh) of the MIS device were almost 103 times greater than those of the MS structure. Using Al2O3 between Au and 4H-n-SiC also led to an increase in the value of barrier height (BH) and a decrease in the value of ideality factor (n). These results confirmed that Al2O3 layer leads to an increase in the performance of MS device with respect to low values of Nss, reverse saturation current (I0) and n and high values of RR, Rsh and BH.