Method of fabricating mask read only memory
AssigneeMacronix International Co., Ltd.
InventorCheng-Chen Calvin Hsueh
Life of this patent
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Abstract
A method of fabricating a mask read only memory. Embedded bit line are formed in a substrate. A gate dielectric layer and a word line are formed on the substrate. The word line is perpendicular to the bit lines. The substrate under the word line and between each pair of the bit lines is referred as a memory unit. A first dielectric layer is formed to cover the substrate. A plurality of coding windows is formed in the first dielectric layer over the memory units. Ions are implanted into the memory cells exposed by the coding windows, and a second dielectric layer is formed to fill the coding windows.
Claims18
A method of fabricating a masked read only memory, comprising:
- providing a substrate;
- forming a plurality of embedded bit lines in the substrate;
- forming a dielectric layer and a plurality of word lines on the substrate, wherein the word lines perpendicularly cross over the embedded lines, and the substrate between two neighbouring bit lines under the word lines is referred as a plurality of memory units;
- forming a first dielectric layer over the substrate;
- forming a plurality of coding windows in the first dielectric layer over the memory units;
- forming a plurality of spacers on sidewalls of the coding windows;
- implanting the memory units under the coding windows with ions using the first dielectric layer and the spacers as a mask;
- and
- filling the coding windows with a second dielectric layer.
A method of fabricating a mask read only memory, comprising:
- providing a substrate, the substrate comprising a plurality of embedded bit lines and a plurality of word lines perpendicularly crossing over the bit lines, wherein the substrate between each pair of bit lines and under the word lines is referred as a memory unit;
- forming a dielectric layer over the substrate;
- forming a plurality of coding windows in the first dielectric layer over a part of the memory units;
- forming a plurality of spacers on sidewalls of the coding windows;
- and
- implanting ions into the memory units under the coding windows.
Dependencies are inferred from the claim text.