A novel silicon power device with high-permittivity material for better drain voltage vs. on-resistance behavior and improved performance

摘要

We propose a novel vertical metal oxide semiconductor device with high permittivity (HK) trenches interleaved inside of the drift region (HKMOS). The novel structure guarantees uniform potential distribution for a wide voltage range at the blocking state owing the potential modulation effect of HK trenches, which also introduce accumulation effect to significantly reduces the specific on-resistance (Rons) of the HKMOS. Because the accumulation voltage is determined by the drain voltage because of the unique structure of the HKMOS, the device Rons will decrease with the increase of the drain voltage. As the result, indifferent from the conventional output characteristics, the drain current of HKMOS rises super-linearly instead of sub-linearly with the linear increase of the drain voltage, which is suitable for high-power applications. The simulation results indicate that the power figures of merit of HKMOS is much higher than that of the super junction device, which is orders of magnitude larger under high drain voltage condition.