沟槽MOSFET耐压与导通电阻的优化设计

Optimal design of breakdown voltage and on-resistance for trench MOSFET

研究了沟槽MOSFET沟槽深度和沟槽宽度对导通电阻与耐压的影响。以击穿电压65 V的沟槽MOSFET器件为研究对象,仅改变沟槽深度或沟槽宽度,详细分析了导通电阻和耐压的变化以及产生相应变化的原因。使用Sentaurus TCAD对器件进行了模拟仿真,仿真结果表明,在控制其他参数不变的条件下,导通电阻随沟槽深度的增大而逐渐减小,随沟槽宽度的增大而略微增大;耐压随沟槽深度的增大先增大后减小,随沟槽宽度的增大逐渐增大。最后,得到了比导通电阻为0.79 mΩ·cm^2,耐压为81 V的优化设计。

This paper studied the effect of trench depth and width on the on-resistance and breakdown voltage of trench MOSFET.To achieve the design object of 65 V breakdown voltage,the breakdown voltage,on-resistance and the cause of corresponding variation were analyzed in detail by only varying the depth and width of the trench.Sentaurus TCAD was used to simulate the device.The simulation results show under the same conditions the on-resistance gradually decreases with larger trench depth and width.The breakdown voltage first increases and then decreases as trench depth increases.And it monotonically increases with the trench width.Finally,an optimal design with on-resistance of 0.79 mΩ·cm^2 and breakdown voltage of 81 V was obtained.