DRAM access transistor

US6498062B2 · kind B2 · utility

Assignee

• Micron Technology, Inc. · US

Inventors

• D. Mark Durcan · Boise, US
• Roger Lee · Boise, US

Key dates

• Filing date: Apr 27, 2001
• Grant date: Dec 24, 2002
• Expiry date: Apr 27, 2021

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D30/608

Abstract

A method of forming memory devices, such as DRAM access transistors, having recessed gate structures is disclose. Field oxide areas for isolation are first formed over a semiconductor substrate subsequent to which transistor grooves are patterned and etched in a silicon nitride layer. The field oxide areas adjacent to the transistor grooves are then recessed, so that subsequently deposited polysilicon for gate structure formation can be polished relative to the adjacent and elevated silicon nitride.