KR20080009832A - Substrate cleaning method - Google Patents

Abstract

A substrate cleaning method is provided to improve the cleaning efficiency by controlling the supply of DI(Deionized) water and the rotation speed of a substrate according to the temperature change of the DI water. A substrate cleaning method includes the steps of: determining whether the temperature of DI water in a cleaning liquid supplying member is normal temperature(S310); determining whether the temperature of the DI water over the normal temperature in case that the temperature of the DI water is not the normal temperature(S320); decreasing the supply of the DI water and/or increasing the rotation speed of a substrate in case that the temperature of the DI water is over the normal temperature(S330); increasing the supply of the DI water and/or decreasing the rotation speed of the substrate in case that the temperature of the DI water is below the normal temperature(S340); and cleaning the chemical liquid remaining on the substrate with the DI water(S350).

Description

Substrate Cleaning Method {SUBSTRATE CLEANING METHOD}

1 is a configuration diagram schematically showing a substrate processing apparatus to which a substrate processing method according to the present invention is applied.

FIG. 2 is a flowchart illustrating a process of the substrate processing apparatus shown in FIG. 1.

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

Explanation of symbols on the main parts of the drawings

100: substrate processing apparatus

110: container

120: spin chuck

130: drive unit

140: nozzle unit

150: nozzle unit driver

160: treatment fluid supply member

170: control unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of cleaning a substrate, and more particularly, to a method of cleaning a semiconductor substrate in a single sheet type.

In general, semiconductor manufacturing apparatus are manufactured by iterative and selective performance of unit processes such as deposition, photolithography, etching, chemical mechanical polishing, cleaning, drying, and the like. Among these unit processes, a cleaning process is a process of removing foreign substances or unnecessary films attached to the surface of the semiconductor substrate during each unit process. In recent years, the cleaning process has become increasingly important as the pattern formed on the semiconductor substrate becomes finer and the aspect ratio of the pattern increases.

Among the apparatuses for performing the cleaning process, the sheet type cleaning apparatus sequentially cleans a single wafer. A common sheet cleaning apparatus includes a process chamber, a spin chuck, a nozzle portion, and a processing fluid supply member. The process chamber provides a space for performing a cleaning process of the substrate. The spin chuck supports and rotates the substrate inside the process chamber. The nozzle unit injects the processing fluid to the substrate seated on the spin chuck. The treatment fluid supply member supplies the chemical liquid, the cleaning liquid, and the dry gas to the nozzle unit. In this case, various kinds of chemicals are used as the chemical liquid, and ultrapure water is used as the cleaning liquid.

The substrate cleaning method of the substrate cleaning apparatus described above cleans the chemical liquid remaining on the substrate with ultrapure water after treating the substrate with the chemical liquid. However, when the chemical liquid is a chemical liquid having a high viscosity, the cleaning of the chemical liquid by ultrapure water was not effective. For example sulfuric acid (H2SO4). When the substrate was treated with a high viscosity chemical liquid such as nitric acid (HNO 3) and phosphoric acid (H 3 PO 4), and then the chemical liquid was washed with ultrapure water at room temperature, it was difficult to effectively remove the chemical liquid from the substrate due to its high viscosity due to its high viscosity.

In addition, in the above-mentioned substrate cleaning apparatus, the supply amount of the cleaning liquid at the time of chemical liquid cleaning is constant. That is, the cleaning efficiency of the chemical liquid is changed by the temperature and the supply amount of the cleaning liquid. However, a general substrate cleaning apparatus processes the substrate with a constant supply amount regardless of the temperature change of the cleaning liquid. Therefore, the cleaning rate of the substrate may decrease due to the temperature change of the cleaning liquid.

In order to solve the above problems, an object of the present invention is to provide a substrate cleaning method for efficiently performing the cleaning of the substrate. In particular, it is an object of the present invention to provide a substrate cleaning method for effectively cleaning a high viscosity chemical liquid remaining on a substrate with ultrapure water at room temperature.

In the substrate cleaning method according to the present invention for achieving the above object, in the method for cleaning a substrate in which the chemical liquid remains in ultrapure water, by supplying ultrapure water of a predetermined reference temperature on the substrate for a predetermined reference time to remove the chemical liquid However, the supply time of the ultrapure water is changed according to the change in the reference temperature.

According to an embodiment of the present invention, the chemical liquid is at least one chemical liquid in the group consisting of sulfuric acid, nitric acid, and phosphoric acid, the reference time is 90 seconds, and the reference temperature is room temperature.

According to an embodiment of the present invention, in the method of cleaning the substrate, if the temperature of the ultrapure water is higher than the reference temperature, the reference time is decreased by increasing the temperature exceeding the reference temperature, and the temperature of the ultrapure water is the reference. If the temperature is lower than the temperature, the temperature decreases by less than the reference temperature, thereby increasing the reference time.

The substrate cleaning method according to the present invention for achieving the above object is a method for cleaning a substrate in which at least one chemical liquid remains in the group consisting of sulfuric acid, nitric acid, and phosphoric acid, (a) loading the substrate on the spin chuck (B) treating the substrate with the chemical liquid, (c) cleaning the chemical liquid by supplying ultrapure water at room temperature for 90 seconds on the rotated substrate, and (d) drying gas on the substrate. Spraying the substrate to dry the substrate, and (e) unloading the substrate from the spin chuck, wherein step (c) is performed by the temperature exceeding the room temperature if the temperature of the ultrapure water is higher than the room temperature. At least one of reducing the supply time of ultrapure water and increasing the rotational speed of the substrate is achieved, and if the temperature of the ultrapure water is lower than the room temperature, the temperature is lower than the room temperature. Temperature by at least one of a reduction in rotational speed is to occur in the increase of the supply time of the ultra-pure water and the substrate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed subject matter is thorough and complete, and that the spirit of the present invention to those skilled in the art will fully convey. Portions denoted by like reference numerals denote like elements throughout the specification.

In addition, in the present embodiment, a method of washing the semiconductor substrate in a single sheet is described as an example. However, the present invention is also applicable to a method for cleaning a glass substrate used for producing flat panel displays.

Example 1

1 is a configuration diagram schematically showing a substrate processing apparatus to which a substrate processing method according to the present invention is applied.

Referring to FIG. 1, the substrate processing apparatus 100 according to the present invention may include a process chamber 110, a spin chuck 120, a driver 130, a nozzle unit 140, a nozzle unit driver 150, and a processing fluid supply. The member 160, a sensing member (not shown), and a controller 170 are included.

The process chamber 110 has a housing 112 and a drain member 114. The housing 112 provides a space in which the cleaning and drying process of the substrate is performed. The housing 112 is open at the top. The open upper portion of the housing 112 is used as a substrate entrance through which the substrate W enters and exits during the process. The drain member 114 drains the treatment liquid in the housing 112 to the outside.

The spin chuck 120 supports and rotates the substrate W in the housing 112 during the process. The spin chuck 120 has a support 122 and a rotation axis 124. The support part 122 supports the substrate W so that the processing surface of the substrate W faces upward. The support part 122 supports the substrate W so that the substrate W is not separated from the support part 122 during the process. The rotating shaft 124 is coupled to the support unit 122 on one side, and coupled to the driving unit 130 on the other side. The rotating shaft 124 transmits the rotational force of the driving unit 130 to the support 122.

The driver 130 drives the spin chuck 120. The driving unit 130 rotates the rotating shaft 124 to rotate the substrate (W). The driving unit 130 may adjust the height of the substrate W by raising and lowering the rotation shaft 124.

The nozzle unit 140 supplies a processing fluid to the processing surface of the substrate W during the process. The nozzle unit 140 includes at least one nozzle. Here, the treatment fluid includes a chemical liquid, a cleaning liquid, and a dry gas. The chemical liquid removes foreign substances remaining on the substrate, such as photoresist, metal contaminants, organic contaminants, and other treatment liquids. Sulfuric acid, nitric acid, and phosphoric acid are used as the chemical liquid. The cleaning liquid removes the chemical liquid remaining on the substrate. Ultrapure water is used as the cleaning liquid. The dry gas dries the substrate. As the dry gas, an inert gas such as nitrogen gas is used.

The nozzle unit 140 supplies a cleaning liquid for a predetermined reference time when cleaning the chemical liquid. Here, the cleaning liquid is ultrapure water (25 ° C.) at room temperature, and the predetermined reference time is any one time selected from at least 90 seconds. This is because when cleaning high viscosity chemicals such as sulfuric acid, nitric acid, and phosphoric acid from the substrate, ultrapure water at room temperature must be supplied for at least 90 seconds to remove the chemicals. Therefore, the nozzle unit 140 preferably supplies the cleaning liquid at room temperature for 90 seconds or more when the chemical liquid is washed. However, when the temperature of ultrapure water exceeds room temperature, it can also supply in 90 second or less.

The nozzle unit driver 150 drives the nozzle unit 140. The nozzle unit driver 150 includes a first arm 152, a second arm 154, and a driver 156. The first arm 152 is installed horizontally at the top of the housing 112. The nozzle unit 140 is coupled to one side of the first arm 152 and coupled to one end of the second arm 154 to the other side. The second arm 154 is installed perpendicular to the first arm 152. The driver 156 rotates and raises and lowers the second arm 154.

Here, the nozzle unit driver 150 moves the nozzle unit 140 between the process position (a) and the standby position (b). The process position (a) is a position for the nozzle unit 140 to supply the processing fluid on the substrate (W), and the standby position (b) is a process chamber before the nozzle unit 140 is moved to the process position (a). 110 is the position to wait outside. In addition, the nozzle unit driver 150 moves the nozzle unit 140 at various angles within the process position a so that the nozzle unit 140 uniformly supplies the processing fluid to the entire processing surface of the substrate W during the process. You can.

The treatment fluid supply member 160 supplies the treatment fluid to the nozzle unit 140. The treatment fluid supply member 160 includes a chemical liquid supply member 162, a cleaning liquid supply member 164, and a dry gas supply member 166. The chemical liquid supply member 162 supplies the chemical liquid to the nozzle unit 140. The cleaning liquid supply member 164 supplies the cleaning liquid to the nozzle unit 140. Here, ultrapure water is used as the cleaning liquid. The cleaning liquid supply member 164 preferably supplies ultrapure water at a predetermined reference temperature, that is, room temperature (25 ° C). The dry gas supply member 166 supplies the dry gas to the nozzle unit 140. As dry gas, an inert gas such as nitrogen gas is used.

The sensing member (not shown) senses the temperature of the cleaning liquid. The sensing member may include at least one temperature sensor. The sensing member senses the temperature of the cleaning liquid during the process and transmits the sensed temperature data to the controller 170.

The controller 170 controls the driver 130, the nozzle unit 140, the driver 156, and the processing fluid supply member 160. The controller 170 controls the driver 130 to adjust the rotational speed of the substrate W during the process. The controller 170 controls the driver 156 to adjust the position of the nozzle unit 140 during the process. In addition, the controller 170 controls the processing fluid supply member 160 to control the supply amount of the processing fluid supplied to the nozzle unit 140.

In addition, the control unit 170 receives the temperature data from the sensing member during the cleaning process to adjust the supply amount of the cleaning liquid. That is, the controller 170 determines the temperature data and, when the temperature of the cleaning liquid exceeds room temperature, shortens the cleaning liquid supply time of the nozzle unit 140 in proportion to the temperature exceeding the room temperature, thereby reducing the supply amount of the cleaning liquid. In addition, the controller 170 determines the temperature data, and when the temperature of the cleaning liquid is lower than room temperature, the cleaning liquid supply time of the nozzle unit 140 is increased in proportion to the temperature lower than the room temperature, thereby increasing the supply amount of the cleaning liquid.

Hereinafter, the substrate cleaning method of the substrate cleaning apparatus 100 described above will be described in detail. Here, the same reference numerals for the same components as the above-described configuration, and the detailed description of the configuration will be omitted.

2 is a flowchart illustrating a process of the substrate processing apparatus shown in FIG. 1, and FIG. 3 is a flowchart illustrating a substrate cleaning method according to the present invention.

Referring to FIG. 2, when the cleaning process of the substrate is started, the substrate W is loaded onto the spin chuck 120. The substrate W loaded on the spin chuck 120 is fixed to the spin chuck 120. The control unit 170 drives the driver 156 of the nozzle unit driver 150 to move the nozzle unit 140 from the standby position b to the process position a. When the nozzle unit 140 is located at the process position (a), the nozzle unit 140 receives the chemical liquid from the chemical liquid supply member 162 and supplies the chemical liquid to the processing surface of the substrate W (S120). In this case, the controller 170 drives the driver 130 so that the driver 130 rotates the spin chuck 120 at a predetermined process speed. The substrate W is rotated at a process speed by the rotation of the spin chuck 120, and the chemical liquid supplied on the substrate W is moved from the center region of the substrate W to the edge region while the processing surface of the substrate W is rotated. Remove foreign substances remaining in the The used chemical liquid is discharged to the outside through the discharge line 114.

When the chemical liquid treatment of the substrate W is completed, ultrapure water is supplied onto the substrate W to clean the substrate W (S300). The cleaning process of the substrate W is as follows. Referring to FIG. 3, the sensing member senses the temperature of the ultrapure water in the cleaning liquid supply member 164, and transmits the sensed temperature data to the controller 170. The controller 170 reads the temperature data to determine whether the temperature of the ultrapure water is room temperature (S310). In addition, when the temperature of the ultrapure water is not room temperature, the controller 170 determines whether the temperature of the ultrapure water exceeds the room temperature (S320).

If the temperature of the ultrapure water is room temperature, the nozzle unit 140 receives the ultrapure water at room temperature from the ultrapure water supply member 164 and sprays the ultrapure water on the substrate W by a predetermined reference amount to remain on the substrate W. To wash the chemical liquid (S350).

If the temperature of the ultrapure water is higher than the room temperature, the control unit 170 controls the nozzle unit 140 to proportionally reduce the amount of ultrapure water supplied by the nozzle unit 140 by exceeding the temperature range. That is, when the temperature of the ultrapure water exceeds room temperature, the control unit 170 increases the ultrapure water supply time of the nozzle unit 140 to reduce the supply amount of ultrapure water. This is because the cleaning rate of the substrate W increases as the temperature of the ultrapure water increases. Therefore, when the temperature of ultrapure water is higher than room temperature, the supply time of ultrapure water is shortened and the cleaning rate of ultrapure water is reduced. The supplied ultrapure water cleans the chemical liquid remaining on the substrate W (S350).

On the contrary, when the temperature of the ultrapure water is lower than the room temperature, the controller 170 controls the nozzle unit 140 to increase the supply amount of the ultrapure water supplied by the nozzle unit 140 below the reference temperature. That is, when the temperature of the ultrapure water is less than or equal to room temperature, the controller 170 reduces the supply time of the ultrapure water by reducing the ultrapure water supply time of the nozzle unit 1400. The lower the ultrapure water temperature, the lower the cleaning rate of the substrate W. Therefore, when the temperature of the ultrapure water is lower than room temperature, the supply time of the ultrapure water is increased to improve the cleaning rate of the ultrapure water, and the supplied ultrapure water cleans the chemical liquid remaining on the substrate W (S350).

In the present exemplary embodiment, the nozzle unit 140 adjusts the ultrapure water supply time by adjusting the supply time of the ultrapure water. For example, the supply amount of the ultrapure water may be controlled in various ways. For example, as another embodiment of the present invention, the nozzle unit 140 may adjust the supply amount of ultrapure water by increasing or decreasing the flow rate of ultrapure water.

In addition, the present invention has been described by changing the cleaning rate of the substrate W by adjusting the supply amount of ultrapure water, but the change of the cleaning rate of the substrate W may be made by changing the rotational speed of the substrate W. For example, as another embodiment of the present invention, if the temperature of the ultrapure water is higher than room temperature, the controller 170 controls the drive unit 130 to increase the rotational speed of the substrate (W) in proportion to the room temperature. This is because, as the rotational speed of the substrate W increases, the time for which the ultrapure water stays on the substrate W decreases, so that the cleaning rate of the ultrapure water substrate W decreases. On the contrary, when the temperature of the ultrapure water is lower than room temperature, the controller 170 controls the driving unit 130 so that the rotational speed of the substrate W is reduced in proportion to the temperature of the ultrapure water. This is because the lower the rotational speed of the substrate W is, the longer the time the ultrapure water stays in the substrate W, and the cleaning rate of the ultrapure water substrate W increases. Accordingly, the controller 170 changes the rotational speed of the substrate W to change the chemical liquid cleaning rate of the ultrapure water.

When the cleaning of the substrate W is completed, the nozzle unit 140 receives the dry gas from the dry gas supply member 168 and injects the dry gas onto the substrate W. At this time, the injected dry gas is dried while removing the foreign matter remaining on the substrate (W). When the drying of the substrate W is completed, the rotation of the spin chuck 120 is stopped, and the substrate W is unloaded from the spin chuck 120 to be carried out of the substrate processing apparatus 100.

The substrate processing apparatus 100 described above adjusts the supply amount of ultrapure water according to the temperature of the ultrapure water when the substrate W is cleaned. In particular, the present invention, when removing the high-viscosity chemical liquid (sulfuric acid, nitric acid, phosphoric acid, etc.) remaining on the substrate with ultra-pure water at room temperature, the supply time of the ultra-pure water over 90 seconds, the ultra-pure water according to the temperature change The supply amount of or changes the rotational speed of the substrate. Therefore, it is possible to prevent the cleaning rate of the chemical liquid from being lowered due to the temperature change of the cleaning liquid, and to perform the cleaning of the high viscosity chemical liquid, which has been difficult to effectively clean conventionally, as the cleaning liquid at room temperature.

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 for explaining 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 efficiently performs the cleaning of the substrate. In particular, the substrate cleaning method according to the present invention effectively cleans the high viscosity chemical liquid remaining on the substrate with ultrapure water at room temperature.

In addition, the substrate cleaning method according to the present invention improves the cleaning efficiency of the substrate by adjusting the supply amount of the ultrapure water according to the temperature change of the ultrapure water.

In addition, the substrate cleaning method according to the present invention improves the cleaning efficiency of the substrate by adjusting the rotational speed of the substrate in accordance with the temperature change of the ultrapure water.

Claims (4)

In the method of cleaning the substrate in which the chemical liquid remains in ultrapure water, And removing the chemical liquid by supplying ultrapure water at a predetermined reference temperature for a predetermined reference time on the substrate, and changing the supply time of the ultrapure water according to the change in the reference temperature. The method of claim 1, The chemical liquid is at least one chemical liquid in the group consisting of sulfuric acid, nitric acid, and phosphoric acid, The reference time is 90 seconds, The reference temperature is a substrate cleaning method, characterized in that the room temperature. The method according to claim 1 or 2, The method for cleaning the substrate, If the temperature of the ultrapure water is higher than the reference temperature, Decrease the reference time by increasing the temperature by exceeding the reference temperature, If the temperature of the ultrapure water is lower than the reference temperature, And decreasing the temperature by less than the reference temperature, thereby increasing the reference time. A method of cleaning a substrate in which at least one chemical liquid remains in the group consisting of sulfuric acid, nitric acid, and phosphoric acid, (a) loading the substrate into the spin chuck, (b) treating the substrate with the chemical liquid; (c) supplying ultrapure water at room temperature to the rotated substrate for 90 seconds to clean the chemical liquid; (d) spraying a dry gas onto the substrate to dry the substrate; (e) unloading the substrate from the spin chuck, Step (c) is, If the temperature of the ultrapure water is higher than the room temperature, At least one of reducing the supply time of the ultrapure water and increasing the rotational speed of the substrate by a temperature exceeding the room temperature, If the temperature of the ultrapure water is lower than the room temperature, At least one of increasing the supply time of the ultrapure water and decreasing the rotational speed of the substrate by a temperature which is lower than the room temperature.

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