Carrier transport mechanisms of p-SiC-Si hetero-junctions

摘要

Hetero-junctions have been fabricated on Al-doped silicon carbide thin films onto n-type silicon single crystals using low-pressure chemical vapor deposition method. Temperature-dependent current—voltage measurements and Hall-effect measurements have been performed to determine the electrical properties of the structures. The temperature-dependent l—V characteristics demonstrated that the forward conduction at lower voltages was dominated by thermionic emission process, while, the forward conduction at higher voltages was determined by multi-step tunneling current. The activation energy of saturation current was about 0.32 eV. Hall-effect measurements proved the p-type properties of obtained SiC films. Deduced from the results of Hall measurements, the junction built-in potential was 1.32 V at room temperature. Moreover, using deep level transient spectroscopy measurements, Al_(Si) acceptor ionization energy was estimated.