Failure analysis and improvement of 60Â V power UMOSFET

In this paper, the failure modes of a 60 V power UMOSFET firstly have been discussed by analyzing the test data of the die, and our hypothesis is that the merger of the P-base regions under the trench leads to larger on-resistance and threshold voltage of 60 V UMOSFET. To further verify the hypothesis, the formula for the resistance of the drift region has been derived, and the simulating model of UMOSFET has been given with various mergers of the P-base regions. Then the simulation model has been corrected and the parameters of UMOSFET have been optimized. The re-design of 60 V UMOSFET has been taped out successfully, with its electric parameters totally meeting the requirements.