Metal-oxide-semiconductor field-effect transistor structure with low leakage current and reserved gate length

Abstract

A metal-oxide-semiconductor field-effect transistor (MOSFET) structure includes a semiconductor substrate, a gate structure, a channel region, a trench, an isolation region, a first conductive region, and a P-N junction. The semiconductor substrate has a semiconductor surface. The gate structure is above the semiconductor surface. The channel region is under the gate structure. The trench is formed below the semiconductor surface and adjacent to the channel region. The isolation region is in the trench. The first conductive region has a first doping type, and the first conductive region is positioned on the isolating layer and electrically coupled to the channel region. The P-N junction extends upward from the isolation region and along an edge of the first conductive region.