Plasma oxidation of a memory layer to form a blocking layer in non-volatile charge trap memory devices

US7799670B2 · kind B2 · utility

Assignee

• Cypress Semiconductor Corporation · US

Inventors

• Krishnaswamy Ramkumar · San Jose, US
• Sagy Levy · Jerusalem, IL
• Jeong Soo Byun · Cupertino, US

Key dates

• Filing date: Mar 31, 2008
• Grant date: Sep 21, 2010
• Expiry date: Dec 4, 2028

Classification

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

Abstract

A blocking layer of a non-volatile charge trap memory device is formed by oxidizing a portion of a charge trapping layer of the memory device. In one embodiment, the blocking layer is grown by a radical oxidation process at temperature below 500° C. In accordance with one implementation, the radical oxidation process involves flowing hydrogen (H2) and oxygen (O2) gas mixture into a process chamber and exposing the substrate to a plasma. In a preferred embodiment, a high density plasma (HDP) chamber is employed to oxidize a portion of the charge trapping layer. In further embodiments, a portion of a silicon-rich silicon oxynitride charge trapping layer is consumptively oxidized to form the blocking layer and provide an increased memory window relative to oxidation of a nitrogen-rich silicon oxynitride layer.