A composition and its use

Abstract

The application provides an etching composition, a semiconductor device and an etching method. The etching composition comprises an organic solvent, a corrosion inhibitor, an etchant and water. The corrosion inhibitor comprises an imidazole ring, a ketone group and R in a chemical formula, wherein R comprises at least one of hydrogen, carbon, nitrogen, oxygen and sulfur. The etching composition can selectively remove an etching stop layer, better retain pattern information, not damage a tungsten layer and effectively control the profile of a low-K material.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of semiconductor preparation, and in particular to an etching composition, a semiconductor device and an etching method. BACKGROUND

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

[0003] In the semiconductor manufacturing process, the tungsten metal surface is deposited with an etch stop layer, which can protect the underlying tungsten metal at the bottom of the via to be produced. Alumina is usually chosen as the etch stop layer, which has high resistance to fluorine-based gases, can be deposited as a thin film, and has the advantage of functioning as an etch barrier. In the subsequent production process, 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, it is a technical difficulty for the cleaning solution to selectively remove the etch stop layer, better preserve the pattern information, and not damage the bottom tungsten layer and the side low-K material profile. SUMMARY

[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, can selectively remove the etch stop layer under the condition of reducing line width and increasing pattern complexity, and does not damage the bottom tungsten layer and the side low-K material profile.

[0006] The present application also provides a semiconductor device prepared by using the above-mentioned etching composition, which has significant advantages in 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 selectively remove the etch stop layer, and better preserve the pattern information.

[0008] In one aspect, the present application provides an etching composition comprising an organic solvent, a corrosion inhibitor, an etchant, and water.

[0009] The etchant includes a fluoride, and the corrosion inhibitor has a chemical formula as shown in Formula 1.

[0010] Formula 1

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

[0012] 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. The etching composition as described above, the corrosion inhibitor includes at least one of 2-imidazolidone, 1-(2-hydroxyethyl)-2-imidazolidone, 1-(2-aminoethyl)-2-imidazolidone, 1-methylsulfonyl-2-imidazolidone, and 1-chloroformyl-2-imidazolidone.

[0013] The etching composition as described above, the organic solvent includes a solubilizing agent and a surface tension adjusting agent, the solubilizing agent 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; and

[0014] The surface tension adjusting agent includes at least one of diethylene glycol monobenzyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-iso-butyl ether, diethylene glycol mono-iso-propyl ether, diethylene glycol monomethyl ether, diethylene glycol monopropyl ether, dipropylene glycol di-iso-propyl ether, dipropylene glycol mono-iso-propyl 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] The etching composition as described above, a mass ratio of the solubilizing agent to the surface tension adjusting agent is (20-50):(0.1-10).

[0016] The etching composition as described above, a mass ratio of the solubilizing agent to the surface tension adjusting agent is (20-50):(0.1-10).

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

[0018] The etching composition as described above has a pH of 3-6.

[0019] In another aspect, the application provides a semiconductor device prepared by using the etching composition as described above. In another aspect, the application provides an etching method for etching an etching stop layer by using the etching composition as described above.

[0020] The application provides an etching composition comprising an organic solvent, a corrosion inhibitor, an etchant, and water, wherein the corrosion inhibitor has a chemical formula as shown in Formula 1. When the etching composition of the application is used to remove an etching stop layer, the etching stop layer can be effectively removed, and the corrosion of tungsten layer and low-k material can be effectively inhibited, a protective adsorption layer is formed on the surface of the tungsten layer and the low-k material, and the attack of the etching process on the materials is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor.

[0022] Figure 1 The pH value trend curve of the etching composition provided for Example 1 in the cycle mode;

[0023] Figure 2 The etching rate curve of the etching composition provided for Example 1 in the cycle mode on AlOx, W, and low-k material (TEOS). DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions, and advantages of the application clearer, the following will combine the embodiments of the application to clearly and completely describe the technical solutions in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, but not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0025] The etching composition is currently the main means for removing the etching stop layer, which is composed of solvent, corrosion inhibitor, etchant, and other components. However, the current etching composition generally needs to be matched with hydrogen peroxide. However, because the etching composition contains hydrogen peroxide, the hydrogen peroxide has an oxidizing effect on the tungsten layer, which is easy to damage the tungsten layer and affect the performance of the final product.

[0026] When the etching composition does not include hydrogen peroxide, a new type of collocation needs to be explored to achieve efficient removal of the etching stop layer.

[0027] In one aspect, the present application provides an etching composition, comprising an organic solvent, a corrosion inhibitor, an etchant, and water.

[0028] The etchant includes a fluoride, and the corrosion inhibitor has a chemical formula as shown in Formula 1.

[0029] Formula 1

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

[0031] The etching composition provided by the present application has high etching selectivity under the synergistic effect of the organic solvent, the corrosion inhibitor with a specific structure, the etchant, and water, and can remove the etching stop layer with high selectivity in the case of reduced line width and increasingly complex patterns, better preserve the pattern information, and not damage the bottom tungsten layer and the side low-K material profile. The etchant in the present application refers to an etchant applied to the etching stop layer.

[0032] On one hand, the etchant in the etching composition of the present application reacts with the etching stop layer to convert the aluminum oxide in the etching stop layer into a soluble compound and dissolve and disperse the soluble compound by the organic solvent, thereby removing the etching stop layer. On the other hand, the corrosion inhibitor having the structure shown in Formula 1 can be physically and chemically adsorbed to the tungsten layer and the side low-K material through the polar group, thereby protecting the tungsten layer and the side low-K material from corrosion by the etchant. Moreover, the corrosion inhibitor having the structure shown in Formula 1 can form a stable complex with metal ions. This complexation can reduce the dissolution and migration of the metal ions, thereby reducing the corrosion rate of the metal.

[0033] In a specific embodiment, 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.

[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, such as a methyl group (CH3-) or an ethyl group (CH3-CH2-). When R is a substituted C1-C2 alkyl group, R can be an alkyl chain with a length of one or two carbon atoms substituted by other groups, which means that there can be other substituents (such as a hydroxyl group, an amino group, etc.) on the methyl group or the ethyl group. In a specific embodiment, the corrosion inhibitor includes at least one of 2-imidazolidone, 1-(2-hydroxyethyl)-2-imidazolidone, 1-(2-aminoethyl)-2-imidazolidone, 1-methylsulfonyl-2-imidazolidone, and 1-chloroformyl-2-imidazolidone.

[0035] The corrosion inhibitor of the above type can selectively adsorb on the surface of the tungsten layer and the low-K material layer through polar groups (hydroxyl, amino, etc.), or form a protective adsorption layer by forming a covalent bond or a coordination bond with the tungsten layer and the low-K material, and has good stability and is not easy to decompose or fail, and can play a long-term role in the corrosion medium, and can also promote the recycling of the etching composition.

[0036] In a specific embodiment, the etchant includes at least one of ammonium fluoride (NH4F), ammonium bifluoride, triethanolammonium fluoride, diethyleneglycolammonium 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, tetrabutylammonium tetrafluoroborate.

[0037] The etchant of the above type can selectively etch the etching stop layer, and has little effect on the tungsten layer and the low-K material, and the organic residue generated during the etching process is easily dissolved in the organic solvent, reducing the residue after etching and simplifying the subsequent cleaning step.

[0038] The organic solvent can dissolve and disperse the etchant and the corrosion inhibitor in the etching composition, ensure that the etching composition can uniformly cover the area to be etched, and improve the uniformity and efficiency of the etching process. In a specific embodiment, the organic solvent includes a solubilizing agent and a surface tension regulator.

[0039] The solubilizing agent refers to a chemical substance that can increase the solubility of other substances in a solvent, and is commonly used to improve the solubility of substances that are difficult or insoluble in water in a specific solvent. The solubilizing agent is chemically inert and can dissolve other solid components in the etching composition without chemical reaction, thereby ensuring the chemical stability of the etching composition. On the other hand, the surface of the wafer after ashing generally has CFx organic residues, which are difficult to dissolve in water, so the addition of the solubilizing agent can efficiently dissolve the organic residues, improve the etching precision and cleanliness, and avoid the adverse effects of residual organic residues on subsequent production processes. x wafer surface generally has CFx organic residues, which are difficult to dissolve in water, so the addition of the solubilizing agent can efficiently dissolve the organic residues, improve the etching precision and cleanliness, and avoid the adverse effects of residual organic residues on subsequent production processes.

[0040] The surface tension modifier can be used to change the surface tension of the liquid. In the present application, the surface tension modifier refers to a chemical substance that can regulate the surface tension of the etching composition. Generally, the higher the amount of the surface tension modifier added, the lower the surface tension. In one embodiment, the surface tension additive is selected to be butyl diglyme (BDG), and the relationship between the amount of BDG added and the surface tension is shown in Table 1. The surface tension additive has good surface activity, can reduce the surface tension of the etching composition, improve the wettability of the etching composition, ensure uniform distribution of the etching composition in the microstructure by improving the wettability, avoid local over-etching or under-etching, and further improve the uniformity and effect of etching.

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

[0042]

[0043] In one embodiment, the solubilizing agent 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 solubilizing agent of the above type is a solubilizing agent with high polarity, which can dissolve most organic substances, so as to quickly remove the fluorocarbon organic residue on the surface of the AlOx wafer after ashing by dissolution.

[0045] In one embodiment, the surface tension modifier 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 surface tension modifier of the above type has strong interaction with water molecules, can effectively reduce the surface tension of the etching composition as a whole, improve the wettability of the etching composition to the wafer, and thus promote the removal of the residue on the wafer surface.

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

[0048] When the mass ratio of the solubilizing agent to the surface tension modifier is within the above range, the solubilizing effect of the solubilizing agent and the wettability adjusting effect of the surface tension modifier can be adjusted, while providing sufficient solubility, the advantages of the surface tension modifier are used to improve the fluidity and surface activity of the liquid, so as to achieve the best balance of performance.

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

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

[0051] As described above, when the etching composition has a suitable surface tension, the wettability can be improved, thereby improving the precision of etching. In a specific embodiment, the surface tension of the etching composition is 30 mN / m-60 mN / m.

[0052] The present application does not limit the test method of surface tension, and the method commonly used in the art can be selected for measurement, such as the pendant drop method.

[0053] In detail, 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 a range formed by any two of them.

[0054] When the surface tension of the etching composition is within the above range, it is ensured that the etching composition can more uniformly cover the surface of the substrate, including small recesses and complex geometries. This helps to achieve uniform etching effects and avoid local over-etching or under-etching. Moreover, by controlling the fluidity of the etching composition, it is ensured that it is accurately distributed in the microstructure, which is particularly important for high-precision pattern etching, and can improve the resolution and fineness of etching.

[0055] When the types and mass percentages of the components in the etching composition are adjusted, the pH of the etching composition will also be different due to the different pH of the components. 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 to control the activity of the etchant, thereby precisely adjusting the etching rate, which is particularly important for etching applications requiring high precision and high resolution. Within this pH range, corrosion inhibitors can more effectively prevent over-etching in non-target areas, ensuring the selectivity of etching.

[0057] In another aspect, the present application provides a semiconductor device prepared using the etching composition as described above.

[0058] In detail, the etching composition is used to etch the etching stop layer during the preparation of the semiconductor device, which can remove the etching stop layer with high selectivity, better preserve the pattern information, and not damage the bottom tungsten layer and the side low-K material profile, even as the line width decreases and the pattern becomes more complex. This enables precise control of the etching process, protects critical materials, improves device performance and reliability, meets the needs of advanced processes, reduces production costs, and has wide application prospects in high-performance computing, storage, and communication.

[0059] In another aspect, the present application provides an etching method using the etching composition as described above to etch the etching stop layer.

[0060] Through the application of this method, high-precision etching can be achieved in complex pattern structures, meeting the needs 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 for etching according to actual conditions, such as heating the etching composition to a certain temperature (30-70℃), immersing the wafer in the etching composition for 5 minutes, then taking it out, rinsing the wafer surface with ultrapure water, and then blowing the wafer surface dry with nitrogen. The etching rate is calculated by dividing the film thickness change before and after wafer etching by the etching time.

[0062] In the following, the present application is further described through specific examples.

[0063] Example 1

[0064] This example provides an etching composition prepared by dissolving and mixing NFM, BDG, NH4F, and 2-imidazolidinone in deionized water, wherein the mass percentage of each component in the prepared etching composition is as follows:

[0065] Water, 69.3%; NFM, 28%, BDG, 2%, NH4F, 0.2%, and 2-imidazolidinone, 0.5%.

[0066] The surface tension of the etching composition is 48 mN / m and the pH is 5.3 as determined by a surface tension meter and a pH meter.

[0067] Example 2

[0068] This example provides an etching composition, the composition and the preparation method of which are basically the same as those of Example 1, except that NFM is replaced by DMSO, and 2-imidazolidone is replaced by 1-(2-hydroxyethyl)-2-imidazolidone, water, 69.3%; DMSO, 28%, BDG, 2%, NH4F, 0.2%, 1-(2-hydroxyethyl)-2-imidazolidone, 0.5%.

[0069] The surface tension of the etching composition is 46 mN / m and the pH is 5.3 as determined by a surface tension meter and a pH meter.

[0070] Example 3

[0071] This example provides an etching composition, the composition and the preparation method of which are basically the same as those of Example 1, except that 2-imidazolidone is replaced by 1-(2-aminoethyl)-2-imidazolidone.

[0072] Water, 69.3%; NFM, 28%, BDG, 2%, NH4F, 0.2%, 1-(2-aminoethyl)-2-imidazolidone, 0.5%.

[0073] The surface tension of the etching composition is 48 mN / m and the pH is 5.4 as determined by a surface tension meter and a pH meter.

[0074] Example 4

[0075] This example provides an etching composition, the composition and the preparation method of which are basically the same as those of Example 1, except that benzotriazole (BTA) is added.

[0076] Water, 68.3%; NFM, 28%, BDG, 2%, NH4F, 0.2%, 2-imidazolidone, 0.5%, BTA, 1.0%.

[0077] The surface tension of the etching composition is 48 mN / m and the pH is 5.3 as determined by a surface tension meter and a pH meter. The etching performance of this example is comparable to that of Example 1, indicating that the etching composition of the present application can be compatible with other functional corrosion inhibitors (such as BTA), and has strong expandability.

[0078] Example 5

[0079] This example provides an etching composition, the composition and the preparation method of which are basically the same as those of Example 1, except that NFM is replaced by DMSO, and 5-methyl-benzotriazole (5M-BTA) is added.

[0080] Water, 68.3%; DMSO, 28%; BDG, 2%; NH4F, 0.2%; 2-imidazolidineone, 0.5%; 5M-BTA, 1.0%.

[0081] After measurement with a surface tension meter and pH meter, the surface tension of the etching composition was 48 mN / m, and the pH was 5.4. The etching performance of this embodiment is comparable to that of Example 1, indicating that the etching composition of this application is compatible with other functional corrosion inhibitors (such as 5M-BTA) and has strong scalability.

[0082] Example 6

[0083] This embodiment provides an etching composition whose composition and preparation method are basically the same as those in Example 1, except that BDG is replaced with NFM.

[0084] Water, 69.3%; NFM, 30%; NH4F, 0.2%; 2-Imidazolidinone, 0.5%.

[0085] After measurement with a surface tension meter and pH meter, the surface tension of the etching composition was 58 mN / m, and the pH was 5.4. Compared with Example 1, replacing BDG with NFM increased the surface tension of the etching composition, reduced wettability, and weakened the ability to clean organic residues on the surface of the ashed wafer compared to Example 1.

[0086] Example 7

[0087] This embodiment provides an etching composition whose composition and preparation method are basically the same as those in Example 1, except that NFM is 5% and BDG is 6%.

[0088] Water, 88.3%; NFM, 5%; BDG, 6%; NH4F, 0.2%; 2-Imidazolidinone, 0.5%.

[0089] After measurement with a surface tension meter and pH meter, the surface tension of the etching composition was 67 mN / m, and the pH was 4.8. Reducing the overall organic solvent content lowers the surface tension of the etching composition, thereby reducing its wettability to the wafer. In addition, due to the lower solubilizer content, the composition has poorer solubility for BTA or 5M-BTA, and its functional expansion is weaker than that of Example 1.

[0090] Example 8

[0091] This embodiment provides an etching composition whose composition and preparation method are basically the same as those in Example 1, except that 2-imidazolidineone is 10% and water is 59.8%.

[0092] Water, 59.8%; NFM, 28%, BDG, 2%, NH4F, 0.2%, 2-imidazolidinone, 10%.

[0093] The surface tension of the etching composition was 48 mN / m and the pH was 5.5 as determined by a surface tension meter and a pH meter. The addition of 2-imidazolidinone in an excessive amount would result in excessive chelation of tungsten metal, leading to an etching effect greater than a protective effect.

[0094] Comparative Example 1

[0095] This comparative example provides an etching composition having a composition and a preparation method substantially identical to Example 1, except that the water is 69.8% and no 2-imidazolidinone is added.

[0096] Water, 69.8%; NFM, 28%, BDG, 2%, NH4F, 0.2%.

[0097] Comparative Example 2

[0098] This comparative example provides an etching composition having a composition and a preparation method substantially identical to Comparative Example 1, except that NFM is replaced by DMSO.

[0099] Water, 69.8%; DMSO, 28%, BDG, 2%, NH4F, 0.2%.

[0100] Comparative Example 3

[0101] This comparative example provides an etching composition having a composition and a preparation method substantially identical to Comparative Example 1, except that no BDG is added.

[0102] Water, 71.8%; NFM, 28%, NH4F, 0.2%.

[0103] Test Example

[0104] 1. Etching rate test

[0105] The etching rate test was performed using the etching compositions provided in all examples and comparative examples, including the following steps:

[0106] The etching composition was heated to 45°C, and the wafer was immersed in the etching composition for 5 min and then removed. The wafer surface was rinsed with ultrapure water and then dried with nitrogen. The film thickness of the AlOx wafer before and after immersion was measured by an ellipsometer, and the film thickness of the TEOS and tungsten wafer before and after immersion was measured by a four-probe. The etching rate (unit: Å / min) was calculated by dividing the film thickness reduction of the wafer after etching by the etching time. The specific test results are shown in Table 2.

[0107] Table 2

[0108]

[0109] 2. Cyclic performance test

[0110] Cyclic etching of different materials using the etching composition provided in Example 1 includes the following steps:

[0111] The etching composition was heated to 45°C, and the etching rate was recorded at different times after heating for 0 / 24 / 48 / 72 hours, according to the etching rate test method. Figure 1 The pH value change trend curve of the etching composition provided in Example 1 under cyclic mode. Figure 2 Etching rate curves of AlOx, W, and low-k materials (TEOS) using the etching composition provided in Example 1 under cyclic mode. From... Figure 1 As can be seen, the pH value of the composition is stable. From... Figure 2 It can be seen that the etching composition can provide AlO x High selectivity for low-k materials (TEOS) and tungsten, with stable etching rate of the etching composition within 72 hours, AlO x The etching rate did not show a significant decrease, and the etching rates of other film layers were also relatively stable.

[0112] 3. AlO x Wafer surface elemental variation test

[0113] AlO x wafer (AlO) x wafer) using CF x Dry etching (i.e., ashing) is performed using a special gas, and the ashed AlO x The wafer was rinsed for 2 minutes with the etching composition provided in Example 1 of this application. The ashed AlO₂ was tested using XPS. x Elemental composition of the wafer before and after rinsing. Specific data are shown in Table 3.

[0114] Table 3

[0115]

[0116] AlO x After ashing treatment, the surface carbon and fluorine elements of the wafer increase, indicating that the surface has CF. x polymer organic residue; AlO after ashing x After the wafer surface was rinsed with the etching composition of Example 1, the C and F elements on the surface decreased significantly, indicating that C content... x The polymer was effectively removed.

[0117] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part 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 for inhibiting corrosion of tungsten layers, characterized in that, Including organic solvents, corrosion inhibitors, etching agents, and water; The etching agent includes fluorides, and the chemical formula of the corrosion inhibitor is shown in Formula 1: Formula 1 R includes at least one of the elements hydrogen, carbon, nitrogen, oxygen, and sulfur.

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

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

4. The etching composition according to claim 1 or 2, characterized in that, The organic solvent includes a solubilizer and a surface tension modifier. The solubilizer includes at least one of N-formylmorpholine, pyridine-N-oxide, N-ethylmorphofolin-N-oxide, N-ethylpyrrolidine-N-oxide, N-methylpyrrolidone, propylene carbonate 4-methylmorphofolin-4-oxide, trimethylamine-N-oxide, triethylamine N-oxide, triethanolamine, sulfolane, tetrahydrofuran, and dimethyl sulfoxide; The surface tension modifier 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 monobutyl ether, diethylene 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 solubilizer to the surface tension modifier is (20~50):(0.1~10).

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

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

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

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

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

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