Self-aligned collar and strap formation for semiconductor devices

US7015145B2 · kind B2 · utility

Assignee

• Infineon Technologies AG · DE

Inventors

• Venkatachalam C. Jaiprakash · Sunnyvale, US
• Norbert Arnold · Pfalzgrafenweiler, DE

Key dates

• Filing date: Jan 8, 2001
• Grant date: Mar 21, 2006
• Expiry date: Jan 8, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/0383

Abstract

A method for fabricating a buried strap forms a dielectric collar along sidewalls of a trench. The trench is formed in a substrate. The trench is filled with a conductive material and the conductive material is recessed in the trench to expose a portion of the collar. A masking layer is deposited in the trench over the exposed portion of the collar. A portion of the masking layer is removed over one side of the collar and a portion of the collar is etched on the one side. A buried strap is formed on the conductive material, which connects to the substrate on the one side.