JP2015099852A - Substrate cleaning device and substrate processing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a substrate cleaning device capable of cleaning the surface of a substrate with high efficiency using a two-fluid jet flow.SOLUTION: A substrate cleaning device includes: a substrate holding part 41 which holds and rotates a substrate W; a two-fluid nozzle 42 which supplies a two-fluid jet flow onto the surface of the substrate W ; and at least one vibrator 61 which vibrates the substrate W by coming into contact with the substrate W. While the substrate W is vibrated by the vibrator 61, the two-fluid jet flow is supplied onto the surface of the substrate W, and the substrate W is cleaned by vibration due to the vibrator 61 and impact of the two-fluid jet flow.

Description

  The present invention relates to a substrate cleaning apparatus for cleaning a substrate by supplying a two-fluid jet composed of a gas and a liquid to a substrate such as a wafer, and in particular, cleaning the substrate by supplying the two-fluid jet to the surface of a polished substrate. The present invention relates to a substrate cleaning apparatus. The substrate cleaning apparatus of the present invention can be applied to cleaning not only a wafer having a diameter of 300 mm but also a wafer having a diameter of 450 mm, and further, a flat panel manufacturing process, an image sensor manufacturing process such as CMOS and CCD, and a magnetic film manufacturing process of MRAM. It is also possible to apply it.

  With the recent miniaturization of semiconductor devices, various material films having different physical properties are formed on a substrate and the material films are processed. In particular, in a damascene wiring formation process in which a wiring groove formed in an insulating film is filled with metal, excess metal is polished and removed by a substrate polishing apparatus after the metal film is formed. Various films such as a metal film, a barrier film, and an insulating film exist on the surface of the substrate after polishing. In these films exposed on the substrate surface, there are residues such as slurry and polishing debris used in polishing. In order to remove such residues, the polished substrate is transported to a substrate cleaning apparatus, and the substrate surface is cleaned.

  If the surface of the substrate is not sufficiently cleaned, problems such as current leakage due to residue and poor adhesion will occur. Therefore, in the manufacture of semiconductor devices, the cleaning of the substrate is an important process for improving the yield of products.

  2. Description of the Related Art As a device for cleaning a substrate, a two-fluid cleaning device that supplies a two-fluid jet composed of a mixed fluid of gas and liquid to the surface of the substrate is known. As shown in FIG. 15, the two-fluid cleaning apparatus supplies a two-fluid jet from the two-fluid nozzle 200 to the surface of the substrate W while moving the two-fluid nozzle 200 in parallel with the surface of the substrate W, Remove existing particles such as abrasive grains and polishing debris.

JP 2005-12197 A Japanese Patent Laid-Open No. 11-58226

  Such a two-fluid cleaning apparatus has an advantage that the substrate W is not back-contaminated because a cleaning tool such as a brush or sponge is not brought into contact with the substrate W. However, in the cleaning using only the two-fluid jet, it is difficult to sufficiently remove particles adhering to the surface of the substrate W. In particular, the two-fluid jet cannot remove minute particles present in a recess (for example, a pattern step or scratch) formed on the substrate surface.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a substrate cleaning apparatus that can clean the surface of a substrate with high efficiency using a two-fluid jet. Moreover, an object of this invention is to provide the substrate processing apparatus provided with such a substrate cleaning apparatus.

  In order to achieve the above-described object, one embodiment of the present invention includes a substrate holding unit that holds and rotates a substrate, a two-fluid nozzle that supplies a two-fluid jet to the surface of the substrate, and a contact with the substrate. A substrate cleaning apparatus comprising: at least one vibrator that vibrates the substrate.

In a preferred aspect of the present invention, the vibrator vibrates the substrate while rotating together with the substrate.
In a preferred aspect of the present invention, the vibrator includes a piezoelectric element and a contact member attached to the piezoelectric element and contacting the substrate.
In a preferred aspect of the present invention, the vibrator vibrates the substrate in a direction perpendicular to the surface thereof.
In a preferred aspect of the present invention, the vibrator vibrates the substrate in a direction parallel to the surface thereof.

In a preferred aspect of the present invention, the at least one vibrator includes at least one first vibrator that vibrates the substrate in a direction perpendicular to the surface thereof, and at least vibrates the substrate in a direction parallel to the surface thereof. It is characterized by comprising one second vibrator.
In a preferred aspect of the present invention, the at least one vibrator is a plurality of vibrators, and at least two of the plurality of vibrators vibrate the substrate at different frequencies and / or amplitudes. Features.
A preferred aspect of the present invention is characterized by further comprising a cleaning liquid nozzle for supplying a cleaning liquid to the lower surface of the substrate, and an ultrasonic vibrator for vibrating the cleaning liquid.

  Another aspect of the present invention is a substrate processing apparatus comprising a polishing unit for polishing a substrate and the substrate cleaning apparatus for cleaning the substrate polished by the polishing unit.

  By applying vibration to the substrate, the particles are easily separated from the substrate. In this state, a two-fluid jet is supplied to the substrate to remove particles from the substrate. Thus, the cleaning efficiency of the substrate can be improved by the combination of the vibration of the substrate and the impact of the two-fluid jet.

It is a top view which shows the whole structure of the substrate processing apparatus provided with the substrate cleaning apparatus which concerns on embodiment of this invention. It is a perspective view which shows the board | substrate cleaning apparatus which concerns on embodiment of this invention currently used for the 2nd cleaning unit. It is sectional drawing which shows the chuck | zipper of a board | substrate cleaning apparatus. It is an enlarged view of a vibrator. It is a top view of a board | substrate holding part. It is a schematic diagram which shows the state which the vibrator is giving the vibration to the wafer. It is a schematic diagram which shows the state which is supplying the two-fluid jet to the surface of a wafer, with a vibrator | oscillator giving a vibration to a wafer. It is a figure which shows other embodiment. It is a figure which shows other embodiment. It is a figure which shows other embodiment. It is a top view of a cleaning liquid nozzle. It is a perspective view of a cleaning liquid nozzle. It is an expanded sectional view of a cleaning fluid nozzle. It is a top view of other examples of a cleaning fluid nozzle. It is a schematic diagram which shows the conventional two fluid washing | cleaning apparatus.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an overall configuration of a substrate processing apparatus including a substrate cleaning apparatus according to an embodiment of the present invention. As shown in FIG. 1, the substrate processing apparatus includes a substantially rectangular housing 10 and a load port 12 on which a substrate cassette that accommodates a large number of wafers and other substrates is placed. The load port 12 is disposed adjacent to the housing 10. The load port 12 can be mounted with an open cassette, a SMIF (Standard Manufacturing Interface) pod, or a FOUP (Front Opening Unified Pod). SMIF and FOUP are sealed containers that can maintain an environment independent of the external space by accommodating a substrate cassette inside and covering with a partition wall.

  Inside the housing 10, a plurality of (four in this embodiment) polishing units 14a to 14d, a first cleaning unit 16 and a second cleaning unit 18 for cleaning the substrate after polishing, and a substrate after cleaning are dried. A drying unit 20 is accommodated. The polishing units 14a to 14d are arranged along the longitudinal direction of the substrate processing apparatus, and the cleaning units 16, 18 and the drying unit 20 are also arranged along the longitudinal direction of the substrate processing apparatus.

  In a region surrounded by the load port 12, the polishing unit 14a, and the drying unit 20, a first substrate transfer robot 22 is disposed, and a substrate transfer unit 24 is disposed in parallel with the polishing units 14a to 14d. The first substrate transfer robot 22 receives the substrate before polishing from the load port 12 and passes it to the substrate transfer unit 24, and receives the dried substrate from the drying unit 20 and returns it to the load port 12. The substrate transport unit 24 transports the substrate received from the first substrate transport robot 22 and delivers the substrate to and from each of the polishing units 14a to 14d. Each polishing unit polishes the surface of a substrate by bringing a substrate such as a wafer into sliding contact with the polishing surface while supplying a polishing liquid (slurry) to the polishing surface.

  A second substrate transport robot 26 is disposed between the first cleaning unit 16 and the second cleaning unit 18 to transport the substrate between the cleaning units 16 and 18 and the substrate transport unit 24, and the second cleaning is performed. A third substrate transport robot 28 is disposed between the unit 18 and the drying unit 20 to transport the substrate between the units 18 and 20. Further, an operation control unit 30 that controls the movement of each unit of the substrate processing apparatus is disposed inside the housing 10.

  As the first cleaning unit 16, there is used a substrate cleaning apparatus that cleans a substrate by rubbing a roll sponge on both the front and back surfaces of the substrate in the presence of a chemical solution. As the second cleaning unit 18, a two-fluid type substrate cleaning apparatus according to an embodiment of the present invention is used. Further, as the drying unit 20, a spin drying apparatus is used that dries the substrate by holding the substrate, ejecting IPA vapor from a moving nozzle to dry the substrate, and rotating the substrate at a high speed.

  The substrate is polished by at least one of the polishing units 14a to 14d. The polished substrate is cleaned by the first cleaning unit 16 and the second cleaning unit 18, and the cleaned substrate is dried by the drying unit 20.

  FIG. 2 is a perspective view showing the substrate cleaning apparatus according to the embodiment of the present invention used in the second cleaning unit 18. As shown in FIG. 2, the substrate cleaning apparatus includes a substrate holder 41 that holds and rotates a wafer W that is an example of a substrate, a two-fluid nozzle 42 that supplies a two-fluid jet to the upper surface of the wafer W, And a nozzle arm 44 for holding the two-fluid nozzle 42.

  A gas supply line 55 and a liquid supply line 57 are connected to the two-fluid nozzle 42. The gas and the liquid are supplied to the two-fluid nozzle 42 through the gas supply line 55 and the liquid supply line 57 and are mixed in the two-fluid nozzle 42 to form the two-fluid. The two fluids are ejected from the two fluid nozzle 42 onto the surface of the wafer W.

  The substrate holding unit 41 includes a plurality of (six in FIG. 2) chucks 45 that hold the peripheral edge of the wafer W, and a motor 48 connected to the chucks 45. The chuck 45 holds the wafer W, and in this state, the wafer W is rotated around its central axis by a motor 48.

  The two-fluid nozzle 42 is disposed above the wafer W. A two-fluid nozzle 42 is attached to one end of the nozzle arm 44, and a turning shaft 50 is connected to the other end of the nozzle arm 44. The two-fluid nozzle 42 is connected to the nozzle moving mechanism 51 via the nozzle arm 44 and the turning shaft 50. More specifically, a nozzle moving mechanism 51 that turns the nozzle arm 44 is connected to the turning shaft 50. The nozzle moving mechanism 51 turns the nozzle arm 44 in a plane parallel to the wafer W by rotating the turning shaft 50 by a predetermined angle. The two-fluid nozzle 42 supported by the nozzle arm 44 moves in the radial direction of the wafer W as the nozzle arm 44 turns.

  FIG. 3 is an enlarged cross-sectional view of the chuck 45. As shown in FIG. 3, the chuck 45 is provided with a vibrator 61 that vibrates the wafer W while being in contact with the peripheral edge of the wafer W. The vibrator 61 has a contact surface 62 parallel to the surface of the wafer W, and this contact surface 62 contacts the lower surface of the peripheral edge of the wafer W supported by the chuck 45. All chucks 45 are provided with vibrators 61, and the plurality of vibrators 61 are arranged at equal intervals along the peripheral edge of the wafer W. When the chuck 45 is rotated by the motor 48, the vibrator 61 is also rotated together with the chuck 45. Therefore, the vibrator 61 vibrates the wafer W while rotating together with the wafer W.

  FIG. 4 is an enlarged view of the vibrator 61. As shown in FIG. 4, the vibrator 61 includes a piezoelectric element (piezo element) 66 and a contact member 67 attached to the piezoelectric element 66. The vibrator 61 is disposed on the chuck 45 such that the contact member 67 contacts the lower surface of the peripheral edge of the wafer W. Therefore, the surface of the contact member 67 constitutes a contact surface 62 that contacts the lower surface of the peripheral edge of the wafer W.

  The contact member 67 is for protecting the piezoelectric element 66 from the liquid supplied to the wafer W and for protecting the wafer W from the piezoelectric element 66. For example, the contact member 67 is a sheet member made of Teflon (registered trademark), PEEK resin (polyether ether ketone), quartz, or the like. This contact member 67 may be omitted. In this case, the contact surface 62 of the vibrator 61 that is in contact with the lower surface of the wafer W is constituted by the surface of the piezoelectric element 66 itself.

  As can be seen from FIG. 3, since the vibrator 61 is in contact with the lower surface of the wafer W, the wafer W is vibrated in a direction perpendicular to the surface of the wafer W. The vibration frequency and amplitude of the vibrator 61 can vary depending on the voltage applied to the piezoelectric element 66. The vibration frequency and / or amplitude of the vibrator 61 provided in each chuck 45 may be the same or different.

  At least two of all the transducers 61 may vibrate at different frequencies and / or amplitudes. For example, the first group of three vibrators 61-1, 61-3, 61-5 shown in FIG. 5 vibrates at a vibration frequency of several tens to several hundreds kHz, and the first group of vibrators The second group of three transducers 61-2, 61-4, 61-6 in between may vibrate at a vibration frequency of 1 MHz. The amplitudes of the first group of transducers 61-1, 61-3, 61-5 may be the same as the amplitudes of the second group of transducers 61-2, 61-4, 61-6, Or it may be different.

  The wafer W is cleaned as follows. The substrate holding unit 41 rotates the wafer W around its central axis, and further vibrates the wafer W with a predetermined frequency and a predetermined amplitude by the vibrator 61. In this state, the two-fluid nozzle 42 supplies a two-fluid jet to the upper surface of the wafer W, and further moves in the radial direction of the wafer W. The upper surface of the wafer W is cleaned by the combined action of the vibration of the vibrator 61 and the impact of the two-fluid jet.

  FIG. 6 is a schematic diagram showing a state in which the vibrator 61 is vibrating the wafer W. FIG. 7 is a diagram showing the state in which the vibrator 61 is vibrating the wafer W while supplying a two-fluid jet to the surface of the wafer W. FIG. As shown in FIG. 6, the particles are easily separated from the wafer W by applying vibration to the wafer W. In this state, a two-fluid jet is supplied to the wafer W to remove particles from the wafer W. Thus, the cleaning efficiency of the wafer W can be improved by the combination of the vibration of the wafer W and the impact of the two-fluid jet.

  The vibrator 61 does not indirectly vibrate the wafer W via the chuck 45 but directly vibrates the wafer W with the contact surface 62 in contact with the wafer W. Therefore, the chuck 45 itself hardly vibrates, and the chuck 45 can hold the wafer W stably. That is, the vibrator 61 of this embodiment can vibrate only the wafer W without vibrating the chuck 45.

  FIG. 8 is a diagram showing still another embodiment. In this embodiment, the vibrator 61 is disposed so as to come into contact with the outer peripheral surface (that is, the outermost end surface) of the wafer W and vibrate the wafer W in a direction parallel to the surface. The vibrator 61 has a contact surface 62 that contacts the outer peripheral surface of the wafer W. The configuration of the vibrator 61 is the same as that of the vibrator 61 shown in FIG. According to the present embodiment, during cleaning of the wafer W by the two-fluid jet, the wafer W is vibrated in a direction parallel to the surface of the wafer W by the vibrator 61.

  FIG. 9 is a diagram showing still another embodiment. In this embodiment, one vibrator 45 is provided with two vibrators 61A and 61B. The first vibrator 61A has the same configuration as the vibrator 61 shown in FIG. 3, and is disposed at the same position. That is, the first vibrator 61A contacts the lower surface of the peripheral edge of the wafer W, and vibrates the wafer W in a direction perpendicular to the surface. The second vibrator 61B has the same configuration as the vibrator 61 shown in FIG. 8, and is arranged at the same position. That is, the second vibrator 61B comes into contact with the outer peripheral surface (that is, the outermost end surface) of the wafer W, and vibrates the wafer W in a direction parallel to the surface.

  According to the present embodiment, the first vibrator 61A vibrates the wafer W in a direction perpendicular to the surface thereof, and the second vibrator 61B vibrates the wafer W in a direction parallel to the surface thereof. Accordingly, the particles are more easily separated from the wafer W. In this state, a two-fluid jet is supplied to the wafer W to remove particles from the wafer W. Thus, the cleaning efficiency of the wafer W can be further improved by the combination of the vibration in the two directions of the wafer W and the impact of the two-fluid jet. The vibration frequency and / or amplitude of the first vibrator 61A may be the same as or different from the vibration frequency and / or amplitude of the second vibrator 61B.

  FIG. 10 is a diagram showing still another embodiment. Although not shown in FIG. 10, the chuck 45 shown in FIG. 10 is provided with the vibrator 61 shown in FIG. 3 and / or the vibrator 61 shown in FIG. The configuration and operation of the present embodiment that are not particularly described are the same as the configuration and operation of the embodiment shown in FIG.

  In this embodiment, a cleaning liquid nozzle 70 that supplies a cleaning liquid to the lower surface of the wafer W is disposed below the wafer W held by the substrate holding portion 41. The cleaning liquid nozzle 70 is fixed to the upper end of the support shaft 75, and a cleaning liquid supply line 80 is connected to the lower end of the support shaft 75. A rotating shaft 81 that connects the chuck 45 and the motor 48 is a hollow shaft, and a support shaft 75 extends inside the rotating shaft 81. The rotating shaft 81 and the chuck 45 are rotated by the motor 48, but the support shaft 75 and the cleaning liquid nozzle 70 do not rotate.

  A cylindrical liquid receiving cup 83 is disposed around the wafer W held by the substrate holding unit 41. The liquid receiving cup 83 is provided to receive the liquid supplied to the rotating wafer W and to flow downward. This liquid receiving cup 83 may also be provided in the substrate cleaning apparatus of the above-described embodiment shown in FIG.

  A flow path 76 is formed inside the support shaft 75, and the cleaning liquid supply line 80 supplies the cleaning liquid to the flow path 76 of the support shaft 75. The cleaning liquid supply line 80 is provided with a cleaning liquid supply source 86 and a gas mixing device 87. The gas mixing device 87 is a device that mixes a gas such as nitrogen or hydrogen with the cleaning liquid supplied from the cleaning liquid supply source 86. The cleaning liquid containing dissolved gas is supplied to the cleaning liquid nozzle 70 through the cleaning liquid supply line 80 and the support shaft 75. Pure water can be used as the cleaning liquid.

  FIG. 11 is a plan view of the cleaning liquid nozzle 70, FIG. 12 is a perspective view of the cleaning liquid nozzle 70, and FIG. 13 is an enlarged cross-sectional view of the cleaning liquid nozzle 70. The cleaning liquid nozzle 70 extends in the diameter direction of the wafer W. As shown in FIG. 13, the cleaning liquid nozzle 70 includes a plurality of injection ports 91 and a plurality of flow paths 92 that respectively communicate with the injection ports 91. A plurality of ultrasonic transducers 95 are embedded in the cleaning liquid nozzle 70 and are arranged so as to be in contact with the cleaning liquid flowing through the respective flow paths 92 and to give vibration. The cleaning liquid to which the vibration energy is applied is supplied to the lower surface of the wafer W from each ejection port 91 through a plurality of flow paths 92. The distance from the injection port 91 to the lower surface of the wafer W is preferably 10 mm or less, and more preferably 5 mm or less.

  Each ultrasonic transducer 95 is disposed below each ejection port 91 and vibrates the cleaning liquid immediately before being supplied to the wafer W. When the ultrasonic vibrator 95 vibrates the cleaning liquid in this way, the gas dissolved in the cleaning liquid appears as bubbles, and the cleaning effect of the cleaning liquid can be improved.

  Cleaning of the wafer W is performed as follows. The substrate holding unit 41 rotates the wafer W around its central axis, and the vibrator 61 vibrates the wafer W at a predetermined frequency and a predetermined amplitude. Further, the cleaning liquid is supplied to the lower surface of the wafer W while the cleaning liquid is vibrated by the ultrasonic vibrator 95. In this state, the two-fluid nozzle 42 supplies a two-fluid jet to the upper surface of the wafer W, and further moves in the radial direction of the wafer W. The upper surface of the wafer W is cleaned by the combined action of the vibration by the vibrator 61 and the impact of the two-fluid jet, and the lower surface of the wafer W is cleaned by a cleaning liquid to which vibration energy is applied.

  The ejection ports 91 of the cleaning liquid nozzle 70 disposed on the lower surface side of the wafer W may be arranged along the movement locus of the two-fluid nozzle 42 disposed on the upper surface side of the wafer W. For example, as shown in FIG. 14, the cleaning liquid nozzle 70 may extend in an arc shape along the movement locus of the arc-shaped two-fluid nozzle 42.

  Although the two-fluid nozzle 42 is used in the embodiment shown in FIGS. 11 to 14, a pen sponge can be used instead of the two-fluid nozzle 42.

  The embodiment described above is described for the purpose of enabling the person having ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in the widest scope according to the technical idea defined by the claims.

10 Housing 12 Load Ports 14a to 14d Polishing Unit 16 First Cleaning Unit 18 Second Cleaning Unit 20 Drying Unit 22 First Substrate Transfer Robot 24 Substrate Transfer Unit 26 Second Substrate Transfer Robot 28 Third Substrate Transfer Robot 30 Operation Control Unit 41 Substrate holder 42 Two-fluid nozzle 44 Nozzle arm 45 Chuck 48 Motor 50 Rotating shaft 51 Nozzle moving mechanism 55 Gas supply line 57 Liquid supply lines 61, 61A, 61B Vibrator 62 Contact surface 66 Piezoelectric element 67 Contact member 70 Cleaning liquid nozzle 75 Support Shaft 76 Flow path 80 Cleaning liquid supply line 81 Rotating shaft 83 Liquid receiving cup 86 Cleaning liquid supply source 87 Gas mixing device 91 Injection port 92 Flow path 95 Ultrasonic vibrator

Claims (9)

A substrate holder for holding and rotating the substrate;
A two-fluid nozzle for supplying a two-fluid jet to the surface of the substrate;
A substrate cleaning apparatus comprising: at least one vibrator that vibrates the substrate in contact with the substrate.   The substrate cleaning apparatus according to claim 1, wherein the vibrator vibrates the substrate while rotating together with the substrate.   The substrate cleaning apparatus according to claim 1, wherein the vibrator includes a piezoelectric element and a contact member attached to the piezoelectric element and contacting the substrate.   The substrate cleaning apparatus according to claim 1, wherein the vibrator vibrates the substrate in a direction perpendicular to the surface thereof.   The substrate cleaning apparatus according to claim 1, wherein the vibrator vibrates the substrate in a direction parallel to the surface thereof.   The at least one vibrator includes at least one first vibrator that vibrates the substrate in a direction perpendicular to the surface thereof, and at least one second vibrator that vibrates the substrate in a direction parallel to the surface thereof. The substrate cleaning apparatus according to claim 1, comprising: The at least one vibrator is a plurality of vibrators;
The substrate cleaning apparatus according to claim 1, wherein at least two of the plurality of vibrators vibrate the substrate at different frequencies and / or amplitudes. A cleaning liquid nozzle for supplying a cleaning liquid to the lower surface of the substrate;
The substrate cleaning apparatus according to claim 1, further comprising an ultrasonic vibrator that vibrates the cleaning liquid. A polishing unit for polishing a substrate;
A substrate processing apparatus comprising: the substrate cleaning apparatus according to claim 1, which cleans the substrate polished by the polishing unit.

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