Diodes Inc.

Industrial Technology Research Institute

Cheng-Chin Huang

Chiao-Shun Chuang

Yun-Pu Ku

Kai-Yu Chen

Chien-Chung Hung

Chwan-Ying Lee

Cheng-Tyng Yen

Young-Shying Chen

A power MOSFET or a power rectifier may be fabricated according to the invention to include a gate trench and a field plate trench. Both trenches can be formed with a two-step etching process as described in detail in the specification. The devices that embody this invention can be fabricated with higher packaging density and better and more tightly distributed device parameters such as the V, R, and BV.

Self-aligned dual trench device

During fabrication of a semiconductor device, a width of semiconductor mesas between isolation trenches in the semiconductor device is varied in different regions. In particular, the width of the mesas is smaller in a termination region of the semiconductor device than in a cell or active region. When an oxide layer is subsequently grown, the semiconductor mesas between the trenches in the termination region are at least partially consumed so that the semiconductor mesas in the cell region and the termination region have different heights. Therefore, a contact photomask is not needed to isolate the semiconductor mesas in the termination region. Furthermore, after a planarization operation (such as chemical mechanical polishing), the semiconductor device may have a planar top surface than if contact holes are created. This may allow the metal layer deposited on top of the cell region and the termination region to be flat.

Trench schottky devices

A SiC-based trench-type Schottky device is disclosed. The device includes: a SiC substrate having first and second surfaces; a first contact metal formed on the second surface and configured for forming an ohmic contact on the substrate; a drift layer formed on the first surface and including a cell region and a termination region enclosing the cell region; a plurality of first trenches with a first depth formed in the cell region; a plurality of second trenches with a second depth less than the first depth; a plurality of mesas formed in the substrate, each defined between neighboring ones of the trenches; an insulating layer formed on sidewalls and bottoms of the trenches; and a second contact metal formed on the mesas and the insulating layer, extending from the cell region to the termination region, and configured for forming a Schottky contact on the mesas of the substrate.

SiC-based trench-type schottky device

Growing community of inventors

Plano, TX, United States of America

Cheng-Chin Huang