Dense trench MOSFET with decreased etch sensitivity to deposition and etch processing

US6635535B2 · kind B2 · utility

Assignee

• FAIRCHILD SEMICONDUCTOR CORPORATION · US

Inventors

• Jifa Hao · Scarborough, US
• Rodney S. Ridley · Scarborough, US
• Gary M. Dolny · Smethport, US

Key dates

• Filing date: Nov 20, 2001
• Grant date: Oct 21, 2003
• Expiry date: Nov 20, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/663

Abstract

A power MOSFET 100 has a source metal 112 that contacts silicided source regions 114 through vias 160 etched in an insulating layer 200. The silicide layer 225 provides for a relatively small but highly conductive contact and thus reduces RDSON. The insulating material may be any suitable material including and not limited to one or a combination of materials such as BPSG, PSG, silicon dioxide and silicon nitride. The insulating layer is relatively thin and does not extend deeply into the gate trench, thereby reducing capacitance.