Trench MOSFET with low gate charge

US6573569B2 · kind B2 · utility

Assignee

• FAIRCHILD SEMICONDUCTOR CORPORATION · US

Inventors

• Jifa Hao · Scarborough, US
• Thomas E. Grebs · Smethport, US
• Rodney S. Ridley · Scarborough, US
• Louise Skurkey · Conyngham, US
• Chris Gasser · Hazleton, US

Key dates

• Filing date: Nov 6, 2001
• Grant date: Jun 3, 2003
• Expiry date: Nov 6, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/519

Abstract

A trench MOS-gated device has an upper surface and includes a substrate having an upper layer of doped monocrystalline semiconductor material of a first conduction type. A gate trench in the upper layer has sidewalls and a floor lined with a first dielectric material and a centrally disposed core formed of a second dielectric material extending upwardly from the first dielectric material on the trench floor and having lateral and top surfaces. The remainder of the trench is substantially filled with a conductive material that encompasses and contacts the lateral and top surfaces of the core of second dielectric material. A doped well region of a second conduction type overlies a drain zone of the first conduction type in the upper layer, and a heavily doped source region of the first conduction type contiguous to the gate trench and a heavily doped body region of the second conduction type are disposed in the well region at the upper surface of the device. An interlevel dielectric layer disposed on the upper surface overlies the gate trench and the source region, and a metal layer in electrical contact with the source and body regions overlies the upper surface and the interlevel d…