DRAM cell with grooved transfer device

US5945707A · kind A · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Gary B. Bronner · Stormville, US
• Toshiharu Furukawa · South Burlington, US
• Mark C. Hakey · Saint Albans, US
• Steven J. Holmes · Colchester, US
• David V. Horak · South Burlington, US
• Jack A. Mandelman · Stormville, US
• Paul A. Rabidoux · Winooski, US

Key dates

• Filing date: Apr 7, 1998
• Grant date: Aug 31, 1999
• Expiry date: Apr 7, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B12/488

Abstract

A memory cell having a grooved gate formed in a sub-lithographic groove, and methods of making thereof are disclosed. The groove extends the channel length to include the groove sidewalls and width of the groove. Sidewall sections of the channel located along the gate sidewalls have a larger length than the bottom channel section length located along the gate bottom width. Thus, the memory device is primarily controlled by the sidewall channel sections, instead of the bottom channel section. The groove may be a stepped groove formed by a two step etch to further increase the channel length and may be formed centered along the gate conductor width.