Abstract—In this brief, we propose a new trench power MOSFET with strained-Si channel that provides lower onresistance than the conventional trench MOSFET. Using a 20% Ge mole fraction in the Si1−xGex body with a compositionally graded Si1−xGex buffer in the drift region enables us to create strain in the channel along with graded strain in the accumulation region. As a result, the proposed structure exhibits 40% enhancement in current drivability, 28% reduction in the on-resistance, and 72% improvement in peak transconductance at the cost of only 12% reduction in the breakdown voltage when compared to the conventional trench-gate MOSFET. Furthermore, the graded strained accumulation region supports the conﬁnement of carriers near the trench sidewalls, improving the ﬁeld distribution in the mesa structure useful for a better damage immunity during inductive switching.
Index Terms—Breakdown voltage, on-resistance, power MOSFET, Si1−xGex, strained Si, trench gate.
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