Achieving high quality and high electric breakdown of oxide on 4H-SiC substrates is still a major research challenge. 500Å Al 2O 3 and TiO 2 were deposited on 4H-SiC by high vacuum and low-temperature e-beam evaporation. AFM (Atomic Force Microscopy) results show that a surface mean height of 4-7 Å of Al 2O 3 was found on Si substrate and 74 Å of Al 2O 3 was found on SiC substrate. MIS capacitors were fabricated using one mask to evaluate the quality of these gate materials. C-V measurements at 10kHz show that Al 2O 3 and TiO 2 have dielectric constants of more than 9 and 20, respectively. The leakage current of an Al 2O 3 MIS capacitor is about 10 -9 A on a capacitor area of 150μm×150μm at a gate voltage of ±10V. An Al 2O 3 MIS capacitor has a lower leakage current than a TiO 2 MIS capacitor due to its large band gap offsets. Its breakdown electric field strength is more than 8MV/cm. This research indicates that e-beam deposited Al 2O 3 may be a promising dielectric material for the pulsed power SiC devices.
|Number of pages||4|
|Journal||Conference Record of the International Power Modulator Symposium and High Voltage Workshop|
|State||Published - 2004|
|Event||2004 IEEE International Power Modulator Conference: 26th International Power Modulator Symposium and 2004 High Voltage Workshop - San Francisco, CA, United States|
Duration: May 23 2004 → May 26 2004