KR100713209B1 - High pressure cleaner for cleaning apparatus - Google Patents

Abstract

The present invention provides a high pressure cleaner for use in a cleaning apparatus which is simple in processing and short in time, and excellent in effect, which includes (i) a wafer mount having protrusions, (ii) a mixture, etc. An upper element having an injection hole for injection, a wafer mount holder for inserting the protrusion of the wafer mount to fix the wafer mount, and a pneumatic cylinder insert for inserting a pneumatic cylinder slid from the side. (iii) a lifting pneumatic cylinder for moving the upper element up and down, (iv) a pneumatic cylinder insertion portion into which a pneumatic cylinder slid from a side can be inserted, and an outlet through which a mixture and the like can be discharged; A lower yoke forming a space between the upper element and the wafer mounter (V) When the upper element is lowered and engaged with the lower element, the pneumatic cylinder insertion part of the upper element slides into the pneumatic cylinder insertion part of the lower element and the lower element, thereby attaching the upper element and the lower element. It provides a high pressure cleaner, characterized in that it comprises a.

Description

High pressure cleaner for cleaning apparatus

1 is a configuration diagram schematically showing a cleaning apparatus used in a cleaning process according to an embodiment of the present invention.

2 is a block diagram schematically showing a cleaning apparatus used in a cleaning process according to another preferred embodiment of the present invention.

3 is a front view schematically showing the high pressure cleaner of FIG.

4A is a front view schematically showing an upper element of the high pressure cleaner of FIG. 3.

4B is a bottom view schematically showing the upper element of the high pressure cleaner of FIG. 3.

FIG. 5A is a conceptual cross-sectional view schematically showing the lower elements of the high pressure cleaner of FIG. 3.

FIG. 5B is a conceptual plan view schematically showing the lower elements of the high pressure cleaner of FIG. 3.

FIG. 6A is a conceptual diagram schematically showing the combination of the upper element of FIG. 4A, the lower element of FIG. 5A, and the single wafer mounter.

6B is a plan view schematically illustrating the wafer mounter of FIG. 6A.

7A is a conceptual diagram schematically illustrating a modification of FIG. 6A.

FIG. 7B is a plan view schematically illustrating the wafer mounter of FIG. 7A.

FIG. 8 is a graph schematically showing a relationship between time and pressure for the entire section of the cleaning process using the cleaning device of FIG. 2.

9 is a photograph showing a homogeneous transparent phase mixture in a supercritical state used for supercritical cleaning.

FIG. 10A is a cross-sectional photograph of a wafer subjected to a back-end-of-the-line (BEOL) process before being cleaned by a cleaning process in accordance with one preferred embodiment of the present invention.

10B to 10E are cross-sectional photographs after cleaning the wafer of FIG. 10A by a cleaning process according to an exemplary embodiment of the present invention.

FIG. 10F is a cross-sectional photograph after cleaning the wafer of FIG. 10A by a wet cleaning process instead of the cleaning process according to the preferred embodiment of the present invention.

FIG. 10G is a cross-sectional photograph after cleaning the wafer of FIG. 10A by a cleaning process that does not satisfy the conditions in accordance with one preferred embodiment of the present invention. FIG.

FIG. 11A is a cross-sectional photograph before cleaning a wafer subjected to a front-end-of-the-line (FEOL) process by a cleaning process according to a preferred embodiment of the present invention, and FIG. 11B is a surface photograph.

11C is a cross-sectional photograph after cleaning the wafers of FIGS. 11A and 11B by a cleaning process according to a preferred embodiment of the present invention, and FIG. 11D is a surface photograph.

12A is a photograph of the surface of a wafer that has undergone a post ion implantation process prior to cleaning the wafer in a cleaning process according to a preferred embodiment of the present invention.

12B and 12C are photographs of the surface after cleaning the wafer of FIG. 12A by a cleaning process according to an exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

1-12: on-off automatic valve 20: gaseous carbon dioxide source

21: liquid carbon dioxide source 22: supply pipe

23: carbon dioxide condensation container 24: high pressure pump

25: additive source for cleaning 26: additive source for rinsing

27: additive supply pump for cleaning 28: additive supply pump for rinsing

29: circulation pump 31, 32, 33: heater

51: liquid carbon dioxide fill valve 52, 53: pressure regulator

54: pressure regulating valve 55: back pressure regulator

60: high pressure cleaner 61: separator

63: washing column 64: adsorption column

70: homogeneous transparent phase mixer

The present invention relates to a cleaning apparatus and a high pressure cleaner used therein, and more particularly, to a cleaning apparatus and a high pressure cleaner used therein which are excellent in effect while simplifying the process and reducing the time required.

During the semiconductor wafer manufacturing process, a photoresist (PR) layer must be formed on the semiconductor substrate and then removed after a predetermined process. This step is called a cleaning step. This cleaning step may include a front end of the line (FEOL), a back end of the line (BEOL) or ion implantation. This may be done after various steps of the same wafer fabrication process, wherein the cleaning step is to remove contaminants such as photoresist or photoresist residues from the surface of the substrate in the ultrafine pattern. To this end, a wet cleaning process using water and various solvents and a dry cleaning process using supercritical carbon dioxide have been developed.

Conventional wet cleaning methods, which are widely used, including the RCA method, have the advantage of suitably performing the cleaning according to the purpose, but have many problems that are not suitable for use in the manufacture of ultra-large scale integrated circuits (ULSI). For example, wet cleaning has a problem in that the wettability of the cleaning solution is insufficient into a high aspect ratio microstructure, and it is vulnerable to particle generation due to repeated rinsing and drying processes. In addition, there is a problem of metal contamination that is contaminated from the chemical liquid in the liquid, water mark (corrosion) and corrosion problems, cost problems for the purification of ultrapure water and high purity of chemicals. In addition, there was a problem that the area occupied by the equipment is large and the process is complicated, so that clustering with other process equipment is not easy, and there is a problem of environmental pollution caused by wastewater and wastewater, and a problem of increased wastewater treatment cost.

In addition, when using conventional RCA cleaning, since a large amount of chemical solvent is used, there is a problem that damage occurs in a wafer or the like and a photoresist to be removed is not completely removed. In order to solve this problem, new solvents have been developed. However, the conventional wet cleaning process is difficult to penetrate into the ultra-fine structure of 65 nm or less due to the nature of the molecular structure of the cleaning liquid. There is a problem that it is not easy to clean the metal and the low-K insulating material.

In order to solve this problem, the development of plasma, gas phase or supercritical dry cleaning technology is required. However, when the photoresist is removed by oxygen plasma ashing, which is used for dry cleaning, the wafer is damaged and contaminated by oxygen plasma, and there is a problem that additional wet cleaning is required due to the remaining contaminants. . In addition, the recently developed cleaning using the oxidation of ozone does not have damage such as a wet method or plasma dry cleaning, but there are problems such as environmental pollution due to ozone generation.

On the other hand, the photoresist and the like remain on the wafer as a result of dry etching, wet etching, ashing, or ion implantation in the semiconductor manufacturing process. Therefore, conventionally, as the wafer is processed through two steps of a partial dry process and a wet process, that is, an ashing and an organic strip process to remove it, the number of processes increases, wastes resources, and enormous cost for wastewater treatment. There was a problem.

In addition, when wet cleaning is involved as described above, a separate drying process such as spin drying, IPA steam drying, and Marangoni drying is required. Such drying methods leave water spots, cause stress, and cause static electricity. There was a problem that the possibility of recontamination caused by. In particular, IPA steam drying has to maintain a high temperature (200 ℃ or more) for IPA vaporization, there was a problem that the IPA usage is large.

Meanwhile, a method of cleaning a semiconductor wafer using a supercritical process using a mixture of supercritical carbon dioxide and various cosolvents has been introduced. However, it is impossible to form a homogeneous transparent phase by simply mixing a polar co-solvent with non-polar carbon dioxide in a supercritical state, which does not solve the problem of conventional wet cleaning, and the cleaning efficiency is low, even if a homogeneous transparent supercritical state is formed. There is a problem in that high cost is required as it requires an ultra high temperature of more than 100 ℃ and an ultra high pressure of more than 300 bar. In order to solve this problem, even when the surfactant is introduced, a separate mixer or an ultrasonic apparatus is required to form a homogeneous transparent phase in a supercritical state, and it takes a long time.

In addition, the use of high-purity carbon dioxide of 99.99% or more for semiconductor manufacturing, there was a problem that conventionally does not implement an efficient purification process for purifying and recovering used carbon dioxide.

The present invention has been made to solve various problems including the above problems, and an object of the present invention is to provide a cleaning apparatus and a high pressure cleaner used therein which are excellent in effect while simplifying the process and reducing the required time.

The present invention provides (i) a wafer mounter having protrusions on which a wafer to be cleaned is mounted, (ii) an injection hole through which a mixture or the like can be injected downward, and a protrusion of the wafer mounter is inserted to fix the wafer mounter. A pneumatic cylinder insert for inserting a pneumatic cylinder slid from the side, and (iii) a lifting pneumatic cylinder for moving the upper element up and down, and (iv) A lower part forming a space in which the wafer mounter can be disposed between the upper element and a pneumatic cylinder insertion part into which a pneumatic cylinder which is slid from a side can be inserted, and an outlet through which a mixture or the like can be discharged; Element and (v) inserting the pneumatic cylinder of the upper element when the upper element is lowered and engaged with the lower element. And is slid into the pneumatic cylinder insertion portion of the bottom element provides a high-pressure cleaner, characterized in that it comprises a pneumatic cylinder-mounted coupling the upper element and the lower element.

According to another aspect of the present invention, the space between the upper element and the lower element is sealed from the outside between the edge of the surface in the lower element direction of the upper element and the edge of the surface in the upper element direction of the lower element. It is possible to further provide a sealing material.

According to another feature of the invention, the first bent portion is provided at the edge of the surface in the lower element direction of the upper element, the second bent portion is provided at the edge of the surface in the upper element direction of the lower element, The first bent portion and the second bent portion may be provided with a first sealing material and a second sealing material, respectively.

According to another feature of the present invention, a groove is formed in the circumferential direction of the wafer mounter on a surface of the wafer mounter in the direction of the upper element, and a plurality of spray outlets are provided along the groove in the circumferential direction of the wafer mounter. It can be done.

According to another feature of the invention, the injection hole provided in the upper element may be provided so that the material injected through the injection hole provided in the upper element is injected in the groove direction of the wafer mounter.

According to another feature of the invention, the upper element may be further provided with an upper element guide pin, the lower element may be further provided with a guide pin insertion portion into which the upper element guide pin is inserted.

According to another feature of the invention, the inlet and the outlet may be provided in opposite directions to each other.

According to still another feature of the present invention, a heating source or cooling source for controlling the temperature of the high-pressure cleaner may be further provided.

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

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

1 is a configuration diagram schematically showing a cleaning apparatus used in a cleaning process according to an embodiment of the present invention.

As shown in FIG. 1, a washing apparatus used in a washing process according to an exemplary embodiment of the present invention includes a high pressure cleaner 60, a gaseous carbon dioxide source 20 and a liquid carbon dioxide source (connected to the high pressure cleaner 60). 21), a high pressure pump 24 for sending carbon dioxide at a high pressure, a cleaning additive source 25 for supplying a cleaning additive, a rinsing additive source 26 for supplying a rinsing additive, carbon dioxide and an additive The heaters 31, 32, and 33 installed on the supply pipes L2, L3, and L4 for heating the same, and the homogeneous transparent phase mixer for supplying a certain amount of the cleaning additive while forming the homogeneous transparent phase mixture in the supercritical state. 70, a pressure control valve 54 connected to the high pressure cleaner 60 to maintain a constant pressure, and a mixture of the gaseous carbon dioxide and the mixture discharged from the high pressure cleaner 60 connected to the high pressure cleaner 60; Separator 61 for separating body additives, gas washing column 63 and adsorption column 64 for purifying separated gaseous carbon dioxide, and carbon dioxide condensation vessel 23 for condensing and reusing the purified gas. And a heat medium and a refrigerant supply unit, and on-off automatic valves 1 to 12.

Here, the supercritical state means a state at or above a critical temperature and a critical pressure, and the physical properties of the supercritical fluid are very different from those of the fluid in a normal state. That is, in the supercritical state, the physical properties of the fluid such as density, viscosity, solubility, heat capacity, or dielectric constant of the fluid are changed drastically. This supercritical state is a state above the critical temperature and the critical pressure, where the critical temperature refers to the temperature at which the gas does not liquefy into a liquid even when the pressure is increased, and the critical pressure is referred to as the liquid at high temperature. The pressure does not vaporize with gas. For example, for carbon dioxide, the critical temperature is known to be approximately 31.06 ° C. and the critical pressure is approximately 73.8 bar. Such supercritical fluids are fluids indistinguishable from gaseous and liquid states. The supercritical fluid has a liquid-like property, which is high in dissolving power, and also has a gas-like property, which has low viscosity, high diffusion rate, and small surface tension, thereby making it easy to penetrate the microstructure.

The gaseous carbon dioxide source 20 or the liquid carbon dioxide source 21 is connected to the high pressure cleaner 60 through supply pipes L1 and L2 for supplying carbon dioxide. The cleaning additive source 25 and the rinsing additive source 26 are connected together to the supply pipe L3, so that the cleaning additive and the rinsing additive are supplied through the cleaning additive supply pump 27 and the rinse additive supply pump 28. To a homogeneous transparent phase mixer (70). In addition, the homogeneous transparent phase mixer 70 connected to the high-pressure cleaner 60 is a homogeneous transparent phase mixture of the supercritical state at a time by using the mixing effect of the cleaning additive and supercritical carbon dioxide in the atmospheric pressure or the low pressure state by a large pressure difference. To form. In addition, the homogeneous transparent phase mixer 70 may mix the rinse additive and the supercritical carbon dioxide to form a rinse mixture in a supercritical state. This will be described later.

Of course, as shown in the schematic configuration diagram of the cleaning apparatus used in the cleaning process according to another preferred embodiment of the present invention shown in Figure 2, the circulation pipe (L8) and the circulation pump 29 may be further provided. . The circulation tube L8 and the circulation pump 29 are connected to the homogeneous transparent phase mixer 70 to maintain the supplied supercritical homogeneous transparent phase mixture in a stable manner by forming an external circulation flow of the high pressure cleaner 60. It serves to enhance the mixing effect and heat exchange effect.

The cleaning process made using the above cleaning apparatus will be described in detail as follows.

First, the wafer is mounted in the high pressure cleaner 60. Specific methods for mounting the wafer in the high pressure cleaner 60 will be described later.

When the wafer is mounted in the high pressure cleaner 60, the high pressure (more than 20 psig) gaseous carbon dioxide of low pressure (below 20 psig) is first applied by the pressure regulators 52 and 53 to the corresponding on-off automatic valve from the gaseous carbon dioxide source 20. Through 3 and 4 and the supply pipe (L1) is introduced into the high pressure cleaner (60). This serves to remove fine contaminants inside the high pressure cleaner (60). When the high pressure cleaner 60 is sealed (to be described later), high pressure gas (about 30 bar to 50 bar) of high purity gaseous carbon dioxide is introduced, which serves to smoothly introduce the mixed fluid to be made thereafter.

On the other hand, carbon dioxide in a supercritical state at a pressure higher than the cleaning additive and the supercritical cleaning pressure (preferably at a pressure of about 120 bar to 300 bar in a high pressure cleaner) flows into the homogeneous transparent phase mixer 70. This will be described later. Supercritical carbon dioxide is supplied from the carbon dioxide condenser (23), which automatically opens and closes the on-off automatic valves (1, 2, 5, 8) on the supply pipe (L2) and a high pressure pump (24) for supplying carbon dioxide. Supplied by. Of course, before reaching the homogeneous transparent phase mixer 70, it may be heated by the heater 31 to be carbon dioxide in a supercritical state.

The carbon dioxide in the supercritical state is the gas carbon dioxide supplied from the gas cleaning column 63 and the adsorption column 64 condensed by the refrigerant in the carbon dioxide condenser 23. At this time, the first liquid carbon dioxide and carbon dioxide consumed in the process are supplied from the liquid carbon dioxide source 21 through the liquid carbon dioxide fill valve 51.

This supercritical carbon dioxide is mixed with the cleaning additive to be used for the cleaning step, that is, a homogeneous transparent phase mixture of the supercritical state flowing into the closed high pressure cleaner 60. In addition, the carbon dioxide in the supercritical state is mixed with the rinsing additive to be used in the rinsing step, that is, the supercritical rinse mixture introduced into the closed high pressure cleaner 60.

The additives are supplied via the on-off automatic valves 6 and 7 on the feed pipes L3 and L4 and through the metering feed pumps 32 and 33 for supplying the cleaning additives or the rinse additives. Automatically supplied from 26. In this case, the carbon dioxide and the additive to be supplied are heated to a predetermined temperature or a temperature within a predetermined range (for example, approximately 35 ° C. to 100 ° C.) by the heaters 31, 32, 33, or line heaters on the supply pipes L2, L3, and L4.

The cleaning additive is instantaneously mixed with the supercritical carbon dioxide and the homogeneous transparent phase mixer 70 by a large pressure difference, and the supercritical homogeneous transparent phase mixture used for the cleaning step is introduced into the high pressure cleaner 60. do. In more detail, the cleaning additive at atmospheric pressure or at a low pressure of 10 bar or less is supplied to the homogeneous transparent phase mixer 70, and then carbon dioxide at a pressure higher than the supercritical cleaning pressure is supplied to the homogeneous transparent phase mixer 70. As a result, a homogeneous transparent phase mixture in a supercritical state is formed at one time by utilizing the mixing effect of a large pressure difference.

In general, supercritical carbon dioxide is non-polar and the cleaning additive is generally polar. Therefore, in order to maintain the supercritical state by simply mixing them, a higher ultra-high pressure and ultra-high temperature than the above-described conditions are required. There was a problem of rising. Therefore, in order to solve this problem, in the cleaning process according to the present embodiment, the cleaning additive also includes a surfactant, so that the supercritical homogeneous transparent is easy even under the cleaning conditions such as the pressure of the above-mentioned conditions other than the ultra high pressure and the ultra high temperature. Allow phase mixtures to form. In addition, by mixing the cleaning additive and the supercritical carbon dioxide in a homogeneous transparent phase mixer 70 using a large pressure difference, the supercritical state can be easily used without using a separate mixer or an ultrasonic device. Allow a homogeneous clear phase mixture to form in a short time.

To this end, the cleaning additive may include a fluorine-based surfactant. In this case, a fluorine-based carboxylic acid having 2 to 20 carbon atoms, a perfluorinated ether polymer having an average molecular weight of 300 to 5000, or a mixture thereof can be used as the fluorine-based surfactant.

To describe the structure of the cleaning additive in more detail, the cleaning additive includes 0.01% to 90% by weight of a fluorine-based surfactant, 0.01% to 15% by weight of an aliphatic amine, 0.01% to 15% by weight of a polar organic solvent, , 0.1 wt% to 20 wt% of an alcohol solvent, 0.1 wt% to 30 wt% of an ether solvent, 0 wt% to 5 wt% of a corrosion inhibitor, and 0 wt% to 15 wt% of water. . In this case, the fluorine-based surfactant is a fluorine carboxylic acid having 2 to 20 carbon atoms, a perfluorinated ether polymer having an average molecular weight of 300 to 5000, or a mixture thereof, and the aliphatic amine is monoethanol amine, 2- (2-aminoethoxy). Ethanol, diethanol amine, iminobispropylamine, 2-methylaminoethanol, triethylaminoethanol or mixtures thereof, and the polar organic solvent is N, N'-dimethylacetamide, dimethyl sulfoxide, 1-methyl-2- Pyrrolidinone, N, N'-dimethylformamide, ammonium fluoride or mixtures thereof, alcohol solvents are methanol, ethanol, isopropanol or mixtures thereof, ether solvents are ethylene glycol methyl ether, ethylene glycol ethyl ether , Ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol methyl ether, triethylene glycol It may be ethyl ether or a mixture thereof, and the corrosion inhibitor may be catechol, gallic acid or a mixture thereof.

Of course, it is also possible to use a cleaning additive having a different composition, for example, 0% to 90% by weight of the fluorine-based surfactant, 0.1% to 15% by weight of the semiconductor cleaning stripper, 0.1% to 20% by weight of the alcohol solvent, It is also possible to use a cleaning additive comprising 0 to 15% by weight of water. In this case, the fluorine-based surfactant may be a fluorine carboxylic acid having 2 to 20 carbon atoms, a perfluorinated ether polymer having an average molecular weight of 300 to 5000, or a mixture thereof, and the alcohol solvent may be methanol, ethanol, isopropanol, or a mixture thereof. Can be.

Meanwhile, the volume of the cleaning additive in the supercritical homogeneous transparent phase mixture in which the cleaning additive and the supercritical carbon dioxide are mixed is preferably 2% by volume to 30% by volume based on the total volume.

A homogeneous transparent phase mixer 70 in which the cleaning additives as described above and carbon dioxide in a supercritical state are mixed to form a homogeneous transparent phase mixture in a supercritical state may be a high pressure cylinder or the like as a high pressure container. It can be adjusted to a predetermined temperature or a temperature within a predetermined range, to enable the quantitative supply of the required amount of the cleaning additive required for cleaning, and the cleaning additive is mixed with the supercritical carbon dioxide in a supercritical homogeneous transparent phase mixture. It has a minimum space that can form. In addition, in order to maximize the mixing effect and heat exchange effect, the homogeneous transparent phase mixer 70 may be further provided with internal and external circulation devices.

On the other hand, when the supercritical homogeneous transparent phase mixture thus formed is directly injected into the high pressure cleaner 60, the homogeneous transparent phase mixture in the supercritical state is not maintained due to a large pressure difference. Therefore, in order to prevent this, before injecting the homogeneous transparent phase mixture of the supercritical state into the high pressure cleaner 60, the auxiliary pipe (using the 3-way on-off automatic valves 5 and 8 on the supply pipe L2) The carbon dioxide of a pressure lower than the supercritical cleaning pressure is injected into the high pressure cleaner 60 through L6). At this time, the pressure of the high pressure cleaner 60 is adjusted to a predetermined pressure or a pressure within a predetermined range (for example, 10 bar to 40 bar lower than the supercritical cleaning pressure) by the pressure regulating valve 54.

As such, before injecting the supercritical homogeneous transparent phase mixture into the high pressure cleaner 60, the carbon dioxide having a pressure lower than the supercritical cleaning pressure is injected into the high pressure cleaner 60 so that the supercritical homogeneous transparent phase is subsequently injected. The mixture can be maintained intact to allow for effective cleaning. In this case, the reason for injecting carbon dioxide into the high pressure cleaner at a pressure lower than the supercritical cleaning pressure is to allow the homogeneous transparent phase mixture of the supercritical state to naturally flow into the high pressure cleaner 60 due to the pressure difference.

The homogeneous transparent phase mixture of the supercritical state formed as described above may be introduced into a high-pressure cleaner 60 filled with carbon dioxide in the supercritical state and used for washing in a stagnant state without a separate device. Of course, unlike FIG. 1, as shown in FIG. 2, the homogeneous transparent phase mixture supplied to the high pressure cleaner 60 is stably maintained and the mixing tube and the circulation pump L8 are provided to enhance the mixing effect and the heat exchange effect. 29) may be used to form an external circulation to allow for cleaning.

When the photoresist or etching residue on the wafer is removed through such cleaning, it is necessary to prevent the cleaning additives and the cleaning contaminants such as dissolved photoresist residue from remaining on the wafer surface. To this end, the rinse additive supplied from the rinse additive source 26 in the homogeneous transparent phase mixer 60 and the carbon dioxide in the supercritical state are mixed to form a rinse mixture in the supercritical state, which is then used in the high pressure cleaner 60. Inject to remove the cleaning mixture. The supercritical rinse mixture composed of the supercritical carbon dioxide and the rinse additive, which is mainly alcohols, can be formed by simple mixing of the rinse additive and the carbon dioxide in the supercritical state. In the case of the rinsing process using the rinsing mixture for such a supercritical state, it is preferable that the reaction is performed under a pressure of approximately 80 bar to 250 bar.

Thereafter, only the supercritical carbon dioxide may remove the rinse additive mixture which may be present on the wafer surface.

After washing and rinsing, the mixture discharged from the high pressure cleaner 60 is separated into gaseous carbon dioxide and liquid additive in the separator 61. At this time, after the rinsing step, the carbon dioxide is removed from the high pressure cleaner 60 in the gas state by lowering the pressure inside the high pressure cleaner 60 at a temperature of about 35 ° C. or more. As a result, unlike a conventional cleaning process, a separate drying device or step is not required, and problems such as formation of water spots, which are problematic after wet cleaning, can be prevented.

The separator 61 is for separating the mixture under high pressure. The high pressure cleaning mixture (finally high pressure carbon dioxide) used in the cleaning, rinsing and drying steps is discharged from the high pressure cleaner (60) to the separator (61) by automatic operation of the 3-way on-off automatic valve (11). And purified and reused. On the other hand, the low pressure gas carbon dioxide is finally discharged by a change of direction of the 3-way on-off automatic valve 11 and is treated separately.

The high pressure carbon dioxide separated from the upper part of the separator 61 is sent to the washing column via the after pressure regulator 55 which is attached to the connection pipe of the upper discharge part of the separator 61 to regulate the pressure, and the on-off automatic valve 12 The liquid additive which is separated into the lower part of the separator 60 by the automatic operation of the separator is separated and purified through a separate treatment process and reused or discharged by a conventional post treatment applied in an existing semiconductor manufacturing factory. At this time, the heat source is attached to the discharge pipe (L7) and the separator (61) to compensate for the latent heat loss caused by the adiabatic expansion of carbon dioxide or liquid carbon dioxide in the supercritical state to induce a smooth gas discharge.

The gaseous carbon dioxide separated in the separator 61 is moved to the gas cleaning column 63 through the after pressure controller 55 to remove impurities, and then to the adsorption column 64 to remove impurities. It goes through a purification step that results in high purity (more than 99.99%) gaseous carbon dioxide. Of course, only one of the cleaning column 63 and the adsorption column 64 may be used. That is, purification may be possible using only the adsorption column 64, but this is determined by the generation of highly volatile gas due to the component of the additive or the cleaning reaction which may vary depending on the target wafer.

After such a purification step, the high purity gaseous carbon dioxide is condensed into a liquid state by a circulating refrigerant system in the carbon dioxide condensation vessel 23 and undergoes a condensation step that is recycled for a cleaning process.

According to the cleaning process according to the preferred embodiment of the present invention as described above, the two-stage process of the plasma ashing process (dry process) and the wet process, which has been used for removing the conventional photoresist or residue, is homogeneous in a supercritical state. Only a one-step dry process using a transparent phase mixture can be made possible. In addition, since cleaning, rinsing and drying are carried out continuously in a single high pressure cleaner, no separate drying device and step are required. In addition, carbon dioxide, which has undergone the pressurization and depressurization steps, may have an advantage of leaving no residue at all through a phase change.

On the other hand, when only the supercritical carbon dioxide is used in the cleaning process, the cleaning effect is limited, but according to the cleaning process according to the present embodiment, the cleaning effect is maximized by mixing the supercritical carbon dioxide and the cleaning additive. Can be. In this case, carbon dioxide in the supercritical state is non-polar and the additive for cleaning is usually polar, so to maintain the supercritical state by simply mixing them, a higher ultra-high pressure and ultra-high temperature than the above-described conditions are required. There was a problem of rising. Therefore, in order to solve this problem, in the cleaning process according to the present embodiment, the cleaning additive includes a surfactant, so that a homogeneous transparent phase mixture in a supercritical state is easily formed even under cleaning conditions such as the pressure as described above. To be maintained. In this case, by using a large pressure difference in the homogeneous transparent phase mixer 70 to mix the cleaning additive and carbon dioxide in a supercritical state, the supercritical state can be easily used without using a separate mixer or an ultrasonic device. The homogeneous transparent phase mixture of can be formed in a short time.

Thus, by using the cleaning process according to the present embodiment, it is possible to easily form and maintain the homogeneous transparent phase of the homogeneous transparent phase mixture in the supercritical state in a short time, and to design and configure the automatic opening and closing cleaning device, the automatic valve, and the like. In addition to the control system, cleaning can be easily performed through process automation.

In addition, by using the high diffusion rate of carbon dioxide in the supercritical state, it is possible to overcome the limitations of the microstructure that can penetrate the semiconductor chemicals, and maximize the wettability of the microstructure by using the low surface tension property. Therefore, it is possible to perform the ultra-fine cleaning required in the pattern formation and manufacturing process of the ultra-fine structure.

On the other hand, for the removal of photoresist and residues that are hard to remove by using only pure supercritical carbon dioxide or a supercritical fluid mixture that is difficult to form a homogeneous transparent phase, surfactants as shown in the following table Washing additive formulations may be used.

The specific structure of the high pressure cleaner 60 and the cleaning therein will be described below.

3 is a front view schematically showing the high pressure cleaner 60 of FIGS. 1 and 2, FIG. 4A is a front view schematically showing an upper element of the high pressure cleaner of FIG. 3, and FIG. 4B is a view of the high pressure cleaner of FIG. 3. FIG. 5A is a conceptual cross-sectional view schematically showing the lower element of the high pressure cleaner of FIG. 3, and FIG. 5B is a conceptual view schematically showing the lower element of the high pressure cleaner of FIG. 3. FIG. 6A is a conceptual view schematically illustrating the coupling of the upper element of FIG. 4A, the lower element of FIG. 5A, and the single wafer mounter, and FIG. 6B is a plan view schematically showing the wafer mounter of FIG. 6A, and FIG. 7A is a conceptual diagram schematically illustrating a modification of FIG. 6A, and FIG. 7B is a plan view schematically illustrating the wafer mounter of FIG. 7A.

The high pressure cleaner 60 has an upper element 101 and a lower element 102, the upper element 101 is to be able to move up and down by the upper element elevating pneumatic cylinder 105. When the upper element 101 is lowered, the attachable pneumatic cylinder 106 slides into the attachable pneumatic cylinder insertion portion 107 of the upper element 101 and the lower element 102 so that the upper element 101 and the lower element ( 102 is combined and fixed. If necessary, the upper element 101 of the high pressure cleaner 60 is provided with an upper element guide pin 230 and the lower element 102 is provided with a guide pin insertion portion 231, the upper element guide pin 230 The upper element 101 and the lower element 102 may be coupled in the correct position by being inserted into the guide pin insertion portion 231. In addition, the heating or cooling source 108 is attached to the high pressure cleaner 60, so that the high pressure cleaner 60 can be adjusted to a predetermined temperature or a temperature within a predetermined range. In this case, as shown in FIG. 3, the heating source or the cooling source 108 surrounds the lower element 102 of the high pressure cleaner 60, and the fruit or the refrigerant flows into the heating source or the cooling source 108. Can be. Of course, various modifications are possible, such as a coil having a high resistance as a heating source.

The inside or outside diameter of the high pressure cleaner 60 may vary depending on the diameter of the wafer to be cleaned. The number of the attachable pneumatic cylinders 106 joining the upper element 101 and the lower element 102 may vary depending on the size of the wafer to be cleaned. For example, about 6 to 8 may be provided for an 8 inch wafer. (See FIGS. 4B and 5B).

As described above, the wafer is mounted in the high pressure cleaner 60 prior to cleaning, which is performed before the upper element 101 and the lower element 102 are combined. The wafer to be cleaned is mounted to a wafer mounter 201 as shown in FIGS. 6A and 6B, in which the pins (protrusions) 210 of the wafer mounter 201 are mounted on the wafer mounter of the upper element 101. It is inserted into and fixed to the fixing part 210a (see FIG. 4A). In this case, the pin 210 of the wafer mounter 201 is provided with a screw thread and the screw valley is provided at the wafer mounter fixing portion 210a of the upper element 101 so that the wafer mounter 201 is more securely attached to the upper element 101. It can also be fixed. For reference, in FIG. 4B, a plurality of wafer mounter fixing portions 210a are illustrated, but only two are shown in FIG. 4A for convenience.

Of course, as shown in FIG. 5B, the auxiliary element 211 may be provided on the lower element 102 as necessary to support the wafer to be inserted into the wafer mounter 201. Of course, as shown in FIG. 5B, only two auxiliary pins 211 need not be provided, and various modifications are possible.

The wafer mounter 201 may be a wafer mounter 201 in which a single wafer is mounted as shown in FIG. 6A, or a wafer mounter 201 in which a plurality of wafers may be simultaneously mounted as shown in FIG. 7A. It may be.

After the wafer is mounted in the wafer mounter 201, the upper element 101 is lowered, and the high purity (99.99% or more) of low pressure (20 psig or less) is primarily performed by the pressure regulator 52, 53, FIG. 1 or 2). Gas carbon dioxide is introduced into the high pressure cleaner 60 from the gas carbon dioxide source 20 (see FIG. 1 or FIG. 2) to remove fine contaminants inside the high pressure cleaner 60. When the upper element 101 and the lower element 102 of the high pressure cleaner 60 are engaged with each other, the upper element 101 and the lower element 102 are coupled by the attachable pneumatic cylinder 106.

Thereafter, a high pressure (about 30 bar to 50 bar) of high-purity gaseous carbon dioxide is introduced, and a pressure lower than the supercritical cleaning pressure (e.g., 120 bar to 300 bar supercritical pressure) in order to prevent the supercritical homogeneous transparent phase mixture to be introduced later Carbon dioxide at a pressure of 10 bar to 40 bar lower than the cleaning pressure is introduced into the high pressure cleaner 60. At this time, the pressure of the high pressure cleaner 60 is adjusted to a predetermined pressure or a pressure within a predetermined range by the pressure regulating valve 54. Then, a homogeneous transparent phase mixture in a supercritical state is introduced to perform cleaning.

In this case, the high pressure cleaner 60 should be completely sealed so that the carbon dioxide introduced into the high pressure cleaner 60 or the homogeneous transparent phase mixture in the supercritical state does not leak, and a sealing material may be further provided for this purpose. 6A and 7A illustrate a case in which the first sealing material 220 and the second sealing material 221 are provided. That is, the first bent portion is provided at the edge of the surface in the direction of the lower element 102 of the upper element 101, and the second bent portion is provided at the edge of the surface in the direction of the upper element 101 of the lower element 102, The first sealing member 220 and the second sealing member 221 are provided in the first bent part and the second bent part, respectively. The first seal member 220 and the second seal member 221 may have various shapes, and are illustrated as having a 'c' shape in FIGS. 6A and 7A.

As the first sealant 220 and the second sealant 221, commercially available energized Teflon seals, metal seals, and the like may be used. Energized Teflon seals are made of pure Teflon or Teflon mixed with filler. In this case, for the elasticity required for the restoring force of the first sealing material 220 and the second sealing material 221, the first sealing material 220 and the second sealing material 221 may have a cantilever or a helicoil shape. It may be. In the case of using a metal seal, it may be formed of stainless steel, Hastelloy-C, or elgiloy of SUS316, which does not generate corrosion in consideration of components of the additive.

Of course, the material for the first sealing material 220 and the second sealing material 221 is not limited thereto, and those formed of various other materials may be used as long as they are excellent in corrosion resistance, durability, and sealing at high pressure in a supercritical state.

Meanwhile, as described above, high pressure (more than 99.99%) gas carbon dioxide at low pressure (20 psig or less), high-purity gas carbon dioxide at high pressure (about 30 bar to 50 bar), and pressure lower than the supercritical cleaning pressure (for example, into the high pressure cleaner 60). 10 bar to 40 bar pressure lower than the supercritical cleaning pressure of 120 bar to 300 bar, and the supercritical homogeneous transparent phase mixture, etc., are introduced, which is an injection port 110 provided in the upper element 101 of the high-pressure cleaner 60. Inflow through)

The injection hole 110 is connected to the top of the wafer mounter 201. A groove 202a is formed in the upper surface of the wafer mounter 201 in the circumferential direction of the wafer mounter 201 as shown in FIG. 6B, and a plurality of spray outlets 202 are mounted in the groove 202a. It is provided in the direction of the upper surface of the wafer to be. The injection hole 110 is provided such that the material injected through the injection hole 110 is injected in the direction of the groove 202a of the wafer mounter 201, so that the material passing through the injection hole 110 is circumferentially attached to the wafer mounter 201. It moves along the groove 202a in the direction and passes through the spray outlet 202 to clean the mounted wafer. That is, the wafer mounter 201 distributes the homogeneous transparent phase mixture in the supercritical state in the high pressure cleaner 60 to maximize the cleaning effect. Referring to FIG. 7B, in which a plurality of wafers are mounted in one wafer mounter 201, the spray outlet 202 is provided in the direction of each wafer to be mounted so that each wafer is effectively cleaned when the plurality of wafers are mounted. Do it.

As such, the homogeneous transparent phase mixture in the supercritical state is introduced into the high pressure cleaner 60 to clean the wafer while maintaining the homogeneous transparent phase at a constant pressure or at a constant temperature. The homogeneous transparent phase mixture in the supercritical state decomposes or dissolves the photoresist polymer together with the cleaning additive added by infiltration and swelling into the photoresist polymer. In this step, substantially no photoresist or etching residue or the like on the wafer is removed.

On the other hand, when the photoresist or etching residue on the wafer is removed in this way, the rinse additive source 26 to prevent the cleaning additive and the cleaning contaminants such as the dissolved photoresist residue from remaining on the wafer surface. The cleaning mixture is removed with a supercritical rinse mixture consisting of a rinse additive supplied from the supercritical carbon dioxide and a supercritical state. The supercritical carbon dioxide alone removes the rinse additive mixture that may be present on the wafer surface.

The material used in this cleaning and rinsing step is discharged to the outside through the outlet 111 as shown in Figs. 5a and 5b is post-treated and reused or treated separately as described above. Of course, the position and shape of the outlet 111 is not limited to those shown in Figures 5a and 5b, various modifications are possible. In this case, as shown in Figure 5b, it is preferable that the outlet 111 is in the opposite direction to the position of the injection port 110 as shown in 4b. Through this, the supercritical homogeneous transparent phase mixture or the supercritical rinse mixture injected through the inlet 110 is discharged to the outside after passing through the inside of the high-pressure cleaner 66, thereby cleaning and rinsing the wafer. Etc. can be made efficiently.

By using the high pressure cleaning device as described above and the cleaning process and the cleaning device as described above, the supercritical carbon dioxide and the additive form a homogeneous transparent phase mixture in the supercritical state, and the surface of the wafer placed in the high pressure cleaner 60 is removed. It can be washed. In addition, unlike the conventional method, the wet process is not mixed, so that excellent cleaning results can be obtained.

In addition, when a homogeneous transparent phase mixture of the supercritical state is formed in the homogeneous transparent phase mixer 70, the mixture is supplied onto the wafer at a rapid flow through the spray-type wafer mounter 201, thereby causing a stagnant state (Fig. 1) can achieve excellent cleaning effect, and the cleaning by circulation flow contacting (see Fig. 2) gives the fluidity of the mixture to maximize the contact effect of the mixture and the wafer to dissolve the photoresist and photoresist. The residue is continuously removed to further enhance the cleaning effect.

As described above, the cleaning additives and contaminants remaining on the wafer after the cleaning step may be removed by supplying a supercritical rinse mixture, which is a mixture of supercritical carbon dioxide and a rinse additive, and then the remaining rinsing. The solvent additive can be removed by only supplying carbon dioxide in a supercritical state. The supercritical rinse mixture used in this process can maximize the cleaning action by performing not only rinsing but also an auxiliary cleaning role.

In the rinsing step, the homogeneous transparent phase mixture in the supercritical state is supplied in a rapid spray-like manner as in the cleaning step to contact the wafer to be cleaned by pump flow only (see FIG. 1) or in parallel with the circulating flow (see FIG. 2). Can be cleaned.

The preprocessing time including the cleaning time and the rinsing time as described above may be within 10 minutes.

FIG. 8 is a graph schematically showing a relationship between time and pressure for the entire section of the cleaning process using the cleaning device of FIG. 2, which is a simple graph of the above-described process. In FIG. 8, P _C means a supercritical pressure, and P _O means a desired supercritical cleaning pressure. P ₁ is a pressure larger than P _C and a cleaning pressure P _O , that is, about 10 to 40 bar lower than P ₂ , so that the supercritical homogeneous transparent phase mixture formed in the homogeneous transparent phase mixer can maintain the homogeneous transparent phase.

As described above, the high pressure cleaner 60 is initially filled with only carbon dioxide in a supercritical state up to the pressure P ₁ , and thereafter, a cleaning is performed by filling a homogeneous transparent phase mixture in a supercritical state within a short time. Rinsing is also possible at pressures lower than the cleaning pressure P _O , as can be seen in the rinsing section of FIG. 8. Of course, the process shown in FIG. 8 is exemplary, and the present invention is not limited thereto.

EXAMPLES 1-4

Dry-cleaned wafers subjected to back-end-of-the-line (BEOL) processing using a supercritical homogeneous transparent phase mixture to retain rabbit-shaped photoresist residues after aluminum metal etching It was experimented to remove.

The wafer is a layer of silicon / silicone peroxide film 4000Å / titanium 300Å / titanium nitride 900Å / aluminum 8000Å / titanium 100Å / titanium nitride 400Si (Si / Si rich Oxide 4000Å / Ti 300Å / TiN 900Å / Al 8000Å / Ti 100Å / TiN 400 층) It had a structure, and the photoresist residue generated during the metal etching process remained on the wafer.

At this time, the cleaning additive mixed with the carbon dioxide in the supercritical state was a mixture of a surfactant, a stripper or cosolvent for semiconductor cleaning, and ethanol. Only the ethanol was used as the primary rinse additive mixed with the supercritical carbon dioxide, and only the supercritical carbon dioxide was used without the additive in the final rinse.

The wafers under the same conditions as described above were used in the same manner, and cleaning experiments were conducted using different surfactants or different cleaning and rinsing conditions. The conditions are shown in Table 1 below.

division Example 1 Example 2 Example 3 Example 4 Combination composition of cleaning additives (% by weight) PFOA 83.5 Stripper 6.0 Ethanol 10.5 monohydrated-PFOA 87.4 stripper 5.2 ethanol 7.4 PFHA 83.5 stripper 6.0 ethanol 10.5 PFOA 82.7 MEA 2.5 1-M-2-P 1.7 Ethanol 13.1 Volume of cleaning additive 13.6% 16.2% 13.6% 13.6% First rinse additive ethanol ethanol ethanol ethanol Volume of additive for first rinse 16.7% 16.7% 16.7% 16.7% Cleaning condition 55 ℃ 148bar 3 minutes (Static) 51 ℃ 165bar 3 minutes (Static) 54 ℃ 163bar 3 minutes (Static) 52 ° C 160bar 3 minutes (Static) 1st rinse condition 36 ℃ 132 ± 6bar 2min (flow) 45 ± 1 ℃ 153 ± 12bar 2min (flow) 42 ℃ 125 ± 3bar 2min (flow) 40 ± 1 ℃ 145 ± 5bar 2min (flow) 2nd rinse condition 39 ° C 122 ± 7bar 2min (flow) 42 ° C 148 ± 7bar 2min (flow) 46 ℃ 121 ± 3bar 2min (flow) 40 ± 3 ℃ 136 ± 6bar 2min (flow)

Here, the first rinsing step is a step of rinsing using a homogeneous transparent phase mixture in a supercritical state, in which a rinsing additive and carbon dioxide in a supercritical state are mixed, and the second rinsing step is a step of rinsing with only supercritical carbon dioxide. And PFOA means perfluorooctanoic acid (perfluorooctanoic acid), PFHA means perfluoroheptanoic acid (perfluoroheptanoic acid).

The premise of supercritical fluid cleaning and rinsing is to create and maintain a homogeneous transparent phase mixture in which the components of the supercritical fluid mixture are not separated from each other, and the supercritical homogeneous transparent phase mixture formed in the cleaning process according to the present embodiment. The photo of is shown in FIG.

After cleaning, the results of observing the cleaning before and after using a scanning electron microscope (SEM) are shown in FIGS. 10A (before cleaning), FIG. 10B (Example 1), FIG. 10C (Example 2), FIG. 10D (Example 3), and 10E (Example 4). Here, in the case of FIGS. 10B, 10C, and 10D, as the result of washing the cosolvent using the same solvent as the semiconductor cleaning stripper and the ethanol, and combining the cleaning additives with different surfactants, the surfactant and the cleaning additive. In order to show the cleaning characteristics according to the composition of FIG. 10E, the co-solvent is selected and used by itself as shown in Table 1 without using a semiconductor cleaning stripper.

Referring to FIG. 10A, which shows a wafer before cleaning, a photoresist residue of a polymer material generated during the etching process remains on an aluminum-etched wafer surface, which is a rabbit ears-like stain on the wafer. Is shown.

10B to 10E are photographs after cleaning the wafer of FIG. 10A using a homogeneous transparent phase mixture in a supercritical state under the conditions shown in Table 1. FIGS. As can be seen in Figures 10b to 10e, it can be seen that excellent cleaning results in which all of the rabbit ear-shaped photoresist residues are removed within a total process time of 10 minutes.

[Comparative Examples 1 and 2]

10F is a cross-sectional photograph after cleaning the wafer of FIG. 10A by a conventional wet cleaning process, and FIG. 10G is a cross-sectional photograph after cleaning the wafer of FIG. 10A by a cleaning process that does not satisfy the conditions according to a preferred embodiment of the present invention. to be.

In the case of FIG. 10F, the conventional wet cleaning was performed for 120 minutes using the cleaning additive used in Example 1, and despite the wet cleaning for 120 minutes, unlike the cleaning results of Examples 1 and 2, the shape of a rabbit's ear was used. It can be seen that the photoresist residue of remains. Through this, it can be seen that the supercritical dry cleaning of the present invention shows breakthrough cleaning results compared to conventional wet cleaning.

In the case of FIG. 10G, when the surfactant is not used under the conditions of Examples 1 to 4 or the process conditions are not changed to form a homogeneous transparent phase, it may be confirmed that the cleaning state is poor. Even when no rinsing in the process according to the preferred embodiment of the present invention showed similar results to FIG. 10g. Through this, it can be seen that forming a homogeneous transparent phase is an essential requirement in the dry cleaning of the present invention.

Example 5

A supercritical homogeneous transparent phase mixture was used to remove photoresist on the wafer during wafer fabrication which was subjected to a front-end-of-the-line (FEOL) process.

The wafer had a layer structure of silicon / HLD 1000Å / nitride 4500Å / BPSG 21000Å / photoresist 10500Å (Si / HLD 1000Å / Nitride 4500Å / BPSG 21000Å / PR 10500Å), and the wafer used was positive photoresist. (positive photoresist) coated p-type wafer (p-type wafer), it was heat-treated at 120 ℃.

In the present embodiment, the cleaning additive to be mixed in the carbon dioxide in the supercritical state was simply used ethanol, and rinsing was carried out once using only carbon dioxide in the supercritical state.

Cleaning conditions are shown in Table 2 below.

Cleaning additive ethanol Volume of cleaning additives (%) 13.6% Cleaning condition       58 ° C, 150 bar, 2 minutes (still) Rinsing Condition    48 ± 1 ° C, 142 ± 6bar, 2 minutes (flow)

FIG. 11A is a cross-sectional photograph before cleaning a wafer subjected to a front-end-of-the-line (FEOL) process by a cleaning process according to a preferred embodiment of the present invention, and FIG. 11B is a surface photograph. Referring to Fig. 11A, a photoresist layer is provided on the wafer, and grooves are formed in the photoresist layer. When viewed from the top, as shown in FIG. 11B, protrusions formed of photoresist having a circular cross section are formed on the wafer.

11C is a cross-sectional photograph after cleaning the wafers of FIGS. 11A and 11B by a cleaning process according to a preferred embodiment of the present invention, and FIG. 11D is a surface photograph. Referring to FIG. 11C, unlike in FIG. 11A, it can be seen that the photoresist layer is completely removed. This can be seen in FIG. 11D.

EXAMPLES 6 AND 7

During the arsenic (As) ion implantation process on the ion implanted wafers with patterns of various shapes, including numbers, by cleaning the wafers after the post ion implantation process using a supercritical homogeneous transparent phase mixture. Experiments were performed to remove photoresist and photoresist residues protruding from the remaining wafer surface.

The wafer had a layer structure of silicon / oxide 5000Å / poly 2000Å / photoresist 50000Å (Si / Oxide 5000Å / Poly 2000Å / PR 50000Å), arsenic (As) ion implantation energy was 60KeV, and the amount of doping ions A wafer subjected to a post ion implantation process with a dose of 5E13 / cm was used.

The cleaning additive mixed in the supercritical carbon dioxide was a mixture of a surfactant, a semiconductor cleaning stripper, and ethanol, and only ethanol was used as the primary rinse additive mixed in the supercritical carbon dioxide. Rinsing only used carbon dioxide in the supercritical state without additives.

The cleaning was carried out while forming and maintaining a homogeneous transparent phase mixture (FIG. 9) in a supercritical state, as in the cleaning treatment of wafers subjected to back-end-of-the-line (BEOL) processes (Examples 1-4). . Cleaning conditions are shown in Table 3 below.

division Example 6 Example 7 Combination Composition of Cleaning Additives (wt%)  PFOA 83.5 Stripper 6.0 Ethanol 10.5 PFOA 83.8 Stripper 7.1 Ethanol 9.1 Volume of cleaning additives (%) 13.6% 17.5% First rinse additive ethanol ethanol Volume (%) of first rinse additive 16.7% 16.7% Cleaning condition 59 ℃ 148 bar 3 minutes (Static) 50 ° C 150 bar 3 minutes (still) 1st rinse condition 43 ± 3 ℃ 125 ± 5bar 2min (flow) 42 ℃ 150 ± 3bar 2min (flow) 2nd rinse condition 48 ± 3 ℃ 122 ± 1bar 2min (flow) 40 ° C 150 ± 5bar 2min (flow)

12A is a photograph of the surface of a wafer that has undergone a post-ion implantation process prior to cleaning with a cleaning process in accordance with this embodiment, wherein photoresist residues on the wafer having various shaped patterns including numbers It can be seen that (faint white dots) protrude and remain.

12B and 12C are photographs of the surface after cleaning the wafer of FIG. 12A by the cleaning process according to the present embodiment, showing that the photoresist residue is reliably removed.

In the cleaning process as described above, the cleaning additive may be the same as that used in the above embodiments, that is, a cleaning additive including a fluorine-based surfactant. Such fluorine-based surfactants include fluorine-based carboxylic acids having 2 to 20 carbon atoms, perfluorinated ether polymers having an average molecular weight of 300 to 5000, or mixtures thereof.

In addition, the cleaning additive, as used in the above embodiments, 0.01% to 90% by weight of fluorine-based surfactant, 0.01% to 15% by weight of aliphatic amine, 0.01% to 15% by weight of polar organic solvent and 0.1 wt% to 20 wt% of an alcohol solvent, 0.1 wt% to 30 wt% of an ether solvent, 0 wt% to 5 wt% of a corrosion inhibitor, and 0 wt% to 15 wt% of water. In this case, 0% by weight means that the corresponding element is not included in the cleaning additive. This is also the same in the following description.

In this case, a fluorine-based carboxylic acid having 2 to 20 carbon atoms, a perfluorinated ether polymer having an average molecular weight of 300 to 5000, or a mixture thereof may be used as the fluorine-based surfactant. As the aliphatic amine, monoethanol amine, 2- (2-aminoethoxy) ethanol, diethanol amine, iminobispropylamine, 2-methylaminoethanol, triethylaminoethanol or a mixture thereof can be used. As the polar organic solvent, N, N'-dimethylacetamide, dimethyl sulfoxide, 1-methyl-2-pyrrolidinone, N, N'-dimethylformamide, ammonium fluoride or a mixture thereof may be used. As the alcohol solvent, methanol, ethanol, isopropanol or a mixture thereof can be used. Ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, or a mixture thereof may be used as the ether solvent. Can be. Meanwhile, as a corrosion inhibitor, catechol, gallic acid, or a mixture thereof may be used.

And the cleaning additive, as used in the above embodiments, 0% to 90% by weight of the fluorine-based surfactant, 0.1% to 15% by weight of the semiconductor cleaning stripper, 0.1% to 20% by weight of the alcohol solvent And the thing containing 0 to 15 weight% of water can also be used. In this case, the fluorine-based surfactant may be a fluorine carboxylic acid having 2 to 20 carbon atoms, a perfluorinated ether polymer having an average molecular weight of 300 to 5000 or a mixture thereof, and the alcohol solvent may be methanol, ethanol, isopropanol or a mixture thereof. Can be.

As the cleaning additive, only an alcohol solvent may be used as in the above embodiment, only carbon dioxide in a supercritical state may be used in the rinsing of the wafer, and the alcohol solvent may be methanol, ethanol, isopropanol or the like. It may be a mixture thereof.

In the supercritical homogeneous transparent phase mixture in which the supercritical carbon dioxide and the cleaning additive used in the above example were mixed, the cleaning additive was 30% by volume or less in the total volume. In addition, in the supercritical homogeneous rinse mixture in which the supercritical carbon dioxide and the rinse additive were mixed in the above example, the rinse additive was 30% by volume or less in the total volume. In this case, the rinse additive included methanol, ethanol isopropanol or a mixture thereof.

According to the cleaning apparatus of the present invention and the high pressure cleaner used therein as described above, an excellent cleaning effect can be obtained while simplifying the cleaning process and shortening the time required for cleaning.

Although the present invention has been described with reference to the embodiments shown in the drawings, these are merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Claims (8)

A wafer mounter having a protrusion on which the wafer to be cleaned is mounted; A pneumatic cylinder into which an inlet for allowing a mixture or the like to be injected downward, a wafer mount fixing portion for inserting the protrusion of the wafer mount so that the wafer mount can be fixed, and a pneumatic cylinder sliding in from the side can be inserted. An upper element having an insert; A lifting pneumatic cylinder for moving the upper element up and down; A lower element having a pneumatic cylinder insertion portion into which a pneumatic cylinder sliding in from the side can be inserted, and an outlet through which a mixture or the like can be discharged, and forming a space in which the wafer mounter can be disposed between the upper element ; And an attached pneumatic cylinder sliding down into the pneumatic cylinder inserting portion of the upper element and the pneumatic cylinder inserting portion of the lower element when the upper element is lowered and engaged with the lower element. Characterized by high pressure cleaner. The method of claim 1, A sealing material for sealing the space between the upper element and the lower element from the outside is further provided between the edge of the surface in the lower element direction of the upper element and the edge of the surface in the upper element direction of the lower element. High pressure washer. The method of claim 2, A first bent portion is provided at an edge of the surface of the upper element in the direction of the lower element, and a second bent portion is provided at an edge of the surface of the lower element in the direction of the upper element, and the first bent portion and the second bent portion are provided. The high pressure cleaner, characterized in that the first seal member and the second seal member are respectively provided. The method of claim 1, And a groove is formed in the circumferential direction of the wafer mounter on a surface in the direction of the upper element of the wafer mounter, and a plurality of spray outlets are provided along the groove in the circumferential direction of the wafer mounter. The method of claim 4, wherein The injection hole provided in the upper element is a high pressure cleaner, characterized in that the material injected through the injection hole provided in the upper element is provided to be injected in the groove direction of the wafer mounter. The method of claim 1, The upper element further comprises an upper element guide pin, the lower element is a high-pressure cleaner characterized in that it further comprises a guide pin insertion portion into which the upper element guide pin is inserted. The method of claim 1, The inlet and the outlet is a high pressure cleaner, characterized in that provided in the opposite direction. The method of claim 1, And a heating source or a cooling source for controlling the temperature of the high pressure cleaner.

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