Sonos ono stack scaling

Abstract

A method of scaling a nonvolatile trapped-charge memory device and the device made thereby is provided. In an embodiment, the method includes forming a channel region including polysilicon electrically connecting a source region and a drain region in a substrate. A tunneling layer is formed on the substrate over the channel region by oxidizing the substrate to form an oxide film and nitridizing the oxide film. A multi-layer charge trapping layer including an oxygen-rich first layer and an oxygen-lean second layer is formed on the tunneling layer, and a blocking layer deposited on the multi-layer charge trapping layer. In one embodiment, the method further includes a dilute wet oxidation to densify a deposited blocking oxide and to oxidize a portion of the oxygen-lean second layer.

What is claimed is: 
     
         1 . A method comprising:
 forming a polysilicon channel region;   forming a tunneling layer over the polysilicon channel region;   forming a multi-layer charge trapping layer on the tunneling layer, wherein the multi-layer charge trapping layer comprises an oxygen-rich layer and an oxygen-lean layer; and   forming a blocking layer on the multi-layer charge trapping layer.