BISPHENOL A DERIVATIVE, PREPARATION METHOD THEREFOR AND USE THEREOF IN PHOTOLITHOGRAPHY

Abstract

A bisphenol A derivative, a preparation method therefor and use thereof in photolithography are provided. The compounds feature simple molecular structure, controllable molecular weight, simple synthesis steps, and relatively high thermal stability. They do not precipitate during baking and are not easily denatured during photolithography. The negative molecular glass photoresists have good film-forming property, high thermal stability, less proneness to properties varying during storage, and low viscosity, no need for additional solvents for dilution during use. After exposure at UV wavelength of 365 nm, the exposed pattern shows high contrast, excellent resolution and good sensitivity, and can present the lithographic line width of 3.5 μm.

Claims

1. A compound of formula (I): ##STR00011## wherein R is H, ##STR00012## provided that R is not all H; the * in the above groups is a linking site; n is 1, 2, 3, 4 or 5.

2. The compound according to claim 1, wherein the compound of formula (I) is selected from a compound of formula (IA) and a compound of formula (IB) below, ##STR00013##

3. The compound according to claim 1, wherein R is ##STR00014##

4. The compound according to claim 1, wherein the compound of formula (I) is selected from the following compounds: ##STR00015##

5. A method for synthesizing the compound of formula (I) according to claim 1, comprising: reacting a compound of formula (II) with R.sub.1-L to give the compound of formula (I); ##STR00016## wherein R and n are as defined in claim 1, R.sub.1 is ##STR00017## and L is selected from a leaving group such as halogen or p-toluenesulfonate.

6. The method according to claim 5, wherein R.sub.1-L is selected from epibromhydrin, allyl bromide, α-bromo-γ-butyrolactone and 3-methyl-3-(tosyloxymethyl)oxetane.

7. Use of the compound of formula (I) according to claim 1 as a multi-functional cross-linking agent or in a photoresist composition.

8. A negative photoresist composition, comprising the compound of formula (I) according to claim 1.

9. The negative photoresist composition according to claim 8, further comprising a photoacid generator, a photoresist solvent and other additives; preferably, the negative photoresist composition comprises 2.5-10% (mass ratio relative to that of the compound of formula (I)) of photoacid generator; preferably, the photoacid generator comprises ionic or non-ionic acid generators, such as triphenylsulfonium triflate, triphenylsulfonium nonaflate, bis(4-tert-butylphenyl)iodonium p-toluenesulfonate and N-hydroxynaphthalimide triflate; preferably, the photoresist solvent comprises propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, ethylene glycol monomethyl ether and cyclohexanone.

10. Use of the negative photoresist composition according to claim 8 in electron-beam lithography, ultraviolet lithography, deep ultraviolet lithography and extreme ultraviolet lithography.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG. 1 is a thermogravimetric analysis diagram of the epoxy compound (I-a) in Example 1; and

[0035] FIG. 2 is SEM diagrams of the epoxy compound (I-a) in Example 1 exposed at 365 nm (UV), wherein (a) is the exposure dose and line width; (b) is a dense line graph; (c) is a rectangular dot matrix graph; (d) is a circular dot matrix graph; (e) is an L-shaped graph; and (f) is a concentric circular graph.

DETAILED DESCRIPTION

[0036] The technical solutions of the present invention will be further illustrated in detail with reference to the following specific examples. It should be understood that the following examples are merely exemplary illustration and explanation of the present invention, and should not be construed as limiting the protection scope of the present invention. All techniques implemented based on the aforementioned contents of the present invention are encompassed within the protection scope of the present invention.

[0037] Unless otherwise specified, the raw materials and reagents used in the following examples are all commercially available products or can be prepared by known methods.

[0038] BPA-6OH is prepared in the following examples with reference to the method in Patent No. ZL201210156675.6.

EXAMPLE 1. SYNTHESIS OF EPOXY COMPOUND (I-a)

[0039] 5.98 g (10 mmol) of BPA-60H and 21.50 g (66 mmol) of Cs2CO3 were added into a 150 mL three-necked flask sequentially, followed by the addition of 7 mL (70 mmol) of epibromhydrin and 15 mL of N-methylpyrrolidone, and the mixture was stirred at 50-55° C. under reflux for 18-24 h. After the reaction was completed, the reaction mixture was diluted with chloroform, washed three times with deionized water, dried with anhydrous Na.sub.2CO.sub.3 under stirring, then subjected to solvent exchange with methanol, and dried at 60° C. under vacuum to give the epoxy compound (I-a) completely protected with epoxy groups (5.05 g, 54% yield) in the form of a pale yellow solid. MALDI-TOF (C.sub.57H.sub.56O.sub.12), m/z: 932.376. The TGA diagram is shown in FIG. 1, showing that the thermal stability is high, and only 5% of the mass is lost at around 370° C.

[0040] The structure of the raw material BPA-60H is as follows:

##STR00009##

the structure of the product epoxy compound (I-a) is as follows:

##STR00010##

EXAMPLE 2. PREPARATION OF NEGATIVE PHOTORESIST COMPOSITION COMPRISING EPOXY COMPOUND (I-a)

[0041] 300 mg of the epoxy compound (I-a) completely protected with epoxy groups prepared in Example 1, 22.5 mg of N-hydroxynaphthalimide triflate as a photoacid generator and 10 mL of propylene glycol monomethyl ether acetate (PGMEA) as a photoresist solvent were mixed to give a photoresist solution, and the solution was filtered three times with a 0.20 μm polytetrafluoroethylene film after half an hour of ultrasonic treatment to give a negative photoresist composition.

EXAMPLE 3. PHOTOLITHOGRAPHY PERFORMANCE OF NEGATIVE PHOTORESIST COMPOSITION COMPRISING EPOXY COMPOUND (I-a)

[0042] 30 mg/mL negative photoresist composition was prepared according to Example 2, an untreated blank silicon wafer was selected, the spin-coating parameter was set to 3000 rpm/90 s, the pre-baking parameter was set to 80° C./120 s, and the film thickness was about 50 nm as measured by an ellipsometer. The UV lithography (365 nm) was performed using a front-aligned UV lithography machine from ABM-USA, Inc, with an exposure time set to 30 s, a post-baking parameter of 90° C./120 s, a development parameter of methyl isobutyl ketone/30 s, and a rinsing parameter of isopropanol/30 s. SEM diagrams are acquired using Hitachi 8020 scanning electron microscope after exposure, and specific photolithography results are shown in FIG. 2. As can be seen from FIG. 2, the resulting photoresist composition has high resolution, excellent sensitivity and high contrast.

[0043] The examples of the present invention have been described above. However, the present invention is not limited to the above examples. Any modification, equivalent, improvement and the like made without departing from the spirit and principle of the present invention shall fall within the protection scope of the present invention.