高压P-LDMOS的栅击穿及其改进方法

高压P-LDMOS的失效实验分析表明其沟道区的高峰值电场会导致沟道区的热载流子效应,从而将降低高压P-LDMOS的可靠性.借助半导体器件专业软件Tsuprem-4和Medici的模拟给出了高压P-LDMOS沟道区的电场分布情况,模拟结果显示在沟道区存在2个峰值电场,讨论了产生这2个峰值电场的原因,同时给出了降低这2种峰值电场的有效方法———适当增加沟道的长度和降低沟道区的浓度.实验结果表明采用这2种方法优化得到的高压P-LDMOS的栅击穿电压得到了很大的提高,同时P-LDMOS的可靠性也得以大幅提高.

Gate breakdown of high-voltage P-LDMOS and improved methods

The failure experiments of the P-LDMOS (lateral double diffused metal oxide semiconductor) demonstrate that the high peak electrical fields in the channel region of high-voltage P-LDMOS will reinforce the hot-carrier effect,which can greatly reduce the reliability of the P-LDMOS.The electrical field distribution and two field peaks along the channel surface are proposed by Tsuprem-4 and Medici.The reason of resulting in the two electrical field peaks is also discussed.Two ways of reducing the two field peaks,which are to increase the channel length and to reduce the channel concentration, are also presented.The experimental results show that the methods presented can effectively improve the gate breakdown voltage and greatly improve the reliability of the P-LDMOS.