KR100825965B1 - Substrate cleaning method - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a semiconductor substrate, wherein the substrate cleaning method according to the present invention uses a isopropyl alcohol gas to change the properties of the substrate to a substrate having a hydrophobic property by cleaning with a cleaning liquid during the process, By preventing the prominent substrate from being contaminated by foreign matter remaining in the periphery, the cleaning efficiency of the substrate is improved.

Semiconductor, Substrate, Wafer, Clean, Rinse, Dry, Isopropyl Alcohol, Hydrophobic

Description

Substrate Cleaning Method {SUBSTRATE CLEANING METHOD}

1 is a perspective view of a substrate cleaning apparatus to which a substrate cleaning method according to the present invention is applied.

2 is a flow chart showing a substrate cleaning method according to the present invention.

3A to 3D are views for explaining a substrate cleaning method according to the present invention.

4 is a block diagram of a chemical processing chamber according to an embodiment of the present invention.

5 is a block diagram of a chemical treatment chamber according to another embodiment of the present invention.

6 is a view showing experimental data of the substrate cleaning method according to the present invention.

* Description of symbols on the main parts of the drawings *

10: substrate cleaning device

20: chemical processing chamber

100: drying chamber

200: wash room

300: transfer means

The present invention relates to a method of treating a substrate, and more particularly, to a method of cleaning a semiconductor substrate.

The cleaning process of the semiconductor manufacturing process is a process of removing foreign matter adhering to the wafer surface. The wet cleaning process is a process of cleaning a wafer using a predetermined process liquid. Typical wet cleaning processes include cleaning a substrate with a chemical liquid, rinsing the substrate with the cleaning liquid, and drying the substrate with a dry gas. Here, a variety of chemicals (chemical) are usually used as the chemical liquid, ultrapure water (DIW: Deionized Water) is used as the cleaning liquid, and isopropyl alcohol gas (IPA gas) is used as the drying gas.

However, conventional substrate cleaning methods have been difficult to completely remove foreign matter from the wafer surface. For example, when the wafers are cleaned by immersing the wafers in the cleaning liquid, the wafer surface becomes hydrophobic and generates attraction. Therefore, such hydrophobic wafers adsorb foreign substances remaining around the wafer to the wafer surface again. In particular, when the hydrofluoric acid solution (DHF: Dilute Hydrofluoric Acid solution), Standard cleaning-1 (SC-1: Standard clean-1), hydrogen peroxide (H2O2), ammonium fluoride (NH4F) solution, etc. After the process, the wafer surface has a strong hydrophobic property. Therefore, after the cleaning process is performed with the above-described cleaning liquid, the wafer is contaminated by foreign matter remaining around the wafer. That is, foreign matters removed during the cleaning process are reattached to the wafer surface, which is gradually hydrophobic, to contaminate the wafer surface. In the rinsing process performed after the cleaning process, foreign substances remaining in the cleaning solution reattach to the wafer surface to contaminate the wafer.

An object of the present invention is to provide a substrate cleaning method for improving the cleaning efficiency of a substrate.

In addition, an object of the present invention is to provide a substrate cleaning method for preventing the foreign matter removed from the substrate during the cleaning process is re-adsorbed on the substrate surface again.

In the substrate cleaning method according to the present invention for achieving the above object is performed a rinse process after changing the properties of the substrate to reduce the degree of hydrophobicity of the substrate having a hydrophobic property to perform the cleaning of the substrate with a chemical solution .

According to an embodiment of the present invention, the property change of the surface of the substrate is made by injecting isopropyl alcohol gas into the substrate.

According to an embodiment of the present invention, the cleaning solution is at least one selected from the group consisting of hydrofluoric acid solution, standard cleaning solution-1, hydrogen peroxide, and ammonium fluoride.

The substrate cleaning method according to the present invention for achieving the above object comprises the steps of cleaning the substrate with a chemical solution, changing the properties of the substrate to reduce the hydrophobicity of the substrate having a hydrophobicity, and rinsing the substrate with the cleaning solution do.

According to an embodiment of the invention, the step of changing the properties of the substrate is achieved by injecting isopropyl alcohol gas towards the substrate.

According to an embodiment of the present invention, the changing of the properties of the substrate and the drying of the substrate are performed by spraying the same gas on the substrate.

According to an embodiment of the present invention, the cleaning of the substrate with the chemical liquid is performed by spraying the chemical liquid onto the processing surface of the substrate rotated by the spin chuck to rotate the substrate, or the substrate is immersed in the cleaning tank filled with the chemical liquid. Is done.

The substrate cleaning method according to the present invention includes a washing chamber in which a substrate is cleaned with a chemical liquid, and a washing chamber in which the substrate is rinsed by the cleaning liquid, and a drying chamber disposed above the washing chamber to dry the substrate. Changing the properties of the substrates to reduce hydrophobicity of the hydrophobic substrates, transferring the substrates from the drying chamber to the flush chamber, and the flush chamber using a cleaning liquid Rinsing the substrate, and transferring the substrates from the wash chamber to the drying chamber, the drying chamber spraying a dry gas toward the substrates to dry the substrates.

According to an embodiment of the present invention, the cleaning solution is at least one selected from the group consisting of hydrofluoric acid solution, standard cleaning solution-1, hydrogen peroxide, and ultrapure water, and changing the properties of the substrates isopropyl alcohol gas toward the substrates. It is made by spraying.

According to an embodiment of the present invention, the drying of the substrates is performed by using the same gas as the gas used in changing the properties of the substrates.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosure may be made thorough and complete, and to fully convey the spirit of the invention to those skilled in the art.

In addition, in the present embodiment, a batch substrate cleaning apparatus including a chemical processing chamber, a washing chamber, and a drying chamber to clean a plurality of semiconductor wafers has been described as an example. It is applicable to a manufacturing apparatus.

(Example)

1 is a perspective view of a substrate cleaning apparatus to which a substrate cleaning method according to the present invention is applied. And, Figure 4 is a block diagram of a cleaning chamber according to an embodiment of the present invention, Figure 5 is a block diagram of a cleaning chamber according to another embodiment of the present invention.

1 and 2, a substrate cleaning apparatus 10 according to the present invention performs a cleaning process of a plurality of substrates (W). The cleaning step includes a step of cleaning the substrate with a chemical liquid, a step of rinsing the substrate with a cleaning liquid, and a step of drying the substrate with a dry gas. The substrate cleaning apparatus 10 includes a chemical treating room 20, a dry process room 100, a rinse process room 200, and a transfer method 300. It includes.

The chemical liquid processing chamber 20 cleans the substrate W using the chemical liquid. The chemical processing chamber 20 includes a vessel 22, a spin chuck 24, and a nozzle 26. The container 22 is open at an upper portion thereof, and accommodates a substrate therein to provide a space in which the cleaning process is performed. The spin chuck 24 supports and rotates the substrate inside the vessel 22 during the process. The nozzle 26 supplies the chemical liquid to the processing surface of the substrate which is seated on the spin chuck 24 and rotated. The chemical processing chamber 20 having the above-described structure sequentially cleans the sheet substrate W. FIG. At this time, the chemical liquid may be used a variety of chemical (chemical). For example, the chemical liquid may be at least one chemical selected from the group consisting of dilute hydrofluoric acid solution (DHF), standard clean-1, hydrogen peroxide (H 2 O 2), and ammonium fluoride (NH 4 F). have. The method of cleaning the substrate in the chemical treatment chamber may be applied in various ways, and is not limited due to the examples described above.

Although the chemical processing chamber according to an embodiment of the present invention has been described by taking a method of cleaning the substrate W by a single sheet, various techniques may be applied to the method of cleaning the substrate W by the chemical processing chamber. For example, referring to FIG. 5, the cleaning chamber 30 according to another embodiment of the present invention includes a cleaning tank 32, an injection member 34, and a robot arm 36. The cleaning tank 32 provides a space in which the chemical liquid is filled, and provides a space in which the plurality of substrates W are immersed in the process. The injection member 34 sprays the chemical liquid toward the substrates W immersed in the cleaning tank 32 during the process. The injection member 34 includes at least one injection pipe 34a in which a plurality of injection holes (not shown) are formed. In addition, the robot arm 36 immerses the substrates W in the cleaning tank 32 during the process. The cleaning chamber 30 having the above-described structure cleans the plurality of substrates W in a batch manner.

The drying chamber 100 dries the substrate using a drying gas. The drying chamber 100 includes a housing 110 and an injection member 120. The housing 110 provides a space in which a drying process is performed. In addition, the housing 110 has a space in which the plurality of substrates W are accommodated. The upper portion of the housing 110 is open to allow the substrates W to enter and exit during the process, and the opened upper portion is opened and closed by the cover 112. In addition, the lower portion of the housing 110 is opened such that the substrates W are movable between the housing 110 and the wash chamber 200.

The injection member 120 injects dry gas toward the substrates W positioned in the housing 110 during the drying process. The injection member 120 includes injection pipes 122 in which a plurality of injection holes are formed. Each of the injection pipes 122 has a long bar shape, and injects dry gas toward the substrates W positioned in the housing 110 during the process. Here, isopropyl alcohol gas (IPA gas) is used as the drying gas. In the process, isopropyl alcohol gas dries the substrate W using the marangoni effect.

The wash chamber 200 rinses the substrate using a cleaning liquid. The wash chamber 200 includes a housing 210, a supply part 220, and an open / close member 230. The housing 210 is disposed below the housing 110 of the drying chamber 100. The upper portion of the housing 210 is open to communicate with the housing 110. Therefore, a passage a is provided between the housing 110 and the housing 210 for the movement of the substrates W during the process. In addition, the housing 210 provides a space in which the washing process is performed. The housing 210 provides a space in which a plurality of substrates W are accommodated. In addition, the upper portion of the housing 210 provides a space for the operation of opening and closing the passage (a) by the first and second gates (232, 234) of the opening and closing member 230 to be described later.

The supply member 220 sprays the cleaning liquid toward the substrates W accommodated in the housing 210 during the process. The supply member 220 includes at least one supply pipe 222. The supply pipe 222 has a long bar shape. Each supply pipe 222 is provided with a plurality of supply holes for spraying the cleaning liquid during the process. The supply pipe 222 is installed parallel to the lower side inside the housing 210, and sprays the cleaning liquid toward the substrates W during the process. Ultrapure water (DIW: Deionized Water) may be used as the cleaning liquid.

The opening and closing member 230 opens and closes the passage a between the housing 210 and the housing 110. In an embodiment, the opening and closing member 230 includes first and second gates 232 and 234. The first and second gates 232 and 234 have a symmetrical structure and are installed to be horizontally movable. Each of the first and second gates 232 and 234 operates in opposite directions to open and close the open upper portion of the housing 210. That is, when the passage a is opened, the first gate 232 is moved to the left and the second gate 234 is moved to the right, and when the passage a is closed, the first gate 234 is moved to the right. Is moved and the second gate 234 is moved to the left.

The transfer means 300 transfers the substrates W between the drying chamber 100 and the wash chamber 200 during the process. To this end, the transfer means 300 is provided with a support member 310 for supporting the substrates (W) during the process to move between the drying chamber 100 and the washing chamber 200. The support member 310 supports the substrates W vertically and vertically, and each processing surface or surface to be processed faces each other. In addition, the support member 310 is installed to enable a linear reciprocating movement between the housing 110 and the housing 210 in the drying chamber 100 and the washing chamber 200, the drying chamber 100 and the washing chamber ( 200) The substrates W are transferred to each other.

In the present exemplary embodiment, the substrate cleaning apparatus 10 including the drying chamber 100 and the flushing chamber 200 vertically adjacent to each other has been described as an example. However, the substrate cleaning apparatus 10 applicable to the substrate cleaning method according to the present invention may be applied. The structure and configuration of the can be changed and modified in various ways.

Hereinafter, the process of the substrate cleaning apparatus 10 described above will be described in detail. Here, the same reference numerals for the same components as the above-described components are the same, and detailed description of the components is omitted. In this embodiment, the substrate is cleaned by using hydrofluoric acid solution, ultrapure water, and isopropyl alcohol gas sequentially or selectively as an example. However, a variety of fluids may be used for the processing fluids for cleaning the substrate.

2 is a flowchart illustrating a substrate cleaning method according to the present invention, Figures 3a to 3d are views for explaining a substrate cleaning method according to the present invention. Referring to FIG. 2, when the cleaning process of the substrate W is started, the chemical processing chamber 20 cleans the substrates W using the cleaning liquid (S110). That is, the chemical processing chamber 20 loads the single substrate W onto the spin chuck 24, and the nozzle 26 supplies the hydrofluoric acid solution toward the substrate W rotated by the spin chuck 24. (W) Clean the foreign substances remaining on the surface. Alternatively, as another embodiment of the present invention, the chemical treatment chamber 30 may immerse the substrates W in a liquid tank 32 filled with a hydrofluoric acid solution to clean foreign substances remaining on the surfaces of the substrates W. At this time, foreign matters include unnecessary treatment liquids, metal pollutants, organic pollutants, and other particles. When the cleaning process by the hydrofluoric acid solution is completed, the substrates W are moved from the chemical processing chambers 20 and 30 to the drying chamber 100.

The drying chamber 100 injects isopropyl alcohol gas to the transferred substrates W to change the properties of the substrates W to reduce hydrophobicity (S120). That is, referring to FIG. 3A, the substrates W having the cleaning process completed are loaded into the housing 110 of the drying chamber 100 and then placed in the support member 310. When the substrates W are supported by the support member 310, the support member 310 is moved to a position where a drying process is performed, and the cover 112 seals the open upper portion of the housing 110. Then, each of the injection pipes 122 of the injection member 120 injects isopropyl alcohol gas toward the substrate (W). The injected isopropyl alcohol gas changes the properties of the hydrophobic substrate surface by completing the cleaning process with hydrofluoric acid solution. That is, in general, when the cleaning of the substrate by the hydrofluoric acid solution is completed, the substrate surface is hydrophobic. When the substrate is hydrophobic, foreign matter remaining in the periphery is attracted to the substrate by attraction with the substrate. To prevent this, isopropyl alcohol gas is sprayed onto the substrate before the rinsing process is performed, thereby changing the properties of the hydrophobic substrate to prevent foreign substances from adsorbing onto the substrate surface.

When the property of the substrate is changed, the washing process of the substrates W is performed using ultrapure water (S130). That is, referring to FIGS. 3B and 3C, when the primary drying process of the substrates W is completed, the supply of isopropyl alcohol gas from the injection member 120 is stopped and the first gate of the opening / closing member 230 is stopped. The second gate 234 is moved to the left side 232 to the left, thereby opening the passage between the drying chamber 100 and the wash chamber 200. When the passage is opened, the support member 310 is moved from the drying chamber 100 to the washing chamber 200. At this time, the inside of the housing 210 of the washing chamber 200 is filled with ultrapure water that satisfies the predetermined process temperature. Therefore, the substrates W are immersed in ultrapure water by the lowering of the support member 310. When the substrates W are immersed, the first gate 232 of the opening and closing member 230 moves to the right and the second gate 234 moves to the left to seal the passage. Then, supply pipes 222 of the supply member 220 sprays ultrapure water toward the substrates (W). The injected ultrapure water rinses the hydrofluoric acid solution remaining on the substrates W surface.

When the washing process of the substrates W is completed, the substrates W are dried (S140). That is, referring to FIG. 3D, the opening and closing member 230 opens the passage, and the support member 310 is moved from the washing chamber 200 to the drying chamber 100. When the support member 310 is moved to the drying chamber 100, the opening and closing member 230 seals the passage. Then, the injection pipes 122 of the injection member 120 injects isopropyl alcohol gas toward the substrate (W). The injected isopropyl alcohol gas dries the substrates W. When the drying process of the substrate is completed, after the cover 112 of the housing 110 is opened, the substrates W are carried out from the support member 310 to a facility (not shown) where a subsequent process is performed.

The substrate cleaning method described above changes the properties of the hydrophobic substrate before the washing process is performed to prevent foreign substances remaining in the cleaning liquid during the washing process. In particular, when the substrate is cleaned with a standard cleaning solution-1, a hydrofluoric acid solution, and a cleaning solution such as ammonium chloride, since the substrate has strong hydrophobicity, the substrate may be easily contaminated by foreign substances around the substrate. Accordingly, the substrate cleaning method according to the present invention changes the properties of the substrate by spraying isopropyl alcohol gas on the surface of the hydrophobic substrate before performing the washing process to prevent foreign substances from contaminating the substrate.

In addition, the above-described substrate cleaning method can shorten the washing time. That is, in order to rinse a conventional hydrophobic substrate, a long time washing process was performed to prevent contamination by foreign matter in the cleaning liquid. However, if the water washing process is performed after changing the hydrophobic substrate property, the contamination rate due to foreign matter in the cleaning liquid is audited, and thus the water washing process of the substrate can be performed in a short time.

Here, the substrate cleaning method according to the present invention and the substrate cleaning method according to the prior art are compared. 6 is a view showing experimental data of the substrate cleaning method according to the present invention. At this time, the chemical solution used in the experiment was a standard cleaning solution-1 and hydrofluoric acid solution, ultrapure water was used as the cleaning liquid, isopropyl alcohol gas was used as the dry gas.

Referring to FIG. 6, in the substrate cleaning method according to the related art, the number of foreign matters (particles) on the substrate may be increased after the cleaning process is performed. That is, the number before and after the cleaning process increases from 119 to 837. This is because in the conventional substrate cleaning method, since the substrate having high hydrophobicity after the cleaning process is performed by the chemical liquid strongly adsorbs the foreign matter remaining in the surroundings, it is contaminated by the foreign matter during the cleaning process. However, the substrate cleaning method according to the present invention reduces the number before and after the cleaning process from 178 to 115. This is because by changing the properties of the prominent hydrophobic substrate so as to reduce the hydrophobicity, the foreign matter is prevented from adsorbing the substrate around the substrate during the cleaning process.

The foregoing detailed description illustrates the present invention. In addition, the foregoing description merely shows and describes preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications may be made within the scope of the concept of the invention disclosed in this specification, the scope equivalent to the disclosed contents, and / or the skill or knowledge in the art. The above-described embodiments are intended to illustrate the best state in carrying out the present invention, the use of other inventions such as the present invention in other state known in the art, and the specific fields of application and uses of the present invention. Various changes are also possible. Accordingly, the detailed description of the invention is not intended to limit the invention to the disclosed embodiments. Also, the appended claims should be construed to include other embodiments.

As described above, the substrate cleaning method according to the present invention prevents the substrate from being contaminated during the cleaning process. In particular, the cleaning process by the chemical liquid is performed to change the properties of the hydrophobic substrate to prevent the substrate from being contaminated by foreign substances, thereby improving the cleaning efficiency of the substrate.

In addition, the substrate cleaning method according to the present invention can change the hydrophobic substrate properties before the washing step to prevent contamination by foreign matter in the cleaning liquid, it is possible to shorten the washing time.

Claims (10)

delete delete delete delete delete delete delete A method for cleaning a substrate comprising a washing chamber in which a substrate is rinsed with a cleaning liquid, and a washing chamber in which the substrate is rinsed with a cleaning liquid, and a drying chamber disposed above the washing chamber to dry the substrate. Injecting isopropyl alcohol gas toward the substrates in the drying chamber to change the properties of the substrates to reduce the hydrophobicity of the hydrophobic substrates; Transferring the substrates from the drying chamber to the wash chamber and rinsing the substrate using a cleaning solution in the wash chamber; Transferring substrates from the wash chamber to the drying chamber, and drying the substrates by spraying a dry gas toward the substrates in the drying chamber. The method of claim 8, The cleaning liquid, At least one selected from the group consisting of hydrofluoric acid solution, standard cleaning solution-1, and hydrogen peroxide. The method according to claim 8 or 9, Drying the substrates, A substrate cleaning method comprising the use of the isopropyl alcohol gas.

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