A method of fabricating an 
oxide-
nitride-
oxide (ONO) layer in a 
memory cell to retain charge well in the 
nitride layer includes the steps of forming a bottom 
oxide layer on a substrate, depositing a 
nitride layer and oxidizing a top oxide layer, thereby causing 
oxygen to be introduced into the nitride layer. Another method includes the steps of forming a bottom oxide layer on a substrate, depositing a nitride layer and oxidizing a portion of a top oxide layer, thereby causing 
oxygen to be introduced into the nitride layer and depositing a remaining portion of the top oxide layer, thereby assisting in controlling the amount of 
oxygen introduced into the nitride layer. A further method includes the steps of forming a bottom oxide layer on a substrate, depositing a nitride layer, depositing a portion of a top oxide layer and oxidizing a remaining portion of the top oxide layer, thereby causing oxygen to be introduced into the nitride layer.