Stability of electrical properties of high-temperature operated H-2 sensorbased on Pt-I-SiC diode

Pt-I-SiC diodes with a thin oxide layer were annealed for 6 h at 600 degree sC in air. Forward and reverse current-voltage (I-V and capacitance-voltage (C-V characteristics were measured in two ambients, 20% O-2 in N-2 and 20% H-2 in N-2, at room temperature and 300 degreesC repeatedly The parameters of the diode as ideality factor. series resistance, change in barrier heig ht were evaluated as a function of the number df repetition times. Annealin g has reduced the current, the capacitance and the gas sensitivity in the I -V characteristics. though the stability of the electrical properties of th e I-V and C-V characteristics of the diode was maintained under temperature conditions lower than 300 degreesC. However, the gas sensitivity in the C- V characteristics was not affected by annealing. The results presented in t his paper substantiate the possibility of formation of thin oxide layer at SiC surface as mechanism of the degradation of Schottky diode based on SiC.