Method for making anti-fuse structures
AssigneeVLSI Technology, Inc.
InventorsWilliam J. Boardman, David P. Chan, Kuang-Yeh Chang, Calvin T. Gabriel, Vivek Jain, Subhash R. Nariani
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Abstract
An anti-fuse structure characterized by a substrate, an oxide layer formed over the substrate having an opening formed therein, an amorphous silicon material disposed within the opening and contacting the substrate, a conductive protective material, such as titanium tungsten, disposed over the amorphous silicon material, and oxide spacers lining the walls of a recess formed within the protective material. The protective material and the spacers provide tighter programming voltage distributions for the anti-fuse structure and help prevent anti-fuse failure.
Claims15
A method for making an anti-fuse structure comprising:
- providing a substrate surface;
- forming an insulating layer over said substrate surface;
- forming an opening in said insulating layer which extends down to said substrate surface;
- depositing an anti-fuse material into said opening such that it generally conforms to the contours of said opening to form a anti-fuse material recess;
- depositing a conductive, protective material over said anti-fuse material such that it generally conforms to the contours of said anti-fuse material to form a protective material recess having sidewall portions and a base portion which meet at an interface;
- and
- forming spacers comprising an insulating material within said recess of said protective material to substantially cover said interface between said sidewall portion and said base portion.
A method for making an array of anti-fuse structures comprising:
- providing a substrate surface;
- depositing an oxide layer over said substrate surface;
- etching said oxide layer to form therein a plurality of openings which extend down to said substrate surface;
- depositing amorphous silicon into said plurality of openings such that said amorphous silicon generally conforms to the contours of said plurality of openings to provide a plurality of amorphous silicon recesses;
- depositing a conductive protective material comprising tungsten over said amorphous silicon such that it generally conforms to the contours of said amorphous silicon recesses to provide a plurality of protective material recesses each having sidewall portions and a base portion which meet at an interface;
- and
- forming oxide spacers within said protective material recesses to substantially cover said interface between said sidewall portion and said base portion of each protective material recess.
Dependencies are inferred from the claim text.