Method for forming a schottky barrier diode integrated with a trench MOSFET

摘要

A method for forming a Schottky diode including forming first and second trenches in a semiconductor layer, forming a thin dielectric layer lining sidewalls of the first and second trenches; forming a trench conductor layer in the first and second trenches where the trench conductor layer fills a portion of each of the first and second trenches and being the only one trench conductor layer in the first and second trenches; forming a first dielectric layer in the first and second trenches to fill the remaining portions of the first and second trenches; and forming a Schottky metal layer on a top surface of the lightly doped semiconductor layer between the first trench and the second trench to form a Schottky junction. The Schottky diode is formed with the Schottky metal layer as the anode and the lightly doped semiconductor layer between the first and second trenches as the cathode.

主权项

1. A method for forming a Schottky diode, comprising:
providing a semiconductor substrate of a first conductivity type; providing a semiconductor layer of the first conductivity type on the semiconductor substrate, the semiconductor layer being lightly doped; forming first and second trenches in the semiconductor layer; forming a thin dielectric layer lining sidewalls of the first and second trenches; forming a trench conductor layer in the first and second trenches, the trench conductor layer filling a portion of each of the first and second trenches and being the only one trench conductor layer in the first and second trenches; forming a first dielectric layer in the first and second trenches to fill the remaining portions of the first and second trenches; forming a Schottky metal layer on a top surface of the lightly doped semiconductor layer between the first trench and the second trench to form a Schottky junction, wherein the Schottky diode is formed with the Schottky metal layer as the anode and the lightly doped semiconductor layer between the first and second trenches as the cathode; and forming an electrical connection between the trench conductor layer in each of the first and second trenches and the anode of the Schottky diode, the trench conductor layer in each of the first and second trenches being insulated by the first dielectric layer in the respective trenches and being physically isolated from the Schottky metal layer forming the anode of the Schottky diode.