Method for forming lightly doped diffusion regions
AssigneeMacronix International Co., Ltd.
InventorChing-Yu Chang
Life of this patent
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Abstract
A method for forming a lightly doped diffusion region comprises providing a substrate structure. A first photoresist layer, having a lightly doped diffusion region pattern, is formed on the substrate structure. Next, dopants of a first type conductivity are implanted into the substrate structure for forming a lightly doped diffusion region in the substrate structure. Then a second photoresist layer is conformal formed on the first photoresist layer and the substrate structure. Next, the second photoresist layer is etched back and then dopants of a second type conductivity are implanted into the substrate structure for forming a source/drain region underlying the lightly doped diffusion region in the substrate structure.
Claims20
A method for forming a lightly doped diffusion region, said method comprising:
- providing a substrate structure;
- forming a first photoresist layer on said partial substrate structure;
- implanting dopants of a first type conductivity into said substrate structure for forming a lightly doped diffusion region in said substrate structure;
- conformal forming a second photoresist layer on said first photoresist layer and said substrate structure;
- etching said partial second photoresist layer;
- and
- implanting dopants of a second type conductivity into said substrate structure for forming a source and drain region underlying said lightly doped diffusion region in said substrate structure.
A method for forming lightly doped diffusion regions in a semiconductor read only memory, said method comprising:
- providing a silicon substrate of a first type conductivity;
- forming a first photoresist layer on said partial silicon substrate;
- implanting dopants of said first type conductivity into said silicon substrate for forming a lightly doped diffusion region in said silicon substrate;
- forming a second photoresist layer on and at, said surface and sidewalls of said first photoresist layer, and on said surface of said silicon substrate;
- etching back said partial second photoresist layer to show said partial surface of said silicon substrate and said surface of said first photoresist layer;
- and
- implanting dopants of a second type conductivity into said partial silicon structure for forming a source and drain region underlying said lightly doped diffusion region in said silicon substrate.
A method for forming lightly doped diffusion regions in a mask read only memory, said method comprising:
- providing a silicon substrate of a first type conductivity;
- forming a first photoresist layer on said partial silicon substrate;
- implanting dopants of said first type conductivity into said partial silicon substrate for forming a lightly doped diffusion region in said partial silicon substrate;
- forming a second photoresist layer on and at, said surface and sidewalls of said first photoresist layer, and on said surface of said silicon substrate;
- etching back said second photoresist layer and thereafter said second photoresist layer left as spacer-shaped at sidewalls of said first photoresist layer and at corners between said first photoresist layer and said silicon substrate;
- and
- implanting dopants of a second type conductivity into said partial silicon substrate for forming a source and drain region underlying said lightly doped diffusion region.
A method for forming lightly doped diffusion region in a mask read only memory device, said method comprising:
- providing a silicon substrate of a first type conductivity;
- forming a first photoresist layer on said partial silicon substrate;
- implanting dopants of said first type conductivity into said partial silicon substrate for forming a lightly doped diffusion region in said silicon substrate;
- forming a second photoresist layer on and at, said surface and sidewall of said first photoresist layer, and on said surface of said silicon substrate;
- and
- implanting dopants of a second type conductivity into said partial silicon substrate for forming a source and drain region underlying said lightly doped region in said silicon substrate.
Dependencies are inferred from the claim text.