Controlled recrystallization of buried strap in a semiconductor memory device

US5543348A · kind A · utility

Assignees

• Kabushiki Kaisha Toshiba · JP
• Siemens Aktiengesellschaft · DE
• International Business Machines Corporation · US

Inventors

• Erwin Hammerl · Stormville, US
• Jack A. Mandelman · Stormville, US
• Herbert L. Ho · New Windsor, US
• Junichi Shiozawa · Yokkaichi, JP
• Reinhard Stengl · Stadtbergen, DE

Key dates

• Filing date: Mar 29, 1995
• Grant date: Aug 6, 1996
• Expiry date: Mar 29, 2015

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/038

Abstract

A method of forming a coupled capacitor and transistor is provided. A trench is formed in a semiconductor substrate and an impurity-doped first conductive region is then formed by filling the trench with an impurity-doped first conductive material. The impurity-doped first conductive region is etched back to a first level within the trench. An insulating layer is then formed on a sidewall of the portion of the trench opened by the etching back of the impurity-doped first conductive region and a second conductive region is formed by filling the remainder of the trench with a second conductive material. The insulating layer and the second conductive region are etched back to a second level within the trench and an amorphous silicon layer is formed in the portion of the trench opened by the etching back of the insulating layer and the second conductive region. The undoped amorphous silicon layer is etched back to a third a level within the trench. The undoped amorphous silicon layer is then recrystallized. Impurities are outdiffused from the impurity-doped first conductive region to the semiconductor substrate through the recrystallized silicon layer. A source/drain region of the tran…