Protection layer formation during plasma etching conductive materials
AssigneeTokyo Electron Limited
InventorsYen-Tien Lu, Shihsheng Chang, Nicholas Joy
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Abstract
A method of processing a substrate that includes: forming a patterned hardmask layer over a conductive layer to be etched, the conductive layer disposed over a substrate; and patterning the conductive layer using the patterned hardmask layer as an etch mask, by performing a cyclic plasma etch process to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process including exposing the substrate to a first plasma including a halogen to etch the conductive layer, and exposing the substrate to a second plasma including a silicon-containing precursor to deposit a silicon-containing protective layer over a top surface of the patterned hardmask layer.
Claims20
A method of processing a substrate, the method comprising:
- forming a patterned hardmask layer over a conductive layer to be etched, the conductive layer disposed over a substrate;
- and
- patterning the conductive layer using the patterned hardmask layer as an etch mask, by performing a cyclic plasma etch process to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising
- exposing the substrate to a first plasma comprising a halogen to etch the conductive layer, and
- exposing the substrate to a second plasma comprising a silicon-containing precursor to deposit a silicon-containing protective layer over a top surface of the patterned hardmask layer, wherein the deposition of the silicon-containing protective layer is selective to the top surface of the patterned hardmask layer relative to sidewalls of the conductive layer.
A method of processing a substrate, the method comprising:
- forming a patterned hardmask layer over a conductive layer to be etched, the conductive layer disposed over a substrate;
- flowing a halogen-containing etch gas into a plasma processing chamber, the substrate being loaded in the plasma processing chamber;
- while flowing the halogen-containing etch gas, sustaining a plasma generated from the halogen-containing etch gas in the plasma processing chamber;
- etching the conductive layer using the patterned hardmask layer as an etch mask by exposing the substrate to the plasma;
- while flowing the halogen-containing etch gas, flowing a silicon-containing precursor into the plasma processing chamber to modify a composition of the plasma;
- depositing a silicon-containing layer over a top surface of the patterned hardmask layer by exposing the substrate to the modified plasma, the silicon-containing layer being formed to a first thickness over the top surface of the patterned hardmask layer, the first thickness being greater than a second thickness of the silicon-containing layer over the conductive layer;
- and
- repeating the etching and the depositing.
A method of processing a substrate, the method comprising:
- forming a patterned hardmask layer over a conductive layer to be etched, the conductive layer disposed over a substrate, the conductive layer comprising ruthenium, the patterned hardmask layer comprising silicon, the substrate comprising an etch stop layer (ESL) underlying the conductive layer;
- and
- patterning the conductive layer using the patterned hardmask layer as an etch mask, by performing a cyclic plasma etch process in a plasma processing chamber to gradually form a recess in the conductive layer, each cycle of the cyclic plasma etch process comprising
- sustaining a plasma comprising an etchant,
- exposing the substrate to the plasma, the etchant etching the conductive layer,
- while exposing the substrate to the plasma, flowing a silicon-containing precursor to the plasma processing chamber to selectively form a protective layer on a top surface of the patterned hardmask layer relative to sidewalls of the conductive layer and to the surface of the conductive layer, and
- stopping the flow of silicon-containing precursor to stop the formation of the protective layer.
Dependencies are inferred from the claim text.