Self aligned narrow storage elements for advanced memory device
AssigneeSpansion LLC
InventorSuketu Arun Parikh
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Abstract
A method of forming a sub-lithographic charge storage element on a semiconductor substrate is provided. The method can involve providing first and second layers on a semiconductor substrate, a thickness of the first layer being larger than a thickness of the second layer; forming a spacer adjacent a side surface of the first layer and on a portion of an upper surface of the second layer; and removing an exposed portion of the second layer that is not covered by the spacer. By removing the exposed portion of the second layer while leaving a portion of the second layer that is protected by the spacer, the method can make a sub-lithographic charge storage element from the remaining portion of the second layer on the semiconductor substrate.
Claims20
A method of forming a sub-lithographic charge storage element for a semiconductor structure, comprising:
- providing a first layer and a second layer side-by-side on a semiconductor substrate, a portion of a side surface of the first layer being in contact with a side surface of the second layer, the first layer having a height larger than a height of the second layer, the first layer adjacent the second layer, the second layer comprising a charge-trapping material;
- forming a spacer adjacent the side surface of the first layer having the portion that is in contact with the side surface of the second layer and on a portion of an upper surface of the second layer;
- and
- removing an exposed portion of the second layer not covered by the spacer.
A method of making a sub-lithographic charge storage element for a memory device, comprising:
- providing a first oxide layer, a nitride layer, a second oxide layer, and a first poly layer over a semiconductor substrate;
- forming an opening in the first oxide layer, nitride layer, second oxide layer, and first poly layer;
- forming a implanted portion through the opening in the semiconductor substrate;
- forming a first layer in the opening;
- removing the first poly layer;
- forming a spacer adjacent a side surface of the first layer and on a portion of an upper surface of the first oxide layer;
- and
- removing an exposed portion of the second oxide layer and nitride layer not covered by the spacer.
Dependencies are inferred from the claim text.