A positive photoresist developer, a preparation method and application thereof

Abstract

The application relates to the technical field of semiconductor manufacturing, in particular to a positive photoresist developer and a preparation method and application thereof. The positive photoresist developer is composed of the following components in percentage by weight: 100-140 ‰ of tetrabutylammonium hydroxide, 6-10 ‰ of a penetrating agent, 1-3 ‰ of a surfactant, 0.1-0.3 ‰ of a corrosion inhibitor, 9-10 ‰ of an anti-overdevelopment agent, and the balance of water; the anti-overdevelopment agent is composed of N-(2-hydroxyethyl) ethylenediamine and ammonium citrate. The positive photoresist developer prepared in the application effectively balances the photoresist stripping property and the anti-overdevelopment property, the copper surface and the circuit quality after treatment are relatively good, that is, the copper surface is not prone to oxidation lattice disproportionation, and the circuit is not prone to the drawbacks of being thin and tender, open circuit and the like.

Description

Technical Field

[0001] This application relates to the field of semiconductor manufacturing technology, and more specifically, to a positive photoresist developer, its preparation method, and its application. Background Technology

[0002] Photolithography is a core step in semiconductor integrated circuit manufacturing. It involves coating a substrate with positive photoresist to form a thin film (8-20µm thick), pre-baking the film, then exposing it with a mask, and finally developing it with a developer to remove any uncured or cross-linked parts to obtain the desired image.

[0003] Therefore, the quality of the developer often directly affects the etching or ion implantation results and the final performance of semiconductor devices. The developer in related technologies is mainly composed of developer-tetramethylammonium hydroxide, corrosion inhibitor, surfactant, defoamer and solvent.

[0004] The aforementioned developer (2.38% TMAH) is mainly used for developing photoresist layers with a film thickness of 1 micrometer or even thinner. However, when applied to COF carrier tapes, it cannot meet the application requirements because the minimum linewidth is above 8 μm and the coating thickness is also above 8 μm. In addition, although the development speed can be increased by simply increasing the TMAH concentration, problems such as overdevelopment and copper surface lattice dissimilation often occur due to high alkali concentration, which cannot meet the quality requirements of the development process and cause quality problems. Therefore, this paper provides a positive photoresist developer that is less prone to overdevelopment problems, as well as its preparation method and application. Summary of the Invention

[0005] To ensure the development yield and copper surface quality of the developer, and to reduce defects such as fine lines or open circuits caused by overdevelopment, this application provides a positive photoresist developer, its preparation method, and its application.

[0006] In a first aspect, this application provides a positive photoresist developer, employing the following technical solution: A positive photoresist developer, characterized in that it is composed of the following components in parts by weight: Tetrabutylammonium hydroxide 100-140‰, penetrant 6-10‰, surfactant 1-3‰, corrosion inhibitor 0.1-0.3‰, anti-overdevelopment agent 9-10‰, balance water; The anti-over-development agent is a compound of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate.

[0007] By adopting the above technical solution, the positive photoresist developer with the above anti-over-development agent effectively balances the photoresist stripping and anti-over-development properties. The quality of the copper surface and the circuit after treatment is better, that is, the copper surface is less prone to lattice dissimilation and the circuit is less prone to defects such as thinness and open circuit. Based on the above experimental results, the possible reasons are as follows: 1) The main developing component used, tetrabutylammonium hydroxide (TBAH), can reduce the expansion of photoresist during development compared to the same type of tetramethyl(propyl)ammonium hydroxide, and make the surface of the photoresist pattern less hydrophilic, thereby effectively reducing the drawbacks caused by line collapse. 2) The anti-overdevelopment agent used has N-(2-hydroxyethyl)ethylenediamine that can be compounded with ammonium citrate. After the photoresist is exposed, the active hydrogen on the nitrogen atom synergistically opens the epoxy groups on the photoresist, causing it to cross-link and solidify rapidly, thereby achieving protection for the non-developable area and the junction with the developed area. 3) In addition, thanks to the specific ionic groups of ammonium citrate, it is very easy to adsorb onto the copper surface and form a complex with copper ions, which significantly enhances the stability of the copper surface, making it less susceptible to oxidation. Furthermore, under the action of penetrants and surfactants, it is easier to act on the junction between the developing and non-developing areas.

[0008] Preferably, the anti-over-development agent is a compound of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate in a weight ratio of 1:(0.1-0.3).

[0009] By adopting the above technical solution, the anti-overdevelopment agent prepared by the above ratio has the best compounding effect of N-(2-hydroxyethyl)ethylenediamine with ammonium citrate. It can effectively promote the cross-linking and curing of photoresist, thereby achieving protection of the non-developable area and the junction with the developed area.

[0010] Preferably, the penetrant is selected from one or more of 3-methoxy-3-methyl-1-butanol, octyldodecyl alcohol, 3-methoxybutanol, isohexanediol, and methyl isobutylmethanol.

[0011] Preferably, the penetrant is 3-methoxy-3-methyl-1-butanol.

[0012] By adopting the above technical solution, the selected penetrant can form strong hydrogen bonds between molecules through the hydroxyl and methoxy groups in its molecule, and exhibit amphiphilicity, thereby improving the residual adhesive and ensuring the etching quality of subsequent processes.

[0013] Preferably, the surfactant is selected from one or more of the following: 465 acetylenic diol modified nonionic surfactant, BASF LF-901, Dow CA-60, and Wanhua LF91.

[0014] Preferably, the surfactant is a 465 acetylenic diol modified nonionic surfactant.

[0015] Preferably, the corrosion inhibitor is selected from one or more of 3-amino-1,2,4-triazole, 1,2,4-triazole, 1-methylpyrazole and 2-methylimidazole.

[0016] Preferably, the corrosion inhibitor is 3-amino-1,2,4-triazole.

[0017] By adopting the above technical solution, the selected surfactant can effectively improve the dynamic wetting ability of the system on the copper surface, reduce its static and dynamic surface tension, and promote flow leveling; In addition, the aforementioned penetrant also has a certain compounding effect, which can effectively promote the dissolution rate of photoresist, improve the phenomenon of residual photoresist, and thus ensure the photoresist stripping properties of the developer.

[0018] Secondly, this application provides a method for preparing a positive photoresist developer, wherein tetrabutylammonium hydroxide, penetrant, surfactant, corrosion inhibitor, and anti-overdevelopment agent are added at room temperature, and after thorough stirring and filtration to remove impurities, a positive photoresist developer is obtained.

[0019] By adopting the above technical solution, the process is significantly simplified, all conditions are easy to achieve, and the resulting positive photoresist developer has stable performance and is not easily affected by fluctuations in the production process. When applied to the positive photoresist development process of COF carrier tape, it has excellent development yield and copper surface quality.

[0020] Thirdly, this application provides an application of a positive photoresist developer in the field of COF carrier positive photoresist development, characterized by the following application steps: S1. First, spin-coat positive photoresist onto the substrate at a rotation speed of 4000±500r / min; S2. Bake on a heating plate at 100-120℃ for 60-120 seconds. S3. Then, the photoresist layer is exposed to ultraviolet light with a wavelength of 400-410nm using a mask, so that the predetermined pattern on the mask is transferred to the photosensitive material layer. S4. Soak the sample in ultrasonic waves at 27±2℃ and 25-60KHZ for 2-3 minutes. Remove the sample to complete the development process. Then rinse with ultrapure water and dry. The development quality can then be observed using a scanning electron microscope.

[0021] By adopting the above technical solutions, the COF carrier tapes processed by the above process all have excellent photoresist stripping performance and resistance to development transition. Their photoresist stripping performance is ○ or ◎, which can be regarded as basically completely stripped. The copper surface quality and circuit quality are both ◎, which can be regarded as basically without drawbacks.

[0022] In summary, this application has the following beneficial effects: 1. The positive photoresist developer containing the above-mentioned anti-overdevelopment agent in this application effectively protects the non-developable area and the interface with the developed area through the selection of tetrabutylammonium hydroxide and the synergistic effect of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate, thereby ensuring the development yield. 2. The penetrant selected in this application can form strong hydrogen bonds between molecules through the hydroxyl and methoxy groups in its molecule, and exhibit amphiphilicity, thereby improving the residual photoresist and ensuring the etching quality of subsequent processes; 3. The preparation process in this application is significantly simplified, and all conditions are easy to achieve. Moreover, the performance of the obtained positive photoresist developer is not easily affected by fluctuations in the production process. Therefore, when applied to COF carrier tape, it can ensure stable development yield and copper surface quality; 4. The COF carriers processed by the above process in this application all have excellent photoresist stripping performance and resistance to overdevelopment. Their photoresist stripping performance is ○ or ◎, which can be regarded as basically completely stripped. The copper surface quality and circuit quality are both ◎, which can be regarded as basically without defects. Attached Figure Description

[0023] Figure 1 It is the reference standard sample for the photoresist peelability evaluation (◎). Figure 2 It is the reference standard sample for evaluating the peelability of photoresist; Figure 3 It is the reference standard sample for × in the evaluation of photoresist peelability; Figure 4 It is a reference standard sample for evaluating the copper surface quality in the evaluation of resistance to overdevelopment; Figure 5 It is a reference standard sample for evaluating the copper surface quality ○ in the evaluation of resistance to overdevelopment; Figure 6 It is a reference standard sample for copper surface quality × in the evaluation of resistance to over-development; Figure 7 It is a reference standard sample for evaluating the circuit quality in the evaluation of resistance to over-development; Figure 8 It is a reference standard sample for evaluating the circuit quality in the evaluation of resistance to over-development; Figure 9 It is a reference standard sample for evaluating the circuit quality in the evaluation of resistance to over-development. Detailed Implementation

[0024] The following combination Figure 1-9 The present application will be further described in detail with reference to the embodiments.

[0025] Performance testing First, the positive photoresist developer solutions prepared in each embodiment and comparative example were selected as the test objects for later use, and then used to process the photoresist on the COF carrier tape. The specific test conditions and test methods are as follows: COF carrier tape: minimum line width 7um, minimum line spacing 10um; Positive photoresist: Jingrui Electric Materials RZJ-307 model, 20um thickness; Test method: S1. First, spin-coat positive photoresist onto the copper substrate at a speed of 4500 r / min. S2. Bake on the heating plate at 110℃ for 90 seconds. S3. Expose the photoresist layer to ultraviolet light with a wavelength of 405nm using a photomask, so that the predetermined pattern on the photomask is transferred to the photoresist layer. S4. Immerse the sample in ultrasonic waves at 27℃ and 45KHZ for 2 minutes. Remove the sample to complete the development process. Rinse with ultrapure water and observe the surface after drying at room temperature for 3 minutes using a scanning electron microscope.

[0026] Then, its photoresist stripping properties and resistance to over-development are evaluated. The specific evaluation method is as follows: Photoresist stripping performance: This is mainly characterized by evaluating the presence or absence of photoresist residue. Specific standards are as follows: ◎: The COF carrier tape surface has no fogging areas at all, which means that the photoresist has been completely removed; ○: There are slightly foggy areas on the surface of the COF carrier tape, and the photoresist has been almost completely washed off; ×: More than half of the COF carrier tape surface is fogged, indicating insufficient washing and stripping. The reference standard samples for the above ◎, ○, and × symbols can be referred to respectively. Figure 1-3 This means that by comparing the test sample with the control standard sample, if the performance of the test sample is better than or equal to that of the control standard sample, it can be regarded as achieving the corresponding performance.

[0027] Resistance to over-development: This is mainly characterized by the quality of the copper surface (determined by the proportion of EDS elemental composition to determine whether the copper surface is damaged) and the quality of the circuit (whether there are defects such as thin lines or open circuits). The specific standards for copper surface quality are as follows: ◎: The copper surface of the COF carrier is completely free of oxide lattice disproportionation; ○: Slight oxidation and lattice disproportionation on the copper surface of the COF carrier; ×: Severe oxidation and lattice disproportionation of the copper surface on the COF carrier; The reference standard samples for the above ◎, ○, and × symbols can be referred to respectively. Figure 4-6This means that by comparing the test sample with the control standard sample, if the performance of the test sample is better than or equal to that of the control standard sample, it can be considered to have achieved the corresponding performance.

[0028] The specific standards for line quality are as follows: ◎: The line has no thin or open circuits; ○: The line has a small number of thin sections and open circuits; ×: The line has a large number of fine, open-circuit defects; The reference standard samples for the above ◎, ○, and × symbols can be referred to respectively. Figure 7-9 This means that by comparing the test sample with the control standard sample, if the performance of the test sample is better than or equal to that of the control standard sample, it can be considered to have achieved the corresponding performance. Example

[0029] Examples 1-6 A positive photoresist developer, with its components and corresponding weights per kg as shown in the table below, is prepared by the following method: After weighing out the tetrabutylammonium hydroxide, penetrant, surfactant, corrosion inhibitor, anti-overdevelopment agent and water, stir for 30 minutes at 25℃ and 1000r / min, and then filter through 1um and 0.1um two-stage filters to remove impurities, the positive photoresist developer is obtained. The penetrant was 3-methoxy-3-methyl-1-butanol, which was purchased from Kuraray, Japan. The surfactant was a 465 acetylenic diol modified nonionic surfactant, purchased from Chongqing Aikemi; The corrosion inhibitor is 3-amino-1,2,4-triazole; The anti-over-development agent is composed of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate, with a weight ratio of 1:0.2.

[0030] Table: Components and weights (g) of the positive photoresist developer in Examples 1-6 Comparative Examples 1-2 A positive photoresist developer, differing from Example 1 in that its components and their corresponding weights are shown in the table below (per kg): Table: Components and weights (g) of the positive photoresist developer in Comparative Examples 1-2 Positive photoresist developer solutions from Examples 1-6 and Comparative Examples 1-2 were extracted and their photoresist stripping properties and resistance to overdevelopment were evaluated according to the above test methods. The average values ​​of the test results were recorded in the table below.

[0031] Table: Performance test results of Examples 1-6 and Comparative Examples 1-2 As can be seen from the table above, the positive photoresist developer solutions prepared in Examples 1-6 all have excellent photoresist stripping performance and resistance to overdevelopment. Their photoresist stripping performance is ○ or ◎, and their copper surface quality and line quality are both ◎, which are all improved to varying degrees compared with Comparative Examples 1-2. Based on the above analysis of the embodiments and comparative data, the possible reasons are as follows: 1) N-(2-hydroxyethyl)ethylenediamine can be compounded with ammonium citrate and, after exposure of the photoresist, it can synergistically open the epoxy groups on the photoresist through the active hydrogen on the nitrogen atom, so that it can be rapidly cross-linked and cured. Therefore, compared with Comparative Example 1, it is easier to achieve protection of the non-developable area and the junction with the developed area. 2) In addition, thanks to the specific ionic groups of ammonium citrate, it is very easy to adsorb onto the copper surface and form a complex with copper ions, thereby significantly enhancing the stability of the copper surface, making it less susceptible to oxidation, and under the action of penetrants and surfactants, it is easier to act on the junction between the developing and non-developing areas.

[0032] 3) The main developing component used, tetrabutylammonium hydroxide (TBAH), can reduce the expansion of photoresist during development compared to the same type of tetramethyl(propyl)ammonium hydroxide (Comparative Example 2), and make the surface of the photoresist pattern less hydrophilic, thereby effectively reducing the drawbacks caused by line collapse.

[0033] Example 7 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is composed of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate in a weight ratio of 1:0.1.

[0034] Example 8 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is composed of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate in a weight ratio of 1:0.3.

[0035] Example 9 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is composed of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate in a weight ratio of 1:0.5.

[0036] Comparative Example 3 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is N-(2-hydroxyethyl)ethylenediamine and does not contain ammonium citrate.

[0037] Comparative Example 4 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is ammonium citrate and does not contain N-(2-hydroxyethyl)ethylenediamine.

[0038] Comparative Example 5 A positive photoresist developer, which differs from Example 1 in that the anti-overdevelopment agent is composed of N-(2-hydroxyethyl)ethylenediamine and citric acid in a weight ratio of 1:0.2.

[0039] Positive photoresist developer solutions from Examples 7-9 and Comparative Examples 3-5 were extracted and their photoresist stripping properties and resistance to overdevelopment were evaluated according to the above test methods. The average values ​​of the test results were recorded in the table below.

[0040] Table: Performance Test Results of Examples 7-9 and Comparative Examples 3-5 As can be seen from the table above, the positive photoresist developer solutions prepared in Examples 7-9 all have excellent photoresist stripping performance and anti-development transition properties. Their photoresist stripping performance is ◎, and the copper surface quality and line quality are both ○ or ◎, which are all improved to varying degrees compared with Comparative Examples 3-5. Based on the above examples and comparative data, the following conclusions and analyses can be drawn: When the anti-over-development agent is composed of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate, it has a better compounding effect, and the preferred ratio of the two is 1:(0.1-0.3). It has excellent and stable performance within this ratio range. Its performance will decrease when it exceeds this range. Furthermore, data from Comparative Examples 3-5 also show that the two components of the anti-overdevelopment agent are indispensable and cannot be replaced by equivalent substances. Referring to Comparative Example 5, although citric acid containing similar ionic groups was used, the expected effect could not be achieved, and the effect decreased instead of increased. The principle behind this has not been fully deduced, and the analysis may be related to the foaming properties and functional group activity of both.

[0041] Example 10 A positive photoresist developer, which differs from Example 1 in that the penetrant is methyl isobutyl alcohol.

[0042] Example 11 A positive photoresist developer, which differs from Example 1 in that the penetrant is 3-methoxybutanol.

[0043] Example 12 A positive photoresist developer, which differs from Example 1 in that the penetrant is composed of methyl isobutyl methanol and 3-methoxybutanol in a weight ratio of 1:0.5.

[0044] Positive photoresist developer solutions from Examples 10-12 were extracted and their photoresist stripping properties and resistance to overdevelopment were evaluated according to the above test methods. The average values ​​of the test results were recorded in the table below.

[0045] Table: Performance Test Results of Examples 1 and 10-12 As can be seen from the table above, the positive photoresist developer solutions prepared in Examples 1 and 10-12 all have excellent photoresist stripping performance and resistance to overdevelopment. Their photoresist stripping performance is ○ or ◎, and their copper surface quality and line quality are both ◎. Based on the data from the above embodiments, it can be seen that the most preferred penetrant is 3-methoxy-3-methyl-1-butanol. By utilizing the hydroxyl and methoxy groups in its molecule, it forms strong hydrogen bonds between molecules and exhibits amphiphilicity, thereby improving the residual adhesive and ensuring the etching quality of subsequent processes.

[0046] Example 13 A positive photoresist developer, which differs from Example 1 in that the surfactant is BASF LF-901.

[0047] Example 14 A positive photoresist developer, which differs from Example 1 in that the surfactant is Dow CA-60.

[0048] Example 15 A positive photoresist developer, which differs from Example 1 in that the surfactant is composed of BASF LF-901 and Dow CA-60 in a weight ratio of 1:1.

[0049] Positive photoresist developer solutions from Examples 13-15 were extracted and their photoresist stripping properties and resistance to overdevelopment were evaluated according to the above test methods. The average values ​​of the test results were recorded in the table below.

[0050] Table: Performance Test Results of Examples 1 and 13-15 As can be seen from the table above, the positive photoresist developer solutions prepared in Examples 1 and 13-15 all have excellent photoresist stripping performance and resistance to overdevelopment. Their photoresist stripping performance is ◎, their copper surface quality is ○ or ◎, and their line quality is ◎. Based on the data from the above embodiments, it can be seen that the most preferred surfactant is 465 acetylenic diol modified nonionic surfactant. The selected surfactant can effectively improve the dynamic wetting ability of the system on the copper surface, making its static and dynamic surface tension low, thus promoting the protection of the copper surface.

[0051] Example 16 A positive photoresist developer, which differs from Example 1 in that the etching inhibitor is BTA.

[0052] Example 17 A positive photoresist developer, which differs from Example 13 in that the etching inhibitor is BTA.

[0053] Example 18 A positive photoresist developer, which differs from Example 14 in that the etching inhibitor is BTA.

[0054] Positive photoresist developer solutions from Examples 16-18 were extracted and their photoresist stripping properties and resistance to overdevelopment were evaluated according to the above test methods. The average values ​​of the test results were recorded in the table below.

[0055] Table: Performance Test Results of Examples 1 and 13-15 As can be seen from the table above, the positive photoresist developer solutions prepared in Examples 1 and 16-18 all have excellent photoresist stripping performance and resistance to overdevelopment. Their photoresist stripping performance is ◎, the copper surface quality is ○ or ◎, and the line quality is ◎. Based on the data from the above embodiments, it can be determined that the most preferred corrosion inhibitor is 3-amino-1,2,4-triazole; Furthermore, a comparison between Examples 17-18 and Example 16 also shows that the special surfactant used in Example 16 can disrupt the film-forming phenomenon of the corrosion inhibitor by combining it with the ammonium citrate used. This allows the corrosion inhibitor of this application to overcome the drawback of being limited by the requirement of poor film-forming properties, and the traditional BTA benzotriazole can also be effectively applied to the system of this application without interfering with its performance.

[0056] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A positive photoresist developer, characterized in that, It consists of the following components in parts per thousand by weight: Tetrabutylammonium hydroxide 100-140‰, penetrant 6-10‰, surfactant 1-3‰, corrosion inhibitor 0.1-0.3‰, anti-overdevelopment agent 9-10‰, balance water; The anti-over-development agent is a compound of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate; The anti-over-development agent is a compound of N-(2-hydroxyethyl)ethylenediamine and ammonium citrate in a weight ratio of 1:(0.1-0.3); The penetrant is selected from one or more of 3-methoxy-3-methyl-1-butanol, 3-methoxybutanol and methyl isobutyl methanol; The surfactant is selected from one or more of the following: 465 acetylenic diol modified nonionic surfactant, BASF LF-901, and Dow CA-60. The corrosion inhibitor is selected from 3-amino-1,2,4-triazole.

2. The method for preparing the positive photoresist developer according to claim 1, characterized in that, Add tetrabutylammonium hydroxide, penetrant, surfactant, corrosion inhibitor, and anti-overdevelopment agent at room temperature. After thorough stirring and filtration to remove impurities, a positive photoresist developer is obtained.

3. The application of the positive photoresist developer according to claim 1 in the field of COF carrier positive photoresist development, characterized in that, The application steps are as follows: S1. First, spin-coat the positive photoresist onto the substrate at a rotation speed of 4000±500r / min; S2. Bake on a heating plate at 100-120℃ for 60-120 seconds. S3. Then, the photoresist layer is exposed to ultraviolet light with a wavelength of 400-410nm using a mask, so that the predetermined pattern on the mask is transferred to the photosensitive material layer. S4. Soak the sample in ultrasonic waves at 27±2℃ and 25-60KHZ for 2-3 minutes. Remove the sample to complete the development process. Then rinse with ultrapure water and dry. The development quality can then be observed using a scanning electron microscope.

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