Molybdenum film etching solution composition and etching method using the same

Abstract

This invention provides an etching solution composition and an etching method using the composition that sufficiently etch the molybdenum film by simultaneously removing the molybdenum film and the modified molybdenum film while significantly suppressing the etching of the insulating film. [Solution] The etching solution composition consists of 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 remainder being water, based on the total weight of the composition. The etching method etches the molybdenum film and the modified molybdenum film while suppressing the etching of the aluminum oxide film and the silicon oxide film.

Description

Technical Field

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

Background Art

[0002] Generally, in semiconductor manufacturing processes, a molybdenum (Mo) film is 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 a semiconductor manufacturing process, the molybdenum (Mo) film is used as a conductive metal, and can be used alone or by laminating the aluminum oxide film (AlOx) and the silicon oxide film (SiOx). Among semiconductor manufacturing processes, processes for removing a molybdenum (Mo) film include a dry etching process and a wet etching process, and these may also be used in combination. At this time, since an etching process that can etch a molybdenum (Mo) film while suppressing etching of an aluminum oxide (AlOx) film and a silicon oxide (SiOx) film at specific portions is difficult to achieve with a dry etching process, a wet etching process is required. Furthermore, there is a need for an etching solution composition that can remove a molybdenum (Mo adsorbent) film while simultaneously removing modified molybdenum films such as a molybdenum oxide (MoOx) film generated during such an etching process. Korean Published Patent Application No. 10-2021-0051085 discloses a technique related to an etching solution composition for etching a molybdenum (Mo) film and a pattern forming method using the same. However, in the case of the above-mentioned patent document, while it is disclosed that a fluorine compound is used to prevent damage to the aluminum oxide film (AlOx) and silicon oxide film (SiOx) during the etching process of the molybdenum film (Mo), which is the film to be etched, it is not specifically disclosed that a modified molybdenum film such as molybdenum oxide film (MoOx) is removed at the same time. In other words, conventional technology can only etch molybdenum films (Mo) while suppressing the etching of aluminum oxide films (AlOx) and silicon oxide films (SiOx). However, it cannot simultaneously remove modified molybdenum films such as molybdenum oxide films (MoOx) that are generated during the etching process of molybdenum films (Mo). As a result, it is not possible to provide an etching solution composition that satisfies the etching requirements for molybdenum films (Mo). [Overview of the project] [Problems that the invention aims to solve]

[0003] The object of the present invention is to solve the problems of conventional etching solution compositions that, when performing various wet etching processes for molybdenum films (Mo), can etch molybdenum films (Mo) while suppressing the etching of aluminum oxide films (AlOx) and silicon oxide films (SiOx), but cannot simultaneously remove modified molybdenum films such as molybdenum oxide (MoOx), resulting in particle generation. The object of the present invention is to provide an etching solution composition that significantly suppresses the etching of aluminum oxide films (AlOx) and silicon oxide films (SiOx), while simultaneously removing molybdenum films (Mo) and modified molybdenum films such as molybdenum oxide films (MoOx), thereby satisfying the etching requirements for molybdenum films (Mo), being widely applicable in semiconductor manufacturing processes, and 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 comprising an inorganic acid, an oxidizing agent, a fluorine compound, a pH adjuster, an additive represented by the following chemical formula 1, and the remainder being water, and is an etching solution composition that satisfies the etching of molybdenum film (Mo) by simultaneously removing molybdenum film (Mo) and modified film quality (molybdenum oxide film (MoOx)) while significantly suppressing the etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx). 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. Here, the inorganic acid content may be 0.1 to 10% by weight relative to the total weight of the etching solution composition. Furthermore, 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 amount of the oxidizing agent may be 0.001 to 5% by weight relative to the total weight of the etching solution composition. Furthermore, 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. In this case, the fluorine compound may be present in an amount of 0.001 to 3% by weight relative to the total weight of the etching solution composition. Furthermore, the pH adjusting agent contained in the etching solution composition of the present invention may be any one selected from the group consisting of phosphates and sulfates. In this case, the pH adjusting agent may be present in an amount of 0.1 to 10% by weight relative to the total weight of the etching solution composition. Furthermore, 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% by weight relative to the total weight of the etching solution composition.

[0005] [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the formula, x is an integer in the range of 1 to 10.) The etching solution composition allows for adjustment of its compositional components and compositional ratios in order to suppress etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx) while maintaining a significantly faster etching rate of the molybdenum film (Mo) and modified film quality (molybdenum oxide film (MoOx)) required in the process. In particular, the content of the additive represented by chemical formula 1 can be adjusted, thereby enabling etching of the molybdenum film (Mo) and modified film quality (molybdenum oxide film (MoOx)) while suppressing etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx). The etching temperature of the etching solution composition may be room temperature to 60°C. To increase the stability of the etching process, the inorganic acid and the remaining components can be mixed within the facility before use. If mixed outside the facility, the mixture can be mixed immediately before use. [Effects of the Invention]

[0006] The etching solution composition according to the present invention solves the problems of conventional etching solution compositions that, when performing various wet etching processes on a molybdenum film (Mo), can etch the molybdenum film (Mo) while suppressing the etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx), but cannot simultaneously remove modified molybdenum films such as molybdenum oxide film (MoOx), resulting in particle generation. The present invention demonstrates the effect of providing an etching solution composition that significantly suppresses the etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx), while simultaneously removing the molybdenum film (Mo) and modified molybdenum films such as molybdenum oxide film (MoOx), thereby satisfying the etching requirements for the molybdenum film (Mo), and is not only widely applicable in semiconductor manufacturing processes but also improves the problem of particle generation, as well as providing an etching method using the same. [Modes for carrying out the invention]

[0007] The present invention will now be described in more detail. Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as they would normally be understood by a skilled professional in the art to which the present invention pertains. In general, the nomenclature used in the specification of this invention is well known and commonly used in the art to which this invention pertains. When a part of the specification of this invention "includes" a certain component, this does not exclude other components, unless otherwise stated, but rather means that other components may be further included. An etching composition according to one embodiment of the present invention is an etching solution composition comprising an inorganic acid, an oxidizing agent, a fluorine compound, a pH adjuster, an additive, and a residual amount of water, which satisfies the etching amount for the molybdenum film (Mo) by simultaneously removing the molybdenum film (Mo) and the modified film quality (molybdenum oxide film (MoOx)) while significantly suppressing the etching of the aluminum oxide film (AlOx) and the silicon oxide film (SiOx). The inorganic acid contained in the etching solution composition according to one 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 inorganic acid content can be 0.1 to 10% by weight relative to the total weight of the etching solution composition. Furthermore, 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. Here, the content of the oxidizing agent can be 0.001 to 5% by weight relative to the total weight of the etching solution composition. Furthermore, 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. Here, the fluorine compound content can be 0.001 to 3% by weight relative to the total weight of the etching solution composition. Furthermore, the pH adjusting agent contained in the etching solution composition of the present invention may be any one selected from the group consisting of phosphates and sulfates. Here, the pH adjusting agent can be included in an amount of 0.1 to 10% by weight relative to the total weight of the etching solution composition. Furthermore, 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 can be 0.0001 to 2% by weight relative to the total weight of the etching solution composition.

[0008] [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the equation, x is a natural number in the range of 1 to 10.) According to an embodiment of the present invention, there is provided 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, characterized by comprising, based on 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 being water, and relates to an etching method using the same. The etching solution composition is capable of adjusting the composition components and composition ratio of the composition to suppress etching of an aluminum oxide film (AlOx) and a silicon oxide film (SiOx) while maintaining a significantly high etching rate for a molybdenum film (Mo) and modified film quality (a molybdenum oxide film (MoOx)) required in the process; in particular, the content of the additive represented by Chemical Formula 1 can be adjusted, thereby enabling suppression of etching of the aluminum oxide film (AlOx) and the silicon oxide film (SiOx) while etching the molybdenum film (Mo) and the modified film quality (the molybdenum oxide film (MoOx)). The temperature of the etching step using the etching solution composition may be from room temperature to 60°C; in order to increase the stability of the etching step, the inorganic acid and the remaining composition components may be mixed in an apparatus before use, and when mixed outside the apparatus, the mixture may be mixed immediately before the etching step before use.

Examples

[0009] Examples 1-22 and Comparative Examples 1-9 The etching solution compositions of Examples and Comparative Examples were added in the composition ratios described in [Table 1] into respective experimental beakers each provided with a magnetic bar. After sealing the top of the beaker, the composition was produced by stirring at a speed of 400 rpm for 30 minutes at room temperature.

Table 1

[0010] <Evaluation Criteria> Molybdenum film (Mo) ◎: Etching rate of 10 Å / min or higher ○: Etching rate 3 Å / min to less than 10 Å / min △: Etching rate less than 1 Å / min to 3 Å / min ×: Etching rate 0 Å / min or less Molybdenum oxide film (MoOx) ◎: Etching rate of 10 Å / min or higher ○: Etching rate 1 Å / min to less than 10 Å / min △: Etching rate less than 1 Å / min ×: Etching rate 0 Å / min or less Aluminum oxide film (AlOx) ◎: Etching rate less than 1 Å / min ○: Etching rate 1 Å / min to less than 2 Å / min △: Etching rate less than 2 Å / min to 3 Å / min ×: Etching rate of 3 Å / min or higher Silicon oxide film (SiOx) ◎: Etching rate less than 1 Å / min ○: Etching rate 1 Å / min to less than 2 Å / min △: Etching rate less than 2 Å / min to 3 Å / min ×: Etching rate of 3 Å / min or higher [Table 2] As shown in Table 2 above, the results of Experimental Examples 1 to 22 demonstrate that the etching of aluminum oxide films (AlOx) and silicon oxide films (SiOx) is significantly suppressed while satisfying the etching requirements for molybdenum films and modified film materials (molybdenum oxide films (MoOx)).

[0011] In contrast, the results of comparative experiments 1 to 9 show that while the etching amount for molybdenum film (Mo) and modified film material (molybdenum oxide film (MoOx)) is satisfied, the etching of aluminum oxide film (AlOx) and silicon oxide film (SiOx) cannot be significantly suppressed, and therefore, it cannot be used as the etching solution of the present invention. Although specific parts of the present invention have been described in detail above, it will be clear to those with ordinary skill 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. 0.1 to 10% by weight of inorganic acid relative to the total weight of the composition. Oxidizing agent 0.001 to 5% by weight, Fluorine compound 0.001 to 3% by weight, pH adjuster 2-4% by weight, Additives 0.0001 to 2% by weight, and An etching solution composition comprising the remaining amount of deionized water for etching molybdenum films and modified molybdenum films while suppressing the etching of aluminum oxide films and silicon oxide films, The inorganic acid is selected from the group consisting of sulfuric acid, phosphoric acid, and mixtures thereof. The oxidizing agent is selected from the group consisting of hydrogen peroxide, periodic acid, and mixtures thereof. An etching solution composition for etching molybdenum films and modified molybdenum films while suppressing etching of aluminum oxide films and silicon oxide films, characterized in that the additive is a compound represented by the following chemical formula 1. [Chemical formula 1] F(CF2CF2)xCH2CH2OH (In the equation, x is a natural number in the range of 1 to 10.)

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, characterized in that the fluorine compound is selected from the group consisting of hydrofluoric acid, ammonium fluoride, tetrafluoroboric acid, and hexafluorosilicate, as described in claim 1.

3. 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, characterized in that the pH adjusting agent is selected from the group consisting of phosphates and sulfates, as described in claim 1.

4. 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, characterized in that the additive is an integer in the range of 3 to 7 in the compound represented by the chemical formula 1.

5. An etching method for etching a molybdenum film and a modified molybdenum film while suppressing the etching of an aluminum oxide film and a silicon oxide film, using the etching solution composition according to any one of claims 1 to 4.

6. 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, as described in claim 5, 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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