Device structure and methods of making high density MOSFETs for load switch and DC-DC applications

US9484453B2 · kind B2 · utility

Assignee

• Alpha and Omega Semiconductor, Ltd. · US

Inventors

• Hamza Yilmaz · Saratoga, US
• Madhur Bobde · Sunnyvale, US
• Hong Chang · Saratoga, US
• Yeeheng Lee · San Jose, US
• Daniel Calafut · San Jose, US
• Jongoh Kim · Hsinchu, TW
• Sik Lui · Sunnyvale, US
• John Chen · Palo Alto, US

Key dates

• Filing date: Sep 3, 2015
• Grant date: Nov 1, 2016
• Expiry date: Sep 3, 2035

Classification

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

Abstract

Aspects of the present disclosure describe a high density trench-based power. The active devices may have a two-step gate oxide. A lower portion may have a thickness that is larger than the thickness of an upper portion of the gate oxide. A lightly doped sub-body layer may be formed below a body region between two or more adjacent active device structures of the plurality. The sub-body layer extends from a depth of the upper portion of the gate oxide to a depth of the lower portion of the gate oxide It is emphasized that this abstract is provided to comply with rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.