Institute of Solid State Physics
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SS22 WS22 SS23 WS23 SS24 WS24 Guidelines for Master Students
Influence of Process Variations on Avalanche Breakdown in Power Trench MOSFETS In this talk I will present you my results on the investigation of the impact of semiconductor production process parameter variations on the avalanche breakdown of complex Si power trench MOSFETs. During various modern applications (for example buck converters) the transistors are reverse biased in the off state. This leads to avalanche breakdown and furthermore to hot-carrier injection, which results in the creation of trap states in the oxides and their interfaces to silicon. This impacts the device characteristics and reliability. Various charge pumping measurements and stress tests can give insights on properties of diverse kinds of trap states differing in location, donor-/acceptor-like behavior and their energy level in the band gap. Process variations like a change of the trench depth or the source contact depth result in different electric field distributions and avalanche locations and change the degradation physics. The understanding the impact of the different process parameters on the avalanche breakdown and the physics behind it is will be explained. Insights on the behavior of traps in the oxide-semiconductor interfaces of complex structures as well as improvement of electrical parameters of future devices will be suggested. |
