Buried-strap formation in a dram trench capacitor

US5827765A · kind A · utility

Assignees

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

Inventors

• Reinhard Stengl · Stadtbergen, DE
• Erwin Hammerl · Stormville, US
• Herbert L. Ho · New Windsor, US
• Jack A. Mandelman · Stormville, US
• Radhika Srinivasan · Mahwah, US
• Alvin P. Short · Chester, US

Key dates

• Filing date: Feb 22, 1996
• Grant date: Oct 27, 1998
• Expiry date: Feb 22, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/373

Abstract

A method for making an electrical connection between a trench storage capacitor and an access transistor in a DRAM cell. The electrical connection is formed through the selectively controlled outdiffusion of either N-type or P-type dopants present in the trench through a single crystalline semiconducting material which is grown by epitaxy (epi) from the trench sidewall. This epitaxially grown single crystalline layer acts as a barrier to excessive dopant outdiffusion which can occur in the processing of conventional DRAMs.