Composition for forming anti-reflective coating for use in lithography
There is provided a composition for forming anti-reflective coating for use in a lithography which has a high effect of inhibiting reflected light, causes no intermixing with resist layers, affords excellent resist patterns, has a higher dry etching rate compared with the resist, and has broader margin of depth of focus and higher resolution than the prior compositions. Concretely, the composition is one for forming anti-reflective coating for use in a lithographic process in manufacture of a semiconductor device, and comprises a resin containing a lactone structure. The resin is one which a γ-lactone structure or a δ-lactone structure is introduced to a main chain thereof or a side chain bonded to the main chain.
1. A composition for forming anti-reflective coating for use in a lithographic process in manufacture of a semiconductor device, comprising a resin having a lactone structure, and a crosslinking agent, wherein the resin is a resin in which a γ-lactone structure is introduced to a main chain thereof or a side chain bonded to the main chain.
2. The composition for forming anti-reflective coating according to claim 1 , wherein the resin has a structural unit of formula (1):
wherein Q is a divalent linking group through which P and R 1 are linked, R 1 is a substituted or unsubstituted propylenyl or butylenyl, P is a linking group constituting the main chain, and R 2 is a hydrogen atom, methyl or a halogen atom.
3. The composition for forming anti-reflective coating according to claim 1 , wherein the resin is composed of a polymer of formula (2):
wherein x and y is the number of repeating units, x is 5 to 5,000, y is 2 to 5,000, Q is a divalent linking group through which a carbon atom constituting the main chain and R 1 are linked, R 1 is a substituted or unsubstituted propylenyl or butylenyl, R 2 and R 3 are a hydrogen atom, methyl or a halogen atom, and R 4 is a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aralkyl group, a substituted or unsubstituted carbocyclic aromatic group, or a substituted or unsubstituted heterocyclic aromatic group, structural unit (A′) is in an amount of 1 to 76 mol % and structural unit (B) is in an amount of 99 to 24 mol %.
4. The composition for forming anti-reflective coating according to claim 1 , wherein the resin is composed of a polymer of formula (3):
wherein x, y 1 and y 2 are the number of repeated units, x is 5 to 5,000, y 1 and y 2 are 1 or more and the sum of y 1 and y 2 is 2 to 5,000, R 5 is a hydrogen atom or methyl, R 6 is hydroxyethyl or hydroxypropyl, R 7 is phenyl, benzyl, naphthyl, anthryl or anthrylmethyl, and L is (L- 1 ) or (L- 2 ) described below
structural unit (A″) is in an amount of 1 to 76 mol % and structural units (B′) and (B″) are in an amount of 1 mol % or more and the sum of (B′) and (B″) is 99 to 24 mol %.
5. The composition for forming anti-reflective coating according to claim 1 , wherein the resin has a structure with an absorption at 248 nm, 193 nm or 157 nm.
6. The composition for forming anti-reflective coating according to claim 1 , wherein the crosslinking agent has at least two crosslink-forming functional groups.
7. A method of forming an anti-reflective coating for use in a lithographic process in a manufacture of a semiconductor device, comprising the steps of; coating the composition according to claim 1 on a substrate, and baking it.
8. A process for manufacturing a semiconductor device comprising the steps of:
coating the composition according to claim 1 on a substrate and baking it to form an anti-reflective coating,
covering the anti-reflective coating with a photoresist,
exposing the substrate covered with the anti-reflective coating and the photoresist to light,
developing the exposed substrate, and
transferring an image on the substrate by dry etching to form an integrated circuit element.
9. The process for manufacturing a semiconductor device according to claim 8 , wherein the exposure is carried out with light having a wavelength of 193 nm.