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We have investigated the annealing of fixed oxide charge and interfacial traps in MISiC strucures by means of the photo capacitance voltage technique at temperatures up to 500°C. Elevated temperature measurements show reduced hysteresis and reduced fixed oxide charge at the interface. The photo capacitance technique shows a real-time measurement at elevated temperatures, in which electrons are populated by photo energy, in a 4H-SiC MIS structure. We also confirm the reduction of fixed oxide charge at the interface by means of high temperature post deposition annealing, which occurs during the high temperature measurements.

In this paper we demonstrate the recovery of Ohmic contacts formed on C-face 4H-SiC following high temperature post-processing. After a typical high-κ dielectric anneal in O2 for 3 minutes at 650 °C, replacing the metallization stack is revealed to significantly reduce the damage produced in the I-V characteristics. Using C-AFM we have also studied the mechanisms responsible for Ohmic contact formation, presenting a possible relationship between changes in the SiC crystal orientation and the establishment of Ohmic behaviour.

For the first time SiC-based gas sensor arrays have been demonstrated, which are capable of discriminating gas species under harsh environments. The structures utilise either a TiO 2 or HfO 2 dielectric layer and a Pt or Pd catalytic contact. We show that the defects in the dielectric dominate the response to hydrogen and oxygen, resulting in array behaviour, without the need for large numbers of catalytic metals. Simple multiple linear regression techniques can be used with the array to provide a real time prediction of the gas contents of a mixture.I.

In this work SiC-based MIS capacitors have been fabricated with different contact/high-k dielectric combinations and the temperature dependence of the characteristics have been examined in an N2ambient at temperatures between 323K and 673K. The structures utilise either a Pt or Pd catalytic gate contact and a TiO2or HfO2high-k dielectric, all of which are grown on a thin SiO2layer, thermally grown on the Si face of a 4H SiC epitaxial layer. The MIS capacitors have been studied in an N2 ambient between 323K and 673K and observations show that VFBreduces with increasing temperature. The majority of this variation is caused a reduction in the Ditinfluencing the structures electrical characteristics, due to a shift in the semiconductors bulk potential, which is due to the lower VTHof SiC-based MOSFETs at high temperatures.