  The trench gate MOSFET has established itself as the most suitable power
device for low to medium power applications by offering the lowest possible ON
resistance among all MOS devices. The evolution of the trench gate power MOSFET
has been discussed in this chapter, starting right from its beginnings to the
recent trends. The innovations in the structural improvements to meet the
requirements for an efficient operation, the progress in the fabrication
technology, the characterization methods and various reliability issues have
been emphasized.
