Composition for forming a developable bottom antireflective coating

1. A composition for forming a bottom anti-reflective coating, comprising

a solvent,

a polymer represented by the following formula (I):

-A m -B n —  (1)

in which

A and B are repeating units represented by the following formulas (A) and (B), respectively

wherein

each of R 11 and R 12 is independently hydrogen or an alkyl group;

L 11 is a single bond, COO or a straight- or branched chain alkylene containing one or more carbon atoms;

Y is a condensed polycyclic aromatic group containing two or more benzene rings wherein one of the benzene rings is optionally replaced with a quinone ring; and

Z is a group selected from the group consisting of R 3 COOR 4 and R 3 OR 4 , provided that R3 is a single bond, oxygen or a straight- or branched chain alkylene which may have a fluorine atom and which contains one or more carbon atoms and also provided that R 4 is hydrogen or a substituted or non-substituted hydrocarbon group; each of m and n is a number indicating the polymerization degree provided that m is not less than 10 and n is not less than 0;

and,

a compound represented by formulas (3)

in which each of R 31 to R 36 is independently a group selected from the group consisting of hydrogen, alkyl, aryl, halogen, alkoxy, nitro, aldehyde, cyano, amido, dialkylamino, sulfonamido, imido, carboxylic acid, carboxylic acid ester, sulfonic acid, sulfonic acid ester, alkylamino, and arylamino; and L 31 is an alkylene or an arylene; and further comprising a photo acid generator.

2. The composition according to claim 1 , where Y is a condensed polycyclic aromatic group containing two or more benzene rings provided that one of the benzene rings is replaced with a quinone ring and that the condensed polycyclic aromatic group may optionally have a substituent selected from the group consisting of alkyl, aryl, halogen, alkoxy, nitro, aldehyde, cyano, amido, dialkylamino, sulfonamido, imido, carboxy, carboxylic acid ester, sulfo, sulfonic acid ester, alkylamino, and arylamino.

3. The composition according to claim 1 , further comprising a crosslinking agent.

4. The composition according to claim 1 ,

wherein

each of R 11 and R 12 is independently hydrogen or methyl,

L 11 is COO, and

Z is R 3 COOR 4 , provided that R 3 is a single bond or a straight chain alkylene group having 1 to 6 carbon atoms and that R 4 is hydrogen or a branched chain alkyl group having 1 to 10 carbon atoms.

5. A bottom anti-reflective coating formed on a substrate the composition of claim 1 and then heating for forming a bottom anti-reflective coating.

6. The bottom anti-reflective coating according to claim 5 , formed by a heat-induced Diels-Alder reaction between the polymer represented by the formula (I) and the compound represented by formula (3).

7. A pattern formation method comprising the steps of:

spreading the composition according to claim 1 for forming a bottom anti-reflective coating on a semiconductor substrate and then baking, to form a bottom anti-reflective coating;

forming a photoresist layer on the bottom anti-reflective coating;

exposing to light the semiconductor substrate covered with the bottom anti-reflective coating and the photoresist layer; and

after the exposure, developing them by use of a developing solution selected from the group consisting of alkaline developing solution and organic solvent, thereby forming a pattern in the photoresist and the antireflective coating.

8. The pattern formation method according to claim 7 , wherein the photoresist layer is a positive-working photoresist, R 4 is hydrogen, and the developing solution is an alkaline aqueous solution.

9. The pattern formation method according to claim 7 , wherein the photoresist layer is made of a positive-working photoresist, R 4 is a substituted or non-substituted hydrocarbon group, and the developing solution is an alkaline aqueous solution.

10. The pattern formation method according to claim 7 , wherein the photoresist layer is a negative-working photoresist, R 4 is hydrogen, and the developing solution is an alkaline aqueous solution.

11. The pattern formation method according to claim 10 , wherein the composition for forming a bottom anti-reflective coating further contains a crosslinking agent.

12. The pattern formation method according to claim 7 , wherein the photoresist layer is a positive-working photoresist, R 4 is a substituted or non-substituted hydrocarbon group, and the developing solution is an organic solvent.

13. The pattern formation method according to claim 7 , wherein the exposure is carried out by use of light in the wavelength range of 13.5 to 248 nm.

14. A pattern formation method comprising the steps of:

spreading the composition according to claim 1 for forming a bottom antireflective coating on a semiconductor substrate and then baking, to form a bottom anti-reflective coating;

forming a photoresist layer on the bottom anti-reflective coating;

exposing to light the semiconductor substrate covered with the bottom anti-reflective coating and the photoresist layer; and after the exposure,

developing them by use of a developing solution selected from the group consisting of alkaline developing solutions and organic solvents thereby forming a pattern in the photoresist and not in the antireflective coating.