Metal-insulator-semiconductor capacitors are fabricated from a YBa2Cu3O7-δ (YBCOVYttria-Stabilized Zirconia(YSZ)/Si structure. Current-voltage(I-V) measurements reveal that thicker YBCO films(≤150Å) tend to result in more stable capacitors. Results of capacitance-voltage(C-V) measurements during bias-temperature cycling suggest the presence of a thermally activated process in the YSZ and/or YSZ/Si interface. This process is probably related to trapping/detrapping mechanisms in the SiOx, layer formed between YSZ and Si. It is shown that the distribution of mobile ions in YSZ can be “set” with biases at room temperature and then “frozen” by lowering the temperature, giving rise to adjustable threshold voltages at 80K.