Claims
- 1. An aqueous-processable, positive-working, photoresist composition consisting essentially of
- a) a polymeric material having
- (1) pendant acid labile groups selected from the group consisting of isobornyl ester, alpha-alkoxy alkyl ester, secondary or tertiary alkyl ester and silyl ester and
- (2) free acid groups having a pKa of at least 2 wherein the free acid groups consist essentially of carboxylic acid groups, wherein the polymeric materials has an acid number of from 25 to 300 and an adherent coating of said material in a thickness within a range of 0.00025 to 0.005 inch on a substrate takes at least 1 minute to be removed when sprayed at 25 to 30 p.s.i. with 1% by weight aqueous sodium carbonate solution at 30.degree. C., and
- b) a substance comprising 0.1 to 10 weight present of the photoresist composition that forms an acid having a pKa equal to or less than 2 upon exposure to actinic radiation.
- 2. The composition of claim 1 wherein the acid number is not greater than 100 and substance b) is present in an amount of from 0.5 to 6% in the composition.
- 3. The composition of claim 1 wherein the pendant acid labile group is unsubstituted or substituted isobornyl or norbornyl esters wherein substitution is by at least one alkyl or alkoxy groups having 1 to 4 carbon atoms, or an alpha-alkoxy alkyl ester group represented by the formula: ##STR2## where n is an integer of 0 to 4; R.sub.1 is hydrogen or lower alkyl of 1 to 6 carbon atoms; R.sub.2 is lower alkyl of 1 to 6 carbon atoms; and R.sub.3 and R.sub.4 independently are hydrogen or lower alkyl of 1 to 6 carbon atoms or R.sub.1 and R.sub.2, or R.sub.1 and either R.sub.3 or R.sub.4, or R.sub.2 and either R.sub.3 or R.sub.4 taken together form a 5-, 6-, or 7-membered ring.
- 4. The composition of claim 3 wherein the pendant acid labile group is 6-isobornyl methacrylate or acrylate.
- 5. The composition of claim 3 wherein the pendant acid labile group is 1-ethoxyethyl methacrylate or acrylate; 1-butoxyethyl methacrylate or acrylate; 1-ethoxy-1-propyl methacrylate or acrylate; tetrahydropyranyl methacrylate or acrylate; tetrahydropyranyl p-vinylbenzoate; 1-ethoxy-1-propyl p-vinylbenzoate; tetrahydropyranoxy-4-benzyl methacrylate or acrylate or 1-butoxyethoxy-4-benzyl methacrylate or acrylate.
- 6. The composition of claim 1 wherein the carboxylic acid group is acrylic acid, methacrylic acid, maleic acid, its half ester or half amide; fumaric acid, its half ester or half amide; and itaconic acid, its half ester or half amide.
- 7. The composition of claim 1 wherein the polymeric material is a copolymer.
- 8. The composition of claim 1 wherein the copolymer is formed from a monomer of methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, benzyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, N-butylacrylamide, N-octylacrylamide, acrylonitrile, styrene, p-methyl styrene, butadiene or isoprene.
- 9. The composition of claim 1 wherein the substance that forms an acid upon exposure to actinic radiation comprises an initiator that decomposes to form the acid.
- 10. The composition of claim 9 wherein the initiator is a diazonium salt, diaryliodonium salt or triarylsulfonium salt of a complex metal halides ion of tetrafluoroborate, hexafluoroantimonate, hexafluoroarsenate, and hexafluorophosphate.
- 11. The composition of claim 1 wherein the substance that forms an acid upon exposure to actinic radiation comprises an initiator that decomposes to form the acid and a spectral sensitizer that absorbs actinic radiation and sensitizes the initiator.
- 12. The composition of claim 11 wherein the spectral sensitizer is benzophenone, perylene, pyrene, anthracene, or derivative thereof.
Parent Case Info
This is a continuation of application Ser. No. 07/508,023 filed Apr. 10, 1990, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
672947 |
Oct 1963 |
CAX |
0264908 |
Oct 1987 |
EPX |
Non-Patent Literature Citations (3)
Entry |
Printed Circuits Handbook, Coombs, Clyde F., Jr., 1979 Chapter 6, pp. 6-1 through 6-30. |
Photoresist Materials and Processes, DeForest, W. S., 1975 Chapter 5, pp. 132-162. |
Polymers and Copolymers of Unsaturated Tetrahydropyranyl Esters, Julie E. Kearns, et al., 1974; pp. 673-685. |
Continuations (1)
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Number |
Date |
Country |
Parent |
508023 |
Apr 1990 |
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