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US 12,684,768 B2Granted
Flash memory with improved gate structure and a method of creating the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsSheng-Chieh Chen, Ming Chyi Liu, Shih-Chang Liu
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Abstract
Various embodiments provide a flash memory with an improved gate structure and a method of creating the same. The flash memory includes a plurality of memory cells that include a memory gate, a selection gate, a gate dielectric layer, and a protective cap formed on an upper surface of the gate dielectric layer. The protective cap protects the gate dielectric layer, and prevents the memory and selection gates from being unintentionally electrically connected to each other by conductive material.
Claims20
A method, comprising:
- forming a first conductive layer on a substrate;
- forming a second conductive layer on the substrate;
- forming a dielectric layer on the substrate, the dielectric layer including first and second portions on opposite sides of the second conductive layer, the first portion being between the first and second conductive layers;
- removing a part of the first portion of the dielectric layer that separates the first and second conductive layers from each other;
- removing a part of the second portion of the dielectric layer;
- and
- forming a protective layer on the first portion of the dielectric layer at a position where the part of the first portion of the dielectric layer was removed, and on the second portion of the dielectric layer at a position where the part of the second portion of the dielectric layer was removed, such that uppermost surfaces of the first conductive layer, the second conductive layer, the protective layer over the first portion of the dielectric layer, and the protective layer over the second portion of the dielectric layer are coplanar with each other.
4 more elements
A method, comprising:
- forming a first conductive layer on a substrate;
- forming a second conductive layer on the substrate;
- forming a dielectric layer on the substrate, the dielectric layer including a first portion between the first conductive layer and the second conductive layer, and a second portion on an opposite side of the second conductive layer from the first portion;
- forming a first cavity between the first conductive layer and the second conductive layer by removing a part of the first portion of the dielectric layer between the first conductive layer and the second conductive layer;
- forming a second cavity by removing a part of the second portion of the dielectric layer;
- and
- forming a protective layer on the first portion of the dielectric layer and in the first cavity, and on the second portion of the dielectric layer and in the second cavity, such that uppermost surfaces of the first conductive layer, the second conductive layer, the protective layer over the first portion of the dielectric layer, and the protective layer over the second portion of the dielectric layer are coplanar with each other.
4 more elements
A method of forming a memory, the method comprising:
- forming a conductive memory gate on a substrate;
- forming a conductive selection gate on the substrate;
- forming a gate dielectric layer having a first portion between the memory gate and the selection gate and a second portion, the first and second portions positioned on opposites sides of the selection gate;
- forming a first cavity between the conductive memory gate and the conductive selection gate by removing a part of the first portion of the gate dielectric layer;
- forming a second cavity by removing a part of the second portion of the gate dielectric layer;
- forming a first protective cap in the first cavity, on the first portion of the gate dielectric layer, and between the conductive memory gate and the conductive selection gate;
- forming a second protective cap in the second cavity and on the second portion of the gate dielectric layer;
- and
- removing portions of the first and second protective caps such that a surface of the memory gate, a surface of the selection gate, and surfaces of the first and second protective caps are at a same level with each other.
6 more elements
Dependencies are inferred from the claim text.