Hetero-structure variable silicon rich nitride for multiple level memory flash memory device

US7602067B2 · kind B2 · utility

Assignee

• Spansion LLC. · US

Inventors

• Yi Ma · Orlando, US
• Robert B. Ogle · San Jose, US

Key dates

• Filing date: Dec 17, 2007
• Grant date: Oct 13, 2009
• Expiry date: Dec 17, 2027

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10D64/037

Abstract

Charge storage stacks containing hetero-structure variable silicon richness nitride for memory cells and methods for making the charge storage stacks are provided. The charge storage stack can contain a first insulating layer on a semiconductor substrate; n charge storage layers comprising silicon-rich silicon nitride on the first insulating layer, wherein numbers of the charge storage layers increase from the bottom to the top and a k-value of an n−1th charge storage layer is higher than a k-value of an nth charge storage layer; n−1 dielectric layers comprising substantially stoichiometric silicon nitride between each of the n charge storage layers; and a second insulating layer on the nth charge storage layers.