TW200538875A - Coating composition of positive photosensitive polyimide - Google Patents

Abstract

A coating composition of positive photosensitive polyimide is disclosed, which includes an organic solvent and the following components dissolved in the organic solvent: (a) a polyimide having a phenolic hydroxyl group or carboxyl group at the end of a principal chain of the polymer; (b) a compound having a phenolic hydroxyl group; and (c) a quinonediazide sulfonate as a photosensitive agent. The amount of the components (b) and (c) are 1-50 parts by weight per 100 parts by weight the component (a) in the coating composition. A film of the coating composition can be developed with an alkaline aqueous solution, which has a high photosensitivity, excellent resolution, low post-cure temperature, high film residual rate in thickness, and a pattern having a tapered-angle at the cross section. The coating solution can be used for forming an insulating layer in displays or in other suitable applications.

Description

200538875 (1) Description of the invention: [Technical field to which the invention belongs] The present invention relates to a positive photosensitive polyimide coating composition, which can be used to form an insulating layer of a display. [Prior technology] Polyimide (PI) is widely used in the semiconductor and display industries due to its excellent thermal stability and good mechanical, electrical, and chemical properties, such as 1C wafer protection films, wafer-level packaging ( Chip scaie package (CSP) and the insulation layer (insuiator) on the display. The use of light-sensitive polyimide (PSPI) has become a trend because it can simplify the process, reduce costs, and increase product yield. Positive light-sensitive polyimide has a lot of related literatures, but most of them are precursors of polyimide such as polyarnic acid esters, such as US 6329110, US 6291619, US 6232032 and US 5858584 and other patents. The pattern of the polyurethane after development is a standard rectangle, but the insulation layer in the display needs a tapere (J_angle μ the cross section) cross-section, and the final polyurethane needs to be 35 °. 〇c Imidized at a high temperature, which conflicts with process requirements below 250. (: PSPI made with polyamidate is not suitable. In addition,

There are imidized PSPI such as US 6627377, US 5441845, US 5573 886 and other patents. Although the hard baking temperature can be lower, it is generally soluble PI, so it is solvent resistant. The performance is generally poor, and high-concentration alkaline developing solution is required to develop, so its practicality 200538875 is low.

Masao Tomikawa et al. In Journai 〇f ph〇t〇p〇lymer

Science and Technology, 2002, 15,205 ~ 208, US 6593043 and US 6524764 disclose the introduction of polyamino esters with phenolic groups in the main chain and the addition of compounds with phenolic hydroxyl groups as crosslinks Crosslinking agent can make the pattern tapered_angle at the cross section, but its main structure of polyamic acid ester still needs high temperature to ensure its imidization. The imidization is complete. In US 6524764 Example 6-13, it is pointed out that the shrinkage (shrinkage) will be caused when the polyamidate is converted into polyamidoimide, so the PSPI composed of polyamidate has a lower film thickness retention rate ( 66%), and its synthetic steps are more complicated. [Summary of the Invention] A main object of the present invention is to propose a new type of positive light-sensitive polyfluorene imide coating composition. The synthesis step is simple, and it can be developed in a short time using an alkaline aqueous solution. It has high sensitivity and good Resolution, low hard baking temperature, high film thickness retention, and its pattern has a tapered-angle at the cross section after hardening. The coating composition of the present invention has good storage properties at room temperature. The positive photosensitivity polyfluorene imide coating composition of the present invention comprises an organic solvent and polyfluorene imide dissolved in the organic solvent, and the main chain terminal has a phenoxy group or a carboxyl group ( carb〇xyl g UP) (b) a compound having a phenoHc hydroxyl group, 200538875 and (c) quinonediazide sulfonate as a photosensitizer, in which The amount of component (a), the amount of component (b) is 1-50 parts by weight, preferably 5-25 parts by weight, and the amount of component (c) is 1-50 parts by weight, preferably 5-25 Parts by weight. Preferably, 5-25, the polyfluoreneimide has the structure of the following formula (1) or (2) ... Γ 〇 0

In the formulae (1) and (2), 11 is an integer of 10 to 600, Ari is a tetravalent organic group, A ** 2 is a monovalent to tetravalent organic group, An is a divalent aromatic group, and ri is a 10H group or a COOH group. .

A better ’Ar3 is

A better ‘Aq is 7 200538875

Preferably, Ar2 is

0¾ I -H6C3- ^ i-〇-i CH3 LCH3

Or engine ~ Xr < P > where m is an integer from 1-20, and Xi is 8 200538875 -ο—, one s—, one c (cf3) 2—, c (ch3) 2 — -CH,-, -S 〇2-, ^ hco-?

Where m is an integer from 1 to 20 and Z is H or methyl. Preferably, the phenolic hydroxyl group compound of the component (b) has the following structure:

Wherein R3 to R9 are H, -OH group, CVCm alkyl group or C4-C20 cycloaliphatic group, and z is an integer of 0-5. More preferably, the component (1 ^) is: 9 200538875

BisP-B OH, H 丨

Bis-F

or

Preferably, the photosensitizer of the component (C) has the following structure:

CH3

CFs

CF3

OD

10 200538875 where D is hydrogen, ο ο

n2 and D are not all hydrogen.

S〇2

Che Fujia's weight of the ingredients (a), (b) and (c) is 5-50% of the total weight of the composition.

Preferably, the organic solvent is N-fluorenyl · 2-sigmadol, γ-butyrolactone, or ethyl lactate. [Embodiment] The synthesis step of polyimide is to dissolve an appropriate amount of diamine monomer and dianhydride monomer in a suitable organic solvent such as N-methyl-2-pyrrolidone (NMP), and Stir vigorously at 0 ~ 4 ° C

4 hours' and then add an endcapped agent, such as a primary amine with a carbonyl or carboxyl group, and stir for 4 hours. Add Xylene and heat to 180 ° C to reflux. After about 3 hours, add After cooling, a polyimide (PI) solution having a pentyl group or a Wei group at the end of the main chain is obtained. The light sensitive polyimide (PSPI) solution of the present invention is prepared by taking an appropriate amount of a PI solution, adding a phenolic hydroxyl group crosslinking agent and a photosensitizer, and NMP, γ-butyrolactone (γ -Butyrolactone (GBL), or ethyl lactate and other solvents will dilute the PSPI solution to the required concentration for use. The lithography process using the PSPI solution of the present invention is as follows: (i) PSPI 11 200538875 solution is applied on a suitable substrate by spin coating or other methods; pre-baking; (iii) exposure; (iv) development; and ( v) Hard roast, the resulting pattern is polyimide. In the above step (i), the positive PSPI solution is coated on an appropriate substrate, and the substrate is, for example, a silicon substrate, glass, or ITO glass. The above coating methods include spin coating, roller coating, screen coating, curtain coating, and dipping. The plating method (dip coating) and the spray coating method are not limited to the above-mentioned coating methods. In a preferred embodiment of the present invention, the thin film formed by coating is prebake for several minutes at 70 to 120 ° t to evaporate the solvent therein. Then, the coated substrate is exposed to actinic rays under a photomask. The actinic rays are, for example, X-ray rays, electron beam rays, ultraviolet rays, visible rays, or other light sources that can be used as actinic rays. Wait. After the exposure, the coated substrate is washed with an alkaline aqueous developer *, ..., and then to expose the exposed portion of the film to obtain a photoresist pattern. The above-mentioned alkaline aqueous developer contains an alkaline aqueous solution, such as an inorganic base (potassium hydroxide, sodium hydroxide), a primary amine (ethylamine), a secondary amine (diethylamine), and a tertiary amine (triethylamine). ), Or an aqueous solution of a quaternary ammonium salt (teti * amethylammoniumhydroxide), of which an aqueous solution containing tetramethylammonium hydroxide is preferred. Development can be accomplished by soaking, spraying, or coating or using other known development methods. The developed photoresist pattern is then washed with deionized water, and is between 180 and 400. A post-cure was performed at 0 ° to drive the remaining solvent to dry, and a polyimide pattern with a tapered cross section was obtained. 12 200538875 The film thickness retention rate is calculated as follows: Film thickness retention rate (%) = [(film thickness after hard baking) / (film thickness after pre-baking)] The present invention can be borrowed from the following examples It is further understood that these examples are for illustration only and are not intended to limit the scope of the invention. drug

Ethylene glycol bis (anhydro-trimellitate) (TMEG),

Bis (3,4-dicarboxyphenyl) ether dianhydride (ODPA), 13 200538875

3,3-dihydroxybenzidine (HAB), Hexofluoro-252-bis (3-amino- 4-hydroxyphenyl) (BisAPAF)) »3,5-diaminobenzoic acid (3,5-DABA)), 4,4'-oxydiphenylamine (4,4'-Oxydianiline (ODA)),

2,2-bis (4- (4-aminophenoxy) phenyl) propane (2,2-bis (4- (4-aminophenoxyl) phenyl) propane (BAPP)),

2,2-bis (4- (3-aminophenoxy) phenyl) fluorene (2,2-bis (4- (3-_aminophenoxyl) phenyl) sulfone 14 200538875 (m-BAPS))

2,3,4-Diacetyl-benzyl-1,2-digassin r5-Luteinate (2,3,4-trihydroxy-benzophenone-1, 2-diazonaphthoquinone-5-sulfonate ( PIC-3), available from KOYO chemicals Inc.) Example 1 A 1000 ml three-necked round bottom flask equipped with a mechanical stirrer and nitrogen inlet was charged with 18.3 g (50 mmol) of Bis-APAF, 12.3 GAPP (30 millimoles) of BAPP, 2_02 grams (10 millimoles) of ODA, 20.5 grams (50 millimoles) of Ding "Ugly 0 and 15.5 grams (50 millimoles) of 0-8, and add 400 g of NMP solvent. After stirring the solution at 0 ° C for 4 hours, add 2.18 g (20 mmol) of 3-aminophenol as the capping agent, and Stir for 4 hours, then add 80 grams of dibenzobenzene, then raise the temperature to 1 80 ° C and stir for 3 hours. After cooling, a viscous PI solution PI-1 can be obtained. Through infrared (IR) spectrum analysis, the PI synthesized in this example is at 1781 cm · 1 and 1377 cm · 1 have the characteristic absorption of fluorene imine C = 〇 and CN, 15 200538875 as shown in Figure 1. Take 50 grams of PI-1 solution, add 1.875 grams of PIC-3, 1.875 grams of DML_PC and mix Even A photosensitive polyimide coating composition PSPI-1 can be obtained, and then the PSPI-1 coating composition is coated on the ITO glass by a spin coating method through a hot plate (Hot-Plate) at 110 ° C. After 2 minutes of prebake, a thin film with a thickness of about 1.1 μm can be obtained. Then, the coated ITO glass is subjected to an unfiltered mercury arc lamp (the measured wavelength thereof). (Between 250 ~ 400nm), energy of about 100 mJ / cm2 is administered, and exposure is performed. A 2.38% (wt%) aqueous solution of tetramethylammonium hydroxide (TMAH) developer is used for development, and the development time is 35 seconds. Then in a hot-air circulation oven at 230 ° C, after 30 minutes of post-cure, you can get a PI graph of financial performance. As shown in Figures 2a and 2b, the above graph has a 10 μm The line width and spacing, the film thickness is about 2.0 μιη. Compared with the thickness of the original soft baked after this hard baking, this figure has a film residual rate of 91% (scanning electron microscopy) (Scanning electron microscope, SEM) The polyimide pattern has a tapered-angle at the cross section. Example 2 A 1000-ml three-necked round bottom flask equipped with a mechanical stirrer and a nitrogen inlet was used. 7.6 grams (50 3,5_DABA, m-BAPS of 12.975 grams (30 millimoles), 0DA of 1.54 grams (7.5 millimoles), TMEG of 32.8 grams (80 millimoles), and 6.2 grams (20 mmol) of 0 DPA, and 400 g of NMP solvent was added. The above solution was stirred at 16 200538875 0 ° C for 4 hours, and then 2.73 g (25 millimoles) of the capping agent 3_T fenaminobenzyl alcohol was added, and stirred at room temperature for another 4 hours, and added to 8 After the temperature was raised to 180 ° C and stirred for 3 hours, a viscous ρ solution PI-2 was obtained after cooling. Take 50 grams of PI · 2 solution, add i 875 grams pic_3, 丨 〇 grams

After mixing, a photosensitive polyimide coating composition pspi_2 can be obtained. Then, a spin coating method was used to coat the PSPI_2 coating composition on ιτο glass, and a soft baking procedure was performed on the heating plate under iurc for 2 minutes to obtain a thin film having a thickness of about 1.1 μm. The coated ITO glass was then exposed to an energy of about 120 mJ / cm2 using an unfiltered mercury arc lamp (whose measured wavelength was between 250 and 400 nm). It was developed with 2 (wt.%) TMAH aqueous developer, and the development time was 35 seconds. Then in a hot-air circulation oven at 23 ° t: under a hard-bake process for 'minutes', a heat-resistant PI pattern can be obtained. The above-mentioned pattern has a line width and pitch of Βμιη, and the film thickness is 0.95um. And this ρι Figure in; Compared with the original soft roasted thickness after hard roasting, it has a film thickness retention of 86%

It is also observed from the SEM image that the polyfluorene imine pattern has a tapered cross section. Example 3 A 1000 ml three-necked round bottom flask equipped with a mechanical stirrer and a nitrogen inlet was charged with 10.8 g (50 mmol) of 莫 ΑΒ, 12 975 g (30 mmol) of m-BAPS. , 2.02 grams (10 millimoles) of ODA and 0.00 grams (100 millimoles) of TMEG, and 400 grams of NMp solvent was added. After the above solution was stirred at 0 ° C for 4 hours, 218 g (2017 200538875 mmol) of 3-aminobenzyl end capping agent was added, and stirred at room temperature for another 4 hours, and 80 g of After xylene, warm up to 18 ° C and stir for 3 hours. After cooling, a thick PI solution PI-3 can be obtained. Take 50 grams of PI-3 solution and add 1.

G of PIC-3 and 2.25 g of BIPC-PC were mixed uniformly to obtain a photosensitive polyimide coating composition PSPI-3. A spin coating method was used to coat the pspi-3 coating composition on the ITO glass, and a soft baking process of 2 minutes was performed on a hot plate under uOt: to obtain a thin film having a thickness of about 100 Å. The coated ITO glass was then exposed to an energy of about 120 mJ / cm2 using an unfiltered mercury arc lamp (whose measured wavelength was between 250 and 400 nm). The developer was developed with a 2.38% (wt.%) Aqueous solution of TMAH, and the development time was 40 seconds. Then in a hot-air circulation oven 23 (rc), a heat-resistant ρι pattern can be obtained after a 30-minute hard roasting process. The above PI pattern has a line width and spacing of 15 arrays, and the film thickness is 105 °. Compared with the original pre-bake thickness, the Pl pattern has a film thickness retention rate (Film) of 87.5% of the original thickness.

® Φ ^ ^ ® t ^ (tapered-angle at the cross section) 〇 Comparative Example 1 A 2,000 ml two-necked round bottom flask equipped with a mechanical stirrer and nitrogen inlet was charged with 36 6 years old A See Bis_APAF (100 mol), qdpa (31.0 g (100 mmol)) DPA 'and add 400 g of NMP solvent. The solution was stirred at 0 ° C for 4 hours, then 80 g of xylene was added, and the temperature was raised to 180 ° C and stirred for 3 hours. After 4 cold steps, a thick PI solution PI-Cl was obtained. Take gram of PK1 solution, add 1.8 grams of PIC-3 and mix well. 18 200538875 shows a photosensitive polyimide coating composition pSPI_ci. The spin-coating method was used to coat the PSPI-C1 coating composition on IT0 glass, and after a soft-bake process at 110 ° C for 2 minutes on a hot plate, a thin film with a thickness of about 0.5 μm was obtained. . The coated IT0 glass was then exposed to energy of about 120 mJ / cm2 using an unfiltered water 5 lamp (the measured wavelength was between 250 and 400 nm). It was developed with a 2.38% (wt%) tmah aqueous developer, and the pattern could not be obtained even after the development time exceeded 3 minutes. In this comparative example, the capping agent was not used in the synthesis of P] [. Comparative Example 2 Take 50 grams of the PI-1 solution prepared in Example 1, add 875 grams of pIC_3, and mix uniformly to obtain a photosensitive polyimide coating composition pSpi_C2. The lithography process of Example 1 was repeated, in which the film thickness after soft baking was 10 μm, and the development time when developed with TMAH aqueous solution was 60 seconds, to obtain a line width and pitch of 20 μm, and the film thickness was 0-8 μm (film (Thickness retention 80%). The SEM image observed that the PI pattern had a rectangular cross section and did not have a tapered shape. In this comparative example, the caramelized polyimide coating composition pjgpi_C2 is not used. (B) A compound having a phenolic hydroxyl group. Comparative Example 3 Synthesis of HAB-0DPA-butanol and polyamic acid ester A three-necked round-bottomed flask of 25 milliliters equipped with a mechanical stirrer and nitrogen inlet was charged with 15.50 grams (50 mol) ODpA, 7.40 gram 19 200538875 g (100 millimolar) of n-butanol (anol) and IIS gram of NMp solvent. The mixture was heated to 8 ° C and stirred at this temperature for 4 hours to carry out the esterification reaction. The solution was cooled to below 40 ° C, and then 6.63 grams (200 millimoles) of ° specific bite ( Pyridine) and 19.50 grams (100 millimoles) of benzylphosphonic acid monochloride {^ henylphosphonic dichlorjde). After stirring at room temperature for 2 hours, the activation reaction of the ⑽η group was performed. The above solution was cooled to 0 ~ 4. (: Then, 10.8 g (50 mmol) of ηαβ was added and stirred at 0 to 4 C for 1 hour, and then stirred at room temperature for 8 hours. (Polymerization polymerization reaction was performed) ). The solution formed was precipitated with 1000 ml of methanol, and filtered to collect the polymer therein, and the collected polymer was washed three times with deionized water. Finally, the obtained polyamide was obtained. The ester was placed in a vacuum environment at 80 ° C for 24 hours to dry. Take 5 grams of polyamidate, 1.25 grams of piC-3 and 187s grams of NMp solvent to prepare a photosensitive polyamidate. Coating composition pspi_C3. The lithography process of Example 1 was repeated, in which the film thickness after soft baking was 10 μm, and the development time with tmah water & valley liquid development was 60 seconds to obtain a line width of 20 and a gap between The thickness of the pattern is 0 · 9 um. Compared with the original soft-baking thickness, the pattern has a film residual rate of 70%, and the pattern is rectangular. Comparative Example 3 is a general photosensitive polyurethane coating composition, but it is only emphasized that it needs to be hard-baked at 350 ° C and Its film thickness retention rate is relatively low. [Schematic description] Figure 1 is the infrared light 20 200538875 spectrum of the polyimide synthesized in Example 1 of the present invention, in which the analyzed polyimide reacts at 180 ° c. Two types of reaction at 3 hours and 3 hours at 190 C. Figures 2a and 2b are top and cross-sectional scans of a pattern of a positive photosensitized polyfluorene imide coating composition prepared using Example 丨 of the present invention, respectively. Electron microscope (SEM) photograph.

twenty one

Claims (1)

200538875 Scope of patent application ·· 1 · Positive type photosensitive polyimide coating composition, comprising an organic compound and (a) polyimide dissolved in the organic solvent, the main chain terminal (B) a compound having a phenol group or a slow group, (b) a compound having a phenol group, and (C) a brewed azide xanthate salt as a photosensitizer, wherein for each hundred parts by weight of the component ⑷, a knife (b) is formed The content is from 1 to 50 parts by weight, and the amount of component 为 is from 1 to 50% by weight. 2. The composition according to item 1 of the patent application scope has the structure of the following formula (1) or (2): Imine Rl-Ar3-N factory 〇Λ 'VU-Ar2 ~ N-, cy II Rl-Ar3-N' η Άγ2— ^ 3—R! (1) In the formulae (1) and (2), 11 is an integer of 10.600, A [gamma] is a tetravalent organic group, 2 Ar2 is a divalent to tetravalent organic group, Ar3 is a divalent aromatic group, and Ri is a mono- or COOH group. 3. The composition according to item 2 of the scope of application for patents 丨 丨 ~ is 22 200538875 4. If the composition of the scope of patent application item 2 or 3, wherein 8 ^ 5. The composition according to item 2 or 3 of the patent application scope, wherein Ar2 is 23 200538875 chl! c «3 i-C3H ^ 0¾ < -h6c3-b-ch3 L〇% ◎ or where m is an integer of 1-20, and Xi is —0—, —S —, — C (CF3) 2 — · —C (CH3) 2 — -S〇2- Λ- -or— (CH2) mli—0—qi— (CH2) nzz where m is an integer from 1 to 20 and Z is H or fluorenyl 6. As for the composition in the second item of the patent application, where One hundred parts by weight of the component (a), and the amount of the component (b) is 5-25 parts by weight. 24 200538875 7. The composition according to item 1 of the scope of patent application, wherein the component (b) having a phenolic compound has the following structure: R8 R9 wherein R3 to 119 are fluorene, -OH group, CVC20 alkyl group or C4-C20 cycloaliphatic group, and z is an integer of 0-5. 8. The composition according to item 7 of the scope of patent application, wherein the component (b) having a phenolic compound is: 25 200538875 OH, H 丨 BisP-B OH Bis-F or 9. The composition according to item 1 of the scope of patent application, wherein the photosensitizer of the component (0 has the following structure: 26 200538875 ch3 cf3 D Where D is hydrogen, 10. The composition according to item 1 of the patent application range, wherein the weight of ingredients (a), (b) and (c) and 5-50% of the total weight of the composition. 11. The composition according to item 1 of the patent application scope, wherein the organic solvent is N-methyl-2-pyrrolidone, butyrolactone, or ethyl lactate. 27