The effect of the collector contact design on the performance and yield of 800V Lateral IGBTs for power ICs

We report here a new physical phenomenon related to contact etch depth in High Voltage Lateral IGBTs (LIGBTs) and propose a design technique to increase yield of LIGBTs in high volume production. We prove for the first time that the contact geometry and placement have direct effect on Collector injection efficiency in LIGBTs. An improved design for 800V LIGBTs obtained by optimising the layout of contact openings is proposed. The new structure resulted in 15% increase in production yield.