Deep trench cell capacitor with inverting counter electrode

US5793075A · kind A · utility

Assignees

• International Business Machines Corporation · US
• Siemens Components, Inc. · US

Inventors

• Johann Alsmeier · San Jose, US
• Jack A. Mandelman · Stormville, US
• James A. O'Neill · New City, US
• Christopher C. Parks · Beacon, US
• Paul C. Parries · Wappingers Falls, US

Key dates

• Filing date: Jul 30, 1996
• Grant date: Aug 11, 1998
• Expiry date: Jul 30, 2016

Classification

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

Abstract

The preferred embodiment provides an integrated circuit capacitor that achieves a high capacitance by using an inversion layer in the substrate as the plate counter electrode for the capacitor. The inversion layer is created by forming a trench capacitor in a lightly doped substrate. With a sufficient workfunction difference between the storage node material and the isolation band the surface of the lightly doped substrate inverts, with the inversion charge being supplied by the isolation band. This inversion layer serves as the plate counter electrode for the capacitor.