JP5130127B2 - Substrate processing apparatus and processing method - Google Patents

Description

  The present invention relates to a substrate processing apparatus and a processing method for cleaning a device surface on which a circuit pattern of a glass substrate of a semiconductor wafer or a liquid crystal display is formed.

  For example, in a manufacturing process of a liquid crystal display device or a semiconductor device, it is required to clean the device surface as a surface to be processed on which a circuit pattern of a substrate such as a semiconductor wafer or a glass substrate is formed with high cleanliness. There is a process.

  As a method for cleaning the device surface of the substrate, a dip method in which the substrate is immersed in the processing solution, a spin method in which the processing solution is sprayed from the nozzle toward the device surface of the substrate held on the rotary table, and the like is cleaned. Each method is selectively employed as appropriate according to the substrate cleaning conditions and the like.

  As one of the dip systems, a processing apparatus described in Patent Document 1 is known. The processing apparatus described in Patent Document 1 has a processing tank for storing a processing liquid, and immerses the substrate in the processing liquid in the processing tank. Ultrasonic vibration is applied to the processing liquid stored in the processing tank by the ultrasonic generator, and particles attached to the substrate are removed by the impact of the ultrasonic vibration on the substrate. Yes.

Further, in Patent Document 1, microbubbles are generated in the liquid supplied to the processing tank by a microbubble generator. Since the microbubbles contained in the liquid have a large surface area as a whole and are charged, the particles removed from the substrate by the impact of ultrasonic vibration are adsorbed by the microbubbles and removed by the flow of the liquid It is.
JP 2006-179765 A

  By the way, there are cases where organic substances such as resist remain firmly attached to the surface to be cleaned of the substrate to be cleaned. In such a case, as shown in Patent Document 1, it may be impossible to reliably remove the dirt attached to the substrate only by applying ultrasonic vibration to the substrate.

  Recently, circuit patterns tend to be miniaturized by increasing the density of circuit patterns formed on the device surface of a substrate. As the circuit pattern becomes finer, the gap between adjacent circuit patterns tends to become narrower and deeper. In such a case, simply applying the ultrasonic vibration to the substrate does not effectively and effectively act on the dirt adhering to the substrate, so that the dirt cannot be removed satisfactorily.

  In order to increase the removal efficiency of the dirt on the substrate, it is conceivable to increase the ultrasonic vibration applied to the substrate. However, if the ultrasonic vibration applied to the substrate is strengthened, the physical energy applied to the substrate increases, so that a fine circuit pattern formed on the substrate may fall down and cause a defective product.

  It is an object of the present invention to provide a substrate processing apparatus and a processing method capable of reliably processing a substrate without increasing physical energy applied to the substrate.

The present invention is a processing apparatus for cleaning a substrate,
A treatment tank to which the substrate is supplied;
A treatment liquid supply means for supplying a treatment liquid containing nanobubbles in which a negative charge is charged on the surface of the substrate of the treatment tank and the positive charge is electrostatically coupled to the negative charge;
Equilibrium state due to static electricity of the nanobubbles, which is supplied from the processing liquid supply means toward the processing liquid supplied to the substrate and removes positive charges electrostatically coupled to the negative charges of the nanobubbles contained in the processing liquid. And a working fluid supply means for supplying a working fluid that causes the nanobubbles to rupture and rupture the nanobubbles.

The processing tank is provided with a turntable on which the substrate is held on the upper surface,
The processing liquid supply means has an arm body that is pivotally driven in a direction crossing the substrate above the substrate, and a processing liquid supply nozzle that is provided at the tip of the arm body and supplies the processing liquid toward the substrate. ,
Preferably, the hydraulic fluid supply means is a hydraulic fluid supply nozzle that is provided at a tip of the arm body and supplies the hydraulic fluid to a portion of the substrate to which the processing liquid is supplied by the processing liquid supply nozzle.

  The hydraulic fluid is preferably a liquid having a negative charge.

  It is preferable that control means for controlling the amount of hydraulic fluid supplied to the hydraulic fluid supply means is provided.

The present invention is a processing method for cleaning a substrate,
Supplying the substrate to the treatment tank;
Supplying a treatment liquid containing nanobubbles having a negative charge on the surface of the substrate of the treatment tank and a positive charge electrostatically coupled to the negative charge;
A working liquid that removes positive charges electrostatically coupled to the negative charges of the nanobubbles contained in the processing liquid in the processing liquid supplied to the substrate, thereby erasing the equilibrium state due to static electricity of the nanobubbles and rupturing the nanobubbles. And a step of supplying the substrate.

  According to this invention, the processing liquid containing nanobubbles is supplied to the surface to be processed of the substrate, and the working liquid is supplied to the processing liquid, which loses the static equilibrium state of the nanobubbles and bursts. Therefore, it is possible to process the substrate by bursting the nanobubbles without adding physical energy for bursting the nanobubbles to the substrate. In addition, since the nanobubbles enter the minute portion of the substrate, the fine portion can be reliably processed.

An embodiment of the present invention will be described below with reference to the drawings.
The processing apparatus shown in FIG. 1 includes a processing tank 1. A rotary table 2 is provided inside the processing tank 1, and the rotary table 2 is rotationally driven by a first rotational drive source 3 provided below the processing tank 1.

  A substrate W such as a semiconductor wafer or a glass substrate is supplied and mounted on the upper surface of the turntable 2 with a device surface as a surface to be processed on which a circuit pattern (not shown) is formed. Retained.

  A processing liquid L1 is supplied to the substrate W. The processing liquid L1 supplied to the substrate W and cleaned on the device surface of the substrate W as will be described later is discharged through a drain pipe 5 having one end connected to the bottom of the processing tank 1. .

  The treatment tank 1 is supplied with nanobubble water which is made by the nanobubble generator 11 and stored in the liquid storage tank 7 and becomes the treatment liquid L1. A gas supply pump 12 and a liquid supply pump 13 are connected to the nanobubble generator 11 by pipes 12a and 13a, respectively. The pipes 12a and 13a are provided with first and second opening / closing control valves 14a and 14b, respectively.

The gas supply pump 12 supplies a gas such as nitrogen gas or carbon dioxide gas to the nanobubble generator 11 at a predetermined pressure, and the liquid supply pump 13 supplies isopropyl alcohol (IPA), pure water, or the like to the nanobubble generator 11. Supply the liquid.
The gas and liquid may be pressurized to a predetermined pressure in advance without using the supply pumps 12 and 13, and the gas and liquid stored in a tank (not shown) may be supplied to the nanobubble generator 11.

  The gas supplied to the nanobubble generator 11 becomes a swirl flow, and the liquid flows as a swirl flow having a swirl speed faster than that of the gas and flows around the gas. As a result, the gas is sheared by the liquid, and a fine bubble having a diameter of 1 μm or less, that is, a nano bubble is generated. The nano bubble is mixed into the liquid and becomes nano bubble water as the treatment liquid L1.

  The particle size of the bubbles contained in the liquid can be set by the swirling speed of the gas and the liquid. In this embodiment, the diameter of the gas sheared by the liquid is nanobubbles of 1 μm or less as described above. The swirl speed between the gas and the liquid supplied to the nanobubble generator 11 is set. Thereby, the treatment liquid L1 supplied to the liquid storage tank 7 from the nanobubble generator 11 and stored therein becomes nanobubble water containing nanobubbles as described above.

  The treatment liquid L1 includes not only nanobubbles but also microbubbles. In that case, by supplying the treatment liquid L produced by the nanobubble generator 11 to the liquid storage tank 7 and leaving it for a predetermined time, the microbubbles contained in the treatment liquid L1 float to the liquid surface by buoyancy. Will be removed. Since the nanobubbles are fine and do not have buoyancy, they do not float in the liquid and are not diffused into the atmosphere from the liquid surface of the treatment liquid L1 like microbubbles.

  In this way, the processing liquid L1 containing nanobubbles stored in the liquid storage tank 7 is disposed above the processing tank 1 through the liquid supply pipe 15 having one end connected to the liquid storage tank 7. It is supplied to the supply nozzle 16. The liquid supply pipe 15 is provided with a first pressurizing pump 17.

  As shown in FIGS. 1 and 2, the treatment liquid supply nozzle 16 is attached with a vertical axis at the center in the longitudinal direction of a mounting plate 19 provided at the tip of a horizontal arm 18 as an arm body. The base end of the horizontal arm 18 is connected to the upper part of the rotary shaft 20 provided with the axis line vertical. The rotary shaft 20 is rotationally driven by a second rotational drive source 21. As a result, the processing liquid supply nozzle 16 moves in a circular arc horizontally above the substrate W rotated by the turntable 2 in a direction crossing the substrate W.

  In this embodiment, the process liquid supply nozzle 16 and the horizontal arm 18 constitute a process liquid supply means for supplying the substrate W with the process liquid L containing nanobubbles produced by the nanobubble generator 11. .

  On both sides of the processing liquid supply nozzle 16 attached to the mounting plate 19 at the tip of the horizontal arm 18, a pair of hydraulic fluid supply nozzles 22a and 22b constituting the hydraulic fluid supply means as shown in FIG. The treatment liquid supply nozzle 16 is attached to be inclined at an angle θ with respect to the axis of the treatment liquid supply nozzle 16. In other words, the tips of the hydraulic fluid supply nozzles 22 a and 22 b face away from the processing liquid supply nozzle 16.

  As shown in FIG. 3, the supply fluid branch pipes 24a and 24b provided with the first and second open / close control valves 23a and 23b are connected to the pair of hydraulic fluid supply nozzles 22a and 22b, respectively. The liquid supply branch pipes 24 a and 24 b are connected to the liquid supply main pipe 25. The liquid supply main pipe 25 is connected to a liquid supply source 26 of a working liquid L2 (shown in FIG. 5) made of a liquid such as alkaline water or ionic water through a flow control valve 27 and a second pressurizing pump 28. Yes.

  As a result, if one of the first and second opening / closing control valves 23a and 23b is opened, the hydraulic fluid L2 can be injected and supplied from one of the pair of hydraulic fluid supply nozzles 22a and 22b toward the substrate W. It has become. Note that the negative charge of the hydraulic fluid L2 is set to be stronger than the negative charge of the nanobubbles.

  As shown in FIG. 2, the hydraulic fluid supply nozzles 22a and 22b are attached to the attachment plate 19 at an angle θ. Therefore, as shown in FIG. 5, before the processing liquid L1 ejected from the processing liquid supply nozzle 16 to the substrate W in the region indicated by S1 reaches the device surface of the substrate W, the pair of working liquid supply nozzles 22a and 22b. For example, the hydraulic fluid L2 ejected in the region S2 from the hydraulic fluid supply nozzle 22a to the substrate W is not mixed.

  In FIG. 5, on the device surface of the substrate W, a region S1 to which the processing liquid L1 is supplied and a region S2 to which the working liquid L2 is supplied are separated, but the horizontal arm 18 is indicated by an arrow R in the same figure. The hydraulic fluid L2 is mixed with the treatment liquid L1 supplied to the region S1 by being rotationally driven in the direction.

  Instead of attaching the hydraulic fluid supply nozzles 22a and 22b to the attachment plate 19 in an inclined manner, the hydraulic fluid supply nozzle 16 is mounted vertically by increasing the distance from the treatment liquid supply nozzle 16 before the hydraulic fluid L2 reaches the substrate W. You may make it prevent mixing with the process liquid L1.

As shown in FIG. 4, the nanobubbles B contained in the treatment liquid L1 are negatively charged. Therefore, the negative charge, that is, the positive charge exists on the surface of the nanobubble B due to electrostatic induction, and the nanobubble B is maintained in an equilibrium state due to static electricity in this state. That is, the nanobubble B is in a stable state due to electrostatic coupling between a negative charge and a positive charge.

  When the working liquid L2 having a negative charge is supplied to the processing liquid L1 containing the nanobubble B, the negative charge of the working liquid L2 is stronger than the negative charge of the nanobubble B. The positive charge that is electrostatically coupled to the negative charge of the nanobubble B is attracted by the negative charge.

  As a result, the positive charge electrostatically coupled to the negative charge is removed from the nanobubble B, and the static state of static electricity of the nanobubble B is lost, so that the nanobubble B is ruptured. When the nanobubbles B burst, energy is generated at the time of bursting, and the energy acts on the dirt adhering to the device surface of the substrate W, and the dirt is removed from the substrate W.

  The operation of the processing apparatus having the above configuration is controlled by the control device 29. The control device 29 includes first and second opening / closing control valves 14a and 14b and first and second hydraulic fluid supplies provided in pipes 12a and 12b for supplying gas and liquid to the nanobubble generator 11. The first and second open / close control valves 23a and 23b provided in the liquid supply branch pipes 24a and 24b for supplying the hydraulic fluid L2 to the nozzles 22a and 22b are controlled to open and close.

  In addition, the control device 29 starts and stops the first pressurization pump 17 that pumps the processing liquid L1 in the liquid storage tank 7 to the processing liquid supply nozzle 16 and the second pressurization pump 28 that is provided in the liquid supply main pipe 25. Control. Further, the control device 29 controls the opening amount of the flow control valve 27 provided in the liquid supply main pipe 25 to control the supply amount of the hydraulic fluid L2 to the first and second hydraulic fluid supply nozzles 22a and 22b. At the same time, the rotational speed of the rotary table 2 by the first rotary drive source 3 and the swing speed of the horizontal arm 18 by the second rotary drive source 21 are controlled.

Next, an operation when the device surface of the substrate W is cleaned by the processing apparatus having the above configuration will be described.
When the substrate W is supplied and mounted on the turntable 2, the turntable 2 is rotated at a predetermined number of revolutions and the horizontal arm 18 is driven, and a treatment liquid supply nozzle 16 provided at the tip of the turntable 2 and a pair of working liquids. The supply nozzles 22a and 22b are reciprocally driven above the substrate W in a direction crossing the substrate W.

  When the horizontal arm 18 is driven, the processing liquid L1 containing nanobubbles B is sprayed from the processing liquid supply nozzle 16 toward the substrate W. At the same time, the hydraulic fluid L2 is sprayed toward the substrate W from one hydraulic fluid supply nozzle 22a or 22b located at the rear of the horizontal arm 18 in the rotational direction.

  When the horizontal arm 18 is driven in the forward movement direction indicated by R in FIG. 5 of the reciprocating drive above the substrate W, the hydraulic fluid L2 is supplied from one hydraulic fluid supply nozzle 22a, and is in a direction opposite to R. When driven in the backward movement direction, the hydraulic fluid L2 is supplied from the other hydraulic fluid supply nozzle 22b.

  That is, when the processing liquid L1 containing nanobubbles B is supplied from the processing liquid supply nozzle 16 to the device surface of the substrate W, the working liquid is supplied to the portion to which the processing liquid L1 is supplied by the pair of hydraulic liquid supply nozzles 22a and 22b. L2 will be supplied.

  That is, when the horizontal arm 18 is driven to reciprocate, the control device 29 causes the hydraulic fluid L2 to be supplied to the device surface of the substrate W from one of the hydraulic fluid supply nozzles 22a or 22b located rearward in the moving direction. One of the first and second opening / closing control valves 23a, 23b is opened and the other is closed. As a result, the working liquid L2 is mixed with the processing liquid L1 supplied to the substrate W.

  Since the hydraulic fluid L2 is made of a liquid having a negative charge stronger than the negative charge of the nanobubble B, the hydraulic fluid L2 is electrostatically coupled to the negative charge of the nanobubble B contained in the processing liquid L by the negative charge of the hydraulic fluid L2. Positive charges are removed by suction. As a result, the static charge balance caused by the negative charge of the nanobubble B and the positive charge charged in the negative charge is lost and the nanobubble B bursts. When the nanobubble B bursts, energy is generated at the time of bursting, so that the dirt attached to the device surface of the substrate W can be removed by the energy.

  If the contamination on the device surface of the substrate W is removed in this way, the nanobubbles B contained in the processing liquid L1 have a fine diameter of 1 μm or less, and thus a fine circuit pattern formed on the device surface. It is surely inserted in between and is ruptured by the hydraulic fluid L2. In other words, even if the circuit pattern formed on the device surface of the substrate W is fine, the dirt between the fine circuit patterns on the device surface can be surely cleaned and removed, so that the cleaning effect can be enhanced. it can.

  Nanobubbles B contained in the treatment liquid L1 are ruptured by the working liquid L2. Therefore, the nanobubbles B can be ruptured without applying large energy to the substrate W, for example, when the substrate W is destroyed by applying a physical force such as ultrasonic vibration.

  Therefore, physical energy for rupturing the nanobubbles B need not be applied to the substrate W, so that it is possible to prevent the circuit pattern formed on the device surface from being damaged by applying more energy than necessary to the device surface of the substrate W. can do.

The supply of the hydraulic fluid L2 to the pair of hydraulic fluid supply nozzles 22a and 22b can be controlled by a flow rate control valve 27 provided in the liquid supply main pipe 25. Therefore, according to the supply amount of the working liquid L2 to the substrate W, the amount of the nanobubbles B to be ruptured by the working liquid L2 among the nanobubbles B contained in the processing liquid L1 supplied to the substrate W can be controlled. .
That is, if the supply amount of the working fluid L2 to the substrate W is changed according to the type and degree of contamination of the substrate W to be cleaned, the number of nanobubbles B that burst on the device surface of the substrate can be controlled. Can be reliably washed according to dirt.

  In the above embodiment, a so-called spin processing apparatus that supplies a cleaning liquid by placing a substrate on a rotary table has been described as an example, but horizontal transport is performed by cleaning the substrate while being transported horizontally by a transport roller. The present invention can be applied even to a processing apparatus of the type. In this case, the supply of the processing liquid to the substrate is not a processing liquid supply nozzle, but a processing liquid supply nozzle body having slit-like nozzle holes that are elongated along the width direction intersecting the transport direction of the substrate to be transported, etc. The working liquid supply nozzle body having the same configuration as the processing liquid supply nozzle body may be provided downstream of the nozzle body in the substrate transport direction.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the processing apparatus which shows one embodiment of this invention. The front view which shows the process liquid supply nozzle provided in the front-end | tip of a horizontal arm, and a pair of hydraulic fluid supply nozzle. The piping diagram which shows the supply system of the hydraulic fluid with respect to a pair of hydraulic fluid supply nozzle. Explanatory drawing which shows the state which positive charge electrostatically couple | bonded with the negative charge of nanobubble. The figure for demonstrating supply of the process liquid by a process liquid supply nozzle with respect to a board | substrate, and the supply of the hydraulic fluid by a hydraulic fluid supply nozzle.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Processing tank, 2 ... Rotary table, 11 ... Nano bubble generator, 16 ... 2 Process liquid supply nozzle (process liquid supply means), 18 ... Horizontal arm (process liquid supply means), 22a, 22b ... Hydraulic fluid supply nozzle ( Hydraulic fluid supply means).

Claims (5)

A processing apparatus for cleaning a substrate,
A treatment tank to which the substrate is supplied;
A treatment liquid supply means for supplying a treatment liquid containing nanobubbles in which a negative charge is charged on the surface of the substrate of the treatment tank and the positive charge is electrostatically coupled to the negative charge;
Equilibrium state due to static electricity of the nanobubbles, which is supplied from the processing liquid supply means toward the processing liquid supplied to the substrate and removes positive charges electrostatically coupled to the negative charges of the nanobubbles contained in the processing liquid. And a working liquid supply means for supplying a working liquid that causes the nanobubbles to disappear and ruptures the nanobubbles. The processing tank is provided with a turntable on which the substrate is held on the upper surface,
The processing liquid supply means has an arm body that is pivotally driven in a direction crossing the substrate above the substrate, and a processing liquid supply nozzle that is provided at the tip of the arm body and supplies the processing liquid toward the substrate. ,
The hydraulic fluid supply means is a hydraulic fluid supply nozzle that is provided at a tip of the arm body and supplies the hydraulic fluid to a portion of the substrate to which the processing liquid is supplied by the processing liquid supply nozzle. The substrate processing apparatus according to 1.   2. The substrate processing apparatus according to claim 1, wherein the hydraulic fluid is a liquid having a negative charge.   2. The substrate processing apparatus according to claim 1, further comprising a control unit that controls a supply amount of the hydraulic fluid supplied to the hydraulic fluid supply unit. A processing method for cleaning a substrate,
Supplying the substrate to the treatment tank;
Supplying a treatment liquid containing nanobubbles to which the negative charge is charged and the positive charge is electrostatically coupled to the negative charge on the surface to be treated of the substrate of the treatment tank;
A working liquid that removes positive charges electrostatically coupled to the negative charges of the nanobubbles contained in the processing liquid in the processing liquid supplied to the substrate, thereby erasing the equilibrium state due to static electricity of the nanobubbles and rupturing the nanobubbles. And a substrate processing method.

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