Two layout and process key parameters for improving high voltage nLEDMOS(n-type lateral extended drain MOS) transistor hot carrier performance have been identified.Increasing the space between Hv-pwell and n-drift region and reducing the n-drift implant dose can dramatically reduce the device hot carrier degradations,for the maximum impact ionization rate near the Bird Beak decreases or its location moves away from the Si/SiO2 interface.This conclusion has been analyzed in detail by using the MEDICI simulator and it is also confirmed by the test results.
研究了常规LEDM O S,带有两块多晶硅场极板LEDM O S以及带有两块多晶硅场极板和一块铝场极板的LEDM O S表面电场分布情况,重点研究了多块场极板在不同的外加电压下,三种LEDM O S的表面峰值电场和导通电阻的变化情况。模拟结果和流水实验结果都表明:多块场极板是提高LEDM O S击穿电压的一种有效方法,而且场极板对导通电阻的影响很小。研究结果还表明:由于金属铝引线下面的氧化层很厚,所以铝引线几乎不会影响到LEDM O S的击穿特性。
