Chemically amplified positive photosensitive resin composition

Abstract

The present invention provides a chemically amplified positive photosensitive composition comprising: an acid generator (A) that generates an acid by irradiation with active light or radiation; a resin (B) in which the solubility of a base increases due to the action of an acid; an acid diffusion inhibitor (C); and a sulfur-containing compound (D) containing a sulfur atom capable of coordinating with the metal layer of the substrate, the sulfur-containing compound (D) containing a nitrogen-containing heterocyclic compound having a mercapto group or a tautomer thereof, and an organic solvent (E). The chemically amplified positive photosensitive composition of the present invention can improve the problem of degumming during electroplating on a metal substrate, and form a resist pattern having excellent adhesion to the metal substrate.

Description

Technical Field

[0001] This invention belongs to the field of chemistry and relates to a chemically amplified positive photosensitive composition. Background Technology

[0002] Currently, photofabrication has become the mainstream of precision micro-machining technology. Photofabrication refers to the general term for technologies that involve coating a photoresist composition onto the surface of a workpiece to form a photoresist layer, using photolithography to pattern the photoresist layer, and then using the patterned photoresist layer (photoresist pattern) as a mask for chemical etching, electrolytic etching, or electroforming (primarily electroplating), to manufacture various precision parts such as semiconductor packages.

[0003] Photoresist compositions are used in the photoelectric processing described above. Among such photoresist compositions, chemically amplified photoresist compositions containing an acid-generating agent are known. Chemically amplified photoresist compositions refer to compositions in which acid is generated from the acid-generating agent by irradiation (exposure), and the diffusion of the acid is promoted by heat treatment, thereby causing an acid-catalyzed reaction relative to the matrix resin or the like in the composition, thus changing its alkali solubility. Such chemically amplified positive photoresist compositions are used, for example, to form plated shapes such as bumps or metal pillars through a plating process.

[0004] Under relatively harsh electroplating conditions, a chemically amplified positive-type photoresist composition is electroplated on a metal substrate in a copper plating bath at 60°C and a current of 0.02A for 1 hour to form a photoresist pattern for use as a mold for plating. If a thicker photoresist film is used as the mold, the plating temperature may need to be set higher, or the plating process may need to be prolonged. During this process, low adhesion and poor resistance to the plating bath can cause the adhesive strip on the metal substrate to detach, resulting in the collapse of the plated shape. Therefore, the photoresist film is required to have high resistance to the plating bath. Summary of the Invention

[0005] In view of the above-mentioned technical problems in the prior art, the present invention provides a chemically amplified positive photosensitive composition, which solves the technical problem that the chemically amplified positive photosensitive composition in the prior art is prone to delamination during electroplating on a metal substrate.

[0006] This invention provides a chemically amplified positive photosensitive resin composition comprising an acid-generating agent (A), a resin (B), an acid diffusion inhibitor (C), a sulfur-containing compound (D), and an organic solvent (E): The acid-producing agent (A) is selected from any of the following structures:

[0007]

[0008]

[0009] The resin (B) is a combination of B-1 and B-3 or a combination of B-2 and B-3, and the structures of B-1, B-2, and B-3 are shown below:

[0010] B-1 (n:m:s=60:20:20), where n, m, and s are integers greater than 0, n is 30 to 70, m is 10 to 30, and s is 10 to 30;

[0011] B-2 (x:y:z=73:15:12), where x, y, and z are integers greater than 0, x is 55 to 85, y is 8 to 25, and z is 8 to 25;

[0012] B-3, where m / p = 40 / 60, m represents m-cresol, p represents p-cresol, and u is an integer greater than 0; b1) The weight-average molecular weight of the PHS resins (B-1 and B-2) is 17 to 27 k; b2) The molecular weight distribution coefficient (PDI) of the PHS resins (B-1 and B-2) is <2.0; b3) The weight-average molecular weight of the phenolic resin (B-3) is 2.5 to 9 kJ, and the molecular weight distribution coefficient (PDI) is <2.0. The acid diffusion inhibitor (C) is selected from any one or a combination of two or more of the following: triethanolamine, tert-butyl 4-hydroxypiperidine-1-carboxylate, tri-n-pentylamine, dimethylpyridine, tris(3,6-dioxaheptyl)amine, triisopropanolamine, triethylenediamine, or diphenylamine. The sulfur-containing compound (D) is selected from any of the following structures:

[0013] The organic solvent (E) is selected from any one or a combination of two or more of propylene glycol methyl ether acetate, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, acetone or N-methylpyrrolidone.

[0014] Furthermore, in the combination of B-1 and B-3, the mass ratio of B-1 to B-3 is 40wt%:60wt%, and in the combination of B-2 and B-3, the mass ratio of B-2 to B-3 is 50wt%:50wt%.

[0015] The weights of the components are as follows: Contains acid-producing agent (A): 0.1~0.3 Resin (B): 25~35 Acid diffusion inhibitor (C): 0.005~0.015 Sulfur-containing compounds (D): 0.02~0.06 Organic solvent (E): 60~80.

[0016] Furthermore, it also contains leveling agents; The weights of each component are as follows: Contains acid-producing agent (A): 0.1~0.3 Resin (B): 25~35 Acid diffusion inhibitor (C): 0.005~0.015 Sulfur-containing compounds (D): 0.02~0.06 Organic solvent (E): 60~80; Leveling agent: 0.1~0.3.

[0017] This invention provides a chemically amplified positive photosensitive composition that forms a pattern for a mold used in a process of creating plated shapes on a substrate having a metal layer on its surface. This chemically amplified positive photosensitive composition improves the problem of delamination during electroplating on metal substrates and forms a resist pattern with excellent adhesion to the metal substrate. In the formulation of this invention, an acid-generating agent (A) generates acid upon irradiation with active light or radiation; a resin (B) has increased solubility for alkalis due to the action of acid; an acid diffusion inhibitor (C); and a sulfur-containing compound (D) containing sulfur atoms capable of coordinating with the metal layer of the substrate, wherein the sulfur-containing compound (D) comprises a nitrogen-containing heterocyclic compound having a thiol group or its tautomer.

[0018] The present invention provides a chemically amplified positive photosensitive composition that can form a rectangular cross-sectional shape for the non-resistant portion and has high resistance to plating solutions, even when forming a patterned resist film with a relatively thick film thickness.

[0019] The chemically magnified positive photosensitive composition provided by this invention combines photosensitive PHS (polyhydroxystyrene) resins (B-1, B-2) and phenolic resin (B-3), which can effectively improve the adhesion of the chemically magnified positive photosensitive composition to metal substrates and the resistance to plating solutions during the electroplating process, thereby improving the problem of delamination of the chemically magnified positive photosensitive composition on metal substrates.

[0020] Compared with existing technologies, the technical effects of this invention are positive and significant. This invention provides a chemically amplified positive photosensitive composition, which improves the problem of delamination during electroplating on metal substrates and forms a resist pattern with excellent adhesion to the metal substrate. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of a cross-section on a copper substrate of the chemically amplified positive photosensitive composition prepared in Comparative Example 1 of the present invention.

[0022] Figure 2 This is a schematic diagram of a cross-section on a copper substrate of the chemically amplified positive-type photosensitive composition prepared in Example 1 of the present invention.

[0023] Figure 3 This is a schematic diagram of a cross-section on a copper substrate of the chemically amplified positive photosensitive composition prepared in Example 2 of the present invention.

[0024] Figure 4 This is a schematic diagram of electroplating in Embodiment 2 of the present invention. Detailed Implementation

[0025] The present invention provides a chemically amplified positive photosensitive composition, which is used to form a coating mold on a substrate using photolithography.

[0026] The chemically amplified positive photosensitive composition of the present invention comprises: an acid-generating agent (A) that generates acid upon irradiation by active light or radiation; a resin (B) whose solubility in alkali is increased by the action of the acid; an acid diffusion inhibitor (C); a sulfur-containing compound (D) comprising sulfur atoms capable of coordinating with a metal layer of a substrate, wherein the sulfur-containing compound (D) comprises a nitrogen-containing heterocyclic compound having a thiol group or a tautomer thereof; and an organic solvent (E).

[0027] A method for manufacturing a patterned resist film, comprising the following steps as preferred methods: Lamination process: A chemically amplified positive photosensitive composition layer composed of a chemically amplified positive photosensitive composition is laminated on the metal surface of a substrate having a metal surface. Exposure process: Selectively (depending on the location) irradiate the chemically magnified positive photosensitive composition layer with active light or radiation and expose it; Development process: The exposed chemically amplified positive photosensitive composition layer is developed.

[0028] The substrate used for laminating the chemically amplified positive photosensitive composition layer is not particularly limited, and conventionally known substrates can be used, such as substrates for electronic components or substrates on which a predetermined wiring pattern is formed. A substrate with a metallic surface is used as the substrate, and copper, gold, or aluminum are preferred as the type of metal constituting the metallic surface; copper is more preferred.

[0029] For example, a chemically amplified positive photosensitive composition layer is laminated on a substrate in the following manner: a liquid chemically amplified positive photosensitive composition is coated on the substrate, and the solvent is removed by heating, thereby forming a chemically amplified positive photosensitive composition layer of desired thickness. The thickness of the chemically amplified positive photosensitive composition layer is not particularly limited as long as the resist pattern used for molding can be formed with the desired film thickness. The film thickness of the chemically amplified positive photosensitive composition layer is not particularly limited, but is preferably 0.5 μm or more, more preferably 0.5 μm or more and 300 μm or less, particularly preferably 1 μm or more and 150 μm or less, and most preferably 3 μm or more and 100 μm or less.

[0030] The non-resist portion (the part removed by the developer) of the molded substrate formed by the above method is plated with an embedded metal conductor, thereby forming a plated shape such as a bump or metal pillar as a connection terminal. Furthermore, the plating process is not particularly limited, and various conventionally known methods can be used. As the plating solution, solder plating solution, copper plating solution, gold plating solution, and nickel plating solution are particularly preferred. The remaining mold is finally removed using a stripping solution or the like using conventional methods.

[0031] According to the above method, it is possible to suppress the problem of descaling and the generation of development residue during photolithography of the chemically amplified positive photosensitive composition on a metal substrate, and to form a resist pattern as a mold. By using such a chemically amplified positive photosensitive composition that improves adhesion to the metal substrate and resistance to plating solutions during electroplating, it is possible to manufacture plated shapes with excellent adhesion to the substrate.

[0032] A copper film substrate with a thickness of 200 nm, obtained by sputtering, was prepared on the surface of a Si substrate. The chemically amplified positive photosensitive composition of the examples and comparative examples was coated on the copper layer of the substrate and dried on a hot plate at 130°C for 120 seconds to form a chemically amplified positive photosensitive composition layer with a thickness of 6 μm (coating of the chemically amplified positive photosensitive composition).

[0033] Next, for the photosensitive layer, an I-12 exposure machine (Conventional: NA 0.57 Sigma 0.34) with a mask and projection exposure apparatus for a line and space pattern of 2.0 μm line width and 2.0 μm spacing was used to expose the substrate to an exposure level sufficient to form a pattern of 2.0 μm line width and 2.0 μm spacing with a resist film thickness of 6.00 μm. After exposure, the substrate was placed on a heated plate and subjected to post-exposure heating (PEB) at 90°C for 200 seconds. Then, the following operation was repeated a total of 3 times: a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) (developer) was added dropwise to the exposed photosensitive layer, and the substrate was left to stand at 23°C for 60 seconds (water pit development). Then, the surface of the resist film patterned by development was rinsed with running water for 60 seconds and then spin-dried to obtain a patterned resist film as a mold for plating.

[0034] For the substrate with a plating mold obtained in each embodiment and comparative example, copper plating is performed under the following conditions to form a plating shape.

[0035] Plating solution: Copper sulfate plating solution; Time: 60 minutes; Current value: 0.02A; The height of the formed plated shape from the substrate surface is measured by microscopic observation.

[0036] The technical solution of this application will be clearly and completely described below with reference to the embodiments of this application. Unless otherwise specified, the reagents and raw materials used can be purchased commercially. Experimental methods in the following embodiments that do not specify specific conditions are performed according to conventional methods and conditions, or according to the product instructions.

[0037] This embodiment is implemented based on the technical solution of the present invention, and provides detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiment.

[0038] A chemically amplified positive photosensitive composition comprising the following components in parts by weight (total 100 parts):

[0039] The photoresist preparation process is as follows: Add each component according to the formula, mix and stir evenly, and then filter through two nylon membranes of 0.22um and 0.1um to complete the preparation of the required photoresist. Example

[0040] A chemically amplified positive photosensitive composition comprising the following components in parts by weight (total 100 parts):

[0041] The photoresist preparation process is as follows: Add each component according to the formula, mix and stir evenly, and then filter through two nylon membranes of 0.22um and 0.1um to complete the preparation of the required photoresist. Example

[0042] A chemically amplified positive photosensitive composition comprising the following components in parts by weight (total 100 parts):

[0043] The photoresist preparation process is as follows: Add each component according to the formula, mix and stir evenly, and then filter through two nylon membranes of 0.22um and 0.1um to complete the preparation of the required photoresist.

[0044] Depend on Figures 1-3 It can be seen that the chemically amplified positive photosensitive composition prepared in Comparative Example 1 collapsed after photolithography on the copper substrate. During the electroplating process, the adhesion and resistance to plating solution of the photosensitive composition were even worse, thus affecting the formation of the plated shape.

[0045] The chemically amplified positive-type photosensitive compositions prepared in Examples 1 and 2 exhibited relatively steep adhesive strips after photolithography on a copper substrate, without collapse, and could form the desired plated shapes after electroplating.

[0046] The results indicate that the chemically amplified positive photosensitive composition provided by the present invention combines photosensitive PHS (polyhydroxystyrene) resins (B-1, B-2) and phenolic resin (B-3), which can effectively improve the adhesion of the chemically amplified positive photosensitive composition to metal substrates and the resistance to plating solutions during the electroplating process, thereby improving the problem of delamination of the chemically amplified positive photosensitive composition on metal substrates.

[0047] The above is a detailed description of the embodiments, which is intended to enable those skilled in the art to correctly understand and use the present invention. Any improvements or modifications to technical solutions obtained by those skilled in the art based on the present invention and on the existing technology, without innovative effort but only through analysis, analogy, or limited enumeration, should be within the scope of protection defined by the claims.

Claims

1. A chemically amplified positive photosensitive resin composition, characterized in that: It contains an acid-producing agent (A), a resin (B), an acid diffusion inhibitor (C), a sulfur-containing compound (D), and an organic solvent (E): The acid-producing agent (A) is selected from any of the following structures: (A-1) (A-2) ； (A-3) (A-4) ； (A-5) (A-6) The resin (B) is a combination of B-1 and B-3 or a combination of B-2 and B-3, and the structures of B-1, B-2, and B-3 are shown below: ； B-1 (n:m:s=60:20:20), where n, m, and s are integers greater than 0, n is 30 to 70, m is 10 to 30, and s is 10 to 30; ； B-2 (x:y:z=73:15:12), where x, y, and z are integers greater than 0, x is 55 to 85, y is 8 to 25, and z is 8 to 25; ； B-3, where m / p = 40 / 60, m represents m-cresol, p represents p-cresol, and u is an integer greater than 0; b1) The weight-average molecular weight of B-1 and B-2 is 17–27 kJ; b2) The molecular weight distribution coefficients (PDI) of B-1 and B-2 are PDI < 2.0; b3) The weight-average molecular weight of the phenolic resin B-3 is 2.5 to 9 kJ, and the molecular weight distribution coefficient (PDI) is <2.

0. The acid diffusion inhibitor (C) is selected from any one or a combination of two or more of the following: triethanolamine, tert-butyl 4-hydroxypiperidine-1-carboxylate, tri-n-pentylamine, dimethylpyridine, tris(3,6-dioxaheptyl)amine, triisopropanolamine, triethylenediamine, or diphenylamine. The sulfur-containing compound (D) is selected from any of the following structures: ； D-1 D-2 D-3 ； D-4 D-5 D-6 The organic solvent (E) is selected from any one or a combination of two or more of propylene glycol methyl ether acetate, propylene glycol monoacetate, propylene glycol monoethyl ether, diethylene glycol methyl ether, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, acetone or N-methylpyrrolidone.

2. The chemically amplified positive photosensitive resin composition according to claim 1, characterized in that: In the combination of B-1 and B-3, the mass ratio of B-1 to B-3 is 40wt%:60wt%, and in the combination of B-2 and B-3, the mass ratio of B-2 to B-3 is 50wt%:50wt%.

3. The chemically amplified positive photosensitive resin composition according to claim 1, characterized in that: The weights of each component are as follows: Contains acid-producing agent (A): 0.1~0.3 Resin (B): 25~35 Acid diffusion inhibitor (C): 0.005~0.015 Sulfur-containing compounds (D): 0.02~0.06 Organic solvent (E): 60~80.

4. The chemically amplified positive photosensitive resin composition according to claim 3, characterized in that: It also contains leveling agents; The weights of each component are as follows: Contains acid-producing agent (A): 0.1~0.3 Resin (B): 25~35 Acid diffusion inhibitor (C): 0.005~0.015 Sulfur-containing compounds (D): 0.02~0.06 Organic solvent (E): 60~80; Leveling agent: 0.1~0.3.

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