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US 12,191,202 B2Granted
Contact openings in semiconductor devices
AssigneeTokyo Electron Limited
InventorsBlaze Messer, Andrew Metz
Life of this patent
Estimating the term…
Abstract
In certain embodiments, a method for processing a semiconductor substrate includes receiving a semiconductor substrate that includes a nitride etch stop layer aligned to a gate electrode and a metal-based etch stop layer aligned to a source/drain contact region. The method further includes selectively etching the metal-based etch stop layer, to remove the metal-based etch stop layer and expose a surface of the source/drain contact region, by exposing the semiconductor substrate to a plasma formed in a gas comprising a corrosive material and fluorocarbon.
Claims20
A method, comprising:
- receiving a semiconductor substrate that comprises:
- a nitride etch stop layer over a gate electrode;
- a metal-based etch stop layer over a source/drain contact region, the source/drain contact region being adjacent to the gate electrode, the gate electrode being to a first side of the source/drain contact region, the metal-based etch stop layer covering a surface of the source/drain contact region over an entire span of the surface between the gate electrode to the first side of the source/drain contact region and another gate electrode adjacent to a second side of the source/drain contact region;
- and
- a dielectric layer overlying the metal-based etch stop layer and the nitride etch stop layer;
- patterning, to expose respective surfaces of the metal-based etch stop layer and the nitride etch stop layer, the dielectric layer using a patterned resist layer over the dielectric layer as an etch mask;
- and
- etching the metal-based etch stop layer using a plasma etching process that selectively etches the metal-based etch stop layer until the surface of the source/drain contact region is exposed, at least a portion of the nitride etch stop layer remaining over the gate electrode after the plasma etching process, the plasma etching process comprising exposing the semiconductor substrate to a plasma comprising a corrosive material and a fluorine-based reducing agent, wherein the corrosive material comprises chlorine and the fluorine-based reducing agent comprises fluorocarbon.
5 more elements
A method, comprising:
- receiving a semiconductor substrate that comprises a nitride etch stop layer aligned to a gate electrode and a metal-based etch stop layer aligned to a source/drain contact region;
- and
- selectively etching the metal-based etch stop layer, to remove the metal-based etch stop layer and expose a surface of the source/drain contact region, by exposing the semiconductor substrate to a plasma formed in a gas comprising a corrosive material and fluorocarbon, wherein exposing the semiconductor substrate to the plasma formed in a gas comprising the corrosive material and the fluorocarbon facilitates forming a passivation layer on the nitride etch stop layer, the passivation layer inhibiting etching of the nitride etch stop layer during the plasma etching process while exposing the semiconductor substrate to the plasma formed in the gas comprising the corrosive material and the fluorocarbon.
A method, comprising:
- positioning a semiconductor substrate in a plasma process chamber of a plasma process tool, the semiconductor substrate comprising:
- a nitride etch stop layer covering a surface of a gate electrode;
- and
- a metal-based etch stop layer covering a surface of a source/drain contact region;
- selectively etching the metal-based etch stop layer, to remove the metal-based etch stop layer and expose the surface of the source/drain contact region, by exposing the semiconductor substrate to a plasma formed in a gas comprising chlorine and fluorocarbon, the plasma forming a passivation layer on a surface of the nitride etch stop layer, inhibiting etching of the nitride etch stop layer during exposure of the semiconductor substrate to the plasma such that the surface of the gate electrode remains covered by at least a portion of the nitride etch stop layer following removal of the metal-based etch stop layer.
2 more elements
Dependencies are inferred from the claim text.