Trench capacitor with epi buried layer

US5945704A · kind A · utility

Assignees

• Siemens Aktiengesellschaft · DE
• International Business Machines Corporation · US

Inventors

• Martin Schrems · Langenbruck, DE
• Jack A. Mandelman · Stormville, US
• Joachim Hoepfner · Planegg, DE
• Herbert Schaefer · Herdorf, DE
• Reinhard Stengl · Stadtbergen, DE

Key dates

• Filing date: Jun 26, 1998
• Grant date: Aug 31, 1999
• Expiry date: Jun 26, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D1/665

Abstract

A trench capacitor with an epi layer in the lower portion of the trench. The epi layer serves as the buried plate of the trench capacitor. A diffusion region surrounds the lower portion of the trench to enhance the dopant concentration of the epi layer. The diffusion region is formed by, for example, gas phase doping, plasma doping, or plasma immersion ion implantation.