Method of fabricating trench capacitors and memory cells using trench capacitors

US7709320B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Kangguo Cheng · Schenectady, US
• Xi Li · Somers, US

Key dates

• Filing date: Jun 28, 2006
• Grant date: May 4, 2010
• Expiry date: May 17, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/37

Abstract

A method of forming a trench capacitor and memory cells using the trench capacitor. The method includes: forming an opening in a masking layer; and forming a trench in the substrate through the opening, the trench having contiguous upper, middle and lower regions, the trench extending from a top surface of said substrate into the substrate, the upper region of the trench adjacent to the top surface of the substrate having a vertical sidewall profile and a first width in the horizontal direction, the middle region of the trench having a tapered sidewall profile, a width in a horizontal direction of the middle region at a juncture of the upper region and the middle region being the first width and being greater than a second width in the horizontal direction of the middle region at a juncture of the middle region and the lower region.