Stabilization of chemically amplified resist coating
OwnerZoilo Chen Ho Taninventor
Life of this patent
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Abstract
Environmental contamination of chemically amplified resist used in lithography is overcome by use of a coating, such as a thin layer of a charge dissipation material, applied over the fresh CAR layer. This overcoat stabilizes process control and also makes it possible to precoat the CAR on wafer or mask blanks, making them usable even several months after the coating takes place. The overcoating is a conductive material in the electron beam lithography regime, thereby providing charge dissipation during electron beam exposure improving accuracy. The conductive material is, for instance, a liquid organic conductive material at its application, such as PanAquas, or a thin layer of sputtered or evaporated metal.
Claims29
An article of manufacture which is a reticle blank suitable for storage and subsequent lithographic exposure, comprising:
- a substrate;
- a layer of non-transmissive material over the substrate;
- a layer of unexposed chemically amplified resist over the non-transmissive layer;
- and
- a layer of protective material over the layer of resist.
An article of manufacture suitable for storage and subsequent lithographic exposure, comprising:
- a substrate;
- a layer of chemically amplified resist over the substrate;
- and
- a layer of protective material over the resist layer.
A method of preparing a substrate for storage and subsequent lithographic exposure, comprising the acts of:
- forming a layer of chemically amplified resist over a principal surface of the substrate;
- forming a layer of protective material over the resist layer;
- and
- exposing the resist to actinic radiation at least one hour after the act of forming.
A method of preparing, storing and lithographically exposing a substrate, comprising the acts of:
- forming a layer of chemically amplified resist over a principal surface of the substrate;
- forming a layer of protective material over the resist layer;
- storing the substrate with the protective material and resist layer for at least one day;
- after the storage, exposing the substrate to exposing energy, thereby exposing selected portions of the resist through the layer of protective material;
- removing at least part of the layer of protective material;
- and
- developing the exposed resist after the act of removing.
Dependencies are inferred from the claim text.