Graded spin-on organic antireflective coating for photolithography
View Patent ↗An antireflective coating that contains at least two polymer components and comprises chromophore moieties and transparent moieties is provided. The antireflective coating is useful for providing a single-layer composite graded antireflective coating formed beneath a photoresist layer.
1. A composition for formation of a spin-on antireflective coating layer, comprising:
(a) a plurality of polymer components, wherein said polymer components are homopolymers or copolymers selected from the group consisting of poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate), poly(isobornyl methacrylate-co-glycidyl methacrylate), poly(pentafluorostyrene-co-glycidyl methacrylate-co-methyl methacrylate), poly(styrene-co-methacrylic acid-co-methyl methacrylate), poly(pentafluorostyrene-co-glycidyl methacrylate), poly(ethenyl hexafluoroisopropyl cyclopentane-co-ethenyl hydroxyethyl cyclopentane, poly(ethenyl hexafluoroisopropyl cyclopentane-co-ethenyl hydroxymethyl cyclopentane), poly(ethenyl cyclopentane methyl ester-co-ethenyl hydroxyethyl cyclopentane), poly(styrene-co-hydroxyethyl methacrylate-co-methyl methacrylate), poly(hydroxystyrene, brominated), poly(o-cresyl glycidyl ether-co-formaldehyde), poly(4-bromostyrene-co-glycidyl methacrylate, poly(4-bromostyrene-co-hydroxyethylmethacrylate), and poly(hydroxystyrene),
wherein the plurality of polymer components comprises a first polymer component that has at least one chromophore moiety at an imaging radiation wavelength, and a second polymer component has at least one transparent moiety at the imaging radiation wavelength,
(b) a separate crosslinking component, and
(c) an acid generator,
wherein the first polymer component has a first segregation preference towards a first interface of the composition and the second polymer component has a second segregation preference towards a second interface of the composition during at least one of a film casting and a film baking process, and
wherein the polymer components have a molecular weight ranging from about 1000 to about 500,000.
2. The composition of claim 1 , wherein said acid generator is a thermally activated acid generator.
3. The composition of claim 1 , wherein said polymer components are random copolymers.
4. The composition of claim 1 , wherein said crosslinking component comprises a glycoluril compound.
5. The composition of claim 1 , wherein said composition consists essentially of components (a), (b), and (c).
6. The composition of claim 1 , wherein the individual polymer components have a refractive index (n) in the range of about 1.3 to about 2.0 at a preselected imaging radiation wavelength.
7. The composition of claim 1 , wherein the individual polymer components have an extinction coefficient (k) in the range of about 0.001 to about 1.1, at a preselected imaging radiation wavelength.
8. The composition of claim 1 , wherein at least one polymer component is highly absorbing at a preselected imaging radiation wavelength.