Thickened sidewall dielectric for memory cell

US8643082B2 · kind B2 · utility

Assignee

• Micron Technology, Inc. · US

Inventors

• Ron Weimer · Boise, US
• Kyu S. Min · San Jose, US
• Tom Graettinger · Boise, US
• Nirmal Ramaswamy · Boise, US

Key dates

• Filing date: Oct 19, 2011
• Grant date: Feb 4, 2014
• Expiry date: Dec 29, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B69/00

Abstract

Methods and devices are disclosed, such as those involving memory cell devices with improved charge retention characteristics. In one or more embodiments, a memory cell is provided having an active area defined by sidewalls of neighboring trenches. A layer of dielectric material is blanket deposited over the memory cell, and etched to form spacers on sidewalls of the active area. Dielectric material is formed over the active area, a charge trapping structure is formed over the dielectric material over the active area, and a control gate is formed over the charge trapping structure. In some embodiments, the charge trapping structure includes nanodots. In some embodiments, the width of the spacers is between about 130% and about 170% of the thickness of the dielectric material separating the charge trapping material and an upper surface of the active area.