Method for forming photoresist

Abstract

The present disclosure provides a photoresist. The photoresist is formed by a crosslinking polymerization reaction between a reactive group-containing biimidazole molecule and a nitrogen-containing compound.

Claims

1. A method for forming a photoresist comprising: a step (S11) of dissolving an alkynyl group containing a biimidazole molecule with a diazidohexane at a molar ratio of 1:1.1 into dimethylformamide (DMF) that is contained in a 100 ml single-necked flask to obtain a uniformly mixed solution; a step (S12) of placing the single-necked flask into liquid nitrogen, wherein an oil pump is connected to the single-necked flask to vacuum the single-necked flask and to reduce pressure inside the single-necked in order to remove bubbles from the mixed solution, and bubbling nitrogen into the mixed solution; a step (S13) of repeating the step (S12) three times; a step (S14) of adding a molar ratio of 10% of copper(I) bromide into the mixed solution (in liquid nitrogen, 77K), and lifting and displacing the single-necked flask to a location under room temperature, and quickly stirring the mixed solution; and a step (S15) of leaving the mixed solution to rest for a few minutes, the mixed solution becoming viscous and completely cured due to a crosslinking polymerization reaction.

2. The method for forming the photoresist according to claim 1, wherein the photoresist, after being developed, is cured at a baking temperature lower than 90° C.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a schematic diagram showing a chemical mechanism involved in a method for forming a photoresist according to EMBODIMENT ONE of the present disclosure.

(2) FIG. 2 is a schematic diagram showing a chemical mechanism involved in a method for forming a photoresist according to EMBODIMENT TWO of the present disclosure.

(3) FIG. 3 is a schematic diagram showing a chemical mechanism involved in a method for forming a photoresist according to EMBODIMENT THREE of the present disclosure.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

(4) The following embodiments refer to the accompanying drawings for exemplifying specific implementable embodiments of the present disclosure. Moreover, directional terms described by the present disclosure, such as upper, lower, front, back, left, right, inner, outer, side, etc., are only directions by referring to the accompanying drawings, and thus the used directional terms are used to describe and understand the present disclosure, but the present disclosure is not limited thereto. In the drawings, the same reference symbol represents the same or similar components.

(5) The present disclosure provides a photoresist formed by a crosslinking polymerization reaction between a reactive group-containing biimidazole molecule and a nitrogen-containing compound. In addition, the present disclosure provides a method for forming a photoresist, comprising steps of having a reactive group-containing biimidazole molecule and a nitrogen-containing compound to crosslink with each other.

Embodiment One

(6) A click reaction has high conversion and does not have side reactions, and can be performed at low temperatures, and thus plays an essential role in organic synthesis and polymeric synthesis. A click reaction between alkynyl group-containing compound and azide compound is shown as below.

(7) ##STR00002##

(8) Therefore, inventors of the present disclosure devise a method for forming a positive photoresist by having tetraalkynyl group-substituted hexaarylbiimidazole and diazidohexane to crosslink with each other. FIG. 1 shows a chemical mechanism of such crosslinking polymerization reaction. Specifically, the method for forming this positive photoresist includes:

(9) a step (S11) of dissolving the alkynyl group-containing biimidazole molecule and diazidohexane at a molar ratio of 1:1.1 into dimethylformamide (DMF) that is contained in a 100 ml single-necked flask to obtain a uniformly mixed solution;

(10) a step (S12) of placing the single-necked flask into liquid nitrogen, wherein an oil pump is connected to the single-necked flask to vacuum the single-necked flask and to reduce pressure inside the single-necked in order to remove bubbles from the mixed solution, and bubbling nitrogen into the mixed solution;

(11) a step (S13) of repeating the step (S12) three times;

(12) a step (S14) of adding copper(I) bromide into the mixed solution (in liquid nitrogen, 77K), according to a molar ratio of 10%, and lifting and displacing the single-necked flask to a location under room temperature, and quickly stirring the mixed solution;

(13) a step (S15) of leaving the mixed solution to rest for a few minutes, the mixed solution becoming viscous and completely cured due to a crosslinking polymerization reaction.

Embodiment Two

(14) An ethylene oxide compound can react with an amine compound at room temperature to form an ethanolamine compound. A chemical reaction between an ethylene oxide compound and an amine compound is shown as below.

(15) ##STR00003##

(16) Therefore, inventors of the present disclosure devise a method for forming a positive photoresist by having tetraethylene oxide group-substituted hexaarylbiimidazole and hexamethylenediamine to crosslink with each other. FIG. 2 shows chemical mechanism of such a crosslinking polymerization reaction. Specifically, the method for forming this positive photoresist includes:

(17) a step (S21) of dissolving an ethylene oxide group-containing biimidazole molecule and hexamethylenediamine at a molar ratio of 1:1.2 into dimethylformamide (DMF) that is contained in a 100 ml single-necked flask to obtain a uniformly mixed solution;

(18) a step (S22) of placing the single-necked flask into liquid nitrogen, wherein an oil pump is connected to the single-necked flask to vacuum the single-necked flask and to reduce pressure inside the single-necked in order to remove bubbles from the mixed solution, and bubbling nitrogen into the mixed solution;

(19) a step (S23) of repeating the step (S22) three times;

(20) a step (S24) of lifting the single-necked flask, and heating the single-necked flask in an oil bath of 50° C. for 6 hours; and

(21) a step (S25) of taking out the single-necked flask, the mixed solution solidifying due to a crosslinking polymerization reaction.

Embodiment Three

(22) An alcohol compound can react with an isocyanate compound to form polyurethane. A chemical reaction between an alcohol compound and an isocyanate compound is shown as below.

(23) ##STR00004##

(24) Therefore, inventors of the present disclosure devise a method for forming a positive photoresist by having tetrahydroxy-substituted hexaarylbiimidazole and 1,6-hexamethylene diisocyanate to crosslink with each other. FIG. 3 shows chemical mechanism of such a crosslinking polymerization reaction. Specifically, the method for forming this positive photoresist includes:

(25) a step (S31) of dissolving a hydroxy-containing biimidazole molecule and 1,6-hexamethylene diisocyanate at a molar ratio of 1:1.2 into dimethylformamide (DMF) that is contained in a 100 ml single-necked flask to obtain a uniformly mixed solution;

(26) a step (S32) of placing the single-necked flask into liquid nitrogen, wherein an oil pump is connected to the single-necked flask to vacuum the single-necked flask and to reduce pressure inside the single-necked in order to remove bubbles from the mixed solution, and bubbling nitrogen into the mixed solution;

(27) a step (S33) of repeating the step (S32) three times;

(28) a step (S34) of lifting the single-necked flask, and heating the single-necked flask in an oil bath of 50° C. for 6 hours; and

(29) a step (S35) of taking out the single-necked flask, the mixed solution solidifying due to a crosslinking polymerization reaction.

(30) Compared with prior art, the present disclosure is characterized by use of crosslinking hexaarylbiimidazole-based polymer as a positive photoresist. This causes a result that a pattern where photolithography is performed has high resolution. In addition, it is known that light emitting layer of OLED display panels cannot bear high baking temperatures (where baking temperature should be generally controlled to be lower than 100° C., and high baking temperatures might cause failure of light-emitting units or shorten lifespan of light emitting units in OLED display panels) in manufacturing OLED displays. However, in the present disclosure, using crosslinking hexaarylbiimidazole-based polymer as positive photoresist in polarizer-less (POL-less) for OLED display panels can make the positive photoresist, after being developed, be cured at a baking temperature lower than 90° C., thus preventing light emitting layers of OLED display panels from being damaged by high temperatures. (Conventional photoresist used in manufacturing OLED displays is baked at 220° C.) Therefore, in the present disclosure, yield rates and lifespan of OLED display panels are improved.

(31) While the present disclosure has been described with the aforementioned preferred embodiments, it is preferable that the above embodiments should not be construed as limiting of the present disclosure. Anyone having ordinary skill in the art can make a variety of modifications and variations without departing from the spirit and scope of the present disclosure as defined by the following claims.