CN118276409A - Polyimide negative photoresist composition and its use - Google Patents

Abstract

The present invention provides a polyimide negative photoresist composition, comprising: 30 to 90wt% of a polyimide precursor; 0.1 to 10wt% of a photoinitiator; 1 to 10wt% of an ester monomer; 0.1 to 3wt% of a cyclizing catalyst represented by the following formula (I); the balance of solvent; Wherein R ₁ is defined as in the specification. In addition, the invention also provides application of the polyimide negative photoresist composition.

Description

Polyimide negative photoresist composition and its use

Technical Field

The present invention relates to a polyimide negative photoresist composition and its application, in particular to a polyimide negative photoresist composition with a specific cyclization catalyst added thereto and its application.

Background technique

Polyimide (PI) has excellent thermal and mechanical properties and has been widely used in semiconductor packaging processes. Currently commercial polyimide products are usually supplied in the form of photosensitive resin compositions containing polyimide precursors. In the packaging process, the photosensitive resin composition is coated on a substrate, and then the polyimide precursor molecules are cross-linked and patterned through exposure and development; then, a hardening step is performed through heat treatment, also known as hard baking, to cause the polyimide precursor to undergo a cyclization reaction and form a polyimide hardened film.

In current photosensitive resin compositions, the cyclization reaction temperature of the polyimide precursor needs to be 350°C to complete the reaction. However, in semiconductor packaging technology, high-temperature hard baking of the polyimide precursor to form a polyimide hardened film may cause the polyimide hardened film to shrink and accumulate stress, resulting in warpage of the substrate or degassing and cracking of other materials on the substrate.

In view of this, there is an urgent need to develop a novel photosensitive resin composition containing a polyimide precursor to solve the above-mentioned problems.

Summary of the invention

The main purpose of the present invention is to provide a polyimide negative photoresist composition, which can carry out a cyclization reaction of a polyimide precursor at a low temperature.

The polyimide negative photoresist composition of the present invention comprises: 30wt% to 90wt% of a polyimide precursor; 0.1wt% to 10wt% of a photoinitiator; 1wt% to 10wt% of an ester monomer; 0.1wt% to 3wt% of a cyclization catalyst represented by the following formula (I); and the remainder of a solvent;

Wherein, _R1 is _C4-7 alkyl, -O- _COOR2 or _-COOR3 , _R2 is _C1-6 alkyl, and _R3 is _C1-6 alkyl or H.

In the composition of the present invention, the added cyclization catalyst represented by formula (I) has a structure of naphthaleneimide-trifluoromethanesulfonic acid, and the benzene ring in the structure has a functional group such as an alkyl group, a carbonate group, an ester group or a carbonyl group, and has properties such as high heat stability (high thermal decomposition temperature), good solvent solubility, high photodecomposability, high transparency, good amine resistance (low decomposition rate in the presence of amines), etc. In addition, by adding the cyclization catalyst represented by formula (I), the polyimide negative photoresist composition can be cyclized at low temperature to solve the problems of substrate warping or degassing or cracking of the material on the substrate caused by the previous high-temperature cyclization reaction. Furthermore, the polyimide hardened film formed by using the polyimide negative photoresist composition of the present invention has good mechanical properties and can be applied to semiconductor devices of different forms of packaging technologies. For example, it can be applied to the insulating layer required for the redistribution layer (RDL) in fan-in (Fan-In) and fan-out (Fan-Out) type packaging, and can also be applied to the surface protection layer and back protection layer of the silicon interposer in the silicon via technology.

In the composition of the present invention, the added amount of the polyimide precursor may be 30wt% to 90wt%, for example, 30wt% to 85wt%, 30wt% to 80wt%, 30wt% to 75wt%, 30wt% to 70wt%, 30wt% to 65wt%, 30wt% to 60wt%, 30wt% to 55wt%, 30wt% to 50wt%, 30wt% to 45wt% or 30wt% to 40wt%.

In the composition of the present invention, the polyimide precursor may be represented by the following formula (II):

Among them, R is n is an integer. In addition, the molecular weight (Mw) of the polyimide precursor may be between 14,000 and 20,000. Furthermore, the polymer dispersity index (PDI, weight average molecular weight/number average molecular weight) of the polyimide precursor may be between 1.5 and 2.4.

In the composition of the present invention, the added amount of the photoinitiator may be 0.1wt% to 10wt%, for example, 0.1wt% to 9wt%, 0.1wt% to 8wt%, 0.1wt% to 7wt%, 0.1wt% to 6wt%, 0.1wt% to 5wt%, 0.1wt% to 4wt%, 0.5wt% to 4wt%, 0.5wt% to 3wt% or 1wt% to 3wt%.

In the composition of the present invention, the type of the photoinitiator is not particularly limited. In one embodiment, the photoinitiator can be represented by the following formula (III):

In the composition of the present invention, the amount of the ester monomer added can be 1wt% to 10wt%. By adding an appropriate amount of the ester monomer, the negative-type effect of the composition can be better. In the composition of the present invention, the type of the ester monomer is not particularly limited. In one embodiment, the ester monomer can be shown in the following formula (IV):

In the composition of the present invention, the amount of the cyclization catalyst added may be 0.1 wt% to 3 wt%, for example, 0.5 wt% to 3 wt%, 0.5 wt% to 2.5 wt%, 0.5 wt% to 2 wt%, or 1 wt% to 2 wt%. When the amount of the cyclization catalyst added exceeds 3 wt%, poor solubility may occur.

In the composition of the present invention, _R1 of formula (I) may be _C4-7 alkyl, -O- _COOR2 or _-COOR3 , wherein _R2 is _C1-6 alkyl, _R3 is _C1-6 alkyl or H. In one embodiment, _R1 of formula (I) may be _C4-7 alkyl or -O- _COOR2 , wherein _R2 is _C1-6 alkyl. In one embodiment, _R1 of formula (I) may be _C4-7 alkyl, for example, _C4-6 alkyl, C4-5 alkyl or _C4 alkyl. In one embodiment, _R1 of formula (I) may be -O- _COOR2 , wherein _R2 is _C1-6 alkyl, for _example , _C2-6 alkyl, _C3-6 alkyl, _C3-5 alkyl, _C4-5 alkyl or _C4 alkyl.

In one embodiment, the cyclization catalyst may be represented by the following formula (I-1):

Wherein, R ₁ may be a C _4-7 alkyl group, for example, a C _4-6 alkyl group, a C _4-5 alkyl group or a C ₄ alkyl group.

In one embodiment, the cyclization catalyst may be represented by the following formula (I-2):

Wherein, R ₁ may be -O-COOR ₂ , and R ₂ may be a C _1-6 alkyl group, for example, a C _2-6 alkyl group, a C _3-6 alkyl group, a C _3-5 alkyl group, a C _4-5 alkyl group or a C ₄ alkyl group.

In one embodiment, the cyclization catalyst may be a compound represented by the following formula (I-3) or (I-4):

The aforementioned compounds can be used alone or in combination.

The solvent included in the composition of the present invention may be an organic solvent. There is no particular limitation on the type of solvent, as long as the components of the composition (e.g., polyimide precursor) can be completely dissolved therein. Examples of solvents include, but are not limited to, N-methylpyrrolidone (NMP), ethyl lactate (EL), N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, hexamethylphosphoric triamide, cyclopentanone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, ethyl lactate, methyl lactate, butyl lactate, tetrahydrofuran or γ-butyrolactone, and the aforementioned solvents may be used alone or in combination of two or more. In one embodiment, the solvent may include N-methylpyrrolidone.

The composition of the present invention may optionally further include 0.1 wt % to 10 wt % of an adhesion promoter to enhance the negative-type effect of the composition. The adhesion promoter may be a compound represented by the following formula (V):

In the present invention, the term "alkyl" refers to a straight chain or branched hydrocarbon group, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

In addition, unless otherwise specified, the alkyl group in the compound includes substituted or unsubstituted groups. Possible substituents include, but are not limited to, alkyl, cycloalkyl, halogen, alkoxy, alkenyl, heterocycloalkyl, aryl, heteroaryl, amine, carboxyl or hydroxyl, but the alkyl group will not be substituted by an alkyl group.

The present invention also provides the use of the aforementioned polyimide negative photoresist composition for use in a low temperature curing process, wherein the low temperature refers to a temperature below 250° C. In one embodiment, the temperature of the low temperature curing process may be between 150° C. and 250° C., for example, between 150° C. and 200° C. In one embodiment, the temperature of the low temperature curing process may be about 170° C.

The present invention also provides a method for forming a patterned hardened film using the aforementioned polyimide negative photoresist composition, comprising: coating the aforementioned polyimide negative photoresist composition on a substrate to form a film layer; performing exposure and development to pattern the film layer; and heat-treating the patterned film layer to form a patterned polyimide hardened film. The temperature of the heat treatment may be below 250°C, for example, between 150°C and 250°C or between 150°C and 200°C.

The present invention also provides a semiconductor device, which includes: a polyimide hardened film formed by using the above-mentioned polyimide negative photoresist composition.

BRIEF DESCRIPTION OF THE DRAWINGS

none

Detailed ways

The following is an explanation of the implementation of the present disclosure by specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways for different viewpoints and applications without departing from the spirit of the present invention.

As used in the specification and the appended claims, the singular forms "a," "an," and "the" include one or plural individuals unless the context dictates otherwise.

Unless otherwise specified herein, the term "or" used in the specification and the appended patent claims generally includes the meaning of "and/or".

In addition, in this article, the term "about" generally means within 20%, or within 10%, or within 5%, or within 3%, or within 2%, or within 1%, or within 0.5% of a given value or range. The number given here is an approximate number, that is, in the absence of a specific description of "about", the meaning of "about" can still be implied. In addition, the term "range is from a first value to a second value" or "range is between a first value and a second value" means that the range includes the first value, the second value and other values between them.

The present disclosure will be described in more detail by way of examples, but these examples are not intended to limit the scope of the present disclosure. Unless otherwise specified, in the following preparation examples, examples and comparative examples, temperatures are in degrees Celsius, and parts and percentages are by weight. The relationship between parts by weight and parts by volume is like the relationship between kilograms and liters.

Preparation of polyimide precursor

151 g of ODPA (4,4'-diphenyl ether dianhydride) was added to a 2L split pill-bottom reaction bottle, and then 427 g of NMP (1-methyl-2-pyrrolidinone) was added and stirred evenly. Then, 131 g of HEMA (2-hydroxyethyl methacrylate) and 0.8 g of MEHQ (4-methoxyphenol) were added, and then 98 g of pyridine was added. The temperature was raised to 60°C and the reaction was stirred for 18 hours.

The reaction solution was cooled in an ice bath, and 165 g of DCC (N, N'-dicyclohexylcarbodiimide) was added to 237 g of NMP to dissolve. Then, 80 g of ODA (4, 4-oxydianiline) was added, and after the addition of ODA, the mixture was reacted at room temperature for 2 hours.

30 g of ethanol was added to react for 1 hour, and then 400 g of NMP was added and filtered. The filtrate was immersed in ethanol to precipitate a precipitate, which was filtered to obtain a precipitate, and then the precipitate was washed with a large amount of deionized water, and the precipitate was dried in a vacuum oven. The dried precipitate was the polyimide precursor.

Here, the obtained polyimide precursor is as shown in formula (II), has a molecular weight (Mw) of about 14,000 to 20,000, and a polymer dispersibility index (PDI) of about 1.5 to 2.4.

Polyimide negative photoresist composition

According to the composition formula shown in Table 1 below, the polyimide negative photoresist compositions of Examples 1 to 5 and Comparative Examples 1 to 3 were prepared, wherein the preparation method is roughly as follows.

The polyimide precursor, photoinitiator, cyclization catalyst, adhesion promoter, ester monomer and solvent were prepared into the polyimide negative photoresist compositions of Examples 1 to 5 and Comparative Examples 1 to 3 according to the composition formula shown in Table 1 below. The polyimide precursor used is the polyimide precursor prepared above; the photoinitiator used is represented by formula (III) (CAS No: 2097490-25-8); the cyclization catalyst used in Example 1 is represented by formula (I-3) (CAS No: 1610827-31-0), the cyclization catalyst used in Examples 2 to 5 and Comparative Example 1 is represented by formula (I-4) (CAS No: 2668228-65-5), and the cyclization catalyst used in Comparative Example 3 is represented by the following formula (I'); the adhesion promoter used is represented by formula (V) (CAS No: 38280-61-4); the ester monomer used is represented by formula (IV) (CAS No: 109-17-1); and the solvent used is NMP.

Test Case

First, prepare a substrate, which is a 6-inch silicon wafer, and clean the surface of the substrate with deionized water and acetone. Then, the polyimide negative photoresist composition prepared in Examples 1 to 5 and Comparative Examples 1 to 3 is evenly coated on the substrate by spin coating. Then, soft bake at 100°C for 4 minutes, and then expose the polyimide negative photoresist composition coated on the surface of the substrate with an exposure machine. Then, spray cyclopentanone at 23°C for development for 15 seconds. Perform at 150°C for 30 minutes; then, hard bake at 170°C for 2 hours. Finally, the substrate and the cured film are cooled to room temperature to obtain the desired sample, and the sample thickness is 8μm.

The obtained samples were subjected to mechanical property measurement using a tensile testing machine, and the measurement results are shown in Table 1 below. In terms of elongation, "◎" indicates an elongation of 60% or more, "○" indicates an elongation between 40% and 60%, and "X" indicates an elongation of less than 40%. Regarding tensile strength, "◎" indicates a tensile strength of 130 MPa or more, "○" indicates a tensile strength between 120 MPa and 130 MPa, and "X" indicates a tensile strength of less than 120 MPa.

Table 1

As shown in the results of Table 1 above, compared to Comparative Example 2 in which no cyclization catalyst is added, the polyimide negative photoresist compositions of Examples 1 to 5 in which Formula (I-3) and Formula (I-4) are added, the resulting cured films have good mechanical properties. Compared to Comparative Example 3 in which the cyclization catalyst of Formula (I') is added (without a functional group at the benzene ring), the polyimide negative photoresist compositions of Examples 1 to 5 can improve the solubility of the components in the composition due to the addition of a cyclization catalyst having a functional group at the benzene ring. In addition, the polyimide negative photoresist compositions of Examples 1 to 5 in which an appropriate amount of cyclization catalyst is added have good solubility, but the polyimide negative photoresist composition of Comparative Example 1 in which the cyclization catalyst content is 5wt% has a problem of poor solubility.

In summary, the polyimide negative photoresist composition of the present invention can make the polyimide negative photoresist composition have good solubility by adding an appropriate amount of cyclization catalyst having a functional group at the benzene ring, and the obtained polyimide has good mechanical properties (elongation of more than 40%, tensile strength of more than 130MPa). In addition, the polyimide negative photoresist composition of the present invention can make the polyimide precursor undergo cyclization reaction at low temperature by adding an appropriate amount of cyclization catalyst having a functional group at the benzene ring, so as to avoid the problems of substrate warping or degassing or cracking of the material on the substrate caused by high-temperature cyclization reaction.

The above embodiments are merely examples for the convenience of explanation. The scope of rights claimed by the present disclosure shall be based on the scope of the patent application, and is not limited to the above embodiments.

Claims (10)

1. A polyimide negative photoresist composition, comprising:

30 to 90wt% of a polyimide precursor;

0.1 to 10wt% of a photoinitiator;

1 to 10wt% of an ester monomer;

0.1 to 3wt% of a cyclizing catalyst represented by the following formula (I); and

The balance solvent;

Wherein R ₁ is C _4-7 alkyl, -O-COOR ₂ or-COOR ₃,R₂ is C _1-6 alkyl, and R ₃ is C _1-6 alkyl or H.

2. The polyimide negative photoresist composition according to claim 1, wherein the polyimide precursor is represented by the following formula (II):

wherein R is N is an integer.

3. The polyimide negative photoresist composition of claim 1, wherein the polyimide precursor has a molecular weight of between 14,000 and 20,000.

4. The polyimide negative photoresist composition according to claim 1, wherein the photoinitiator is represented by the following formula (III):

5. The polyimide negative photoresist composition according to claim 1, wherein the ester monomer is represented by the following formula (IV):

6. the polyimide negative photoresist composition according to claim 1, wherein the formula (I) is represented by the following formula (I-1):

Wherein R ₁ is C _4-7 alkyl.

7. The polyimide negative photoresist composition according to claim 1, wherein the formula (I) is represented by the following formula (I-2):

Wherein R ₁ is-O-COOR ₂ and R ₂ is C _1-6 alkyl.

8. The polyimide negative photoresist composition according to claim 1, wherein the cyclizing catalyst is represented by the following formula (I-3) or (I-4):

9. The polyimide negative photoresist composition according to claim 1, further comprising: 0.1 to 10wt% of an adhesion promoter.

10. Use of the polyimide negative photoresist composition according to any one of claims 1 to 9 in a low temperature curing process, wherein the low temperature is 250 ℃ or lower.