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US 2026/0239905 A1Published application
Metal etching with reduced tilt angle
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChao-Hsuan CHEN, I-Wei YANG, Chang-Han TSAI, Shu-Uei JANG, Shu-Yuan KU, Yih-Ann LIN, Ryan Chia-Jen CHEN
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Abstract
Methods for etching metal, such as for processing a metal gate, are provided. A method includes forming a hard mask over the metal, wherein the hard mask includes a sidewall defining an opening; and performing a plasma etching process including cycles of depositing a carbon nitride film on the sidewall and etching the metal.
Claims20
A method comprising:
- forming a hard mask over a metal structure, wherein the hard mask includes a sidewall defining an opening;
- performing a metal etch process through the opening to etch the metal structure;
- and
- during the metal etch process, depositing a protective film on the sidewall of the hard mask, wherein the protective film prevents accumulation of a byproduct from the metal etch process on the sidewall, and wherein the protective film is absent from a surface of the metal structure being etched.
1 more element
A method comprising:
- forming a plurality of nanostructures over a semiconductor substrate;
- forming a metal gate around the nanostructures;
- patterning a hard mask over the metal gate, wherein the hard mask includes a sidewall defining an opening over a region of the metal gate to be removed;
- and
- performing a plasma etching process through the opening, wherein the plasma etching process includes cycles of depositing a carbon nitride film on the sidewall and etching the metal gate, and wherein the carbon nitride film prevents accumulation of an etching byproduct on the sidewall during the etching.
2 more elements
A semiconductor structure comprising:
- a semiconductor substrate;
- an isolation region in the semiconductor substrate;
- a metal gate over the semiconductor substrate and over the isolation region;
- a trench extending through the metal gate and into the isolation region, wherein the trench has a sidewall, and wherein the sidewall is within 1.5° of perpendicular to the semiconductor substrate;
- and
- a dielectric structure filling the trench and separating the metal gate into two electrically isolated metal gate segments.
3 more elements
Dependencies are inferred from the claim text.