Metal-insulator-metal structures and methods of forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Liang Cheng, Sheng-Chau Chen
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Abstract
Forming a barrier layer and removing the barrier layer from an upper portion of a recess in which a metal-insulator-metal (MIM) structure will be formed allows for forming the MIM structure with fewer voids, which improves capacitance of the MIM structure. For example, a bottom layer anti-reflective coating may be deposited and etched back in order to allow for removal of the barrier layer from the upper portion of the recess but not from a bottom portion of the recess. Additionally, the barrier layer may be formed using physical vapor deposition, which reduces carbon impurities in the barrier layer as compared with using atomic layer deposition, which improves resistance for the MIM structure.
Claims20
A method, comprising:
- forming a recess in a dielectric layer to expose a surface of a copper metallization layer;
- forming, using physical vapor deposition (PVD), a first barrier layer on sidewalls of the recess and the exposed surface of the copper metallization layer;
- forming a carbon-based layer in the recess, wherein a top surface of the carbon-based layer is below a top surface of the dielectric layer;
- etching the first barrier layer to remove a portion of the first barrier layer above the top surface of the carbon-based layer;
- removing the carbon-based layer to re-open the recess;
- forming, using PVD, a second barrier layer over the first barrier layer and on sidewalls of the recess;
- and
- forming a metal-insulator-metal (MIM) structure in the recess,
- wherein the MIM structure has a width, along a top surface of the dielectric layer, that is larger than a width along a bottom surface of the MIM structure, and
- wherein the MIM structure has a width, at a point between a top surface of the dielectric layer and a bottom surface of the MIM structure, that is larger than the width along the bottom surface of the MIM structure and larger than the width along the top surface of the dielectric layer.
A method, comprising:
- forming a recess in a dielectric layer;
- forming a first barrier layer on sidewalls and a bottom surface of the recess;
- forming a carbon-based layer in the recess;
- etching a portion of the carbon-based layer, such that a top surface of a remaining portion of the carbon-based layer is below a top surface of the dielectric layer;
- etching the first barrier layer to remove a portion of the first barrier layer above the top surface of the remaining portion of the carbon-based layer;
- removing the remaining portion of the carbon-based layer to re-open the recess;
- forming a second barrier layer over the first barrier layer and on sidewalls of the recess;
- and
- forming a first metal in the recess, an insulator on the first metal, and a second metal on the insulator, wherein the first metal, the insulator, and the second metal comprise a metal- insulator-metal (MIM) structure,
- wherein the MIM structure has a width, along a top surface of the dielectric layer, that is larger than a width along a bottom surface of the MIM structure, and
- wherein the MIM structure has a width, at a point between a top surface of the dielectric layer and a bottom surface of the MIM structure, that is larger than the width along the bottom surface of the MIM structure and larger than the width along the top surface of the dielectric layer.
A method, comprising:
- forming a metal-insulator-metal (MIM) structure in a dielectric layer;
- forming a first barrier layer between the MIM structure and the dielectric layer and directly contacting a first portion of sidewalls of the dielectric layer;
- and
- forming a second barrier layer between the MIM structure and the dielectric layer and directly contacting a second portion of the sidewalls of the dielectric layer,
- wherein the MIM structure has a width, along a top surface of the dielectric layer, that is larger than a width along a bottom surface of the MIM structure, and
- wherein the MIM structure has a width, at a point between a top surface of the dielectric layer and a bottom surface of the MIM structure, that is larger than the width along the bottom surface of the MIM structure and larger than the width along the top surface of the dielectric layer.
Dependencies are inferred from the claim text.