High-density low on-resistance trench MOSFETs employing oxide spacers and self-align technique for DC/DC converter

A new process technique for fabricating very high-density trench MOSFETs using 4 mask layers with oxide spacers and self-align technique is realized. This technique reduces the process steps, trench width, and source and p-body region with a resulting increase in cell density and current driving capability, and decrease in on-resistance as well as cost-effective production capability. Specific on-resistance of 0.41 m/spl Omega/.cm/sup 2/ with a blocking voltage of 43 is obtained.