Etching method
AssigneeTokyo Electron Limited
InventorsEiichi Nishimura, Takehiko Orii
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Abstract
A method for etching an insulation film through a patterned mask, includes the steps of etching the insulation film until just before an underlayer is about to be exposed by applying a plasma, and modifying a quality of a remaining film of the insulation film by applying another plasma which is different from the plasma used in the above etching process. The method further includes the process of removing the modified remaining film of the insulation film with a liquid chemical. The process of removing the modified remaining film can be also achieved by a dry etching method not employing a plasma.
Claims16
A method for etching an insulation film through a patterned mask, comprising:
- a first process of etching the insulation film until just before an underlayer is about to be exposed by applying a first plasma of a first processing gas;
- a second process of modifying a quality of a remaining film of the insulation film by applying a second plasma of a second processing gas, the second plasma being different from the first plasma;
- and
- a third process of removing the insulation film having a modified film quality with a liquid chemical.
A method for etching an insulation film through a patterned mask, comprising:
- a first process of etching the insulation film until just before an underlayer is about to be exposed by applying a first plasma of a first processing gas;
- a second process of modifying a quality of a remaining film of the insulation film by applying a second plasma of a second processing gas, the second plasma being different from the first plasma;
- and
- a third process of removing the insulation film having a modified film quality through a dry etching process using no plasma.
A method for etching a SiCOH-based low dielectric constant insulation film, comprising:
- a first process of etching the SiCOH-based low dielectric constant insulation film with a fluorocarbon gas plasma without exposing an underlayer such that a thickness of a remaining SiCOH-based low dielectric constant insulation film is smaller than or equal to 100 nm;
- a second process of removing a methyl group from the remaining SiCOH-based low dielectric constant insulation film by applying a plasma containing H2 gas or O2 gas;
- and
- a third process of removing the remaining SiCOH-based low dielectric constant insulation film devoid of the methyl group with a solution containing at least one of hydrofluoric acid, ammonium fluoride and tetramethyl ammonium hydroxide.
Dependencies are inferred from the claim text.