TWI507508B - Micro-processing agent, and micro-processing methods - Google Patents

Description

Micro processing agent and micro processing method

The present invention relates to a microfabrication treatment agent for manufacturing a semiconductor device, a liquid crystal display device, a micro electro mechanical system (MEMS) device, or the like, which is used for microfabrication and cleaning treatment, and microfabrication treatment using the same. In particular, the present invention relates to a microfabrication treatment agent for microfabricating at least a laminated film of a tantalum oxide film and a tantalum nitride film, and a microfabrication treatment method using the same.

In the manufacturing process of a semiconductor element, a ruthenium oxide film, a tantalum nitride film, a polysilicon film, a metal film, or the like formed on the surface of the wafer is patterned into a desired shape, and etching is one of the most important processes. For the wet etching of one of the etching techniques, a fine processing agent which can selectively etch only the film to be etched is required.

In the above-mentioned fine processing agent, a cerium oxide film is used as an object of etching, and for example, hydrofluoric acid and hydrofluoric acid are buffered. However, in the laminated film of the laminated yttrium oxide film and the tantalum nitride film, if the buffered hydrofluoric acid or hydrofluoric acid is used as the fine processing agent, the tantalum nitride film is simultaneously etched. As a result, it is difficult to pattern into a desired shape.

In addition, an anionic surfactant such as ammonium lauryl sulfate may be added to hydrofluoric acid (see Patent Document 1 below). However, since the above-mentioned fine processing agent has a very high foaming property, it is not suitable for use as a microfabrication treatment agent in a manufacturing process of a semiconductor element.

On the other hand, for example, a DRAM (Dynamic Random Access Memory) is used as the semiconductor element to be wet-etched using a micro-processing agent. The DRAM cell is composed of one transistor and one capacitor. The DRAM has been approximately 4 times more integrated in the past three years. The high integration of DRAM is mainly due to the high integration of capacitors. Therefore, while reducing the area occupied by the capacitor and securing the capacity value required for a stable memory operation, the capacitor area is increased, the capacitor insulating film is thinned, and the high dielectric constant film is introduced.

As the capacitor insulating film, a ruthenium oxide film has been used, and thin film formation has hitherto been studied. However, the thinning of the ruthenium oxide film as the insulating film of the capacitor has reached the limit in the 1 M-bit DRAM. Therefore, in the 4M-bit DRAM, a tantalum nitride film is used as the insulating film. Further, the ruthenium oxide film is also used as the high integration progresses.

The capacitor structure of the 64M bit generation DRAM is a cylinder type. After forming the capacitor-type lower electrode of the capacitor, in order to form a capacitor and remove the film-formed yttrium oxide film by wet etching, the problem as described below occurs when the previous etching liquid is used.

That is, after the capacitor lower electrode is formed, the film-forming yttrium oxide film is removed by wet etching. Furthermore, it is rinsed with ultrapure water to dry it. In the drying step, due to the surface tension of the water existing between the lower electrodes of the capacitor, a "leaning" phenomenon occurs in which the lower electrodes are inclined and adhered to each other, and there is a problem of inducing a 2-bit error. . Therefore, in the following Patent Document 2, there is disclosed a technique of forming a support film composed of a tantalum nitride film between the lower electrodes of the capacitor. Further, Patent Document 3 listed below discloses a technique in which a tantalum nitride film is formed as an insulating film in order to improve the insulating property with a bit line. Further, Patent Document 4 below discloses that a tantalum nitride film is used as a follow-up. The etching of the yttrium oxide film is etched to stop the film formation technique.

In the production process of the semiconductor element, the ruthenium oxide film which is the support film of the above-mentioned patent document 1 and the tantalum nitride film of the patent document 2 are oxidized as the etching stop film of the patent document 3, using the etch liquid. The problem of etching the tantalum film together with the etched object.

Advanced technical literature Patent literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2005-328067

Patent Document 2: Japanese Laid-Open Patent Publication No. 2003-297952

Patent Document 3: Japanese Patent Laid-Open No. Hei 10-98155

Patent Document 4: Japanese Patent Laid-Open Publication No. 2000-22112

The present invention has been made in view of the above problems, and an object thereof is to provide a microfabrication process in which a yttrium oxide film can be selectively finely processed when at least a laminated film of a yttrium oxide film and a tantalum nitride film is laminated. Agent, and the micro processing method using the same.

In order to solve the above-mentioned problems, the inventors of the present invention have focused on the microfabrication treatment agent and the microfabrication treatment method using the same. As a result, it has been found that by using a micro-processing agent to which a specific water-soluble polymer is added, a laminated film of a hafnium oxide film and a tantalum nitride film can be laminated, and only the hafnium oxide film can be selectively finely processed to complete. this invention.

In other words, the microfabrication treatment agent of the present invention is characterized in that: (a) at least one of 0.01 to 15% by weight of hydrogen fluoride or 0.1 to 40% by weight of ammonium fluoride; (b) And (c) 0.001 to 10% by weight, at least any one selected from the group consisting of acrylic acid, ammonium acrylate, acrylate, acrylamide, styrene sulfonic acid, ammonium styrene sulfonate, and styrene sulfonate. a water soluble polymer.

According to the above configuration, the fine processing agent of the present invention can reduce the etching effect on the tantalum nitride film by containing the water-soluble polymer without impairing the etching effect on the hafnium oxide film. As a result, for example, in the microfabrication of the laminated film of the laminated yttrium oxide film and the tantalum nitride film, the yttrium oxide film can be selectively finely processed while suppressing the etching of the tantalum nitride film by using the fine processing agent of the present invention. Thereby, it is possible to improve the yield in the manufacturing process of the semiconductor element.

Here, the content of the water-soluble polymer is in the range of 0.001 to 10% by weight. By setting the lower limit value to 0.001% by weight, the effect of adding a water-soluble polymer can be exhibited, and etching of the tantalum nitride film can be suppressed. Moreover, by setting the upper limit value to 10% by weight, it is possible to suppress an increase in metal impurities in the fine processing agent. Further, it is also possible to suppress an increase in the viscosity, thereby preventing the rinsing and removing performance of the fine processing agent from the rinsing agent such as ultrapure water. In addition, the "microfabrication" of the present invention means the etching and surface washing of the film to be processed. In addition, the "water-soluble polymer" refers to a polymer which dissolves 1% by mass or more (10 g/L) at a normal temperature in a mixed solution containing the above components (a) and (b).

In the above configuration, the water-soluble polymer is preferably a copolymer of ammonium acrylate and methyl acrylate.

Further, in the above configuration, the water-soluble polymer is preferably polyacrylamide.

Further, in the above configuration, the weight average molecular weight of the water-soluble polymer is preferably in the range of 1,000 to 1,000,000. When the weight average molecular weight of the water-soluble polymer is 1,000 or more, when the water-soluble polymer is produced, the stabilizer which becomes a polymerization inhibitor can be reduced. As a result, metal contamination of the water-soluble polymer can be prevented. On the other hand, when the weight average molecular weight is 1,000,000 or less, the viscosity of the fine processing agent can be suppressed from increasing, so that workability can be improved. In addition, it is also possible to prevent the rinsing removal performance of the fine processing agent from being lowered by a rinsing agent such as ultrapure water.

Further, in the above configuration, the etching rate of the hafnium oxide film at 25 ° C is preferably in the range of 1 to 5000 nm / min. Thereby, the processing time for the fine processing of the cerium oxide film can be prevented from becoming long, and the production efficiency can be improved, and the control of the film thickness and the surface roughness of the cerium oxide film after the microfabrication can be easily performed.

In order to solve the above problems, the microfabrication processing method of the present invention is characterized in that a laminated film of at least a laminated yttrium oxide film or a tantalum nitride film is finely processed by using the above-described fine processing agent.

In the above method, by adding the water-soluble polymer, it is possible to reduce the etching effect on the hafnium oxide film, and to reduce the etching effect on the tantalum nitride film, and to use at least the lamination. Since the tantalum film and the tantalum nitride film are laminated, it is possible to suppress the etching of the tantalum nitride film and selectively perform fine processing on the tantalum oxide film. As a result, it is also possible to improve the yield in the manufacturing process of the semiconductor element.

The above ruthenium oxide film is a natural oxide film, a thermal ruthenium oxide film, an undoped bismuth silicate glass film, a phosphorus-doped bismuth silicate glass film, a boron-doped bismuth silicate glass film, or a boron boron-doped bismuth silicate glass. Any of a film, a TEOS film, or a fluorine-containing cerium oxide film is preferred.

The tantalum nitride film is preferably a tantalum nitride film or a hafnium oxynitride film.

The present invention can achieve the effects described below by the means described above.

In other words, according to the present invention, since at least a laminated film of a hafnium oxide film and a tantalum nitride film can be laminated, only the hafnium oxide film can be selectively finely processed, for example, a semiconductor device, a liquid crystal display device, or a micromechanical device. The manufacturing can be done in a fine microfabrication.

Hereinafter, an embodiment of the present invention will be described.

The microfabrication treatment agent of the present invention according to the present embodiment includes (a) at least one of hydrogen fluoride or ammonium fluoride; (b) water; and (c) a water-soluble polymer.

The content of the hydrogen fluoride in the component (a) is preferably in the range of 0.01 to 15% by weight based on the total weight of the fine processing agent, and more preferably in the range of 0.05 to 10% by weight. When the content of hydrogen fluoride is less than 0.01% by weight, it is difficult to control the concentration of hydrogen fluoride, and thus the variation in the etching rate of the ruthenium oxide film may become large. On the other hand, when the content of hydrogen fluoride exceeds 15% by weight, the etching rate of the ruthenium oxide film is excessively increased, and the controllability of etching is lowered.

Further, the content of the ammonium fluoride is preferably in the range of 0.1 to 40% by weight, more preferably in the range of 5 to 25% by weight, based on the total weight of the fine processing agent. When the content of ammonium fluoride is less than 0.1% by weight, it is difficult to control the concentration of ammonium fluoride, and thus the variation in the etching rate of the ruthenium oxide film may become large. In addition, when the content of the ammonium fluoride is more than 40% by weight, the solubility of the fine processing agent is lowered, and if the liquid temperature of the fine processing agent is lowered, the fine processing agent reaches a saturated solubility, and crystals are precipitated in the liquid. .

In the present embodiment, by including the component (a), the etching rate of the tantalum nitride film can be selectively suppressed, and the etching selectivity (yttrium oxide film/tantalum nitride film) can be improved. More specifically, for example, the etching rate of the tantalum nitride film can be suppressed to 80% or less as compared with the case where the above component (a) is not added.

The above component (a) may be hydrogen fluoride or ammonium fluoride alone or in a mixture. Further, the third component may be contained. The third component may, for example, be a surfactant or a mineral acid. However, when an organic acid such as formic acid is added, it is not preferable because the etching effect on the tantalum nitride film is selectively suppressed.

The surfactant is not particularly limited. For example, when the component (a) is hydrofluoric acid alone, it can be preferably exemplified by polyethylene glycol alkyl ether, polyethylene glycol alkyl phenyl ether, and polyethylene glycol. At least one nonionic surfactant of the group consisting of alcohol fatty acid esters. In addition, when the component (a) is a mixture of hydrofluoric acid and ammonium fluoride or ammonium fluoride alone, an aliphatic alcohol, an aliphatic carboxylic acid, a hydrofluoroalkyl alcohol or a hydrofluoroalkyl carboxylic acid may be optionally used. At least one of a group consisting of a salt of a hydrofluoroalkylcarboxylic acid, an aliphatic amine salt, and an aliphatic sulfonic acid may be in a form of a solid or a liquid.

The amount of the surfactant to be added is preferably in the range of 0.001 to 0.1% by weight based on the total weight of the fine processing agent, and more preferably in the range of 0.003 to 0.05% by weight. By adding a surfactant, it is possible to suppress the roughness of the surface of the tantalum nitride film or the semiconductor substrate subjected to the etching treatment. In addition, the conventional etching liquid is more likely to be locally deposited on the back surface of the semiconductor substrate to which the fine pattern is applied, and the resist interval is about 0.5 μm or less, which makes it more difficult to uniformly Etching. However, when the fine processing agent of the present invention containing a surfactant is used as the etching liquid, the wettability to the surface of the semiconductor substrate is improved, and the uniformity in the surface of the etching substrate can be improved. However, when the amount of addition is less than 0.001% by weight, the surface tension of the fine processing agent cannot be sufficiently lowered, so that the effect of improving the wettability may be insufficient. Further, when the amount added is more than 0.1% by weight, not only a satisfactory effect is not obtained, but also the defoaming property is deteriorated, and the bubbles are adhered to the etching surface, and etching unevenness occurs, or bubbles enter the fine gap, and etching defects occur.

The inorganic acid is not particularly limited, and examples thereof include hydrochloric acid, sulfuric acid, and phosphoric acid. The amount of the inorganic acid to be added is preferably from 0.01 to 30% by weight based on the total weight of the fine processing agent, and more preferably from 0.05 to 10% by weight. When the amount of addition is less than 0.01% by weight, it is difficult to control the concentration of the inorganic acid, so that the variation in the etching rate of the ruthenium oxide film is increased. On the other hand, when it is more than 30% by weight, for example, when hydrochloric acid is used, the vapor pressure becomes large, and there is an uncomfortable discomfort in which the chemical composition changes due to evaporation.

The water-soluble polymer of the above component (c) is selected from the group consisting of acrylic acid, ammonium acrylate, acrylate, acrylamide, styrene sulfonic acid, ammonium styrene sulfonate, and styrene sulfonate. 1 species.

Among the water-soluble polymers listed above, the copolymer of ammonium acrylate and methyl acrylate is etched on the tantalum nitride film when the component (a) is composed of hydrogen fluoride alone or when hydrogen fluoride and ammonium fluoride are used. The suppression effect is particularly high. Further, the copolymerization ratio of ammonium acrylate to methyl acrylate is preferably in the range of 9.9:0.1 to 5:5. When the copolymerization of methyl acrylate is large in the above numerical range, there is a problem that the solubility of the copolymer of ammonium acrylate and methyl acrylate becomes small. Further, in the case of the polyacrylamide, when the component (a) is hydrogen fluoride or ammonium fluoride, or when hydrogen fluoride and hydrochloric acid are used, the effect of suppressing the ruthenium nitride film is particularly high.

The content of the water-soluble polymer in the component (c) is preferably from 0.001 to 10% by weight, more preferably from 0.1 to 5% by weight, based on the total weight of the fine processing agent. When the content is less than 0.001% by weight, the effect of adding the water-soluble polymer is lowered, and the effect of suppressing the etching rate of the tantalum nitride film is insufficient. In addition, when the content is more than 10% by weight, the metal impurities in the fine processing agent are increased, and the viscosity is increased, so that the rinse removal performance of the fine processing agent by the rinsing agent such as ultrapure water is lowered. As a result, it is not suitable as a microfabrication treatment agent for a manufacturing process of a semiconductor device.

The weight average molecular weight of the water-soluble polymer is preferably in the range of 1,000 to 1,000,000, more preferably in the range of 1,000 to 10,000. When the weight average molecular weight is less than 1,000, the amount of the stabilizer which becomes a polymerization inhibitor increases. As a result, there is a case where metal contamination of the fine processing agent is caused. When the weight average molecular weight exceeds 1,000,000, the viscosity of the fine processing agent becomes large, and the workability is lowered. In addition, there is a case where the rinsing removal performance of the fine processing agent by the rinsing agent such as ultrapure water is lowered.

The fine processing agent of the present embodiment may be mixed with an additive other than the surfactant, insofar as the effect is not inhibited. The above additives may, for example, be hydrogen peroxide, a chelating agent or the like.

According to the required purity of the surface treatment agent, the added water-soluble polymer can be purified by distillation, ion exchange resin, ion exchange membrane, electric dialysis, filtration, etc., or can be subjected to cyclic filtration of the micro processing agent. And then purified.

Next, a wet processing method using the fine processing agent of the present embodiment will be described by taking wet etching as an example.

The fine processing agent of the present embodiment is used in various wet etching methods. The etching method may be a immersion type or a spray type, and any of the methods may employ the fine processing agent of the present invention. In the immersion type, it is preferable that the composition of the fine processing agent changes little due to evaporation in the etching step.

The etching temperature (liquid temperature of the etching liquid) when the fine processing agent is used as the etching liquid is preferably in the range of 5 to 50 ° C, more preferably in the range of 15 to 35 ° C, and further preferably 20 to 30 ° C. The range is better. Within the above range, evaporation of the fine processing agent can be suppressed, and composition change can be prevented. Further, at a high temperature, it is difficult to control the etching rate due to evaporation of the fine processing agent, and at a low temperature, the components in the fine processing agent are easily crystallized, and the etching rate cannot be reduced, and the defects of the liquid particles are increased. Further, depending on the etching temperature, the etching rate of each film changes, and the difference between the etching rate of the hafnium oxide film and the etching rate of the tantalum nitride film may also be affected.

Further, in the fine processing agent of the present embodiment, the etching rate of the hafnium oxide film at 25 ° C is preferably in the range of 1 to 5000 nm / min, more preferably in the range of 15 to 1000 nm / min. When the etching rate is less than 1 nm/min, the microfabrication processing such as etching is time consuming, which may result in a decrease in production efficiency. In addition, when the thickness exceeds 5000 nm/min, the controllability of the film thickness after etching and the roughness of the surface of the substrate (the surface opposite to the surface on which the ruthenium oxide film is formed) are remarkably deteriorated, and the yield is lowered.

Example

Hereinafter, a good embodiment of the invention will be described in detail by way of examples. However, the materials, blending amounts, and the like described in the examples are not intended to limit the scope of the invention, and are merely illustrative examples.

(etching rate of yttrium oxide film and tantalum nitride film)

The film thickness of the cerium oxide film and the cerium nitride film before and after the etching was measured using an optical film thickness measuring device (Nanoometrics Japan Co., Ltd., Nanospec 6100), and the film thickness change due to etching was measured. The above measurement was repeated over three different etching times to calculate the etching rate.

(water soluble polymer)

The water-soluble polymer used in each of the examples described below and the additives used in the respective comparative examples are shown in Table 1 below.

(Example 1)

In an amount of 7.0 parts by weight of hydrogen fluoride (a high purity grade for semiconductors, 50% by weight of a semiconductor), ammonium fluoride (manufactured by Stella-Chemifa, high purity grade for semiconductor, concentration: 40% by weight) 50.0 parts by weight, and 40.5 parts by weight of ultrapure water, 2.5 parts by weight of ammonium polyacrylate (concentration: 40% by weight, weight average molecular weight: 6000) as a water-soluble polymer, and after mixing and mixing, the mixture was adjusted to 25 Allow to stand at °C for 3 hours. Thereby, an etching liquid (fine processing agent) of 3.5% by weight of hydrogen fluoride, 20.0% by weight of ammonium fluoride, and 1% by weight of ammonium polyacrylate was prepared.

Next, the etching rate of the TEOS film as the hafnium oxide film and the tantalum nitride film was measured. Further, the selection ratio of the etching rate (yttrium oxide film/tantalum nitride film) was evaluated. The results are shown in Table 2 below.

(Examples 2 to 10)

In Examples 2 to 10, an etching liquid was prepared in the same manner as in Example 1 except that the contents of hydrogen fluoride and ammonium fluoride and the content and type of the water-soluble polymer were changed as shown in Table 1. Further, using the etching liquid obtained in each of the examples, the etching rate and the etching rate selection ratio (yttrium oxide film/tantalum nitride film) for the TEOS film and the tantalum nitride film were evaluated. The results are shown in Table 2 below.

(Comparative Examples 1, 2)

In Comparative Examples 1 and 2, the contents of hydrogen fluoride and ammonium fluoride were changed as shown in Table 1, and an etching liquid was prepared in the same manner as in Example 1 except that the water-soluble polymer was not added. Further, the etching rate and the etching rate selection ratio (yttrium oxide film/tantalum nitride film) for the TEOS film and the tantalum nitride film were evaluated using the etching liquids obtained in the respective comparative examples. The results are shown in Table 2 below.

(Comparative examples 3 to 7)

In Comparative Examples 3 to 7, the contents of hydrogen fluoride and ammonium fluoride were changed as shown in Table 1, and an etching liquid was prepared in the same manner as in Example 1 except that the water-soluble polymer was used instead of the additive shown in Table 1. Further, the etching ratio of the etching rate and the etching rate of the TEOS film and the tantalum nitride film (the hafnium oxide film/tantalum nitride film) was evaluated using the etching liquid obtained in each of the comparative examples. The results are shown in Table 2 below.

As apparent from the above Table 2, the additives to the etching liquids of Comparative Examples 3 to 7 were not able to selectively suppress the etching of the tantalum nitride film, and the etching ratio of the tantalum oxide film to the tantalum nitride film was selected. (The cerium oxide film/tantalum nitride film) becomes large.

On the other hand, with respect to the finely processed surface treatment agents of Examples 1 to 10, by adding a water-soluble polymer, the etching rate of the tantalum nitride film can be selectively suppressed, and it is confirmed that the tantalum oxide film can be used for the tantalum nitride film. The selection ratio of the etching rate is larger than that of the (yttrium oxide film/tantalum nitride film).

(Example 11)

27.8 parts by weight of hydrogen fluoride (manufactured by Stella-Chemifa Co., Ltd., high purity grade for semiconductor, concentration: 50% by weight), hydrochloric acid (manufactured by Linzhi Pharmaceutical Co., Ltd., electronic grade, concentration: 36% by weight), 27.8 parts by weight And 51.2 parts by weight of ultrapure water solution, adding 1.0 part by weight of polyacrylamide (concentration: 50% by weight, weight average molecular weight: 10,000) as a water-soluble polymer, stirring and mixing, and then adjusting the temperature of the mixture to 25 ° C. Set for 3 hours. Thereby, an etching liquid (fine processing agent) of 10% by weight of hydrogen fluoride, 10% by weight of hydrochloric acid, and 0.5% by weight of polyacrylamide was prepared.

Next, the etching rate of the BPSG film as the hafnium oxide film and the tantalum nitride film was measured. Further, the selection ratio of the etching rate (yttrium oxide film/tantalum nitride film) was evaluated. The results are shown in Table 3 below.

(Embodiment 12)

In the same manner as in the above Example 11, except that the content of the polyacrylamide was changed as shown in Table 3, the etching liquid was prepared. Further, using the etching liquid obtained in the present example, the etching rate and etching rate selection ratio (ruthenium oxide film/tantalum nitride film) for the BPSG film and the tantalum nitride film were evaluated. The results are shown in Table 3 below. .

(Comparative Example 8)

In Comparative Example 8, as shown in Table 3, an etching liquid was prepared in the same manner as in Example 12 except that the water-soluble polymer was not added. Further, using the etching liquid obtained in this comparative example, the etching rate and the etching rate selection ratio (yttrium oxide film/tantalum nitride film) for the BPSG film and the tantalum nitride film were evaluated. The results are shown in Table 3 below.

As is apparent from the above Table 3, in the etching liquids of Examples 11 to 12, by adding polyacrylamide as a water-soluble polymer, the etching rate of the tantalum nitride film can be selectively suppressed, and it is confirmed that cerium oxide can be formed. The selection ratio of the etching rate of the film to the tantalum nitride film becomes larger (the hafnium oxide film/tantalum nitride film).

(Example 13)

25.0 parts by weight of ammonium fluoride (made by Stella-chemifa (manufactured by Stella-Chemifa), high purity grade for semiconductors, concentration: 40% by weight), hydrochloric acid (manufactured by Linzhuang Pharmaceutical Co., Ltd., electronic grade, concentration 36% by weight) 27.8 To a solution of 45.2 parts by weight of ultrapure water and 2.0 parts by weight of polyacrylamide (concentration: 50% by weight, weight average molecular weight: 10,000) as a water-soluble polymer, the mixture was stirred and mixed, and then the mixture was adjusted to a temperature of 25 Allow to stand at °C for 3 hours. Thereby, an etching liquid (fine processing agent) of 10% by weight of ammonium fluoride, 10% by weight of hydrochloric acid, and 1% by weight of polyacrylamide was prepared.

Next, the etching rate of the TEOS film as the hafnium oxide film and the tantalum nitride film was measured. Further, the selection ratio of the etching rate (yttrium oxide film/tantalum nitride film) was evaluated. The results are shown in Table 4 below.

(Comparative Example 9)

In Comparative Example 9, as shown in Table 4, an etching liquid was prepared in the same manner as in Example 13 except that the water-soluble polymer was not added. Further, using the etching liquid obtained in the comparative example, the etching rate and the etching rate selection ratio (the hafnium oxide film/tantalum nitride film) for the TEOS film and the tantalum nitride film were evaluated. The results are shown in Table 4 below.

(Example 14)

25.0 parts by weight of ammonium fluoride (manufactured by Stella-Chemifa Co., Ltd., high purity grade for semiconductor, concentration: 40% by weight), phosphoric acid (manufactured by Kishida Chemical Co., Ltd., electronic industry grade, concentration: 85% by weight), 23.5 parts by weight And 49.5 parts by weight of ultrapure water solution, adding 2.0 parts by weight of polyacrylamide (concentration: 50% by weight, weight average molecular weight: 10,000) as a water-soluble polymer, stirring and mixing, and then adjusting the temperature of the mixture to 25 ° C. Set for 3 hours. Thereby, an etching liquid (fine processing agent) of 10% by weight of ammonium fluoride, 20% by weight of phosphoric acid, and 1% by weight of polyacrylamide was prepared.

Next, the etching rate of the TEOS film as the hafnium oxide film and the tantalum nitride film was measured. Further, the selection ratio of the etching rate (yttrium oxide film/tantalum nitride film) was evaluated. The results are shown in Table 4 below.

(Comparative Example 10)

In Comparative Example 10, an etchant was prepared in the same manner as in Example 14 except that the water-soluble polymer was not added as shown in Table 4. Further, using the etching liquid obtained in the comparative example, the etching rate and the etching rate selection ratio (the hafnium oxide film/tantalum nitride film) for the TEOS film and the tantalum nitride film were evaluated. The results are shown in Table 4 below.

As is apparent from the above Table 4, in the etching liquids of Examples 13 to 14, the etching rate of the tantalum nitride film was selectively suppressed by adding polypropylene decylamine as a water-soluble polymer, and it was confirmed that the ruthenium oxide film was formed. The selection ratio of the etching rate of the tantalum nitride film (the hafnium oxide film/tantalum nitride film) becomes large.

Claims (12)

A micro processing agent characterized by comprising: (a) 0.01 to 15% by weight of hydrogen fluoride, or 0.1 to 40% by weight of at least one of ammonium fluoride; (b) water; and (c) 0.001 to 10 parts by weight % of at least one water-soluble polymer selected from the group consisting of styrenesulfonic acid, ammonium styrenesulfonate, and styrenesulfonate, and the fine processing agent is etched at 25 ° C for the yttrium oxide film The rate is in the range of 1 to 5000 nm/min. The fine processing agent according to claim 1, wherein the water-soluble polymer has a weight average molecular weight of from 1,000 to 1,000,000. The microfabrication treatment agent according to the first aspect of the invention, wherein the microfabrication treatment agent comprises a surfactant. The micro-processing agent according to claim 1, wherein the surfactant is added in an amount of 0.001 to 0.1% by weight. The micro-processing agent according to claim 3, wherein the component (a) is composed only of hydrogen fluoride; and the surfactant is selected from the group consisting of polyethylene glycol alkyl ether, polyethylene glycol alkyl phenyl ether, and At least any one of the nonionic surfactants of the group consisting of polyethylene glycol fatty acid esters. The micro-processing agent according to claim 3, wherein the component (a) is hydrofluoric acid and ammonium fluoride, or only ammonium fluoride; and the surfactant is selected from aliphatic alcohols and aliphatic carboxylic acids. Acid, hydrofluorinated alkane At least one of a group consisting of a base alcohol, a hydrofluorinated alkyl carboxylic acid, a hydrofluorinated alkyl carboxylic acid salt, an aliphatic amine salt, and an aliphatic sulfonic acid. The fine processing agent according to claim 1, wherein the component (a) contains a mineral acid. The fine processing agent according to the first aspect of the invention, wherein the inorganic acid is added in an amount of 0.01 to 30% by weight. A microfabrication processing method characterized in that a laminated film of at least a laminated yttrium oxide film and a tantalum nitride film is finely processed by using a microfabrication treatment agent of the first application of the patent scope. The microfabrication treatment method of claim 9, wherein the ruthenium oxide film is a natural oxide film, a thermal ruthenium oxide film, an undoped bismuth silicate glass film, a phosphorus-doped bismuth silicate glass film, or a boron-doped ruthenium Any of a salt glass film, a phosphorus boron doped silicate glass film, a TEOS film, or a fluorine-containing cerium oxide film. The microfabrication treatment method according to claim 9, wherein the tantalum nitride film is a tantalum nitride film or a hafnium oxynitride film. The microfabrication treatment method according to claim 9, wherein the microfabrication treatment agent is used in a range of a liquid temperature of 5 to 50 °C.