  In this paper, we propose a new trench power MOSFET with strained Si channel
that provides lower on resistance 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.
