Method for plasma hardening photoresist in etching of semiconductor and superconductor films
AssigneeNorthrop Grumman Corporation
InventorRaffi N. Elmadjian
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Abstract
A plasma photoresist hardening technique is provided to improve the etch resistance of a photoresist mask 26. The technique involves the formation of a thin passivation layer 26b on the photoresist mask 26 which substantially slows down the etching rate of the photoresist material 26a. Advantageously, this technique allows preservation of critical dimension features such as via hole openings and transmission lines. The technique hardens the surface of the photoresist film 26 by both chemically and physically bonding halogenated hydrocarbons with cross linked photoresist polymer. This results in a passivation layer 26b which is highly resistant to harsh plasma etch environments.
Claims18
A method of treating a photoresist for enhanced etching resistance comprising the steps of:
- baking said photoresist;
- forming a passivation layer on said baked photoresist by exposing said baked photoresist to a gas plasma, the gas plasma being comprised of CxHyFzClw and O2;
- and
- re-baking said exposed photoresist.
A method of treating a photoresist for enhanced etching resistance comprising the steps of:
- baking said photoresist;
- forming a passivation laver on said baked photoresist by exposing said baked photoresist to a gas plasma;
- and
- re-baking said exposed photoresist at a temperature of about 100 to about 200° C.
A method of treating a photoresist for enhanced etching resistance comprising the steps of:
- cross-linking a polymer of said photoresist;
- disassociating a gas plasma containing CxHyFzClw and Oxygen into a plurality of species including reactive positive and negative ions, radicals and neutrals;
- and
- bombarding said cross-linked polymer of said photoresist with said species such that said species are at least one of absorbed and diffused into said cross-linked polymer of said photoresist.
A method of treating a photoresist for enhanced etching resistance comprising the steps of:
- chemically and physically bonding halogenated hydrocarbons with a cross-linked polymer of said photoresist to form a passivation layer on said photoresist.
Dependencies are inferred from the claim text.