Etching composition, semiconductor device and etching method

Abstract

The invention provides an etching composition, a semiconductor device and an etching method. The etching composition comprises an organic solvent, a corrosion inhibitor, an etching agent and water, wherein the chemical formula of the corrosion inhibitor comprises an imidazole ring, a ketone group and an R group, and R comprises at least one of hydrogen, carbon, nitrogen, oxygen and sulfur. According to the etching composition, the etching stop layer can be removed with high selectivity, pattern information is better reserved, the tungsten layer is not damaged, and meanwhile, the outline of the low-K material is effectively controlled.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing, and particularly to an etching composition, a semiconductor device, and an etching method. Background Art

[0002] With the development of the semiconductor industry, more and more metal materials have been introduced into semiconductor manufacturing. Tungsten is a high-melting-point metal with good thermal stability and chemical stability. In semiconductor chips, tungsten is mainly used as contact plug and via fill materials. It can provide stable electrical connections and has good thermal conductivity, which helps with the thermal management of the chips.

[0003] During the semiconductor manufacturing process, an etch stop layer is deposited on the surface of the tungsten metal, and the etch stop layer can protect the underlying tungsten metal at the bottom of the via to be formed. Alumina is usually selected as the etch stop layer. Alumina has high resistance to fluorine-based gases, can not only be deposited as a thin film, but also has the advantage of functioning as an etch barrier layer. In subsequent production processes, in order to avoid the influence of the etch stop layer on the process effect, it is necessary to selectively remove the etch stop layer.

[0004] However, due to the continuous reduction of line width and the increasing complexity of patterns, highly selectively removing the etch stop layer, better retaining pattern information, and at the same time not damaging the bottom tungsten layer and the profile of the side low-dielectric (low-k) material are the technical difficulties of current cleaning liquids. Summary of the Invention

[0005] The present application provides an etching composition, which, under the synergistic action of an organic solvent, a corrosion inhibitor, an etchant, and water, has high etching selectivity and can highly selectively remove the etch stop layer in the case of reduced line width and increasing pattern complexity, while not damaging the bottom tungsten layer and the profile of the side low-k material.

[0006] The present application also provides a semiconductor device prepared by using the above-mentioned etching composition, which has significant advantages in terms of performance, reliability, and manufacturing efficiency and can meet the requirements of advanced semiconductor technology nodes.

[0007] The present application also provides an etching method, which uses the above-mentioned etching composition to etch the etch stop layer, can highly selectively remove the etch stop layer, and better retain pattern information.

[0008] On the one hand, the present application provides an etching composition, comprising an organic solvent, a corrosion inhibitor, an etchant, and water;

[0009] Among them, the etchant includes fluoride, and the chemical formula of the corrosion inhibitor is as shown in Formula 1:

[0010] Formula 1

[0011] Among them, R includes at least one of hydrogen, carbon, nitrogen, oxygen, and sulfur elements.

[0012] For the etching composition as described above, R includes at least one of a hydrogen group, a substituted or unsubstituted alkyl group, a sulfonyl group, a hydroxyl group, an amino group, a carbonyl group, and an aldehyde group. For the etching composition as described above, the corrosion inhibitor includes at least one of 2-imidazolidinone, 1-(2-hydroxyethyl)-2-imidazolidinone, 1-(2-aminoethyl)-2-imidazolone, 1-methylsulfonyl-2-imidazolidinone, and 1-chlorocarbonyl-2-imidazolidinone.

[0013] For the etching composition as described above, the organic solvent includes a solubilizer and a surface tension regulator. The solubilizer includes at least one of N-formylmorpholine, pyridine-N-oxide, N-ethylmorpholine-N-oxide, N-ethylpyrrolidine-N-oxide, N-methylpyrrolidone, propylene carbonate, 4-methylmorpholine-4-oxide, trimethylamine-N-oxide, triethylamine N-oxide, triethanolamine, sulfolane, tetrahydrofuran, and dimethyl sulfoxide;

[0014] The surface tension regulator includes at least one of diethylene glycol monobenzyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monopropyl ether, polyethylene glycol monomethyl ether, and propylene glycol dimethyl ether.

[0015] For the etching composition as described above, the mass ratio of the solubilizer to the surface tension regulator is (20~50):(0.1~10).

[0016] For the etching composition as described above, based on the total mass of the etching composition, the mass proportion of the organic solvent is 20%-60%, the mass proportion of the corrosion inhibitor is 0.1%-5%, the mass proportion of the etchant is 0.01%-5%, and the balance is water.

[0017] For the etching composition as described above, the surface tension of the etching composition is 30 mN / m - 60 mN / m.

[0018] The etching composition as described above, wherein the pH of the etching composition is 3 - 6.

[0019] On the other hand, the present application provides a semiconductor device prepared by using the etching composition as described above. On the other hand, the present application provides an etching method, using the etching composition as described above to etch an etch stop layer.

[0020] The present application provides an etching composition, comprising an organic solvent, a corrosion inhibitor, an etchant, and water, and the chemical formula of the corrosion inhibitor is shown in Formula 1. When the etching composition of the present application is applied to remove the etch stop layer, through the synergistic effect among various components, it can not only effectively remove the etch stop layer, but also effectively inhibit the corrosion of the tungsten layer and the low-k material, form a protective adsorption layer on the surfaces of the tungsten layer and the low-k material, and reduce the attack on these materials during the etching process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0022] Figure 1 It is a curve graph showing the change trend of the pH value of the etching composition provided in Example 1 in the cyclic mode;

[0023] Figure 2 It is a curve graph showing the etching rates of the etching composition provided in Example 1 on AlOx, W, and low-k material (TEOS) in the cyclic mode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the present application clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0025] Forming an etching composition by combining components such as a solvent, a corrosion inhibitor, and an etchant is the main means to remove the etch stop layer at present. However, current etching compositions generally need to be combined with hydrogen peroxide. However, due to the presence of hydrogen peroxide in the etching composition, hydrogen peroxide has an oxidizing effect on the tungsten layer, easily damaging the tungsten layer and affecting the performance of the final product.

[0026] When hydrogen peroxide is not included in the etching composition, new combinations need to be explored to achieve efficient removal of the etch stop layer.

[0027] On the one hand, the present application provides an etching composition, comprising an organic solvent, a corrosion inhibitor, an etchant, and water;

[0028] Wherein, the etchant comprises a fluoride, and the chemical formula of the corrosion inhibitor is shown in Formula 1:

[0029] Formula 1

[0030] Wherein, R comprises at least one of hydrogen, carbon, nitrogen, oxygen, and sulfur elements.

[0031] Under the synergistic effect of the organic solvent, the corrosion inhibitor with a specific structure, the etchant, and water in the etching composition provided by the present application has a high etching selectivity, can selectively remove the etch stop layer with high selectivity under the condition of reducing line width and making the pattern more complex, better retain the pattern information, and at the same time does not damage the bottom tungsten layer and the side low-k material profile. The etchant in the present application refers to the etchant applied to the etch stop layer.

[0032] On the one hand, the etchant in the etching composition of the present application reacts chemically with the etch stop layer, so that the aluminum oxide in the etch stop layer is converted into a soluble compound and dissolved and dispersed by the organic solvent, realizing the removal of the etch stop layer. On the other hand, the corrosion inhibitor with the structure shown in Formula 1 can physically adsorb and chemically adsorb with the tungsten layer and the side low-k material through polar groups, protecting the tungsten layer and the side low-k material from being corroded by the etchant, and the corrosion inhibitor with the structure shown in Formula 1 can form a stable complex with metal ions. This complexation can reduce the dissolution and migration of metal ions, thereby reducing the corrosion rate of the metal.

[0033] In a specific embodiment, R comprises at least one of a hydrogen group, a substituted or unsubstituted alkyl group, a sulfonyl group, a hydroxyl group, an amino group, a carbonyl group, and an aldehyde group.

[0034] For example, when R is an unsubstituted C1-C2 alkyl group, R can be a simple alkyl chain with a length of one or two carbon atoms. For example, methyl (CH 3 -), or ethyl (CH 3 -CH 2-). When R is a substituted C1-C2 alkyl, R can be an alkyl chain substituted by other groups, with a length of one or two carbon atoms, which means that there can be other substituents (such as hydroxyl, amino, etc.) on the methyl or ethyl group. In a specific embodiment, the corrosion inhibitor includes at least one of 2-imidazolidinone, 1-(2-hydroxyethyl)-2-imidazolidinone, 1-(2-aminoethyl)-2-imidazolidinone, 1-methanesulfonyl-2-imidazolidinone, and 1-chloroformyl-2-imidazolidinone.

[0035] The above-mentioned type of corrosion inhibitor can be selectively adsorbed on the surface of the tungsten layer and the side low-K material layer through polar groups (hydroxyl, amino, etc.), or by forming covalent bonds or coordination bonds with the tungsten layer and the side low-K material to form a protective adsorption layer. In addition, the above-mentioned type of corrosion inhibitor has good stability, is not easy to decompose or fail, can function for a long time in the corrosive medium, and can also promote the recycling of the etching composition.

[0036] In one embodiment, the etchant includes ammonium fluoride (NH 4 F), at least one of ammonium difluoride, triethanolammonium fluoride, diethylene glycolammonium fluoride, methyldiethanolammonium fluoride, tetramethylammonium fluoride, triethylamine trihydrofluoride, hydrogen fluoride, fluoroboric acid, tetrafluoroboric acid, ammonium tetrafluoroborate, fluoroacetic acid, ammonium fluoroacetate, trifluoroacetic acid, fluorosilicic acid, ammonium fluorosilicate, and tetrabutylammonium tetrafluoroborate.

[0037] The above-mentioned type of etchant can selectively etch the etch stop layer, while having little effect on the tungsten layer and the low-K material. The organic residues generated during the etching process are easily dissolved in the organic solvent, which reduces the residues after etching and simplifies the subsequent cleaning steps.

[0038] The organic solvent can dissolve and disperse the etchant and corrosion inhibitor in the etching composition, ensuring that the etching composition can evenly cover the area to be etched, thereby improving the uniformity and efficiency of the etching process. In a specific embodiment, the organic solvent includes a solubilizer and a surface tension regulator.

[0039] Among them, solubilizer refers to a chemical substance that can increase the solubility of other substances in a solvent, and is often used to improve the solubility of poorly soluble or insoluble substances in a specific solvent. The solubilizer is chemically inert and can dissolve other solid insoluble components in the etching composition without chemically reacting with them, thereby ensuring the chemical stability of the etching composition. On the other hand, in actual application, the AlO x The wafer surface generally has CFx organic residues, which are difficult to dissolve in water. Therefore, adding a solubilizer can efficiently dissolve the organic residues, improve etching accuracy and cleanliness, and avoid the residual organic residues from causing adverse effects on subsequent production processes.

[0040] The surface tension regulator can be used to change the surface tension of a liquid. The surface tension regulator in this application refers to a chemical substance that can regulate the surface tension of the etching composition. Generally, the higher the addition amount of the surface tension regulator, the lower the surface tension. In a specific embodiment, the surface tension additive is selected as diethylene glycol monobutyl ether (BDG). The relationship between the BDG addition amount and the surface tension is shown in Table 1. It has good surface activity, can reduce the surface tension of the etching composition, improve the wettability of the etching composition, ensure the uniform distribution of the etching composition in the microstructures by improving the wettability, avoid local over-etching or under-etching, and further improve the uniformity and effect of etching.

[0041] Table 1. Variation table of surface tension with BDG addition amount

[0042]

[0043] In a specific embodiment, the solubilizer includes at least one of N-formylmorpholine (NFM), pyridine-N-oxide, N-ethylmorpholine-N-oxide, N-ethylpyrrolidine-N-oxide, N-methylpyrrolidone, propylene carbonate, 4-methylmorpholine-4-oxide, trimethylamine-N-oxide, triethylamine N-oxide, triethanolamine, sulfolane, tetrahydrofuran, dimethyl sulfoxide (DMSO).

[0044] The above types of solubilizers are solubilizers with high polarity, which can dissolve most organic substances, and thus can quickly remove the carbon-fluorine organic residue on the surface of the ashed AlOx wafer through the dissolution effect.

[0045] In a specific embodiment, the surface tension regulator includes at least one of diethylene glycol monobenzyl ether, diethylene glycol monobutyl ether (BDG), diethylene glycol monoethyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monopropyl ether, polyethylene glycol monomethyl ether, propylene glycol dimethyl ether.

[0046] The above types of surface tension regulators have a strong interaction with water molecules, can effectively reduce the overall surface tension of the etching composition, improve the wettability of the etching composition to the wafer, and thus promote the removal of residues on the wafer surface.

[0047] When the organic solvent includes a solubilizer and a surface tension regulator, different mass ratios between the two will have a certain impact on the etching effect. In a specific embodiment, the mass ratio of the solubilizer to the surface tension regulator is (20 - 50):(0.1 - 10).

[0048] When the mass ratio of the solubilizer to the surface tension regulator is within the above range, it can adjust the solubility - increasing effect of the solubilizer and the wetting - property - adjusting effect of the surface tension regulator. While providing sufficient dissolution ability, it utilizes the advantages of the surface tension regulator to improve the fluidity and surface activity of the liquid, thereby achieving the best balance of performance.

[0049] In a specific embodiment, based on the total mass of the etching composition, the mass proportion of the organic solvent is 20% - 60%, the mass proportion of the corrosion inhibitor is 0.1% - 5%, the mass proportion of the etchant is 0.01% - 5%, and the balance is water.

[0050] When the mass proportions of the organic solvent, corrosion inhibitor, etchant, and water in the etching composition are within the above ranges, it is beneficial to maintain a stable and appropriate etching rate and the ability of differential etching.

[0051] As described above, when the etching composition has an appropriate surface tension, it can improve the wetting property, thereby improving the etching precision. In a specific embodiment, the surface tension of the etching composition is 30 mN / m - 60 mN / m.

[0052] This application does not limit the test method of the surface tension, and common methods in the art can be selected for measurement, such as the pendant - drop method, etc.

[0053] Specifically, the surface tension of the etching composition includes but is not limited to 30 N / m, 35 N / m, 40 N / m, 45 N / m, 50 N / m, 55 N / m, 60 N / m, or the range composed of any two of them.

[0054] When the surface tension of the etching composition is within the above range, it ensures that the etching composition can cover the substrate surface more uniformly, including tiny depressions and complex geometric structures. This helps to achieve a uniform etching effect and avoid local over - etching or under - etching. Moreover, by controlling the fluidity of the etching composition and ensuring its precise distribution in the micro - structures, it is especially important for high - precision pattern etching and can improve the resolution and fineness of etching.

[0055] When adjusting the types and mass proportions of the various components in the etching composition, since the pH values of the various components are different, the pH of the etching composition will also be different. In a specific embodiment, the pH of the etching composition is 3 - 6.

[0056] An acidic environment with a pH value between 3 and 6 helps control the activity of the etchant, thereby precisely regulating the etching rate, which is particularly important for etching applications that require high precision and high resolution. Within this pH range, the corrosion inhibitor can function more effectively to prevent over-etching in non-target areas and ensure the selectivity of etching.

[0057] On the other hand, the present application provides a semiconductor device prepared using the etching composition described above.

[0058] Specifically, during the preparation of the semiconductor device, the etching composition described above is used to etch the etch stop layer. It can selectively remove the etch stop layer with high selectivity in the case of line width reduction and increasingly complex patterns, better retain pattern information, and at the same time not damage the bottom tungsten layer and the profile of the side low-K material. Furthermore, the semiconductor device can precisely control the etching process, protect key materials, improve device performance and reliability, while meeting the requirements of advanced processes, reducing production costs, and having broad application prospects in the fields of high-performance computing, storage, and communication.

[0059] On the other hand, the present application provides an etching method, which uses the etching composition described above to etch the etch stop layer.

[0060] Through the application of this method, high-precision etching can be achieved in complex pattern structures, meeting the requirements of modern semiconductor industry for high integration and high performance.

[0061] The present application does not limit the operating parameters of the etching process, and appropriate methods can be selected according to the actual situation for etching, such as heating the etching composition to a certain temperature (any temperature between 30~70°C), immersing the wafer in the etching composition for 5 minutes and then taking it out, rinsing the surface of the wafer with ultrapure water, and then drying the surface of the wafer with nitrogen. The etching rate is calculated by dividing the change in film thickness before and after wafer etching by the etching time.

[0062] Hereinafter, the present application will be further introduced through specific examples.

[0063] Example 1

[0064] This example provides an etching composition, which is prepared by dissolving and mixing NFM, BDG, NH 4 F, and 2-imidazolidinone in deionized water. Among them, the mass percentages of each component in the prepared etching composition are as follows:

[0065] Water, 69.3%; NFM, 28%, BDG, 2%, NH 4 F, 0.2%, 2-imidazolidinone, 0.5%.

[0066] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 48 mN / m and the pH is 5.3.

[0067] Example 2

[0068] This example provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that NFM is replaced by DMSO, and 2-imidazolidinone is replaced by 1-(2-hydroxyethyl)-2-imidazolidinone.

[0069] Water, 69.3%; DMSO, 28%, BDG, 2%, NH 4 F, 0.2%; 1-(2-hydroxyethyl)-2-imidazolidinone, 0.5%.

[0070] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 46 mN / m and the pH is 5.3.

[0071] Example 3

[0072] This example provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that 2-imidazolidinone is replaced by 1-(2-aminoethyl)-2-imidazolone.

[0073] Water, 69.3%; NFM, 28%, BDG, 2%, NH 4 F, 0.2%; 1-(2-aminoethyl)-2-imidazolone, 0.5%.

[0074] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 48 mN / m and the pH is 5.4.

[0075] Example 4

[0076] This example provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that benzotriazole (BTA) is added.

[0077] Water, 68.3%; NFM, 28%, BDG, 2%, NH 4 F, 0.2%; 2-imidazolidinone, 0.5%; BTA, 1.0%.

[0078] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 48 mN / m and the pH is 5.3. The etching performance of this example is equivalent to that of Example 1, indicating that the etching composition of this application can be compatible with other functional corrosion inhibitors (such as BTA) and has strong expandability.

[0079] Example 5

[0080] This embodiment provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that NFM is replaced by DMSO, and 5-methyl-benzotriazole (5M-BTA) is added.

[0081] Water, 68.3%; DMSO, 28%, BDG, 2%, NH 4 F, 0.2%; 2-imidazolidinone, 0.5%; 5M-BTA, 1.0%.

[0082] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 48 mN / m, and the pH is 5.4. The etching performance of this embodiment is equivalent to that of Example 1, indicating that the etching composition of the present application can be compatible with other functional corrosion inhibitors (such as 5M-BTA), and has strong expansibility.

[0083] Example 6

[0084] This embodiment provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that BDG is replaced by NFM.

[0085] Water, 69.3%; NFM, 30%, NH 4 F, 0.2%; 2-imidazolidinone, 0.5%.

[0086] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 58 mN / m, and the pH is 5.4. Compared with Example 1, replacing BDG with NFM will increase the surface tension of the etching composition, reduce the wettability, and the cleaning ability of the organic residues on the wafer surface after ashing is weaker than that of Example 1.

[0087] Example 7

[0088] This embodiment provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that NFM is 5% and BDG is 6%.

[0089] Water, 88.3%; NFM, 5%, BDG, 6%, NH 4 F, 0.2%; 2-imidazolidinone, 0.5%.

[0090] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 67 mN / m, and the pH is 4.8. Reducing the overall organic solvent content will reduce the surface tension of the etching composition, thereby reducing the wettability of the wafer. In addition, due to the low content of the solubilizer (i.e., the solubilizer), the solubility of the composition in BTA or 5M-BTA is poor, and the functional expansibility is weaker than that of Example 1.

[0091] Example 8

[0092] This example provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that

[0093] 2-imidazolidinone is 10%, and water is 59.8%.

[0094] Water, 59.8%; NFM, 28%, BDG, 2%, NH 4 F, 0.2%, 2-imidazolidinone, 10%.

[0095] After being measured by a surface tension meter and a pH meter, the surface tension of the etching composition is 48 mN / m, and the pH is 5.5. An excessive addition amount of 2-imidazolidinone will cause excessive chelation of tungsten metal, resulting in the etching effect being greater than the protection effect.

[0096] Comparative Example 1

[0097] This comparative example provides an etching composition, whose composition and preparation method are basically the same as those of Example 1, except that water is 69.8% and 2-imidazolidinone is not added.

[0098] Water, 69.8%; NFM, 28%, BDG, 2%, NH 4 F, 0.2%.

[0099] Comparative Example 2

[0100] This comparative example provides an etching composition, whose composition and preparation method are basically the same as those of Comparative Example 1, except that NFM is replaced by DMSO.

[0101] Water, 69.8%; DMSO, 28%, BDG, 2%, NH 4 F, 0.2%.

[0102] Comparative Example 3

[0103] This comparative example provides an etching composition, whose composition and preparation method are basically the same as those of Comparative Example 1, except that BDG is not added.

[0104] Water, 71.8%; NFM, 28%, NH 4 F, 0.2%.

[0105] Test Example

[0106] 1. Etching rate test

[0107] Use the etching compositions provided by all examples and comparative examples to conduct an etching rate test, including the following steps:

[0108] Heat the etching composition to 45 °C, immerse the wafer in the etching composition for 5 minutes and then take it out. Rinse the surface of the wafer with ultrapure water and then dry the surface of the wafer with nitrogen. Measure the film thickness values of the AlOx wafer before and after immersion using an ellipsometer, and measure the film thickness values of tetraethoxysilane (TEOS) and tungsten wafers before and after immersion using a four-probe. Calculate the etching rate (unit: Å / min) by dividing the reduction in film thickness after wafer etching by the etching time. The specific test results are shown in Table 2.

[0109] Table 2

[0110]

[0111] 2. Cycling performance test

[0112] Use the etching composition provided in Example 1 to perform cyclic etching on different materials, including the following steps:

[0113] Heat the etching composition to 45 °C. After heating for 0 / 24 / 48 / 72 h respectively, record the etching rates at different times according to the etching rate test method, where Figure 1 is the curve of the pH value change trend of the etching composition provided in Example 1 in the cyclic mode, Figure 2 is the etching rate curve of the etching composition provided in Example 1 for AlOx, W, and low-k material (TEOS) in the cyclic mode. It can be seen from Figure 1 that the pH value of the composition is stable. It can be seen from Figure 2 that the etching composition can provide a high selectivity ratio for low-k material (TEOS) and tungsten, and the etching rate of the etching composition is stable within 72 h. The etching rate of AlO x shows no obvious attenuation, and the etching rates of other film layers are also relatively stable. x

[0114] 3. Surface element change test of AlO x wafer

[0115] AlO x wafer (AlO x wafer) is dry-etched (i.e., ashed) using a CF x special gas. The ashed AlO x wafer is rinsed with the etching composition provided in Example 1 of the present application for 2 minutes. Test the element content of the ashed AlO x wafer before and after rinsing by XPS. The specific data is shown in Table 3.

[0116] Table 3

[0117]

[0118] AlO x After the surface of the wafer is ashed, the contents of C and F elements on the surface increase, indicating that the surface has CF x polymer organic residue; ashed AlO x After the surface of the wafer is rinsed with the etching composition of Example 1, the contents of C and F elements on the surface decrease significantly, indicating that CF x polymer is effectively removed.

[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An etching composition, characterized in that Including organic solvents, corrosion inhibitors, etchants, water; Wherein, the etchant includes fluoride, and the chemical formula of the corrosion inhibitor is shown in Formula 1: Formula 1 Wherein, R includes at least one of hydrogen, carbon, nitrogen, oxygen and sulfur.

2. The etching composition according to claim 1, characterized in that R includes at least one of a hydrogen group, a substituted or unsubstituted alkyl group, a sulfonyl group, a hydroxyl group, an amino group, a carbonyl group, and an aldehyde group.

3. The etching composition according to claim 1, characterized in that The corrosion inhibitor includes at least one of 2-imidazolidinone, 1-(2-hydroxyethyl)-2-imidazolidinone, 1-(2-aminoethyl)-2-imidazolidinone, 1-methanesulfonyl-2-imidazolidinone, and 1-chloroformyl-2-imidazolidinone.

4. The etching composition according to claim 1 or 2, characterized in that: The organic solvent includes a solubilizer and a surface tension adjuster, The solubilizing agent comprises at least one of N-formylmorpholine, pyridine-N-oxide, N-ethylmorpholine-N-oxide, N-ethylpyrrolidine-N-oxide, N-methylpyrrolidone, propylene carbonate 4-methylmorpholine-4-oxide, trimethylamine-N-oxide, triethylamine N-oxide, triethanolamine, sulfolane, tetrahydrofuran, and dimethyl sulfoxide; The surface tension regulator includes at least one of diethylene glycol monobenzyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, dipropylene glycol diisopropyl ether, dipropylene glycol monoisopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, ethylene glycol diethyl ether, ethylene glycol dimethyl ether, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, monopropyl ether, polyethylene glycol monomethyl ether, and propylene glycol dimethyl ether.

5. The etching composition according to claim 4, characterized in that The mass ratio of the solubilizing agent to the surface tension adjusting agent is (20-50): (0.1-10).

6. The etching composition according to any one of claims 1 to 3, characterized in that: Based on the total mass of the etching composition, the mass proportion of the organic solvent is 20%-60%, the mass proportion of the corrosion inhibitor is 0.1%-5%, the mass proportion of the etchant is 0.01%-5%, and the balance is water.

7. The etching composition according to any one of claims 1 to 3, characterized in that The surface tension of the etching composition is 30 mN / m-60 mN / m.

8. The etching composition according to any one of claims 1 to 3, characterized in that: The pH of the etching composition is 3-6.

9. A semiconductor device, characterized in that: The semiconductor device is prepared by using the etching composition described in any one of claims 1-8.

10. An etching method, characterized in that: The etching stop layer is etched using the etching composition described in any one of claims 1 to 8.

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