Trench metal oxide semiconductor with recessed trench material and remote contacts

US8368126B2 · kind B2 · utility

Assignee

• Vishay-Siliconix, LLC · US

Inventors

• Deva Pattanayak · Saratoga, US
• Kyle Terrill · Santa Clara, US
• Sharon Shi · San Jose, US
• Misha Lee · San Jose, US
• Yuming Bai · Union City, US
• Kam Hong Lui · Santa Clara, US
• Kuo-In Chen · Los Altos, US

Key dates

• Filing date: Apr 7, 2008
• Grant date: Feb 5, 2013
• Expiry date: Dec 4, 2028

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/62

Abstract

Remote contacts to the polysilicon regions of a trench metal oxide semiconductor (MOS) barrier Schottky (TMBS) device, as well as to the polysilicon regions of a MOS field effect transistor (MOSFET) section and of a TMBS section in a monolithically integrated TMBS and MOSFET (SKYFET) device, are employed. The polysilicon is recessed relative to adjacent mesas. Contact of the source metal to the polysilicon regions of the TMBS section is made through an extension of the polysilicon to outside the active region of the TMBS section. This change in the device architecture relieves the need to remove all of the oxides from both the polysilicon and silicon mesa regions of the TMBS section prior to the contact step. As a consequence, encroachment of contact metal into the sidewalls of the trenches in a TMBS device, or in a SKYFET device, is avoided.