Backside buried strap for SOI DRAM trench capacitor

US6815749B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Jack A. Mandelman · Stormville, US
• Herbert L. Ho · New Windsor, US

Key dates

• Filing date: Jul 8, 2003
• Grant date: Nov 9, 2004
• Expiry date: Jul 8, 2023

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D86/201

Abstract

In SOI integrated circuits having trench capacitor DRAM arrays, the decreasing thickness of the insulating layer causes cross-talk between the passing wordline traveling over the trench capacitor. Increasing the depth of the recess at the top of the trench and undercutting the insulating layer laterally permits the buried strap from the capacitor center electrode to make contact to the back side of the SOI layer, thereby increasing the vertical separation between the passing wordline and the strap.