Photoacid-labile polymers and photoresists comprising same
The present invention relates to new polymers that contain photoacid-labile groups that comprise arylalkyl groups. Particularly preferred are polymers having a benzylic carbon directly linked to an ester oxygen. Polymers of the invention are useful as a component of chemically-amplified positive-acting resists.
1. A chemically-amplified positive photoresist composition comprising one or more photoacid generator compounds and a polymer that comprises a structure of the following formula:
wherein X and Y are the same or different and are each non-hydrogen substituents;
Aryl is an aromatic group;
each R is the same or different non-hydrogen substituent;
R 1 , R 2 and R 3 are independently hydrogen or optionally substituted C 1-8 alkyl;
m is an integer of zero to 4; and n is an integer of from zero to five; and a, b and c are mole percents of the each of the depicted units and are each greater than zero,
wherein (i) the polymer further comprises lactone groups or (ii) the photoresist comprises a further resin comprising acetal photoacid labile groups.
2. The photoresist composition of claim 1 wherein the polymer further comprises phenyl groups.
3. The photoresist composition of claim 1 wherein the polymer further comprises anhydride groups.
4. The photoresist composition of claim 1 wherein the polymer further comprises cyano groups.
5. The photoresist composition of claim 1 wherein the polymer comprises an alicyclic group.
6. A method of forming a positive photoresist relief image, comprising:
(a) applying a coating layer of a photoresist of claim 1 on a substrate; and
(b) exposing and developing the photoresist layer to yield a relief image.
7. The method of claim 6 wherein the phororesist layer is exposed with radiation having a wavelength of about 248 nm.
8. An article of manufacture comprising a microelectronic wafer substrate having coated thereon a layer of the photoresist composition of claim 1 .
9. A method of manufacturing a semiconductor microchip wafer, comprising applying a coating layer of a photoresist composition of claim 1 onto a microchip wafer substrate.
10. The photoresist composition of claim 1 wherein X and Y are each alkyl.
11. The photoresist composition of claim 1 wherein X and Y are each alkyl having 1 to 3 carbon atoms.
12. The photoresist composition of claim 1 wherein m is zero.
13. The photoresist composition of claim 12 wherein n is zero.
14. The photoresist composition of claim 1 wherein n is zero.
15. A chemically-amplified positive photoresist composition comprising one or more photoacid generator compounds and a polymer that comprises a structure of the following formula:
wherein X and Y are each the same or different non-hydrogen substituents;
Aryl is an aromatic group;
each R is the same or different non-hydrogen substituent;
R 1 , R 2 and R 3 are independently hydrogen or optionally substituted C 1-8 alkyl;
m and m′ are each independently zero to 4; and d, e and f are mole percents of the each of the depicted units and are each greater than zero.
16. The photoresist composition of claim 15 wherein X and Y are each alkyl.
17. The photoresist composition of claim 15 wherein X and Y are each alkyl having 1 to 3 carbon atoms.
18. The photoresist composition of claim 15 wherein m is zero.
19. The photoresist composition of claim 18 wherein m′ is zero.