Radiation imagery chemistry: process – composition – or product th – Imaging affecting physical property of radiation sensitive... – Radiation sensitive composition or product or process of making
Reexamination Certificate
2001-03-27
2003-06-24
Ashton, Rosemary (Department: 1752)
Radiation imagery chemistry: process, composition, or product th
Imaging affecting physical property of radiation sensitive...
Radiation sensitive composition or product or process of making
C430S920000, C430S921000, C568S028000, C568S030000, C568S034000
Reexamination Certificate
active
06582879
ABSTRACT:
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a reactive photo acid-generating agent and a heat-resistant photoresist composition comprising the same. In particularly, the present invention relates to the heat-resistant photoresist composition comprising the photo acid-generating agent expressed by the following formula (1), which can increase the degree of polymerization, and polyamide oligomers having acetal or its cyclized derivatives, which have an ability of that light-exposed area is dissolved in the developer and light-unexposed area is convertible to a heat-resistant polymer in the latter heating process and thus, it can be used for passivation layer, buffer coat or layer-insulating film of the multilayer printed circuit board,
wherein
represent
in which X represents —CH
2
—, —O—, —S—, —SO
2
—, —CO—, —NHCO—, —C(CH
3
)
2
—, —C(CF
3
)
2
—, or
and R represents —CH
3
, —C
2
H
5
, —C
3
H
7
, —C
4
H
9
, —CF
3
,
Polyimide is useful for layer-insulating films of surface protection layers, semiconductor dielectric, multi-layer chip module, and the like due to high stability against heat and chemicals.
Conventionally, complicated lithography processes such as photoresist coating, prebaking, UV exposure, developing of photoresist, etching of passivation layer and removing of photoresist are required for patterned heat-resistant insulating layer to make electrical connection with the conductor wiring between upper and lower layer or multi-layers.
Therefore, there have been intensive researches on the preparation of direct polyimide pattern as a photosensitive compound with polyimides or polyamide precursors. If the heat-resistant materials have a function of photoresist, several steps for lithographic process such as a photoresist coating and its removing become unnecessary in making via holes for wiring. Moreover, it can reduce the use of resist and chemicals. Accordingly, the use of heat-resistant photoresist can greatly simplify and make the whole process efficient. On top of that it can prevent the degraded resolution and reproducibility which can be happened during the process of etching and resist removal. Since while photoresist is generally removed out from the top of passivation layer after lithographic processes such as light-exposure, development and etching for photoresist, the heat-resistant photoresist of the present invention remains in the semiconductor permanently, it provides not only insulation, heat resistance, mechanical and low dielectric properties which are required as semiconductor materials, but also excellent photosensitivity, resolution, transparency and developing properties which are required as photosensitive materials.
Typical examples of photosensitive chemicals are polyamic acid derivatives containing side chains bonded through ether linkage, ester linkage, amide linkage or acid ammonium salt.
The first attempt for photosensitive polyimides was using polyamic acid chromate as sensitizer [Kerwin and Goldrick,
Polym: Eng. Sci
., 11, 426 (1971)], which was failed to be commercialized since it used an inorganic metal and the storage period was too short.
Negative photosensitive polyamides using photo-crosslinkable polyimide precursors having esters or ionic groups as pendant groups are disclosed in German Patent No. 2,437,348, and this system indicated the possibility of applying polyimides in applications of semiconductors since soluble photosensitive polyamic acid and very little amount of a metallic ion were used. However, in general the negative heat-resistant photoresists may give us lower resolution of relief pattern due to particles or cracks present on the photomask. Further, the resolution may be deteriorated by swelling of the relief pattern, since organic solvents are used for the developer.
On the other hand, U.S. Pat. No. 4,927,736 discloses positive heat-resistant photoresists prepared from aromatic hydroxy polyimides with covalently attached or solution blended naphtoquinone diazide (NQ) as a photosensitive agent. Since aromatic hydroxy polyimides themselves absorbs large amount of light, and consequently lowering the quantum efficiency, a large amount of a photosensitive agent should be used to improve the quantum efficiency. Besides, a large amount of polar residues of used photosensitive agent remains in the film and polar groups such as —OHs also remain in the main chain of the polymer, and thus the dielectric constant is increased and heat-resistance is decreased.
Other methods have been reported by introducing a chemical-amplifying acid-sensitive group to aromatic hydroxy polyimides [
Polymers for Advanced Technology
, vol. 4, 277, 287, 1992] or polyamic t-butyl ester polyimide precursors, [European Patent Publication No. 0502400A1] to improve photosensitivity and resolution. In these methods, —OH or —COOH groups are blocked by a chemical-amplifying acid-sensitive group, thereby the solubility in aqueous alkali solutions is decreased. Then the acid produced by the photo-reaction of photo acid-generating agent decomposes the acid-sensitive group to recover —OH or —COOH groups which help the polymers to be soluble in developer solutions. Even though the quantum efficiency can be improved by the treatments, in the case of using aromatic polyimides containing hydroxyl group, the —OH groups generated after the thermal treatment for curing may remain in the film which increase the dielectric constant of the film; and in the case of using polyamic t-butyl ester polyimide precursors, the dielectric constant is increased and the heat-resistance is decreased because too much of photo acid-generating agent should be used.
SUMMARY OF THE INVENTION
The inventors have made intensive efforts to fundamentally solve the problems of the conventional heat-resistant photoresists such as, increase of electric constant due to hydroxyl groups generated after the thermal treatment for curing, decrease of heat-resistance due to the remaining acid-generating material in the film after the development, and especially poor flatness due to the high viscosity of polymers in the preparation of multiplayer circuit board, and to improve the photosensitivity. As a result, inventors have discovered novel positive heat-resistant photoresists enables of achieving high quantum efficiency through chemical-amplifying photosensitive agent, low dielectric constant and high heat-resistance by minimizing the use of photosensitive agent and by eliminating the unreacted polar groups, and better flatness in the preparation of multiplayer circuit board.
Accordingly, an object of the present invention is to provide an aromatic bissulphonic diamide compound containing a photo acid-generating agent.
Another object of this invention is to provide a novel heat-resistant photoresist composition comprising polyamide oligomers having ester groups as pendant groups and a photo acid-generating agent in an appropriate ratio to obtain advantages in minimizing post-exposure baking process and post-exposure delay effect owing to have.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is characterized by a photo acid-generating agent expressed by the following formula (1),
wherein
and R are the same as defined above.
The present invention is also characterized by a positive heat-resistant photoresist composition comprising the photo acid-generating agent expressed by the following formula (1) and the polyamide oligomer having ester groups as pendant groups expressed by the following formula (2),
wherein Ar
1
is a quaternary aromatic group which is selected from the group consisting of
Ar
2
is a secondary aromatic group which is selected from the group consisting of
R
1
and R
2
are independently a hydrogen atom or C
1
-C
10
alkyl having
wherein R
1
is a C
1
-C
6
alkyl such as ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl and cyclohexyl; and z is an integer of 1-4 (however, excluding the case when both R
1
and R
2
are hydrogen atoms);
R
3
and R
4
are independently a hydrogen atom,
which e
Choi Kil-Yeong
Choi Sang Yeol
Jin Moon Young
Won Jong Chan
Ashton Rosemary
Korea Research Institute of Chemical Technology
LandOfFree
Reactive photo acid-generating agent and heat-resistant... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Reactive photo acid-generating agent and heat-resistant..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Reactive photo acid-generating agent and heat-resistant... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3098606