KR20130049903A - Method and apparatus for cleaning a substrate - Google Patents

Abstract

PURPOSE: A substrate cleaning method and a substrate cleaning apparatus are provided to minimize a splash by moving cleaning solutions to the peripheral area of a substrate. CONSTITUTION: A substrate is fixed to a rotatable support stand(S100). The substrate is rotated through a first nozzle. A first impurity is separated by supplying cleaning solutions to the substrate(S200). A second impurity is separated by simultaneously supplying the cleaning solutions and a 2 fluid mixture(S300). The cleaning solution and the 2 fluid mixture are removed from the substrate(S400). [Reference numerals] (AA) Start; (BB) End; (S100) Step of fixing a substrate with a washing target processed product to a support; (S200) Step of separating a first impurity from the substrate by supplying cleaning solutions through a first nozzle; (S300) Step of separating a second impurity, which is not separated from the substrate, by the cleaning solutions by simultaneously supplying the cleaning solutions and a 2 fluid mixture through a second nozzle; (S400) Step of removing the cleaning solutions and the 2 fluid mixture including the first and second impurities from the substrate

Description

Substrate cleaning method and substrate cleaning apparatus {Method and apparatus for cleaning a substrate}

The present invention relates to a substrate cleaning method and apparatus, and more particularly, to a method and apparatus for cleaning a substrate having a fine pattern.

Generally, a semiconductor device is manufactured by repeatedly performing unit processes such as deposition, photography, etching, ion implantation, polishing, and cleaning on a semiconductor substrate for manufacturing a semiconductor device. Among the unit processes, the washing process is a process of removing residues or contaminants remaining on the substrate after each unit process, and is more importantly handled in a recent micro process in which the size of the pattern is processed in nano units. .

The apparatus for performing the washing process includes a batch apparatus for treating a plurality of substrates at once and a sheet type apparatus for treating substrates in sheets. Batch cleaning apparatus has a disadvantage in that it is not easy to respond to the increase in size of the substrate and use a lot of chemical chemicals. In addition, there is a risk that if the substrate is broken, it may affect the entire substrates. For this reason, recent washing apparatuses are favored by sheet type apparatus.

Single sheet cleaning equipment generally removes impurities or contaminants formed on a substrate having a specific process through cleaning, rinsing and drying processes. The cleaning process supplies chemicals containing chemicals, which are chemicals capable of dissolving impurities, to the rotating substrate to chemically separate impurities or contaminants of a relatively small size from the substrate, and then spray a mixture of high pressure to spray relatively high pressure. Remove impurities and contaminants from the substrate that have a large size and are not chemically soluble. When the cleaning process is completed, the cleaning process is completed by supplying a rinse liquid for purifying the substrate from which the impurities or contaminants have been removed, removing the residue of the chemical liquid or the mixed gas from the substrate, and drying the substrate by dry gas. .

In particular, the cleaning process is a chemical removal step in which impurities or contaminants having a relatively small size are dissolved and removed by a chemical reaction with the chemical solution, and are removed by applying a direct physical collision or vibration to the impurities or contaminants having a relatively large size. It proceeds by performing the physical removal steps sequentially.

At this time, in the chemical removal step, the chemical liquid in which impurities or contaminants are dissolved is separated from the substrate by centrifugal force of the rotating substrate, but in the physical removal step, in order to remove the large size impurities from the surface of the pattern formed on the substrate. Two-fluid jets mixed with gas and chemical are directly sprayed at high speed and high pressure to remove contaminants. In other words, when the chemical solution in which impurities are dissolved is completely removed from the substrate, the two-fluid jet stream is sprayed directly onto the pattern surface in the next step to perform the physical removal step.

However, in recent years, as the substrate becomes larger and the pattern formed on the substrate becomes smaller and denser, high-pressure injection of the two-fluid jets onto the pattern surface frequently causes a problem of damaging the pattern. In the semiconductor manufacturing process, since the cleaning process must be performed for each unit process, such damage of the pattern causes a fatal defect of the semiconductor device.

In addition, chemical removal by chemical liquids includes the concept of wet etching in terms of removing impurities by using polarity change of pattern film quality, so overetching occurs on relatively wide cleaning surfaces such as sidewalls of line patterns. There is a problem. Accordingly, even though the pattern is precisely processed by the unit process prior to the cleaning process, the size of the pattern is reduced in the cleaning process, and thus there is a problem in that the accurate critical dimension cannot be processed in the semiconductor device manufacturing process.

Therefore, there is a need for an improved cleaning process that can prevent damage to the pattern and reduce the size of the pattern.

Embodiments of the present invention have been proposed to solve the above problems, and provide a method of cleaning a substrate which can prevent damage to the pattern and size reduction by improving the spraying process of the chemical liquid and the two-fluid jet stream.

Other embodiments of the present invention provide equipment for cleaning a substrate capable of performing the process as described above.

According to the method for cleaning a substrate according to an aspect of the present invention, the substrate on which the workpiece to be cleaned is formed is fixed to a rotatable support. Subsequently, a cleaning liquid is supplied to a central portion of the upper surface of the substrate rotating through the first nozzle to separate primary impurities from the substrate. A two-fluid mixture is supplied to the upper surface of the substrate rotating through the second nozzle simultaneously with the cleaning liquid to separate secondary impurities not separated by the cleaning liquid from the substrate. The cleaning solution and the diluent mixture containing the primary and secondary impurities are removed from the substrate.

According to one embodiment of the present invention, the cleaning solution is a first standard cleaning solution (SC1, Standard Clean 1), aqueous solution of hydrogen peroxide (H 2 O 2) and ammonium hydroxide (NH 4 OH), phosphoric acid solution, aqueous hydrogen fluoride solution (aqueous HF solution) and buffer And any one of a buffered oxide etch (BOE) solution and the diluent mixture comprises deionized water or a mixture of the rinse and gas. In this case, the gas may include any one selected from an inert gas having nitrogen (N 2) and carbon dioxide (CO 2), an oxidizing gas having ozone (O 3) and nitrogen oxide, and an organic gas having ethylene.

According to an embodiment of the present invention, the two-fluid mixture is sprayed to the upper surface of the substrate in a jet stream of high speed and high pressure through a second nozzle periodically through the central portion and the peripheral portion of the substrate. At this time, the cleaning liquid is moved from the center of the substrate to the periphery by the centrifugal force of the rotating substrate in the shape of a wave having a bone and a rib, and the two-fluid mixture is supplied to the bone of the cleaning liquid. The second nozzle moves between the central portion and the periphery of the substrate at a period of 2.5 seconds to 3.5 seconds and the substrate rotates at a speed of 850 rpm to 950 rpm.

According to an embodiment of the present invention, the substrate includes a semiconductor substrate for manufacturing a semiconductor device or a glass substrate for manufacturing a flat panel display panel.

According to one aspect of the present invention, a substrate cleaning apparatus includes a support for fixing and rotating a substrate such that an upper surface on which a workpiece to be cleaned is disposed is turned upward, and a supplying liquid for separating primary impurities from the substrate to an upper surface of the substrate. One nozzle, a second nozzle for reciprocating between the central portion and the periphery of the substrate at regular intervals, and for injecting a two-fluid mixture separating the secondary impurities not separated by the cleaning liquid from the substrate, and the cleaning liquid and the two-fluid mixture It includes a control unit for controlling to spray at the same time through the first and second nozzles.

According to an embodiment of the present invention, the control unit is rotated and the second rotation speed of the support to spray the two-fluid mixture toward the bone of the cleaning liquid which is pushed to the periphery of the substrate in a blue form by the rotation of the substrate And a speed controller for controlling the scan period of the nozzle.

According to an embodiment of the present invention, a driving motor connected to the control unit to generate a rotational force, a rotation rod for transmitting the rotational force of the drive motor and connected to the rotation rod and the second nozzle in accordance with the rotation of the rotation rod It further comprises a horizontal arm for reciprocating linear motion.

According to one embodiment of the present invention as described above, by simultaneously performing the step of providing a chemical liquid for chemically removing impurities and the step of spraying two-fluid jets for physical removal to remove the surface of the pattern to be cleaned to the chemical liquid The two-fluid jets may be supplied in a pattern in a covered state to prevent direct cleaning between the washing target pattern and the high-pressure two-fluid jets. Accordingly, it is possible to prevent the washing target pattern from being damaged.

In addition, since the cleaning liquid moves to the periphery of the substrate not only by the centrifugal force of the substrate but also by high-pressure jets, the contact time with the pattern surface can be relatively reduced. Thereby, overetching on the pattern surface by the said chemical liquid can be prevented. In particular, when the liquid chemical moves from the center of the substrate to the outer circumferential surface by the centrifugal force of the substrate, it spreads in a blue shape having valleys and ridges at regular intervals by various structures on the substrate formed before the cleaning process, and the jet flows into the ridges. It can be supplied as a to minimize the splash caused by the collision of chemicals and jets.

1 is a block diagram showing a substrate cleaning equipment in an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a method of cleaning a substrate using the substrate cleaning equipment shown in FIG. 1.

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

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. .

1 is a block diagram showing a substrate cleaning equipment in an embodiment of the present invention.

Referring to Figure 1, the substrate cleaning equipment 900 according to an embodiment of the present invention is a support 100 for fixing and rotating the substrate (w) so that the upper surface on which the workpiece to be cleaned is disposed, chemical impurities The first supply part 200 for supplying the cleaning solution dissolved in the upper surface to the central portion of the substrate w, the reciprocating movement between the central portion and the peripheral portion of the substrate w at regular intervals, and the impurities not dissolved in the cleaning liquid. The second supply unit 300 for injecting the two-fluid mixture physically separated from the substrate (w) and the control unit for controlling to simultaneously spray the cleaning liquid and the two-fluid mixture through the first and second supply units (200, 300) 400.

In one embodiment, the support 100 to which the substrate to be cleaned (w) is fixed is disposed in the chamber 102 that performs the cleaning process. For example, inside the chamber 102, a spin chuck is provided to the support 100 to hold the substrate w and rotate at a constant speed. On the top of the spin chuck is formed a hole for providing a vacuum for holding the substrate (w). The lower portion of the support 100 is connected to the rotary shaft 110 for transmitting a rotational force for rotating the support 100, the rotary shaft 110 receives the rotational force from the first drive 112 connected to the lower. The first driving unit 112 is connected to the control unit 400 and operates according to a control signal of the control unit 400.

A cover 114 having a cup shape is provided around the support 100 to prevent scattering of the cleaning liquid and the rinse liquid supplied to the substrate w while the cleaning process for the substrate w is performed. A discharge port 116 for discharging the cleaning liquid and the rinse liquid is connected to the lower part of the cover 114. The second driving unit 120 may be connected to the cover 114 through the driving shaft 118 to drive the cover 114 up and down. The second driver 120 is also connected to the controller 400 to operate according to the control signal of the controller 400.

In this case, the substrate w may include a structure formed by a predetermined process. For example, a unit process for improving a semiconductor device may be performed to include a semiconductor substrate on which various kinds of film structures or conductive structures are disposed, and various unit processes for forming a flat panel display device may be performed to form a film structure or a conductive material. The structure may include a glass substrate disposed.

A workpiece to be cleaned, such as the structures, is disposed on the upper surface of the substrate and is fixed on the support 100 so that the upper surface of the substrate w faces upward in the chamber 102.

The upper portion of the support 100 reciprocates at regular intervals between the first supply portion 200 for supplying a cleaning liquid chemically dissolving impurities to the upper surface center portion of the substrate (w) and the central portion and the peripheral portion of the substrate (w) A second supply part 300 is disposed to move and spray a two-fluid mixture that physically separates impurities not dissolved in the cleaning liquid from the substrate w.

The first supply unit 200 is connected to the cleaning liquid waiting unit 210 for temporarily storing the cleaning liquid and the waiting unit 210 and the first nozzle 220 for spraying the cleaning liquid onto the upper surface of the substrate w. And a first horizontal arm 230 horizontally connected to the cleaning liquid atmospheric part 210 and a fixing unit 240 connected to the first horizontal arm and fixed to the bottom of the chamber 102.

For example, the cleaning liquid waiting part 210 is disposed above the central part of the substrate w and the first nozzle 220 is disposed in the cleaning liquid waiting part toward the upper surface of the substrate w. In this case, the cleaning liquid waiting unit 210 is disposed to be fixed in the chamber 102 by being connected to the fixing unit 240 through the first horizontal arm 230. As long as the fixing unit 240 has a structure capable of fixing the cleaning liquid standby part 210 to the upper portion of the substrate, various modifications are possible, and it is obvious that the fixing unit 240 is not necessarily disposed inside the chamber 102.

In addition, the first horizontal arm 230 may be selectively fixed to the fixing unit 240 to be movable or statically fixed according to the needs of the process. In the case where it is fixed to be movable, it is obvious that the mixture can move in conjunction with the moving speed of the atmospheric portion 310. In addition, when fixed statically, it is preferably fixed to supply the cleaning liquid to the central portion of the substrate. In particular, in the present exemplary embodiment, the first horizontal arm 230 is exemplarily disclosed in a structure in which the fixing unit 240 is fixed. It may be disposed to move in conjunction with the 340. In this case, it is obvious that the fixing unit 240 may also be controlled by the controller 400 to be described later.

The cleaning liquid waiting unit 210 is connected by the first chemical storage tank 250 and the first supply line 252, and the cleaning liquid is supplied from the first chemical storage tank 250 to the cleaning liquid waiting unit 210. A first chemical liquid supply valve 254 is disposed on the first supply line 252 to adjust the amount of the first chemical liquid supplied to the cleaning liquid atmosphere. The first chemical liquid supply valve 254 is connected to the control unit 400 and the amount of the first chemical liquid supplied to the cleaning liquid waiting unit 210 may be automatically controlled as necessary for the cleaning process.

The first chemical solution stored in the first chemical storage tank 250 and supplied as a cleaning solution is an aqueous solution for dissolving fine contaminants or impurities on the surface of the substrate (w), and an aqueous solution of hydrogen peroxide (H 2 O 2) and ammonium hydroxide (NH 4 OH). It may include any one of the first standard cleaning solution (SC1, Standard Clean 1), phosphoric acid aqueous solution, aqueous hydrogen fluoride (aqueous HF solution) and buffered oxide etch (BOE) solution.

The second supply part 300 is connected to the mixture waiting part 310 and the mixture waiting part 310 for temporarily storing a two-fluid mixture for physically separating impurities not dissolved in the cleaning liquid from the substrate. A second nozzle 320 which sprays a two-fluid mixture on the upper surface of the substrate w at a high speed, a second horizontal arm 330 horizontally connected to the mixture atmospheric part 310, and the second horizontal arm 330 And a moving unit 340 connected to the mixture atmospheric portion 310 to reciprocate between the central portion and the peripheral portion of the substrate w.

For example, the mixture atmospheric part 310 is disposed to share the same plane side by side with the cleaning liquid atmospheric part 210 so as to be parallel to the upper surface of the substrate w by driving the rotating rod 340. The reciprocating movement is performed at regular intervals between the periphery and the center of the plane. The second nozzle 320 is fixed to the mixture atmosphere 310 to face the surface of the substrate w and moves together with the mixture atmosphere 310.

For example, the mobile unit 340 may include a rotation rod 340a connected to the second horizontal arm 330 and a drive motor 340b for transmitting rotational force to the rotation rod. The driving motor 340b transmits a rotational force of an appropriate magnitude to the rotation rod 340a according to the signal of the controller 400, and the second horizontal arm 330 corresponds to the rotation of the rotation rod 340a. It reciprocates at regular intervals along the horizontal direction parallel to the substrate w.

The mixture atmospheric portion 310 may increase the pressure and flow rate of the injected fluid to remove impurities that are not removed by the chemical reaction with the cleaning liquid through a physical blow between the injected fluid and the substrate. 2 Store the fluid mixture.

For example, the mixture atmospheric portion 310 is connected to the mixing portion 356 and the second supply line 358 by mixing the liquid and gas to produce a two-fluid mixture and mixed in a sufficient concentration The mixture is supplied to the mixture atmospheric portion 310 through the second supply line 358. The two-fluid mixture stored in the mixture atmospheric portion 310 is sprayed at a high pressure and a high speed through the second nozzle 320 to the upper surface of the substrate w to remove impurities or contaminants that are not removed by a chemical dissolution process. ) Is removed from the surface.

The mixing unit 356 cleans the second chemical liquid and gas supplied from the raw material storage unit 350 including a second chemical liquid storage tank 350a storing the second chemical liquid and a gas storage unit 350b storing the gas. Mix in the proper proportions required for the process to produce the difluid mixture. At this time, the second chemical liquid is supplied to the mixing unit 356 by a chemical liquid supply unit 352 having a chemical liquid supply line 352a and a second chemical liquid supply valve 352b, and the gas is supplied to the gas supply line 354a. And a gas supply valve 354b to the mixing unit 356. The chemical liquid supply valve 352b and the gas supply valve 354b are connected to the control unit 400 so that the amount of the second chemical liquid and gas supplied to the mixing unit is appropriately controlled.

In the present embodiment, the second chemical liquid stored in the second chemical liquid storage tank 350a includes a first chemical liquid or deionized water, and the gas stored in the gas storage tank 350b includes nitrogen (N 2) and carbon dioxide (CO 2). It may include any one selected from an inert gas, an oxidizing gas having ozone (O3) and nitrogen oxide and an organic gas having ethylene. However, it is apparent that the second chemical liquid may use a different kind of chemical liquid according to the type and size of the impurities.

At this time, the two-fluid mixture is injected through the second nozzle 320 to the surface of the substrate in a jet flow of high speed and high pressure by mixing the second chemical liquid with the gas of the gas state. Thus, impurities that are not dissolved by a chemical bond with the cleaning liquid or impurities of relatively large size can be completely separated from the substrate by the jets of the two-fluid mixture.

The controller 400 includes first and second driving units 112 and 120, first and second chemical liquid supply valves 254 and 352b, a driving motor 340b and a gas supply valve 354b of the mobile unit 340. Electrically connected to the substrate to appropriately control the cleaning process of the substrate.

For example, the control unit 400 controls the flow rate of the fluid through the speed control unit 410 and the valves to control the rotational speed of the first and second driving units 112 and 120 and the driving motor 340b. It includes a flow control unit 420.

In particular, the control unit 400 controls the cleaning liquid sprayed through the first nozzle 220 and the two-fluid mixture sprayed through the second nozzle to be sprayed onto the substrate at the same time, thereby controlling the surface of the substrate by the two-fluid mixture. Damage can be prevented. During the chemical dissolution process of impurities by the cleaning solution, the two-fluid mixture may be sprayed onto the substrate to simultaneously perform the chemical dissolution process and the physical separation process. Therefore, the surface of the substrate is in contact with the two-fluid mixture of high speed and high pressure in the state covered with the cleaning liquid to prevent damage to the structure due to the strong impact of the two-fluid mixture.

That is, in the related art, a high speed and high pressure two-fluid mixture is sprayed onto the surface of the substrate from which the cleaning liquid is removed, thereby directly contacting the two-fluid mixture with the surface of the substrate or the structures formed on the surface. Although the structures are damaged, according to the cleaning apparatus of the present invention, since the surface of the substrate and the diluent mixture are indirectly contacted through the cleaning liquid, the strength of the physical impact of the diluent mixture on the substrate surface can be reduced.

For example, by controlling the supply valve through the flow rate control unit 420, it is possible to synchronize the supply timing of the cleaning liquid and the two-fluid mixture supplied to the cleaning liquid waiting unit 210 and the mixture waiting unit 310. Accordingly, the cleaning solution and the two-fluid mixture can be simultaneously supplied to the substrate w.

On the other hand, the control unit 400 may minimize the splash due to the collision of the cleaning liquid and the two-fluid mixture supplied at the same time by controlling the rotational speed of the substrate (w) and the moving speed of the second nozzle (320).

Since the substrate w is rotated at a constant speed by the rotation of the spin chuck, the cleaning liquid supplied to the central portion of the upper surface of the rotating substrate is pushed out to the peripheral portion by the centrifugal force of the substrate. At this time, the cleaning liquid is propagated in a blue form having a constant cycle according to the rotational speed of the substrate to form a valley and a rib.

In this case, the speed controller 410 controls the driving motor 340b in consideration of the rotational speed of the substrate so that the two-fluid mixture injected through the second nozzle 320 collides with the valley of the blue liquid of the cleaning liquid. Induce. That is, by adjusting the scan period of the mixture waiting portion 310 and the second nozzle 320 through the driving motor 340b, the two-fluid mixture and the cleaning liquid blue are relatively contacted at the bone portion instead of the ridges. This can reduce the chance of a splash.

For example, if the substrate is a wafer having a 300 mm diameter and rotates from about 800 rpm to 900 rpm, the second nozzle 320 is controlled by controlling the drive motor 340b to have a scan period of about 2.5 seconds to about 3.5 seconds. The splash due to the direct contact between the cleaning liquid and the diluent mixture can be minimized. In this case, the speed controller 410 may control the scan period of the second nozzle 320 by adjusting the rotational speed of the drive motor 340b in accordance with the rotational speed of the spin chuck that is the support 100.

Accordingly, it is possible to prevent the splash generated by the collision of the cleaning liquid and the two-fluid mixture to function as a pollution source in the substrate or the chamber 102.

Although not shown in FIG. 1, the substrate cleaning apparatus 900 may further include an additional chemical liquid storage unit and a spray nozzle for performing a rinsing and cleaning process after cleaning the substrate w.

The substrate cleaning equipment 900 having such a configuration is operated as follows. FIG. 2 is a flowchart illustrating a method of cleaning a substrate using the substrate cleaning equipment shown in FIG. 1.

1 and 2, the substrate on which the workpiece to be cleaned is formed is fixed on the support 100 of the substrate cleaning equipment 900 (step S100).

After the predetermined structure is formed on the wafer or the glass substrate by a unit process performed before the cleaning process, the substrate is loaded into the spin chuck, which is the support 100 disposed in the chamber 102. Subsequently, the substrate w is fixed to the support 100 by applying a vacuum pressure through a vacuum hole formed in the surface of the spin chuck.

Subsequently, the cleaning liquid is supplied to the central portion of the upper surface of the substrate w rotating through the first nozzle 220 to separate primary impurities from the substrate w (step S200).

The first driving unit 112 is controlled through the speed controller 410 to rotate the spin chuck at a constant speed. Subsequently, by selectively adjusting the first chemical liquid supply valve 254, the first chemical liquid as the cleaning liquid is supplied to the upper surface of the substrate w that rotates on the upper surface of the spin chuck. In the present embodiment, the first nozzle 220 is aligned above the central portion of the substrate by the first horizontal arm 230 and the fixing unit 240 so that the cleaning liquid is constantly at the central portion of the substrate w. Supplied. However, it is apparent that the first nozzle 220 may be disposed to be movable to the fixing unit 240. At this time, the fixed unit 240 is controlled to move in conjunction with the moving speed of the mobile unit 340 by the control unit 400.

For example, the first chemical solution provided as the cleaning solution is a first standard cleaning solution (SC1, Standard Clean 1), an aqueous solution of hydrogen peroxide (H 2 O 2) and ammonium hydroxide (NH 4 OH), an aqueous solution of phosphoric acid, and an aqueous solution of hydrogen fluoride (aqueous HF solution). And a buffered oxide etch (BOE) solution. In addition, the first impurity may include an impurity that may be chemically reacted with the first chemical liquid to dissolve or may be relatively small in size, and thus may be separated from the substrate by the spraying speed of the cleaning liquid.

Subsequently, a two-fluid mixture is supplied to the upper surface of the substrate w which rotates through the second nozzle 320 simultaneously with the cleaning liquid to remove secondary impurities, which are not separated from the substrate by the cleaning liquid, from the substrate w. Separate (step S300).

For example, the second fluid when the second chemical liquid and gas are mixed in the mixing unit 356 and supplied to the mixture atmospheric unit 310 and the cleaning liquid is injected to the substrate through the first nozzle 220. The mixture is also adjusted to be sprayed onto the substrate through the second nozzle 320. The second chemical liquid supply valve 352b and the gas supply valve 354b are controlled by the flow controller 420 so that the injection points through the first and second nozzles 220 and 320 are synchronized with each other. The fluid mixture and the cleaning liquid may be fed to the substrate at the same time.

The diluent mixture may comprise deionized water or a mixture of the first chemical and a gas, the gas comprising an inert gas, ozone (O3) and nitrogen (N2) and carbon dioxide (CO2) and It includes any one selected from an oxidizing gas having nitrogen oxide and an organic gas having ethylene. In addition, the second impurity includes impurities that do not chemically react with the first chemical liquid and are not dissolved or separated from the substrate by the spraying speed of the cleaning liquid because of their relatively large size.

That is, the impurities distributed on the substrate are physically or chemically separated from the substrate by the cleaning liquid and physically separated from the substrate by the dilute mixture of high speed and high pressure.

In this case, the speed controller 410 controls the moving speed of the second nozzle 320 according to the rotational speed of the first driving unit 112 that rotates the substrate w so that the speed of the cleaning liquid and the two-fluid mixture is reduced. Minimize splash caused.

The cleaning liquid supplied to the upper surface of the rotating substrate w spreads out in a blue shape having valleys and ribs from the center of the substrate toward the periphery by the centrifugal force of the substrate. At this time, by adjusting the moving speed of the second nozzle 320 reciprocating between the central portion and the peripheral portion of the substrate so that the two-fluid mixture sprayed through the second nozzle is concentrated in the bone portion, not the ridge of the cleaning liquid blue Minimize the splash caused by the collision of the cleaning liquid and the diluent mixture. For example, when a wafer having a diameter of 300 mm rotates at about 850 rpm to about 950 rpm, the movement period (hereinafter, referred to as a scan cycle) between the periphery and the center of the second nozzle 320 is about 2.5 seconds to about 3.5 seconds. The drive motor 340b is controlled.

Accordingly, the high-pressure, high-pressure two-fluid mixture is sprayed onto the surface of the substrate covered with the cleaning solution, thereby significantly reducing damage to the structure formed on the substrate as compared with the case where the two-fluid mixture is directly sprayed onto the surface of the substrate. In addition, it is possible to minimize the splash phenomenon that can occur by simultaneously supplying the cleaning solution and the two-fluid mixture of high pressure and high speed. Accordingly, contamination in the chamber 102 due to the splash can be minimized.

Subsequently, the cleaning solution and the two-fluid mixture including the primary and secondary impurities are removed from the substrate (step S400). The cleaning solution and the diluent mixture may be removed from the substrate by centrifugal force by rotation of the substrate or forcedly removed by additional external force. In particular, by using the high-speed jet of the two-fluid mixture to push the cleaning liquid to the periphery of the substrate to remove the cleaning liquid only by the centrifugal force of the substrate and to improve the efficiency of the cleaning process compared to the conventional process of supplying the two-fluid mixture There is this.

According to embodiments of the present invention, the step of providing a chemical liquid for chemically removing impurities and spraying two-fluid jets for physical removal are simultaneously performed so that the surface of the pattern to be cleaned is covered by the chemical liquid. In the state, the two-fluid jets may be supplied in a pattern to prevent the washing target pattern and the high-pressure two-fluid jets from directly contacting each other. Accordingly, it is possible to prevent the washing target pattern from being damaged.

In addition, since the cleaning liquid is moved not only by the centrifugal force of the substrate but also by the jet of high pressure, the cleaning liquid can relatively reduce the contact time with the pattern surface. Thereby, overetching on the pattern surface by the said chemical liquid can be prevented. In particular, when the liquid chemical moves from the center of the substrate to the outer circumferential surface by the centrifugal force of the substrate, it spreads in a blue shape having valleys and ridges at regular intervals by various structures on the substrate formed before the cleaning process, and the jet flows into the ridges. It can be supplied as a to minimize the splash caused by the collision of chemicals and jets.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims. It can be understood that it is possible.

100: support 200: first supply
300: second supply unit 400: control unit
900: substrate cleaning device

Claims (10)

Fixing a substrate having a workpiece to be cleaned on an upper surface thereof to a rotatable support;
Separating a primary impurity from the substrate by supplying a cleaning liquid to a central portion of the upper surface of the substrate rotating through a first nozzle;
Supplying a two-fluid mixture to the upper surface of the substrate rotating through a second nozzle simultaneously with the cleaning liquid to separate secondary impurities not separated by the cleaning liquid from the substrate;
Removing the cleaning solution and the secondary fluid mixture containing the primary and secondary impurities from the substrate. The method of claim 1, wherein the cleaning solution is a first standard cleaning solution (SC1, Standard Clean 1), an aqueous solution of hydrogen peroxide (H 2 O 2) and ammonium hydroxide (NH 4 OH), an aqueous solution of phosphoric acid, an aqueous solution of hydrogen fluoride (aqueous HF solution) and a buffered oxidation etching solution ( a buffered oxide etch (BOE) solution, and the diluent mixture comprises deionized water or a mixture of the cleaning liquid and gas. The gas of claim 2, wherein the gas comprises any one selected from an inert gas having nitrogen (N 2) and carbon dioxide (CO 2), an oxidizing gas having ozone (O 3) and nitrogen oxides, and an organic gas having ethylene. Method for cleaning a substrate, characterized in that. The semiconductor substrate of claim 1, wherein the two-fluid mixture is sprayed onto the upper surface of the substrate in a jet stream of high speed and high pressure through a nozzle which periodically moves the central portion and the peripheral portion of the substrate. How to wash. 5. The cleaning solution according to claim 4, wherein the cleaning liquid is moved from the center of the substrate to the periphery in a blue shape having bone and ridges by the centrifugal force of the rotating substrate, and the two-fluid mixture is supplied to the ridge of the cleaning liquid. How to wash the substrate. The method of claim 5, wherein the second nozzle moves between the center portion and the peripheral portion of the substrate at a period of 2.5 seconds to 3.5 seconds, and the substrate rotates at a speed of 850 rpm to 950 rpm. The method of claim 1, wherein the substrate comprises a semiconductor substrate for manufacturing a semiconductor device or a glass substrate for manufacturing a flat panel display panel. Support for fixing and rotating the substrate so that the upper surface is disposed on the workpiece to be cleaned;
A first nozzle supplying a cleaning liquid for separating primary impurities from the substrate to an upper surface of the substrate;
A second nozzle reciprocating between the central portion and the peripheral portion of the substrate at regular intervals and spraying a two-fluid mixture separating secondary impurities not separated by the cleaning liquid from the substrate; And
And a control unit controlling the spraying of the cleaning liquid and the two-fluid mixture through the first and second nozzles at the same time. 10. The method of claim 8, wherein the control unit is scanning the rotational speed of the support and the second nozzle to spray the two-fluid mixture toward the bone of the cleaning liquid pushed to the periphery of the substrate in a blue form by the rotation of the substrate Substrate cleaning apparatus comprising a speed control unit for controlling the cycle. The reciprocating linear motion of claim 8, wherein the driving motor is connected to the control unit to generate a rotational force, the rotational rod transmitting the rotational force of the driving motor, and the rotational rod and the second nozzle are connected to each other. Substrate cleaning apparatus further comprises a horizontal arm.

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