Negative photoresist composition and application

Abstract

The invention discloses a negative photoresist composition and application thereof. The negative photoresist composition is prepared from the following components in parts by mass: 35 to 52 parts of a resin matrix, 0.4 to 0.5 part of a photoinitiator, 0.01 to 0.05 part of an active sensitizing aid, 0.01 to 0.02 part of a free radical initiator, 2 to 7 parts of an active diluent, 0.02 to 0.05 part of an acid diffusion inhibitor and 8 to 13 parts of a solvent. The negative photoresist provided by the invention keeps good contractibility, film-forming property and adhesive force, meanwhile, the pinhole density of the prepared photoresist is greatly reduced, and the yield is improved.

Description

Technical Field

[0001] The present invention belongs to the field of photoresists, and particularly relates to a negative photoresist composition and its application. Background Art

[0002] In the manufacturing processes of liquid crystal panels and semiconductors, photolithography technology is one of the key technologies and the main method for transferring the designed layout onto a silicon wafer. It is an important economic influencing factor in the entire product manufacturing, and the photolithography cost accounts for 35% of the total manufacturing cost. The essence of photolithography is to copy the temporary circuit structure onto the silicon wafer to be etched and ion-implanted later. These structures are first made in the form of a pattern only on a quartz template called a mask. Ultraviolet light passes through the mask and transfers the pattern to the photosensitive film on the surface of the silicon wafer.

[0003] The general photolithography process is as follows: First, the photoresist is spin-coated on the cleaned and dehydrated silicon wafer. After soft baking and hardening, alignment and exposure are carried out, and then baking and development are performed. The pattern of the mask is transferred onto the photoresist. Then, etching is carried out based on the pattern of the photoresist, and the pattern of the photoresist is further transferred onto the semiconductor material under the photoresist. Subsequently, ion implantation is carried out to dope specific regions. In the high-dose ion implantation process, due to the high implantation dose and long implantation time, heat will accumulate on the surface of the silicon wafer, which will cause the edge of the photoresist to warp and peel off, that is, the separation occurs between the photoresist and the silicon wafer. Therefore, before the ion implantation process, the adhesion between the photoresist and the silicon wafer surface must be enhanced to expand the process tolerance.

[0004] According to different photoresist processes, photoresists are divided into two major categories: positive photoresists and negative photoresists. A positive photoresist refers to the part of the photoresist film that is exposed to the pattern during photolithography and is finally washed away by the developer, leaving the unexposed part to form a pattern. On the contrary, for a negative photoresist, during photolithography, the unexposed part of the photoresist film is washed away during development, and the exposed part forms a pattern. In the market, the price cost of negative photoresists is low, while that of positive photoresists is relatively high, so negative photoresists are widely used. However, in practical applications, the resolution of negative photoresists is lower than that of positive photoresists due to the swelling and shrinking of the pattern after development; at the same time, the film-forming property of negative photoresists will also deteriorate; in addition, the adhesion between the components of negative photoresists and the substrate surface also has a great impact on the performance of photoresists. Poor adhesion will cause local lines of the photoresist pattern to fall off, resulting in poor performance or display defects of final products such as liquid crystal displays; in addition, negative photoresists are more likely to have pinholes and there are more pinholes. The holes inside the photoresist after coating will greatly reduce the yield rate.

[0005] The prior art discloses a negative photoresist and its preparation method and application, which improve the film-forming property, thermal stability and etching resistance of the photoresist, and at the same time make the photoresist easy to strip, but it does not solve the problem that the negative photoresist is prone to pinholes and has a high pinhole density.

[0006] The prior art discloses a negative photoresist containing a modified resin, and the modified resin is formed by the double-bond addition of an acrylic resin matrix with a double-bond structure and a monomer containing a catechol group, which improves the adhesion between the negative photoresist formed and the silicon substrate, but it does not solve the problem that the negative photoresist is prone to pinholes and has a high pinhole density.

[0007] In summary, the negative photoresist in the prior art has improved the pinhole density, but the current negative photoresist film still has pinhole phenomena, and the holes existing inside after coating greatly reduce the yield. Therefore, how to provide a negative photoresist composition that maintains good shrinkage, film-forming property and adhesion, and at the same time greatly reduces the pinhole density of the photoresist is an urgent problem to be solved by the present invention. Summary of the Invention

[0008] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a negative photoresist composition, which can maintain good shrinkage, film-forming property and adhesion after film formation, and at the same time greatly reduce the pinhole density, improving the yield.

[0009] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0010] A negative photoresist composition, in parts by mass, includes:

[0011] 35-52 parts of a resin matrix;

[0012] 0.4-0.5 parts of a photoinitiator;

[0013] 0.01-0.05 parts of an active sensitizing adjuvant;

[0014] 0.01-0.02 parts of a radical initiator;

[0015] 2-7 parts of an active diluent;

[0016] 0.02-0.05 parts of an acid diffusion inhibitor;

[0017] 8-13 parts of a solvent.

[0018] In some embodiments of the present invention, the resin matrix includes dicyclopentadienyloxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin and 3-methacryloyldopamine mixed in a mass ratio of (17-24):(4-8):(9-15):(1-6).

[0019] In some embodiments of the present invention, the resin matrix comprises dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin, and 3-methacryloyldopamine mixed in a mass ratio of (18-24):(5-8):(10-15):(2-5).

[0020] In some embodiments of the present invention, the resin matrix comprises dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin, and 3-methacryloyldopamine mixed in a mass ratio of (17-24):(4-8):(9-15):(5-6).

[0021] In some embodiments of the present invention, the epoxy acrylate resin is any one or a combination of two of bisphenol A epoxy acrylate resin and phenolic epoxy acrylate resin.

[0022] In some embodiments of the present invention, the photoinitiator is one or a combination of two of diazonium salts, diaryliodonium salts, triarylsulfonium salts, alkylsulfonium salts, iron arene salts, sulfonyloxy ketones, and triarylsilyl ethers.

[0023] In some embodiments of the present invention, the solvent is any one or a combination of two or more of ethyl acetate, tetrahydrofuran, dioxane, trioxane, n-butyl acetate, tert-butyl acetate, ethylene glycol monoacetate, ethylene glycol methyl ether acetate, N-methylpyrrole, propylene glycol, ethylene glycol alkyl ether acetate, propylene glycol monomethyl ether acetate, ethoxyethyl acetate, dimethoxyacetaldehyde, propylene glycol methyl ether acetate, ethyl 3-ethoxypropionate, propylene glycol methyl ether, and ethylene glycol ethyl ether acetate.

[0024] In some embodiments of the present invention, the solvent is propylene glycol methyl ether acetate.

[0025] In some embodiments of the present invention, the radical initiator is benzoyl peroxide.

[0026] In some embodiments of the present invention, the active diluent is triethylene glycol divinyl ether.

[0027] In some embodiments of the present invention, the active sensitizing aid is 9-phenylacridine.

[0028] In some embodiments of the present invention, the acid diffusion inhibitor is any one or a combination of two or more of methyltriamine, ethyltriamine, dimethylamine, diethylamine, trimethylamine, triethylamine, tributylamine, methanoltriamine, ethanoltriamine, dimethanolamine, diethanolamine, trimethanolamine, triethanolamine, and tributanolamine.

[0029] In some embodiments of the present invention, the acid diffusion inhibitor is triethanolamine.

[0030] In some embodiments of the present invention, the method for preparing the negative photoresist composition of the present invention includes the following steps: After dissolving the resin matrix, photoinitiator, active sensitization aid, radical initiator, active diluent, and acid diffusion inhibitor in a solvent, stir and dissolve them, and then filter the dissolved solution with a filter having a pore size of 0.5 μm or less. The filtered solution is the negative photoresist.

[0031] On the other hand, the present invention also provides an application of the negative photoresist composition.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] 1. The prior art requires that the pinhole density of the film formed by the negative photoresist composition is not greater than 0.89 per cm 2 , and the negative photoresist composition provided by the present invention greatly reduces the pinhole density of the photoresist by using a combination of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin, and 3-methacryloyldopamine.

[0034] 2. The negative photoresist composition provided by the present invention controls the mass ratio of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin, and 3-methacryloyldopamine within the range of (18-24):(5-8):(10-15):(2-5), and the obtained photoresist film has no pinholes. When the mass ratio of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin, and 3-methacryloyldopamine is not within the range, pinholes still exist in the film.

[0035] 3. The negative photoresist composition provided by the present invention has good shrinkage, film-forming property, and adhesion. At the same time, the pinhole density of the prepared photoresist is greatly reduced, improving the yield. Specific Embodiments

[0036] The following will illustrate the present invention in conjunction with specific embodiments. It should be noted that the following examples are examples of the present invention and are only used to illustrate the present invention, rather than to limit the present invention. Without departing from the gist or scope of the present invention, other combinations and various improvements within the concept of the present invention can be made.

[0037] The sources of raw materials and product names used in the examples in the specific embodiments are as follows:

[0038] Bisphenol A epoxy acrylate resin, model: B-100M, purchased from Guangdong Boxin New Materials Technology Co., Ltd.;

[0039] Allylphenol type benzoxazine resin, model: BZ-1702, purchased from Jinan Shengquan Group Co., Ltd.;

[0040] Allylamine type benzoxazine resin, model: BZ-170, purchased from Jinan Shengquan Group Co., Ltd.;

[0041] Dicyclopentadienyloxyethyl acrylate, CAS No.: 65983-31-5, purchased from Shandong Ruibolong Chemical Technology Co., Ltd.;

[0042] Triethylene glycol divinyl ether, model: DVE-3, purchased from Guangzhou Lihou Trading Co., Ltd.

[0043] Diaryliodonium salt, model: JZG-2103, purchased from Nanjing Jiazhong Chemical Technology Co., Ltd.

[0044] 9-phenylacridine, model: WKQ-0024867, selected from Vicky Biotechnology;

[0045] Benzoyl peroxide, CAS No.: 94-36-0, purchased from Shanghai Fuzhe Chemical Co., Ltd.;

[0046] Propylene glycol methyl ether acetate, item number: 108, purchased from Senfida Chemical;

[0047] 3-Methacryloyl dopamine, CAS No.: 471915-89-6, purchased from Aikangyanxuan;

[0048] Triethanolamine, model: T6012, purchased from Macklin.

[0049] The negative photoresist composition prepared in Examples 1-16 comprises the following steps:

[0050] According to the components and content of each component required for the negative photoresist in Table 1, the resin matrix, photoinitiator, active sensitizer, free radical initiator, active diluent and acid diffusion inhibitor are dissolved in a solvent; the mixture is stirred and dissolved, and the dissolved solution is filtered using a filter with a pore size of 0.5 μm. The filtered solution is a negative photoresist.

[0051] The components used in Examples 1-16 and the weight parts of each component are shown in Table 1-3:

[0052] Table 1

[0053]

[0054] Table 2

[0055]

[0056]

[0057] Table 3

[0058]

[0059]

[0060] The test methods for Examples 1-16 are as follows:

[0061] 1. The shrinkage rate is tested according to JB / T6542-1993.

[0062] 2. Adhesion measurement: Apply the photoresist on the substrate, and after drying to form a film, test the adhesion with reference to the detection method of GB / T1720-1979; among them, the adhesion is divided into levels 1-7, and level 1 indicates that the film is intact and has the best performance.

[0063] 3. Test for the pinhole situation of the film layer: Take 100 mL of the photoresist solution in Examples 1-16, spin-coat it on a 1-inch silicon wafer that has been ultrasonically treated with acetone + alcohol, then bake for 5 min, observe the surface of the film layer through a scanning electron microscope, count, and then calculate the pinhole density (pieces / cm 2 ).

[0064] 4. Evaluation method for film-forming property: First, use a spin coater to apply the photoresist composition on the silicon wafer to form a photoresist layer, pre-bake at 90 °C for 60 s, and weigh it with an analytical balance under light-shielded conditions to obtain W1; Immerse the silicon wafer in a 2.38 wt% tetramethylammonium hydroxide solution at 23 °C for 60 s, wash with water and dry, and weigh to obtain W2; then wash the remaining photosensitive resin, wash with water and dry, and weigh to obtain W3. The formula for the film retention rate is: (W2 - W3) / (W1 - W3)×100%. If the film retention rate of the photoresist is above 95%, it indicates good film-forming property.

[0065] The test results of the above Examples 1-16 are shown in Tables 4-6:

[0066] Table 4

[0067]

[0068]

[0069] Table 5

[0070]

[0071] Table 6

[0072]

[0073] As can be seen from Examples 1-16, the combined use of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin and 3-methacryloyldopamine greatly reduces the pinhole density of the photoresist, and the pinhole density is not higher than 0.47 per cm. 2 .

[0074] As can be seen from Examples 1-4, when the mass ratio of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin and 3-methacryloyldopamine is in the range of (18-24):(5-8):(10-15):(2-5), the negative photoresist maintains good shrinkage, film-forming property and adhesion, and the prepared photoresist film has no pinholes; as can be seen from Example 1 and Examples 5-16, when the mass ratio of dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin and 3-methacryloyldopamine is not in the range, although the negative photoresist maintains good shrinkage, film-forming property and adhesion, pinholes still exist in the film.

[0075] In summary, the negative photoresist provided by the present invention has good shrinkage, film-forming property and adhesion, and at the same time, the pinhole density of the prepared photoresist is greatly reduced, improving the yield.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A negative photoresist composition, characterized in that, Comprising, by mass parts: 35 - 52 parts of resin matrix; 0.4 - 0.5 parts of photoinitiator; 0.01 - 0.05 parts of active sensitizing assistant; 0.01 - 0.02 parts of free radical initiator; 2 - 7 parts of active diluent; 0.02 - 0.05 parts of acid diffusion inhibitor; 8 - 13 parts of solvent.

2. The negative photoresist composition according to claim 1, wherein The resin matrix includes dicyclopentadiene oxyethyl acrylate, allyl benzoxazine resin, epoxy acrylate resin and 3 - methacryloyldopamine mixed in a mass ratio of (17 - 24):(4 - 8):(9 - 15):(1 - 6).

3. The negative photoresist composition according to claim 2, wherein The allyl benzoxazine resin is any one or a combination of two of allyl phenol - type benzoxazine resin and allyl amine - type benzoxazine resin.

4. The negative photoresist composition according to claim 2, characterized in that, The epoxy acrylate resin is any one or a combination of two of bisphenol A epoxy acrylate resin and phenolic epoxy acrylate resin.

5. The negative photoresist composition according to claim 1, characterized in that, The photoinitiator is one or a combination of two of diazonium salt, diaryliodonium salt, triarylsulfonium salt, alkylsulfonium salt, iron arene salt, sulfonyloxy ketone and triarylsilyl ether.

6. The negative photoresist composition according to claim 1, characterized in that, The solvent is any one or a combination of two or more of ethyl acetate, tetrahydrofuran, dioxane, trioxane, n - butyl acetate, tert - butyl acetate, ethylene glycol monoacetate, ethylene glycol methyl ether acetate, N - methylpyrrole, propylene glycol, ethylene glycol alkyl ether acetate, propylene glycol monomethyl ether acetate, ethoxyethyl acetate, dimethoxyacetaldehyde, propylene glycol methyl ether acetate, ethyl 3 - ethoxypropionate, propylene glycol methyl ether and ethylene glycol ethyl ether acetate.

7. The negative photoresist composition according to claim 1, characterized in that, The free radical initiator is benzoyl peroxide; The acid diffusion inhibitor is any one or a combination of two or more of methyltriamine, ethyltriamine, dimethylamine, diethylamine, trimethylamine, triethylamine, tributylamine, methanoltriamine, ethanoltriamine, dimethanolamine, diethanolamine, trimethanolamine, triethanolamine, tributanolamine.

8. The negative photoresist composition according to claim 1, wherein The active diluent is triethylene glycol divinyl ether.

9. The negative photoresist composition according to claim 1, characterized in that, The active sensitizing assistant is 9 - phenylacridine.

10. Application of the negative photoresist composition according to any one of claims 1 - 9.

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