Anomalous MOS capacitance behavior in depletion-mode structures

Room-temperature and liquid-nitrogen temperature capacitance measurements on enclosed-channel depletion-mode structures have shown anomalous behavior in the accumulation region of operation. Simulation has shown that the potential minimum in the buried channel of the depletion-mode device prevents high frequency variation in the accumulation-layer hole concentration. It is postulated that similar effects may be expected in depletion-mode devices using recessed oxide isolation.