Molybdenum film etching solution composition and etching method using the same

Abstract

The present invention relates to an etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film, the composition comprising, relative to the total weight of the composition, 0.1 to 10 wt % of an inorganic acid, 0.001 to 5 wt % of an oxidizing agent, 0.001 to 3 wt % of a fluorine compound, 2 to 4 wt % of a pH adjuster, 0.0001 to 2 wt % of an additive, and the balance water, and an etching method using the same.

Description

[Technical field]

[0001] The present invention relates to an etching solution composition capable of etching a molybdenum film in a process for manufacturing a semiconductor device, and an etching method using the composition. Specifically, the present invention relates to an etching solution composition capable of sufficiently etching a molybdenum film by simultaneously removing a molybdenum film and a modified molybdenum film while significantly suppressing etching of an insulating film, and an etching method using the composition. [Background technology]

[0002] In general, in the process of manufacturing semiconductors, molybdenum (Mo) films are used for gate electrodes of thin film transistors in semiconductor devices and liquid crystal displays, wiring, barrier layers, and filling of contact holes or via holes. In the process of manufacturing semiconductors, the molybdenum film (Mo) is used as a conductive metal, either alone or in combination with the aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) can be stacked and used. Among the processes for manufacturing semiconductors, the process for removing molybdenum (Mo) films includes a dry etching process and a wet etching process, and these processes may be used together. At this time, the aluminum oxide film (AlO x ) and silicon oxide film (SiO x In order to etch the molybdenum film (Mo) while suppressing the etching of the metal oxide (SiO2), a wet etching process is necessary because a dry etching process is not feasible. In addition, the molybdenum film (Mo adsorbent) can be removed while the molybdenum oxide film (MoO x Therefore, there is a need for an etching solution composition that can simultaneously remove modified molybdenum films such as those described above. Korean Patent Publication No. 10-2021-0051085 discloses an etching solution composition for etching a molybdenum film (Mo) and a technique for forming a pattern using the same. However, in the case of the above-mentioned patent document, a fluorine compound is used to etch an aluminum oxide film (AlO x ) and silicon oxide film (SiO x ), but the prevention of damage to the molybdenum oxide film (MoO x There is no specific disclosure regarding the simultaneous removal of modified molybdenum films such as those described above. That is, according to the conventional technology, an aluminum oxide film (AlO x ) and silicon oxide film (SiO x The molybdenum film (Mo) can be etched while suppressing the etching of the molybdenum oxide film (MoO x Therefore, it is impossible to provide an etching solution composition that satisfies the etching of molybdenum film (Mo). Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to provide a method for forming an aluminum oxide (AlO x ) and silicon oxide film (SiO x It is only possible to etch the molybdenum film (Mo) while suppressing the etching of the molybdenum oxide (MoO x The purpose of this invention is to solve the problem of the conventional etching solution composition that generates particles without being able to simultaneously remove modified molybdenum films such as aluminum oxide films (AlO x ) and silicon oxide film (SiO x) and significantly suppresses the etching of molybdenum film (Mo) and molybdenum oxide film (MoO x The present invention aims to provide an etching solution composition that can simultaneously remove modified molybdenum films such as fluorine-containing fluorine-containing fluorine, and can satisfy the etching requirements for molybdenum films (Mo), and can be widely applied in semiconductor manufacturing processes while improving the problem of particle generation. Another object of the present invention is to provide an etching method using such an etching solution composition. [Means for solving the problem]

[0004] The etching solution composition according to the present invention is an etching solution composition containing an inorganic acid, an oxidizing agent, a fluorine compound, a pH adjuster, an additive represented by the following chemical formula 1, and the balance of water, and is used to etch an aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) while significantly suppressing the etching of molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x )) at the same time, thereby satisfying the etching requirements for molybdenum film (Mo). The inorganic acid contained in the etching solution composition of the present invention may be any one selected from the group consisting of sulfuric acid, phosphoric acid, polyphosphoric acid, hydrochloric acid, p-toluenesulfonic acid, and mixtures thereof. The content of the inorganic acid may be 0.1 to 10% by weight based on the total weight of the etching liquid composition. The oxidizing agent contained in the etching solution composition of the present invention may be any one selected from the group consisting of hydrogen peroxide, nitric acid, ammonium nitrate, ammonium phosphate, ammonium persulfate, periodic acid, urea-hydrogen peroxide, tert-butyl hydroperoxide, and 2-butane peroxide. In this case, the content of the oxidizing agent may be 0.001 to 5% by weight based on the total weight of the etching liquid composition. The fluorine compound contained in the etching liquid composition of the present invention may be any one selected from the group consisting of hydrofluoric acid, ammonium fluoride, tetrafluoroboric acid, and hexafluorosilicate. In this case, the content of the fluorine compound may be 0.001 to 3% by weight based on the total weight of the etching liquid composition. The pH adjuster contained in the etching liquid composition of the present invention may be any one selected from the group consisting of phosphates and sulfates. In this case, the content of the pH adjuster may be 0.1 to 10% by weight based on the total weight of the etching liquid composition. The additive contained in the etching solution composition of the present invention is represented by the following chemical formula 1, and the content of the chemical formula 1 may be 0.0001 to 2 wt % based on the total weight of the etching solution composition.

[0005] [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the formula, x is an integer ranging from 1 to 10.) The etching solution composition is used to form a molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x )) while maintaining a significantly faster etching rate of aluminum oxide (AlO x ) and silicon oxide film (SiO x In order to suppress the etching of the molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x ) while etching the aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) etching can be suppressed. The temperature of the etching step of the etching solution composition may be room temperature to 60° C., and in order to increase the stability of the etching step, the inorganic acid and the remaining composition components may be mixed in a facility and used. When mixed outside the facility, they may be mixed immediately before the etching step and used. Effect of the Invention

[0006] The etching solution composition according to the present invention is effective in removing aluminum oxide (AlO x ) and silicon oxide film (SiO x It is only possible to etch the molybdenum film (Mo) while suppressing the etching of the molybdenum oxide film (MoO x The present invention has the effect of solving the problems of the conventional etching solution composition that generates particles without simultaneously removing modified molybdenum films such as aluminum oxide films (AlO x ) and silicon oxide film (SiO x ) and significantly suppresses the etching of molybdenum film (Mo) and molybdenum oxide film (MoO x The present invention provides an etching solution composition that can simultaneously remove modified molybdenum films such as fluorine-containing molybdenum (HF) films, and is therefore widely applicable to semiconductor manufacturing processes, thereby improving the problem of particle generation, and an etching method using the same. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The present invention will now be described in more detail. Unless otherwise defined, all technical and scientific terms used in the present specification have the same meaning as commonly understood by a skilled artisan in the art to which the present invention belongs. In general, the nomenclature used in the present specification is one that is well known and commonly used in the technical field to which the present invention pertains. Throughout the present specification, when a part "comprises" a certain component, this does not mean that other components are excluded, but that other components may be further included, unless otherwise specified to the contrary. The etching composition according to one embodiment of the present invention is an etching solution composition containing an inorganic acid, an oxidizing agent, a fluorine compound, a pH adjuster, an additive, and the balance of water, and is used to form an aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) while significantly suppressing the etching of molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x )) at the same time, the etching solution composition satisfies the etching amount for the molybdenum film (Mo). The inorganic acid contained in the etching solution composition according to an embodiment of the present invention may be any one selected from the group consisting of sulfuric acid, phosphoric acid, polyphosphoric acid, hydrochloric acid, p-toluenesulfonic acid, and mixtures thereof. In this case, the content of the inorganic acid may be 0.1 to 10% by weight based on the total weight of the etching solution composition. The oxidizing agent contained in the etching solution composition of the present invention may be any one selected from the group consisting of hydrogen peroxide, nitric acid, ammonium nitrate, ammonium phosphate, ammonium persulfate, periodic acid, urea-hydrogen peroxide, tert-butyl hydroperoxide, and 2-butane peroxide. The content of the oxidizing agent may be 0.001 to 5% by weight based on the total weight of the etching solution composition. The fluorine compound contained in the etching solution composition of the present invention may be any one selected from the group consisting of hydrofluoric acid, ammonium fluoride, tetrafluoroboric acid, and hexafluorosilicate. The content of the fluorine compound may be 0.001 to 3% by weight based on the total weight of the etching liquid composition. The pH adjuster contained in the etching solution composition of the present invention may be any one selected from the group consisting of phosphates and sulfates. The content of the pH adjuster may be 0.1 to 10% by weight based on the total weight of the etching liquid composition. The additive contained in the etching solution composition of the present invention is represented by the following chemical formula 1, and the content of the chemical formula 1 may be 0.0001 to 2 wt % based on the total weight of the etching solution composition.

[0008] [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the formula, x is a natural number ranging from 1 to 10.) According to one embodiment of the present invention, the present invention relates to an etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film, the composition comprising, relative to the total weight of the composition, 0.1 to 10% by weight of an inorganic acid, 0.001 to 5% by weight of an oxidizing agent, 0.001 to 3% by weight of a fluorine compound, 2 to 4% by weight of a pH adjuster, 0.0001 to 2% by weight of an additive, and the balance being water, and an etching method using the same. The etching solution composition is used to form a molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x )) while maintaining a significantly faster etching rate of aluminum oxide (AlO x ) and silicon oxide film (SiO x In order to suppress etching of the molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x ) while etching the aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) etching can be suppressed. The temperature of the etching step of the etching solution composition may be room temperature to 60° C., and in order to increase the stability of the etching step, the inorganic acid and the remaining composition components may be mixed in a facility and used. When mixed outside the facility, they may be mixed immediately before the etching step and used. EXAMPLES

[0009] Examples 1 to 22 and Comparative Examples 1 to 9 The etching solution compositions of the Examples and Comparative Examples were poured into each experimental beaker equipped with a magnetic bar in the composition ratios shown in [Table 1], the tops of the beakers were sealed, and the mixture was stirred at room temperature for 30 minutes at a speed of 400 rpm to prepare the compositions. [Table 1] A-1: Phosphate A-2: Sulfuric acid B-1: Hydrogen peroxide B-2: Periodic acid C-1: Hexafluorosilicate C-2: Ammonium fluoride C-3: Tetrabutylammonium Fluoride D-1: Phosphate E-1: x=3 in chemical formula 1 E-2: x=4 in chemical formula 1 E-3: x=5 in Chemical Formula 1 E-4: x=6 in chemical formula 1 E-5: x=7 in chemical formula 1 F-1: Deionized water Experimental Examples 1 to 22 and Comparative Experimental Examples 1 to 9 The molybdenum films (Mo) and modified films (molybdenum oxide films (MoO x )), aluminum oxide film (AlO x ) and silicon oxide film (SiO x The etching rates of the above were measured, and the results are shown in Table 2 as Experimental Examples 1 to 22 and Comparative Experimental Examples 1 to 9. First, for the measurement, a molybdenum film (Mo) and an aluminum oxide film (AlO x ) and silicon oxide film (SiO x ) wafers were prepared. In addition, a modified film (molybdenum oxide film (MoO)) was formed on the surface of Mo by heat-treating the surface of Mo at a temperature of 500°C for 30 minutes. x )) was formed. x A / Mo wafer was prepared. Before starting etching, the thickness before etching was measured using a scanning electron microscope. After that, molybdenum film (Mo), modified film (molybdenum oxide film (MoO x )), aluminum oxide film (AlO x ), and silicon oxide film (SiO x ) The wafer was immersed in the etching process for 1 minute. After etching was completed, the substrate was washed with ultrapure water, and then the remaining etching solution and water were completely dried using a drying device. The dried wafer coupons were then subjected to scanning electron microscopy to measure the thickness of the film after etching. This allowed the calculation of the difference in film thickness before and after etching, and the thickness of the molybdenum film, modified film quality (molybdenum oxide film (MoO)) at a given temperature. x )), aluminum oxide film (AlO x ), and silicon oxide film (SiO x The etching amount per minute of the sample was measured.

[0010] <Evaluation criteria> Molybdenum film (Mo) ◎: Etching speed 10 Å / min or more ○: Etching speed 3 Å / min to less than 10 Å / min △: Etching speed 1Å / min to less than 3Å / min ×: Etching speed 0 Å / min or less Molybdenum oxide film (MoO x ) ◎: Etching speed 10 Å / min or more ○: Etching speed 1 Å / min to less than 10 Å / min △: Etching speed less than 1 Å / min ×: Etching speed 0 Å / min or less Aluminum oxide film (AlO x ) ◎: Etching speed less than 1 Å / min ○: Etching speed 1 Å / min to less than 2 Å / min △: Etching speed 2Å / min to less than 3Å / min ×: Etching speed 3 Å / min or more Silicon oxide film (SiO x ) ◎: Etching speed less than 1 Å / min ○: Etching speed 1 Å / min to less than 2 Å / min △: Etching speed 2Å / min to less than 3Å / min ×: Etching speed 3 Å / min or more [Table 2] As shown in Table 2, the results of Experimental Examples 1 to 22 show that the molybdenum film and the modified film (molybdenum oxide film (MoO x )) while satisfying the etching amount of aluminum oxide film (AlO x ), silicon oxide film (SiO x ) is shown to have a remarkable effect of suppressing etching.

[0011] In contrast, the results of Comparative Experiments 1 to 9 show that the molybdenum film (Mo) and modified film (molybdenum oxide film (MoO x )) but the etching amount of the aluminum oxide film (AlO x ), silicon oxide film (SiO x ) cannot be significantly inhibited from being etched, and therefore cannot be used as the etching solution of the present invention. Although the specific parts of the present invention have been described in detail above, it is clear to those skilled in the art that such specific descriptions are merely preferred embodiments and do not limit the scope of the present invention. Therefore, the substantial scope of the present invention should be defined by the claims and their equivalents.

Claims

1. inorganic acid, Oxidizing agents, Fluorine compounds, pH adjuster, Additives, and An etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film, the composition comprising water.

2. 0.1 to 10% by weight of an inorganic acid, based on the total weight of the composition; 0.001 to 5% by weight of an oxidizing agent, 0.001 to 3% by weight of a fluorine compound, 2 to 4% by weight of a pH adjuster, 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, comprising 0.0001 to 2 wt % of an additive and the balance being water.

3. 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, wherein the inorganic acid is any one selected from the group consisting of sulfuric acid, phosphoric acid, polyphosphoric acid, hydrochloric acid, p-toluenesulfonic acid, and mixtures thereof.

4. 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, wherein the oxidizing agent is any one selected from the group consisting of hydrogen peroxide, nitric acid, ammonium nitrate, ammonium phosphate, ammonium persulfate, periodic acid, urea-hydrogen peroxide, tert-butyl hydroperoxide, and 2-butane peroxide.

5. 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, wherein the fluorine compound is any one selected from the group consisting of hydrofluoric acid, ammonium fluoride, tetrafluoroboric acid, and hexafluorosilicate.

6. 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, wherein the pH adjuster is any one selected from the group consisting of a phosphate and a sulfate.

7. 2. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 1, wherein the additive is a compound represented by the following Chemical Formula 1: [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the formula, x is a natural number ranging from 1 to 10.)

8. The etching solution composition for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 7, wherein the additive is a compound represented by Chemical Formula 1, in which x is an integer ranging from 3 to 7.

9. 9. An etching method for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film, using the etching solution composition according to claim 1.

10. 10. The etching method for etching a molybdenum film and a modified molybdenum film while suppressing etching of an aluminum oxide film and a silicon oxide film according to claim 9, characterized in that the etching rate of the molybdenum film is 3 Å / min or more, the etching rate of the molybdenum oxide film is 3 Å / min or more, the etching rate of the aluminum oxide film is less than 2 Å / min, and the etching rate of the silicon oxide film is less than 2 Å / min.

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