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US 10,312,107 B2Granted
Forming interconnect structure using plasma treated metal hard mask
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChung-Chi Ko, Chia-Cheng Chou, Shing-Chyang Pan, Keng-Chu Lin, Shwang-Ming Jeng
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Abstract
A method includes forming a metal hard mask over a low-k dielectric layer. The step of forming the metal hard mask includes depositing a sub-layer of the metal hard mask, and performing a plasma treatment on the sub-layer of the metal hard mask. The metal hard mask is patterned to form an opening. The low-k dielectric layer is etched to form a trench, wherein the step of etching is performed using the metal hard mask as an etching mask.
Claims20
A method comprising:
- forming a metal hard mask over a low-k dielectric layer, wherein the step of forming the metal hard mask comprises:
- depositing a first layer of the metal hard mask comprising horizontal grains and vertical grains;
- performing a plasma treatment on the first layer of the metal hard mask, wherein the first layer of the metal hard mask has a first thickness, and wherein after the plasma treatment, the metal hard mask is substantially free from vertical grains;
- depositing a second layer of the metal hard mask, wherein the second layer of the metal hard mask has a second thickness different from the first thickness of the first layer of the metal hard mask;
- and
- performing a plasma treatment on the second layer of the metal hard mask;
- patterning the metal hard mask to form an opening;
- etching the low-k dielectric layer to form a trench, wherein the step of etching is performed using the metal hard mask as an etching mask;
- forming a diffusion barrier layer in the trench;
- filling a metallic material into the trench, wherein the metallic material is over the diffusion barrier layer, and the diffusion barrier layer and the metallic material comprise portions overlapping the metal hard mask;
- and
- performing a chemical mechanical polish (CMP) to remove excess portions of the metallic material over the metal hard mask.
9 more elements
A method comprising:
- forming a low-k dielectric layer over a semiconductor substrate;
- forming a metal hard mask over the low-k dielectric layer, wherein the metal hard mask comprises a plurality of sub-layers distinguishable from each other, with the plurality of sub-layers comprising boron nitride, wherein the forming the metal hard mask is performed at least in part with an atomic layer deposition, wherein a first sub-layer of the plurality of sub-layers of the metal hard mask is formed directly over the low-k dielectric layer prior to forming the remainder of the plurality of sub-layers of the metal hard mask, wherein the first sub-layer of the plurality of sub-layers of the metal hard mask has a first thickness, and wherein at least one of the plurality of sub-layers of the metal hard mask has a second thickness different from the first thickness of the first sub-layer of the plurality of sub-layers of the metal hard mask;
- patterning the metal hard mask to form an opening in the metal hard mask;
- etching the low-k dielectric layer to form a trench using the metal hard mask as an etching mask;
- etching the low-k dielectric layer to form a via opening in the low-k dielectric layer;
- and
- forming a metal line and a via in the trench and the via opening, respectively, wherein the forming the metal line and the via comprises:
- filling a conductive material into the trench and the openings;
- and
- performing a planarization to remove excess portions of the conductive material and the metal hard mask, with remaining portions of the conductive material forming the metal line and the via.
7 more elements
A method comprising:
- forming a metal hard mask over a low-k dielectric layer, wherein the forming the metal hard mask comprises:
- depositing a first sub layer of the metal hard mask comprising horizontal grains and vertical grains, wherein the first sub layer of the metal hard mask has a first thickness;
- modifying directions of longitudinal axis of grains in the first sub layer of the metal hard mask, wherein substantially all vertical grains are converted to horizontal grains;
- depositing a second sub layer of the metal hard mask comprising horizontal grains and vertical grains, wherein the second sub layer of the metal hard mask has a second thickness different from the first thickness of the first sub layer of the metal hard mask;
- and
- modifying directions of longitudinal axis of grains in the second sub layer of the metal hard mask, wherein substantially all vertical grains are converted to horizontal grains;
- patterning the metal hard mask to form an opening;
- etching the dielectric layer to form a trench, wherein the etching is performed using the metal hard mask as an etching mask;
- filling the trench with a conductive material, wherein the conductive material comprises:
- a first portion in the trench;
- a second portion extending into the metal hard mask;
- and
- a third portion higher than the metal hard mask;
- and
- performing a planarization to remove the metal hard mask and the second portion and the third portion of the conductive material.
12 more elements
Dependencies are inferred from the claim text.