CONCAVE-DMOSFET - A NEW SUPER-LOW ON-RESISTANCE POWER MOSFET

This paper describes a new super-low on-resistance power MOSFET. The new transistor ''CONCAVE-DMOSFET'' has a concave channel structure fabricated not by trench etching technique, but by a combination of local oxidation of silicon (LOGOS) and diffusion self-alignment using oxide film as a double diffusion mask. The CONCAVE-DM OS FET based on 16 mu m cell design has been fabricated for the first time, and the specific on-resistance of 75 m Omega . mm(2) with breakdown voltage of 50 V has been achieved. This specific on-resistance is the lowest ever reported for power MOSFETs of comparable same design rule. The lowest value has been realized by means of the CONCAVE-DMOS technology, which eliminates JFET resistance and provides a damage-free concave surface resulting in high channel mobility of 300 cm(2)/V . s.