JP2012142343A - Cleaning method and cleaning device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning method and a cleaning device capable of efficiently removing a foreign material attached to a substrate and suppressing the reattachment of a foreign material.SOLUTION: The cleaning device includes: a processing chamber for processing a substrate; a support base that is provided in the processing chamber and supports the substrate; a gas injection mechanism that is provided in the processing chamber and injects gas to the substrate; and a temperature control mechanism that controls so that the temperature of the gas injected to the substrate is higher than the temperature of the inner wall of the processing chamber. A foreign material attached to the substrate is removed by the wind pressure of the gas injected from the gas injection mechanism.

Description

  The present invention relates to a cleaning method and a cleaning apparatus for removing foreign matter adhering to a substrate.

  In a manufacturing process of a semiconductor device, a liquid crystal display device or the like, foreign matter may adhere to the substrate being manufactured due to some trouble.

  Foreign matter adhering to the substrate may cause a decrease in manufacturing yield or cause new troubles such as contamination of the manufacturing equipment. When restarting production, a cleaning process should be performed to remove the foreign matter adhering to the substrate. Is required.

  As a method for removing the foreign matter adhering to the substrate, for example, a cleaning process has been proposed in which a gas is jetted onto the substrate and the foreign matter on the substrate is blown off by wind pressure.

JP 2009-267005 A JP 11-330033 A

  However, in the cleaning process in which the foreign matter on the substrate is blown away by the wind pressure, it has been difficult to completely prevent the foreign matter that has been blown away from reattaching. Moreover, in order to perform in a clean room, it is necessary to perform processing in an environment where measures against dust generation are taken, but sufficient measures against dust generation have not been taken.

  An object of the present invention is to provide a cleaning method and a cleaning apparatus that can efficiently remove foreign matter adhering to a substrate and suppress reattachment of foreign matter.

  According to one aspect of the embodiment, in the processing chamber, cleaning is performed by injecting a gas having a temperature higher than the temperature of the inner wall of the processing chamber onto the substrate, and removing foreign matter attached to the substrate by the wind pressure of the injected gas. A method is provided.

  Further, according to another aspect of the embodiment, the cleaning apparatus removes the foreign matter attached to the substrate by injecting gas, the processing chamber for processing the substrate, and provided in the processing chamber, A support table for supporting the substrate, a gas injection mechanism for injecting the gas to the substrate, and a temperature of the gas to be injected to the substrate are higher than the temperature of the inner wall of the processing chamber. And a temperature control mechanism that controls the cleaning device.

  According to the disclosed cleaning method and cleaning apparatus, it is possible to prevent the foreign matter removed from the substrate from reattaching to the substrate. Thereby, the removal efficiency of a foreign material can be improved.

FIG. 1 is a schematic diagram illustrating a structure of a cleaning device according to an embodiment. FIG. 2 is a schematic diagram illustrating a method of supplying a gas to the substrate. FIG. 3 is a schematic diagram for explaining a substrate lift-up mechanism. FIG. 4 is a schematic diagram illustrating a substrate rotation mechanism. FIG. 5 is a schematic view showing the structure of the gas ejection nozzle. FIG. 6 is a schematic diagram for explaining a method of moving the gas ejection nozzle. FIG. 7 is a schematic view showing the structure of the cooling plate.

  A cleaning apparatus and a cleaning method according to an embodiment will be described with reference to FIGS.

  FIG. 1 is a schematic view showing the structure of the cleaning apparatus according to the present embodiment. FIG. 2 is a schematic diagram illustrating a method of supplying a gas to the substrate. FIG. 3 is a schematic diagram for explaining a substrate lift-up mechanism. FIG. 4 is a schematic diagram illustrating a substrate rotation mechanism. FIG. 5 is a schematic view showing the structure of the gas ejection nozzle. FIG. 6 is a schematic diagram for explaining a method of moving the gas ejection nozzle. FIG. 7 is a schematic view showing the structure of the cooling plate.

  First, the structure of the cleaning apparatus according to the present embodiment will be described with reference to FIGS.

  The cleaning apparatus according to the present embodiment has a box-shaped processing chamber 10 for processing a substrate. A perforated plate 12 provided with a plurality of through holes is provided in the processing chamber 10, and the inside of the processing chamber 10 is divided into two. On the perforated plate 12, a carrier support 20 is provided on which a substrate carrier 30 that holds a plurality of substrates 32 to be processed is placed. A gas ejection nozzle 40 is provided above the substrate carrier 30 placed on the carrier support 20. Around the processing chamber 10, a cooling plate 50 for cooling the inner wall of the processing chamber 10 is provided. A vacuum pump 16 is connected to a lower portion of the perforated plate 12 in the processing chamber 10 via a filter 14 for capturing foreign substances such as particles. The gas ejection nozzle 40 and the cooling plate 50 are provided with a temperature control mechanism (not shown) for controlling the temperature of the gas ejected from the gas ejection nozzle 40 and the temperature of the cooling plate 50.

  The processing chamber 10 is a container for cleaning the substrate 32. A box type for isolating the processing environment from the external environment in order to prevent foreign matters such as particles removed from the substrate 32 by the cleaning process from being released into the environment (for example, in a clean room) and becoming a new source of contamination; It is desirable to do.

  The perforated plate 12 has a structure for facilitating the downward flow of the gas ejected from the gas ejection nozzle 40. The gas ejected from the gas ejection nozzle 40 toward the substrate 32 passes through the porous plate 12 and is exhausted by the vacuum pump 16 through the filter 14. An exhaust duct may be connected instead of the vacuum pump 16. The foreign matter removed from the substrate 32 by the gas ejected from the gas ejection nozzle 40 is carried by the gas flow and is captured by the filter 14 and therefore is not released outside the apparatus. The porous plate 12 is not necessarily required, but is effective in forming a one-way air flow from the gas ejection nozzle 40 toward the vacuum pump 16 and preventing reattachment of foreign matter to the substrate 32.

  The carrier support 20 is for mounting the substrate carrier 30 and has a mechanism for changing the direction of the surface of the substrate 32 with respect to the direction of gas ejection from the gas ejection nozzle 40. For example, as shown in FIG. 2, the substrate 32 is inclined with respect to the gas injection direction, and the gas is incident on the surface of the substrate 32 from an oblique direction, whereby the foreign matter removal efficiency can be improved. The angle θ of the surface of the substrate 32 with respect to the jet direction of the gas ejected from the gas ejection nozzle 40 may be constant when the substrate 32 is cleaned, or the cleaning process may be performed while changing.

  The carrier support 20 may be provided with a lift-up mechanism that lifts the substrate 32. By lifting the substrate 32 from the substrate carrier 30, the foreign matter adhering to the contact portion between the substrate carrier 30 and the substrate 32 can be efficiently removed without being disturbed by the substrate carrier 30.

  The lift-up mechanism for the substrate 32 is not particularly limited. For example, two substrate support plates 22 having an up-and-down mechanism as shown in FIG. 3 can be used. Two substrate support plates 22 having a vertical mechanism are provided on the carrier support base 20 (FIG. 3A), and the substrate 32 can be lifted by moving the substrate support plate 22 upward (FIG. 3B). ).

  The carrier support 20 may be provided with a substrate rotation mechanism that rotates the substrate 32. By rotating the substrate 32, gas can be incident on the substrate 32 from various directions, and the foreign matter removal efficiency can be improved.

  The substrate rotation mechanism is not particularly limited. For example, as shown in FIG. 4, a shaft 24 having a rotation mechanism provided at the front end portion of the substrate support plate 22 can be used. The substrate 32 can be rotated by rotating the shaft 24 while the substrate 32 is lifted by the substrate support plate 22.

  The substrate carrier 30 is not particularly limited, and for example, a general substrate carrier used in a semiconductor device manufacturing process can be applied. A plurality of substrates 32, for example, 25 substrates 32 can be supported on the substrate carrier 30.

  Since the lift-up mechanism and the substrate rotating mechanism described above can be operated while the substrate 32 is accommodated in the substrate carrier 30, it is possible to perform an efficient cleaning process and reduce the number of processing steps. .

  The gas ejection nozzle 40 is for injecting a foreign substance removing gas toward the substrate 30.

  The gas ejection nozzle 40 has a plurality of ejection holes, and has a shape for ejecting gas therefrom. As the gas ejection nozzle 40, for example, as shown in FIG. 5, a nozzle in which ejection holes 42 are arranged in a straight line can be applied. Alternatively, for example, the ejection holes 42 may be two-dimensionally arranged like a shower head. Moreover, the ejection hole 42 does not necessarily need to be circular, and may be a slit-shaped hole.

  The gas ejection nozzle 40 may be provided with a moving mechanism. For example, even when gas cannot be ejected onto all the substrates 32 simultaneously by the gas ejection nozzle 40, all the substrates 32 can be processed sequentially by moving the gas ejection nozzle 40. Moreover, by moving the gas ejection nozzle 40, the incident direction of the gas to the substrate 32 can be changed with the movement, and an improvement in the foreign matter removal effect can be expected.

  For example, as shown in FIG. 6, when a long gas ejection nozzle 40 is provided in the direction parallel to the surface of the substrate 32 (the depth direction of the paper surface), the direction perpendicular to the extending direction of the gas ejection nozzle 40 (the paper surface) The gas ejection nozzle 40 can be moved in the left-right direction).

  Note that the movement of the gas ejection nozzle 40 is to change the relative positional relationship between the substrate carrier 30 and the gas ejection nozzle 40. Instead of providing the gas ejection nozzle 40 with a moving mechanism, the carrier support 20 may be provided with a moving mechanism. Alternatively, a moving mechanism may be provided on both the gas ejection nozzle 40 and the carrier support base 20.

  The gas ejected from the gas ejection nozzle 40 is not particularly limited, and for example, air, carbon monoxide, carbon dioxide, nitrogen, argon, xenon, or the like can be applied. In particular, inert gases such as nitrogen, argon, and xenon are preferable.

  The ejection speed of the gas from the gas ejection nozzle 40 can be appropriately set according to the required foreign matter removal effect. The gas ejection speed from the gas ejection nozzle 40 is not particularly limited, and can be, for example, about 30 m / sec to 300 m / sec.

  The gas ejected from the gas ejection nozzle 40 is set to a temperature higher than the temperature of the inner wall of the processing chamber 10. This is because a temperature gradient is provided between the substrate 32 and the inner wall of the processing chamber 10 to induce thermophoresis of the foreign matter removed from the substrate 32. The temperature of the gas ejected from the gas ejection nozzle 40 varies depending on the temperature of the inner wall of the processing chamber 10, but is, for example, 50 ° C. to 100 ° C.

  The cooling plate 50 is for cooling the inner wall of the processing chamber 10. The cooling plate 50 is not particularly limited as long as it can cool the inner wall of the processing chamber 10. For example, as shown in FIG. 7, a mechanism can be applied in which the introduced nitrogen gas is cooled by a gas cooling unit 52 using a refrigerant such as liquid nitrogen and introduced into a cooling plate 50 surrounding the processing chamber 10.

  The cooling plate 50 is for inducing thermophoresis of the foreign matter removed from the substrate 32 by providing a temperature gradient between the substrate 32 and the inner wall of the processing chamber 10. For this purpose, it is desirable to control the temperature so that the temperature of the substrate 32 is higher than the temperature of the inner wall of the processing chamber 10. More preferably, the temperature of the substrate 32 is set higher by about 50 ° C. to 100 ° C. than the temperature of the inner wall of the processing chamber 10. Assuming that the temperature of the substrate 32 is equal to the temperature of the jet gas (for example, 50 ° C. to 100 ° C.), it is desirable that the temperature of the inner wall of the processing chamber 10 cooled by the cooling plate 50 be about 0 ° C.

  Next, the cleaning method according to the present embodiment will be described with reference to FIGS.

  First, the substrate carrier 30 that supports the substrate 32 to be processed is placed on the carrier support 20 in the processing chamber 12.

  Next, the inner wall of the processing chamber 12 is cooled to a predetermined temperature by the cooling plate 50. For example, as shown in FIG. 7, the cooling plate 50 is cooled with nitrogen gas cooled with liquid nitrogen, and the temperature of the inner wall of the processing chamber 12 is set to 0 ° C.

  Next, the direction of the surface of the substrate 32 is tilted with respect to the direction in which the gas is ejected from the gas ejection nozzle 40 so that the gas is incident on the surface of the substrate 32 from an oblique direction. For example, as shown in FIG. 2, by tilting the carrier support base 20, the direction of the surface of the substrate 32 is tilted with respect to the jet direction of the gas jetted from the gas jet nozzle 40.

  Next, as necessary, the substrate 32 is lifted from the substrate carrier 30 by the substrate support plate 22 of the carrier support 20 (see FIG. 3). Moreover, the board | substrate 32 is rotated with the shaft 24 provided in the board | substrate support plate 22 of the carrier support stand 20 as needed (refer FIG. 4).

  Next, a gas heated to about 50 ° C. to 100 ° C., for example, nitrogen heated to 50 ° C. is ejected from the gas ejection nozzle 40 at a predetermined speed, for example, about 30 m / sec to 300 m / sec, and is incident on the substrate 32. .

  At this time, if necessary, the relative position of the gas ejection nozzle 40 with respect to the substrate carrier 30 is moved, and all the substrates 32 supported by the substrate carrier 30 are cleaned. Further, the cleaning process is performed while changing the angle θ of the surface of the substrate 32 with respect to the ejection direction of the gas ejected from the gas ejection nozzle 40 as necessary.

  Foreign matter adhering to the surface of the substrate 32 is removed from the substrate 32 by the injected gas. Since a temperature gradient is provided between the substrate 32 and the temperature of the inner wall of the processing chamber 12, foreign matter removed from the substrate 32 moves from the substrate 32 side to the inner wall side of the processing chamber 12 due to the action of thermophoresis. Move. In addition, the foreign matter moves on a one-way air flow from the gas ejection nozzle 40 toward the vacuum pump 16. Thereby, it is possible to suppress the foreign matter removed from the substrate 32 from reattaching to the substrate 32.

  Thereafter, the ejection of gas from the gas ejection nozzle 40 is stopped and the inside of the processing chamber 12 is returned to room temperature, and then the substrate carrier 30 is taken out of the processing chamber to complete the cleaning process.

  As described above, according to this embodiment, a temperature gradient is provided between the substrate and the temperature of the inner wall of the processing chamber, and the foreign matter removed from the substrate by the action of thermophoresis is prevented from reattaching to the substrate. The removal efficiency of foreign matters can be improved.

[Modified Embodiment]
The present invention is not limited to the above embodiment, and various modifications are possible.

  For example, in the above-described embodiment, the semiconductor wafer is assumed as the substrate 32, but the substrate 32 is not limited to the semiconductor wafer. For example, the present invention can be applied to cleaning of a substrate such as a glass substrate used for manufacturing a liquid crystal display device.

  In the example of FIG. 1, the cooling plate 50 is provided only on the upper side surface of the processing chamber 10. However, the place where the cooling plate 50 is provided is not limited to this. For example, the cooling plate 50 may be provided at the bottom of the processing chamber 10. It is desirable that the cooling plate 50 be appropriately selected according to the structure of the processing apparatus so that the foreign matter removed from the substrate 32 is separated from the substrate 32 by the action of thermophoresis.

  Further, in the above embodiment, the temperature gradient is provided between the substrate 32 and the inner wall of the processing chamber 10 by increasing the temperature of the gas injected to the substrate 32 and lowering the temperature of the inner wall of the processing chamber 10. It is not always necessary to control both temperatures. The temperature of the gas injected into the substrate 32 may be appropriately controlled so as to be relatively higher than the temperature of the inner wall of the processing chamber 10, and only the temperature of the gas injected into the substrate 32 may be increased. The temperature of the 10 inner walls may be lowered.

  Regarding the above embodiment, the following additional notes are disclosed.

(Supplementary Note 1) A substrate is disposed inside the processing chamber, a gas having a temperature higher than the temperature of the inner wall of the processing chamber is sprayed onto the substrate, and foreign matter attached to the substrate is removed by the wind pressure of the sprayed gas. A cleaning method characterized by:

(Appendix 2) In the cleaning method described in Appendix 1,
The temperature of the gas is 50 to 100 ° C. higher than the temperature of the inner wall of the processing chamber.

(Appendix 3) In the cleaning method according to Appendix 1 or 2,
The cleaning method, wherein the gas is jetted in a state where the substrate is kept in a substrate carrier.

(Appendix 4) In the cleaning method described in Appendix 3,
The cleaning method, wherein the gas is jetted in a state where the substrate is lifted from the substrate carrier.

(Appendix 5) In the cleaning method according to any one of appendices 1 to 4,
A cleaning method, wherein the gas is jetted from an oblique direction with respect to the surface of the substrate.

(Appendix 6) In the cleaning method according to any one of appendices 1 to 5,
The cleaning method, wherein the gas is jetted while rotating the substrate.

(Supplementary note 7) In the cleaning method according to any one of supplementary notes 1 to 6,
The gas is nitrogen, argon, or xenon.

(Supplementary Note 8) A cleaning device that removes foreign matter adhering to a substrate by injecting gas,
A processing chamber for processing the substrate;
A support base provided in the processing chamber and supporting the substrate;
A gas injection mechanism that is provided in the processing chamber and injects the gas onto the substrate;
And a temperature control mechanism for controlling the temperature of the gas sprayed onto the substrate to be higher than the temperature of the inner wall of the processing chamber.

(Supplementary note 9) In the cleaning apparatus according to supplementary note 8,
The temperature control mechanism controls the temperature of the gas so as to be higher by 50 ° C. to 100 ° C. than the temperature of the inner wall of the processing chamber.

(Supplementary Note 10) In the cleaning device according to Supplementary Note 8 or 9,
The cleaning device, wherein the support base supports a substrate carrier that accommodates the plurality of substrates.

(Supplementary note 11) In the cleaning apparatus according to supplementary note 10,
The cleaning device, wherein the support base has a lift-up mechanism that lifts the substrate from the substrate carrier.

(Supplementary note 12) In the cleaning apparatus according to any one of supplementary notes 8 to 11,
The cleaning apparatus according to claim 1, wherein the support has a substrate tilting mechanism that tilts the substrate so that the gas jetted from the gas jetting mechanism is incident on the surface of the substrate from an oblique direction.

(Supplementary note 13) In the cleaning apparatus according to any one of supplementary notes 8 to 12,
The cleaning device according to claim 1, wherein the support has a substrate rotation mechanism that rotates the substrate.

(Supplementary note 14) In the cleaning apparatus according to any one of supplementary notes 8 to 13,
The said gas injection mechanism has a moving mechanism which changes the injection position of the said gas with respect to the said board | substrate. The washing | cleaning apparatus characterized by the above-mentioned.

DESCRIPTION OF SYMBOLS 10 ... Processing chamber 12 ... Porous plate 14 ... Filter 16 ... Vacuum pump 20 ... Carrier support stand 22 ... Substrate support plate 24 ... Shaft 30 ... Substrate carrier 32 ... Substrate 40 ... Gas ejection nozzle 42 ... Injection hole 50 ... Cooling plate

Claims (6)

A substrate is disposed inside the processing chamber, a gas having a temperature higher than the temperature of the inner wall of the processing chamber is jetted onto the substrate, and foreign matter attached to the substrate is removed by the wind pressure of the jetted gas. Cleaning method. A cleaning device that removes foreign matter adhering to the substrate by injecting gas,
A processing chamber for processing the substrate;
A support base provided in the processing chamber and supporting the substrate;
A gas injection mechanism that is provided in the processing chamber and injects the gas onto the substrate;
And a temperature control mechanism for controlling the temperature of the gas sprayed onto the substrate to be higher than the temperature of the inner wall of the processing chamber. The cleaning apparatus according to claim 2, wherein
The temperature control mechanism controls the temperature of the gas so as to be higher by 50 ° C. to 100 ° C. than the temperature of the inner wall of the processing chamber. The cleaning apparatus according to claim 2 or 3,
The cleaning device, wherein the support base supports a substrate carrier that accommodates the plurality of substrates. The cleaning apparatus according to claim 4, wherein
The cleaning device, wherein the support base has a lift-up mechanism that lifts the substrate from the substrate carrier. The cleaning apparatus according to any one of claims 2 to 5,
The cleaning apparatus according to claim 1, wherein the support has a substrate tilting mechanism that tilts the substrate so that the gas jetted from the gas jetting mechanism is incident on the surface of the substrate from an oblique direction.

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