KR100597656B1 - Cleaning method and apparatus for manufacturing semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method and a cleaning apparatus for manufacturing a semiconductor capable of improving productivity by easily performing a cleaning process without requiring a drying process by applying dry cleaning using supercritical carbon dioxide and a cosolvent. A cleaning method for the manufacture of a semiconductor manufacturing process comprising a photolithography process, the method comprising: (1) mounting a wafer to be cleaned in a high pressure cleaning container with a heating source attached thereto; (2) the supercritical carbon dioxide while supplying carbon dioxide at a pressure of 100 to 200 atm in a temperature range of 40 to 100 ° C. so that the supercritical carbon dioxide and the cosolvent form a single phase to clean the surface of the wafer. And a cleaning step of supplying a mixed solvent in which a cosolvent is mixed with a single phase to clean the wafer. (3) a rinsing step of rinsing the wafer with a mixture of supercritical carbon dioxide and ethanol and / or supercritical or liquid carbon dioxide after the cleaning step; (4) a step of removing carbon dioxide and cosolvent and ethanol from the high pressure washing vessel; (5) a condensation step of condensing into a liquid state to separate and reuse gaseous carbon dioxide after the removing step; And (6) after the decompression of the high-pressure cleaning container, withdrawal step of withdrawing the wafer; comprises.

Supercritical, carbon dioxide, cosolvent, cyclohexanone, single phase, mixed solvent, photoresist.

Description

Cleaning method and apparatus for manufacturing semiconductor device

1 is a block diagram showing a cleaning apparatus for manufacturing a semiconductor according to the present invention.

2A to 2C are photographs taken before and after cleaning of a wafer using a scanning electron microscope (SEM) to confirm a cleaning result using only supercritical carbon dioxide as a comparative example.

3A to 3E are photographs taken before and after the cleaning of the wafer using a scanning electron microscope to confirm the result of cleaning by using the cosolvents and other cosolvents (comparative example) according to the present invention.

Figures 4a to 4c are photographs taken before and after the cleaning of the wafer using a scanning electron microscope in order to confirm the results of cleaning according to the content of one co-solvent while varying the content of the co-solvent in accordance with the present invention.

5A to 5E are photographs taken before and after cleaning a wafer using a scanning electron microscope to confirm the cleaning result according to the cosolvent after metal etching.

※ Explanation of code for main part of drawing

11 carbon dioxide source 12 supply pipe

13 high pressure pump 14 common solvent supply source

15 ethanol source 16 heater

17: high pressure cleaning container 18: circulation pump

19: circulation tube 20: separator

21: discharge pipe 22: recovery pipe

23: carbon dioxide condensation container 24: exhaust pipe

The present invention relates to a cleaning method and a cleaning apparatus for manufacturing a semiconductor. More particularly, the present invention provides a cleaning method and apparatus for manufacturing a semiconductor that can improve productivity by easily performing cleaning without requiring a drying process by applying dry cleaning using supercritical carbon dioxide and a cosolvent. It is about.

The wet cleaning method, which is widely used in semiconductor manufacturing technology, is complicated by repeated cleaning and drying processes, and it is easy to generate particles that contaminate the wafer, which is likely to cause back contamination. Problems have arisen due to the formation of water spots on the effluent, the possibility of high corrosion, the increase of ultrapure water purification and wastewater treatment costs.

In particular, conventional conventional RCA cleaning has caused damage due to a large amount of chemical solvents or polymers have not been completely removed. Therefore, new wet solvents have been developed. It is difficult to penetrate into ultra-fine structures of less than 100 nm due to the nature of the film. Especially, it is not easy to penetrate into vias / trench having low aspect ratios and high aspect ratios. Since the removal of the photoresist is not easy, in order to solve this situation, the development of a gas phase or dry cleaning technology is required.

Dry cleaning has the advantages of adaptability to ultra fine structures, elimination of drying processes, ease of recovery and recovery of contaminants, suppression of waste water generation and reduction of production costs. However, when the photoresist is removed by oxygen plasma ashing, which is used for dry cleaning, there are problems such as damage caused by oxygen plasma and metal contamination. Cleaning does not have damage such as wet method or plasma dry cleaning, but there are many problems to be solved such as environmental problems caused by ozone generation.

Currently, in the conventional semiconductor manufacturing process, the wafer is processed not only after metal etching but also through two steps of partial dry and wet processes, ie, ashing and organic strip process, to remove photoresist and etching residues. As the progress of the painting process after the deposition of the metal layer is increasing, there is a problem that wastes a lot of resources, there is a problem such as a large cost to waste water treatment.

Therefore, as described above, in the semiconductor manufacturing process, there is a demand for a wafer cleaning method that enables the elimination of the drying process, the easy recovery and recovery of contaminants, the suppression of waste water generation, and the reduction of operating costs. In particular, in order to manufacture next-generation semiconductors, ultra-precision cleaning is essential in forming and manufacturing ultra-fine patterns.

Meanwhile, in the known patent technology, a semiconductor wafer cleaning method using a supercritical process using a mixture of various co-solvents such as supercritical carbon dioxide and propylene carbonate has been introduced, but most of the wafer cleaning methods have omitted the etching process. It was limited to the removal of the photoresist on the photolithography process.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning method and a cleaning apparatus for manufacturing a semiconductor that can improve productivity by easily performing cleaning without requiring a drying process by applying dry cleaning using supercritical carbon dioxide and a cosolvent. There is.

Another object of the present invention is to introduce a process that uses environmentally friendly supercritical carbon dioxide while retaining the solubility of liquids, the diffusivity, penetration, and dispersing properties of gas, and supplementing the disadvantages of conventional wet cleaning. To provide a cleaning method and a cleaning device for the production of.

Cleaning method for manufacturing a semiconductor according to the present invention, in the semiconductor manufacturing process including a photolithography process, (1) a high-pressure cleaning container with a heating source (hereinafter, the high-pressure cleaning container in the present invention is a 'heating source is Attaching the wafer to be cleaned in the attached high pressure cleaning container; (2) the supercritical state of carbon dioxide and co-solvent in a supercritical state while supplying carbon dioxide at a pressure of 100 to 200 atm in a temperature range of 40 to 100 ° C. to form a single phase to clean the surface of the wafer. A cleaning step of supplying a mixed solvent in which carbon dioxide and a cosolvent are mixed in a single phase to clean the wafer; (3) a rinsing step of rinsing the wafer with a mixture of supercritical carbon dioxide and ethanol and / or supercritical or liquid carbon dioxide after the cleaning step; (4) a step of removing carbon dioxide and cosolvent and ethanol from the high pressure washing vessel; (5) a condensation step of condensing in a liquid state to separate and reuse carbon dioxide after the removing step; And (6) withdrawing the wafer after depressurizing the high pressure cleaning container.

The cosolvent in the mixed solvent consists of cyclohexanone, meta-cresol, ACT935 (trade name of Air Products, Inc., U.S.A .; specific gravity of 1.040 at 25 ° C, boiling point of 125.0 ° C, pH 11.0), or a mixture of two or more thereof. It may be selected from the group.

The wafer to be cleaned in the cleaning step is a wafer after an oxide etch or poly etch including a hard-baked wafer, and in the case of a photoresist and an etch removing process, cyclohexanoxy with the co-solvent Non or meta-cresol may be used.

ACT935 may be used as the co-solvent when the wafer to be cleaned in the cleaning process is a wafer after metal etching, and a photoresist and metal etching removal process.

The cosolvent in the mixed solvent may be less than 15% by volume of the total volume of the mixed solvent.

In the cleaning step, the mixed solvent may be cleaned by a pulsed phase supply intermittently contacting the wafer.

Cosolvents and contaminants remaining on the wafer after the cleaning step may be removed by supplying a mixture of supercritical carbon dioxide and ethanol and / or only supercritical or liquid carbon dioxide.

In addition, the cleaning apparatus for manufacturing a semiconductor according to the present invention, a carbon dioxide supply source connected to the high pressure washing vessel through a supply pipe for supplying carbon dioxide, a high pressure pump for sending the carbon dioxide at a high pressure, connected to the supply pipe common Cosolvent supply source for supplying a medium and ethanol source for supplying ethanol, a heater installed on the supply pipe for heating the carbon dioxide and the co-solvent and ethanol, a circulation pump for circulating the solvent connected to the high pressure washing vessel and circulation Tube, a separator connected to the high pressure washing vessel to separate the solvent drawn out from the high pressure washing vessel into a gaseous carbon dioxide and a liquid co-solvent and ethanol, a recovery tube for conveying the separated gaseous carbon dioxide to the liquid state And carbon dioxide condensation vessels. .

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

A cleaning method for manufacturing a semiconductor according to the present invention includes: a semiconductor manufacturing process including a photolithography process, comprising: (1) a mounting step of mounting a wafer to be cleaned on a high pressure cleaning container (17); (2) the supercritical carbon dioxide while supplying carbon dioxide at a pressure of 100 to 200 atm in a temperature range of 40 to 100 ° C. so that the supercritical carbon dioxide and the cosolvent form a single phase to clean the surface of the wafer. And a cleaning step of supplying a mixed solvent in which a cosolvent is mixed with a single phase to clean the wafer. (3) a rinsing step of rinsing the wafer with a mixture of supercritical carbon dioxide and ethanol and / or supercritical or liquid carbon dioxide after the cleaning step; (4) removing the carbon dioxide, co-solvent and ethanol from the high-pressure cleaning container (17); (5) a condensation step of condensing into a liquid state to separate and reuse gaseous carbon dioxide after the removing step; And (6) depressurizing the high-pressure cleaning container 17 and then withdrawing the wafer. The mounting step of (1) is a step of mounting the wafer to be cleaned in the high pressure cleaning container 17, by supplying carbon dioxide into the same container as the high pressure cleaning container 17 having a constant volume of the high pressure cleaning container ( 17) The carbon dioxide is pressurized in the supply pipe 12 for supplying carbon dioxide to the high-pressure cleaning container 17 to maintain a supercritical state, and the supercritical carbon dioxide forms a single phase with the cosolvent and ethanol, respectively. Contact with the surface of the wafer to enable cleaning and rinsing. Accordingly, each of the mixed solvents in which the carbon dioxide, the co-solvent and the ethanol are mixed in a supercritical state in the high pressure cleaning container 17 forms a single phase, and comes into contact with the wafer introduced into the high pressure cleaning container 17 to perform cleaning and rinsing. Make it possible. The cleaning step of (2) is to supply carbon dioxide at a pressure of 100 to 200 atm over a temperature range of 40 to 100 ° C. so that the supercritical carbon dioxide and the cosolvent form a single phase to clean the surface of the wafer. Thereby cleaning the wafer by supplying a mixed solvent in which the supercritical carbon dioxide and the cosolvent are mixed into a single phase. In this step, the carbon dioxide causes the penetration and expansion of the photoresist polymer to dissolve the photoresist polymer together with the added cosolvent. In this step, substantially no photoresist or metal etchant on the wafer is removed. In this case, the cleaning can be efficiently performed by providing all of the advantages of the gas, which is an advantage of the gas by the carbon dioxide in the supercritical state, the superiority of the penetration, the dispersibility, and the solubility of the liquid by the cosolvent. When the mixed solvent is heated to less than 40 ℃, the effect of improving the cleaning power is not enough, there may be a problem that takes a lot of time to wash the productivity is lowered, on the contrary, if it exceeds 100 ℃, supercritical carbon dioxide at a constant pressure There may be a problem that the density of the lower so that the solubility is reduced. In addition, when the pressure for supplying the carbon dioxide is less than 100 atm, there may be a problem that the solubility of the supercritical carbon dioxide is lowered, on the contrary, if the pressure exceeds 200 atm, it is difficult to maintain, repair, etc. due to excessive pressure There may be a problem. The rinsing step (3) is a step of rinsing the wafer with a mixture of supercritical carbon dioxide and ethanol and / or supercritical or liquid carbon dioxide only after the cleaning step, wherein the dissolved polymer is desorbed from the wafer surface, Removing remaining solvent components that may be present on the surface of the. After rinsing, only by exposing to atmospheric pressure to reduce the pressure, or by slightly heating, all of the supercritical or liquid carbon dioxide can be easily vaporized and removed, and no drying process is required, which is a problem after wet cleaning. It will provide an advantage to prevent the problem, such as the formation of spots at the source. Removing step (4) is a step of removing carbon dioxide, co-solvent and ethanol from the high-pressure cleaning container 17, the gaseous carbon dioxide separated therefrom is in a liquid state in the subsequent condensation step (5) Condensed into carbon dioxide, recovered and reused for cleaning. The finally cleaned wafer is decompressed separately through the exhaust pipe 24 connected to the high-pressure cleaning container 17 in the subsequent drawing out step (6). After that, the wafer can be taken out.

According to the cleaning method for fabricating a semiconductor according to the present invention as described above, carbon dioxide, which has been subjected to pressurization and decompression, leaves no residue at all through a phase change. As a result, there is no need for a drying step due to deionized water rinsing in the existing wet process. The low surface tension and low viscosity of the supercritical carbon dioxide allows the removal of particles by reducing the thickness of the boundary layer of the surface. In addition, it is possible to overcome the limited microstructure that liquid chemicals can penetrate due to the low surface tension of supercritical carbon dioxide, thereby enabling ultra-fine pattern patterning and ultra-precision cleaning required in the manufacturing process. . After the heat treatment, the photoresist has chemical and physical resistance, and it is very difficult to remove it completely, but it is a very important matter that is essential for the semiconductor manufacturing process. Therefore, in order to remove photoresist that is hardly removed using only supercritical carbon dioxide, the present invention has led to the development of a process of adding a cosolvent.

The cosolvent in the mixed solvent may be selected from the group consisting of cyclohexanone, meta-cresol, ACT935 or a mixture of two or more thereof. These cosolvents provide the solubility which is an advantage of the liquid, and serve to easily remove polymers such as photoresist which are not removed by the supercritical carbon dioxide. However, the supercritical carbon dioxide which forms a single phase together compared to the conventional cleaning by the use of a co-solvent provides superior gas diffusion, penetration, and dispersibility, which enables the fabrication of ultra-fine semiconductors. do.

In the cleaning process, the wafer to be cleaned is an oxide etched or polyetched wafer, and in the case of the photoresist and etching removal process, cyclohexanone or meta-cresol is used as the cosolvent. Can be used. This is because the cleaning effect can be greatly improved by using the cyclohexanone or meta-cresol as the cosolvent which is excellent in solubility in photoresist.

ACT935 may be used as the co-solvent when the wafer to be cleaned in the cleaning process is a wafer after metal etching, and a photoresist and metal etching removal process. This is due to the fact that the cleaning effect can be greatly improved by using ACT935, which has excellent cleaning properties for the metal etchant as a cosolvent by decomposing or dissolving the metal etchant.

The cosolvent in the mixed solvent may be within 15% by volume of the total volume of the mixed solvent.

In the cleaning step, the mixed solvent may be cleaned by a pulsed phase supply intermittently contacting the wafer. The cleaning by the pulsed phase supply increases the contact effect between the mixed solvent and the wafer by imparting fluidity of the mixed solvent to continuously remove dissolved photoresist and metal etchant, thereby enhancing the cleaning effect, and external filter. There is an advantage that can prevent the particle removal effect and re-contamination of the wafer by.

Cosolvents and contaminants remaining on the wafer after the cleaning step may be removed by supplying a mixture of supercritical carbon dioxide and ethanol and / or only carbon dioxide in a supercritical or liquid state. The supercritical mixture of carbon dioxide and ethanol may be rinsed as well as rinsing to maximize the cleaning action. Preprocessing time, including cleaning time and rinsing time, may range from 10 to 60 minutes.

In addition, as shown in Figure 1, the cleaning device for manufacturing a semiconductor according to the present invention, is initially connected to the high-pressure cleaning vessel 17 through a supply pipe 12 to supply carbon dioxide and to replenish atmospheric emissions A carbon dioxide supply source 11, a high pressure pump 13 for sending the carbon dioxide at a high pressure, a co-solvent supply source 14 for supplying a cosolvent connected to the supply pipe 12 and an ethanol source 15 for supplying ethane In addition, a heater 16 installed on the supply pipe 12 to heat the carbon dioxide and the cosolvent and ethanol, a circulation pump 18 and a circulation pipe connected to the high pressure washing vessel 17 to circulate the solvent ( 19), a separator 20 and a gaseous carbon dioxide which are connected to the high pressure washing vessel 17 to separate the solvent withdrawn from the high pressure washing vessel 17 into gaseous carbon dioxide, a liquid cosolvent and ethanol. It comprises a recovery pipe 22 and a carbon dioxide condensation container 23 for collecting, condensing and reusing the cow. By the above configuration, the high pressure pump 13 for sending the carbon dioxide at high pressure pressurizes the carbon dioxide to a pressure of 100 to 200 atm so that the carbon dioxide is discharged from the carbon dioxide supply source 11 and the carbon dioxide condensation container 23. Pressurized and supplied to the high-pressure washing vessel 17 through the supply pipe 12 to form a closed space having a constant volume of carbon dioxide can be maintained in a supercritical state. On the other hand, the supply pipe 12 is connected to the co-solvent supply source 14 and the ethanol supply source 15, the single phase mixed solvent in which the carbon dioxide and co-solvent or ethanol of the supercritical state is mixed in the washing and rinsing step, respectively It can be supplied to the high pressure cleaning container (17). In order to heat the carbon dioxide, co-solvent and ethanol, a heater 16 is installed on the supply pipe 12 to heat the mixed solvent in a temperature range of 40 to 100 ° C. to improve the cleaning effect. The circulation pump 18 is connected to the high-pressure cleaning container 17 and circulates the mixed solvent through a circulation pipe 19 with a filter to prevent recontamination of particles and the like on the wafer. In addition, the separator 20 is connected to the high pressure washing vessel 17 to separate the solvent withdrawn from the high pressure washing vessel 17 into a gaseous carbon dioxide, a liquid co-solvent and a liquid ethanol so that the gaseous carbon dioxide is Condensation is recovered and reused in the liquid state, and the liquid cosolvent and ethanol are finally discharged by post treatment. The post-treatment in the above may be understood to mean the atmospheric treatment and water treatment, such as normal air purification and crystallization so as not to cause environmental pollution problems by filtration, water purification, and the like.

According to the above configuration, the supercritical carbon dioxide and cosolvent constitute a single phase mixed solvent to clean the surface of the wafer introduced into the high pressure cleaning container 17, and after the cleaning, the single phase of supercritical carbon dioxide and ethanol or Only rinse with supercritical or liquid carbon dioxide.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described.

The following examples are intended to illustrate the invention and should not be understood as limiting the scope of the invention.

Comparative Example 1

First, the experiment was performed to remove the heat-treated photoresist on the wafer using only supercritical carbon dioxide. The wafer used here was a p-type wafer coated with a positive photoresist, which was heat-treated, and the resist film thickness was about 1.18 mu m. The pressure was 140 atm and the temperature was performed at 40 deg. C and 80 deg. After the execution, the results of observing the cleaning before and after using a scanning electron microscope (SEM) are shown in FIGS. 2A (before washing), FIG. 2B (after washing at 40 ° C) and FIG. 2C (after washing at 80 ° C). . As a result, it was confirmed that the photoresist was not removed as shown in FIGS. 2A to 2C.

Comparative Examples 2 to 4 and Examples 1 to 2

The wafers treated in the same manner as the wafers used in Comparative Example 1 were used, and the cleaning conditions were as shown in Table 1, and the pressure of carbon dioxide was treated at 140 atm, and the results are shown in FIGS. 3A to 3E. .

division Common solvent Volume% (of cosolvent) Cycle time (minutes) Temperature (℃) Comparative Example 2 Propylene carbonate 5% 20 minutes 40 ℃ Comparative Example 3 Acetylacetone 5% 20 minutes 40 ℃ Comparative Example 4 Hydrogen peroxide 5% 20 minutes 40 ℃ Example 1 Cyclohexanone 5% 20 minutes 40 ℃ Example 2 Meta-cresol 5% 20 minutes 40 ℃

As shown in Figures 3a to 3e, it was confirmed that propylene carbonate, acetylacetone, hydrogen peroxide, cyclohexanone and meta-cresol all showed an excellent cleaning effect.

Examples 3 to 5

A wafer treated in the same manner as the wafer used in Comparative Example 1 was used, and the content of cyclohexanone was 5% by volume (Example 3), 10% by volume (Example 4) and 15% by volume (Example). 5) were treated at 80 ° C. and 140 atm, and the results are shown in FIGS. 4A (5% by volume), 4B (10% by volume) and 4C (15% by volume).

As shown in Figure 4a to 4c, it was confirmed that the cleaning effect is excellent in all.

Example 6 and Comparative Examples 5-7

The cleaning effect of the wafer after metal etching with the cosolvent was examined.

The layer structure is made of silicon / silicone Busan film 4000 막 / titanium 300Å / titanium nitride 900Å / aluminum 8000Å / titanium 100Å / titanium nitride 400 (Si / Si rich Oxide 4000 Ox / Ti 300Å / TiN 900Å / Al 8000Å / Ti 100Å / TiN 400Å) The wafer has a minimum feature size of 0.18 μm and a photoresist produced during the metal etching process.

The cleaning conditions were as shown in Table 2 below, and the pressure of carbon dioxide was treated at 140 atmospheres, and the results are shown in FIGS. 5A to 5E.

division Common solvent Volume% (of cosolvent) Cycle time (minutes) Temperature (℃) Example 6 ACT935 2% 20 minutes 40 ℃ Comparative Example 5 Tetramethyl ammonium hydroxide 2% 20 minutes 40 ℃ Comparative Example 6 Propylene carbonate 2% 20 minutes 40 ℃ Comparative Example 7 Dimethyl sulfoxide 2% 20 minutes 40 ℃

FIG. 5A shows an untreated control, in which a polymer material generated during an etching process remains on a metal line on an aluminum-etched wafer surface, which shows a rabbit ears-like contamination pattern on the surface. In FIG. 5B (Example 6), it was confirmed that the rabbit-ear-shaped contamination was cleanly removed. However, in FIG. 5C (Comparative Example 5), FIG. 5D (Comparative Example 6), and FIG. 5E (Comparative Example 7), it was confirmed that there was almost no decontamination effect as in Example 6 according to the present invention.

As a result of the synthesis of the above embodiments, according to the present invention, photoresist, in particular, photoresist after oxide etching or polyetch, and photoresist after etching and metal etching, and metal etching after taking advantage of both dry and wet cleaning It was confirmed that the cleaning effect of the contaminants, such as very excellent.

Accordingly, the present invention provides a cleaning method and a cleaning apparatus for manufacturing a semiconductor that can improve productivity by easily performing a cleaning process without requiring a drying process by applying dry cleaning using supercritical carbon dioxide and a cosolvent. It is effective. In addition, by rinsing only with a mixture of supercritical carbon dioxide and ethanol and / or carbon dioxide in a supercritical or liquid state, the drying process may be omitted and water spots may not remain on the wafer after drying, thereby improving productivity. To provide.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (8)

delete In the semiconductor manufacturing process including a photolithography process, (1) mounting step of mounting a wafer to be cleaned in a high pressure cleaning container; (2) the supercritical carbon dioxide while supplying carbon dioxide at a pressure of 100 to 200 atm in a temperature range of 40 to 100 ° C. so that the supercritical carbon dioxide and the cosolvent form a single phase to clean the surface of the wafer. And a cleaning step of supplying a mixed solvent in which a cosolvent is mixed with a single phase to clean the wafer. (3) a rinsing step of rinsing the wafer with a mixture of carbon dioxide and ethanol in a supercritical state or only carbon dioxide in a supercritical or liquid state after the cleaning step; (4) a step of removing carbon dioxide and cosolvent and ethanol from the high pressure washing vessel; (5) a condensation step of condensing into a liquid state to separate and reuse gaseous carbon dioxide after the removing step; And (6) a withdrawal step of withdrawing the wafer after depressurizing the high pressure cleaning container; It is made, including The cosolvent in the mixed solvent is selected from the group consisting of cyclohexanone, meta-cresol, ACT935 or a mixture of two or more thereof. The method of claim 2, In the cleaning process, the wafer to be cleaned is an oxide etched or polyetched wafer, and in the case of the photoresist and etching removal process, cyclohexanone or meta-cresol is used as the cosolvent. Cleaning method for the manufacture of a semiconductor, characterized in that it is used. The method of claim 2, And ACT935 is used as the co-solvent when the wafer to be cleaned in the cleaning step is a wafer after metal etching and the photoresist and metal etching removal process. The method of claim 2, And said cosolvent in said mixed solvent is within 15 volume% of the total volume of said mixed solvent. The method of claim 2, And a mixed solvent in the cleaning step is cleaned by a pulsed phase supply intermittently contacting the wafer. The method of claim 6, The cosolvent and contaminants remaining on the wafer after the cleaning step are removed by supplying a mixture of supercritical carbon dioxide and ethanol or only carbon dioxide in a supercritical or liquid state. A carbon dioxide source connected to a high pressure washing vessel through a supply pipe to supply carbon dioxide, a high pressure pump for delivering the carbon dioxide at high pressure, a cosolvent supply source connected to the supply pipe to supply a cosolvent, and an ethanol source to supply ethanol, A heater installed on the supply pipe for heating the carbon dioxide and the cosolvent and ethanol, a circulation pipe connected to the high pressure cleaning container and a circulation pump and a filter for circulating a solvent, and a high pressure cleaning container connected to the high pressure cleaning container A semiconductor comprising a separator for separating the solvent extracted from the cleaning vessel into gaseous carbon dioxide and a liquid co-solvent and ethanol, and a recovery tube and a carbon dioxide condensation vessel for recovering, condensing and reusing the separated gaseous carbon dioxide. Above manufacture One cleaning device.

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