High voltage metal-oxide-semiconductor transistor device having stepped gate structure and manufacturing method thereof

摘要

A high voltage metal-oxide-semiconductor transistor device having stepped gate structure and a manufacturing method thereof are provided. The manufacturing method includes following steps. A gate structure is formed on a semiconductor substrate. The semiconductor substrate includes a first region and a second region disposed on a side of a first part of the gate structure and a side of a second part of the gate structure respectively. A patterned mask layer is formed on the semiconductor substrate and the gate structure. The patterned mask layer covers the first region and the first part. The second part is uncovered by the patterned mask layer. An implantation process is performed to form a drift region in the second region. An etching process is performed to remove a part of the second part uncovered by the patterned mask layer. A thickness of the second part is less than that of the first part after the etching process.

主权项

1. A high-voltage metal-oxide-semiconductor (HV MOS) transistor device, comprising:
a semiconductor substrate; a gate structure disposed on the semiconductor substrate, wherein the gate structure comprises a first part and a second part, and a thickness of the second part is less than a thickness of the first part, a top surface of the first part of the gate structure and a top surface of the second part of the gate structure are not coplanar, and a bottom surface of the first part of the gate structure and a bottom surface of the second part of the gate structure are substantially coplanar, wherein the top surface of the second part is lower than the top surface of the first part; and a drift region disposed on a side of the second part of the gate structure.