Dual gate oxide process for deep submicron ICS
AssigneeLSI Logic Corporation
InventorsGail D. Shelton, Gayle W. Miller
Life of this patent
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Abstract
An improved dual gate oxide process for dual-gated devices using oxygen ion implantation to vary the thickness of gate oxide layers. The desired layers are identified by photoresist layer patterning prior to an ion implantation. A subsequent heat treatment oxidizes the implanted region.
Claims33
A method of forming gate oxide layers of different thicknesses on an integrated circuit device which comprises the steps of:
- (a) growing a gate oxide layer on the device;
- (b) applying a photoresist mask layer over the oxide layer;
- (c) removing the photoresist mask where thicker oxide areas are desired;
- (d) performing an oxygen ion implantation on the surface of the device;
- (e) removing the photoresist layer;
- and,
- (f) heating the device to oxidize the implanted silicon.
A method of forming gate oxide layers of different thicknesses on a metal oxide semiconductor device having a layer of gate oxide, the method comprising the steps of:
- (a) applying a patterned photoresist layer over the oxide layer;
- (b) performing an oxygen ion implantation on the surface of the integrated circuit;
- (c) removing the photoresist layer;
- and,
- (d) heating the device to oxidize an ion implanted layer.
A method for forming gate oxide on a substrate, the method comprising:
- forming a gate oxide layer on the substrate;
- selectively forming a photoresist layer over the gate oxide, wherein a portion of the gate oxide layer remains exposed to from an exposed portion;
- introducing oxygen ions into the exposed portion;
- and,
- oxidizing the substrate, wherein the exposed portion of the gate oxide layer is thicker than other portions of the gate oxide layer.
A method of forming a dual gate oxide comprising:
- forming a first gate region and a second gate region;
- depositing an oxide layer over the first gate region and the second gate region;
- masking the first gate region, wherein a surface of the second gate region remains exposed to from an exposed surface;
- implanting oxygen ions into the exposed surface;
- and
- oxidizing a substrate, wherein a thickness of the oxide layer over the first gate region is thinner that a thickness of the oxide layer over the second gate region.
Dependencies are inferred from the claim text.