A Zero-Cost Technique to Improve ON-State Performance and Reliability of Power LDMOS Transistors

In this paper, we have proposed a simple and zero-cost technique to improve ON-state and reliability performance of LDMOS transistors. We introduced doping gradient in the channel by optimizing position of the P-Well mask during test structure design/layout. Through proper device design, fabrication and measurement on different test structures, we have shown that the graded channel significantly improves the drive capability (upto ~30%), analog FoMs and hot-carrier reliability of LDMOS transistors without any penalty on the OFF-state performance. The performance improvement is independent of drift region design (breakdown voltage). The device physics behind different observations is also discussed with detailed TCAD simulations.