High-voltage metal-oxide semiconductor transistor and method of fabricating the same

摘要

The present invention provides a high-voltage metal-oxide-semiconductor (HVMOS) transistor comprising a substrate, a gate dielectric layer, a gate electrode and a source and drain region. The gate dielectric layer is disposed on the substrate and includes a protruded portion and a recessed portion, wherein the protruded portion is disposed adjacent to two sides of the recessed portion and has a thickness greater than a thickness of the recessed portion. The gate electrode is disposed on the gate dielectric layer. Thus, the protruded portion of the gate dielectric layer can maintain a higher breakdown voltage, thereby keeping the current from leaking through the gate.

主权项

1. A method of fabricating a HVMOS transistor, comprising:
providing a substrate; forming a patterned shielding layer, covered on the substrate; performing an ion implantation by using the patterned shielding layer as a mask, to form a first doped region, and removing the patterned shielding layer; performing a thermal process to form a gate dielectric layer on the substrate, wherein the gate dielectric layer comprises a protruded portion and a recessed portion, the protruded portion is disposed at two sides of the recessed portion and comprises a thickness greater than a thickness of the recessed portion, and a border between the protruded portion and the recessed portion is vertically aligned with a side edge of the first doped region; forming a gate electrode on the gate dielectric layer; and forming a source and drain region embedded in the substrate at two sides of the gate electrode.