JP3071398B2 - Cleaning equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a liquid crystal glass substrate,
The present invention relates to a cleaning apparatus for cleaning a substrate to be cleaned such as a semiconductor wafer and a magnetic disk.

[0002]

2. Description of the Related Art Conventionally, liquid crystal glass substrates, semiconductor wafers,
To clean an object to be processed such as a magnetic disk, a plurality of the substrates to be cleaned are vertically arranged in a processing tank, and a cleaning liquid is stored in the processing tank. It has been practiced to vibrate and emit high-frequency sound waves to the cleaning liquid to wash a plurality of substrates to be cleaned in the processing bath at a time.

However, in the above-described method, it is difficult to uniformly clean the entirety of the objects to be processed with an increase in the area of the liquid crystal glass substrate and an increase in the diameter of the semiconductor wafer. Also, with the miniaturization and high integration of thin film transistors formed on the liquid crystal glass substrate and the elements formed on the semiconductor wafer, not only precision cleaning of the front side (the formation surface side of the elements and the like) of these substrates but also the back side thereof Also, precision cleaning is required.

For this reason, a substrate to be cleaned (for example, a semiconductor wafer) is transported in a single-wafer manner and rinsed by a rinse shower, a chemical solution scrub, a pure water scrub, a cleaning by a high frequency cleaning nozzle, a pure water shower, a spinner. Drying and cleaning are performed.

However, scrub cleaning is performed by mechanically bringing a pair of sponge-shaped rolls into contact with the front and back surfaces of the semiconductor wafer, so that the front and back surfaces of the wafer are scratched, and contaminant fine particles ( There is a problem of causing re-adhesion and re-contamination of particles).

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a high-frequency cleaning apparatus capable of simultaneously and precisely cleaning the front and back surfaces of a substrate to be cleaned such as a semiconductor wafer. Another object of the present invention is to provide a cleaning apparatus that prevents re-contamination of a substrate to be cleaned such as a semiconductor wafer due to scattering of a cleaning liquid without using a large-sized shielding member.

[0007]

A cleaning apparatus according to the present invention comprises a rotating support member for holding a substrate to be cleaned in a horizontal state.
Holding means having : a cylindrical fixed shaft also serving as a cleaning liquid supply unit; and the rotation support unit
Drive mechanism for rotating the material about the fixed axis
Rotating means for rotating said holding means having bets; disposed above the holding means, for injecting cleaning liquid riding high frequency sound waves toward the supported rotary support member surface of the substrate to be cleaned A first cleaning liquid spraying means; and a second cleaning liquid spraying means disposed below the holding means for spraying a cleaning liquid toward a back surface of the substrate supported by the rotation support member. Is what you do.

[0008] Another cleaning apparatus according to the present invention is a holding means having a rotation support member for holding a substrate to be cleaned in a horizontal state; a cylindrical fixed shaft also serving as a cleaning liquid supply unit;
Drive mechanism for rotating the material about the fixed axis
Rotating means for rotating the holding means having : a cleaning liquid, which is disposed below the holding means and is placed on the back surface of the substrate to be cleaned supported by the rotation supporting member , in which a cleaning liquid on which high frequency sound waves are applied is jetted in a band shape; first cleaning solution spray means for; disposed above and of the holding means, said rotating supporting
It is characterized in that it comprises the; second cleaning solution spray means for spraying the washing liquid towards the support surface of the substrate to the support member.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a cleaning apparatus according to the present invention will be described in detail. The cleaning apparatus includes a holding unit for holding the substrate to be cleaned in a horizontal state. This holding means is rotated by the rotating means. A high-frequency vibration nozzle, which is a first cleaning liquid ejecting unit for ejecting a cleaning liquid on which high-frequency sound waves are directed toward a surface of the substrate to be cleaned held by the holding unit, is disposed above the holding unit.
A second cleaning liquid ejecting unit is disposed below the holding unit for injecting the cleaning liquid toward the back surface of the substrate to be cleaned held by the holding unit.

The high-frequency vibration nozzle (first cleaning liquid spraying means) is a cylindrical type having a structure reciprocating in a radial direction from the rotation center of the substrate, and a rectangular shape having an elongated cleaning liquid discharge port. What is called a bar type is used.

The holding means has, for example, a structure in which a rotatable support member for horizontally supporting the substrate to be cleaned is rotatably engaged with a cylindrical fixed shaft also serving as a supply portion of the cleaning liquid.

The rotating means has a structure including, for example, a cylindrical fixed shaft also serving as a cleaning liquid supply unit, and a drive mechanism for rotating the rotation support member about the fixed shaft. The driving mechanism includes a driven-side timing pulley attached to the rotation support member, a driving-side timing pulley, a timing belt pivotally supported between the pulleys, and a motor for rotating the driving-side timing pulley. Consists of

[0013] The second cleaning liquid jetting means has a cleaning liquid flow section integrally connected in a horizontal direction to the cylindrical fixed shaft, which also serves as a cleaning liquid supply section, and communicates with a cavity of the fixed shaft. A plurality of cleaning liquid injection holes communicating with the circulation part are formed of a shower nozzle having an upper opening.

In the cleaning apparatus according to the present invention described above, a substrate to be cleaned, for example, a semiconductor wafer, held horizontally by the holding means, is rotated by the rotating means, and at the same time, for example, a cylindrical type is disposed above the semiconductor wafer. While the high frequency vibration nozzle is swept in the radial direction of the wafer, the cleaning liquid on the high frequency sound wave passing through the wafer is sprayed from the vibration nozzle toward the surface of the semiconductor wafer. At this time, the entire surface of the semiconductor wafer is sprayed with the cleaning liquid on the high frequency sound wave from the high frequency vibration nozzle. For this reason, the particles on the wafer surface are washed away together with the cleaning liquid, and re-adhesion of the particles is prevented, so that precision cleaning is performed.

In addition, a cleaning liquid on which the high-frequency sound wave is applied from the high-frequency vibration nozzle is jetted onto the surface of the semiconductor wafer, and at the same time, the cleaning liquid is jetted from a second cleaning liquid jetting means disposed below the semiconductor wafer, for example, a shower nozzle. When jetted toward the back surface of the wafer, high-frequency sound waves from the high-frequency vibration nozzle pass through the semiconductor wafer and also act on particles existing on the back surface, and the particles are washed by the liquid film of the cleaning liquid jetted from the shower nozzle. Can be washed away. At this time, the high-frequency sound wave reaching the liquid film is reflected by an air layer having a significantly different acoustic impedance, passes through the inside of the wafer and returns to the front surface side while acting on particles on the back surface of the wafer. The high-frequency sound wave returning to the surface side is reflected at the interface between the liquid film and the air layer on the wafer surface, and thereafter attenuates while repeating the same reflection as described above. In this way, the cleaning liquid from the shower nozzle is sprayed onto the back surface of the semiconductor wafer, and the liquid film is formed, so that the back surface of the semiconductor wafer can be precisely cleaned simultaneously without disposing a high-frequency vibration nozzle below the semiconductor wafer, that is, on the back surface side. It becomes possible to do.

It is preferable that the frequency of the high-frequency sound wave passing through the wafer is adjusted to be a wavelength of 1 / 2λ of the resonance frequency of the wafer. Specifically, a 5-inch wafer (thickness: 0.55 mm) is used, and the sound speed is 8000.
In the case of m / sec, the frequency is a positive multiple of 7.27 MHz, and a 6-inch wafer (thickness: 0.65 mm) is used.
When the sound speed is 8000 m / sec, the frequency is 6.1.
8 inch wafer (thickness: 0.75m)
m), and when the sound speed is 8000 m / sec, the frequency is set to a positive multiple of 5.33 MHz.

Next, another cleaning apparatus according to the present invention will be described in detail. The cleaning apparatus includes a holding unit for holding the substrate to be cleaned in a horizontal state. This holding means is rotated by the rotating means. A bar-type high-frequency vibration nozzle that is a first cleaning liquid ejecting unit that ejects a cleaning liquid riding on high-frequency sound waves in a band shape toward the back surface of the substrate to be cleaned supported by the holding unit is disposed below the holding unit. I have. A second cleaning liquid ejecting unit is disposed above the holding unit for injecting the cleaning liquid toward the surface of the substrate to be cleaned supported by the holding unit.

The holding means is rotatably engaged with, for example, a cylindrical fixed shaft, and has a structure provided with a rotation support member for horizontally supporting the substrate to be cleaned. The rotation unit has a structure including, for example, the cylindrical fixed shaft, and a drive mechanism for rotating the rotation support member about the fixed shaft. The driving mechanism includes, for example, a driven-side timing pulley attached to the rotation support member, a driving-side timing pulley, a timing belt pivotally supported between the respective pulleys, and a device for rotating the driving-side timing pulley. It consists of a motor.

The bar-type high-frequency vibration nozzle (first cleaning liquid injection means) is, for example, a rectangular nozzle having one end fixed to the upper end of the cylindrical fixed shaft of the rotating means and having an elongated cleaning liquid discharge port on the upper surface. A rectangular block having a hole, a vibrator disposed in the block at a bottom side of the nozzle hole so as to face the discharge port, and a flow of a cleaning liquid formed in the block so as to communicate with the nozzle hole. Road. The vibrator is connected to a power supply cable introduced through the inside of the cylindrical fixed shaft. The flow path is connected to a cleaning liquid supply pipe introduced through the inside of the cylindrical fixed shaft.

The second cleaning liquid spraying means may be, for example, a bar-shaped shower nozzle having a horizontally elongated nozzle body having a plurality of spray ports opened at a lower portion, or a cylinder having a cylindrical nozzle body having a spray port opened at a lower end. It is now possible to use a shaped shower nozzle. In particular, when a cylindrical shower nozzle is used as the second cleaning liquid ejecting means, it is preferable that the shower nozzle is disposed above the center of the substrate to be cleaned.

In another cleaning apparatus according to the present invention described above, the substrate to be cleaned, for example, a semiconductor wafer, held by the holding means by the rotating means, is rotated in a horizontal state while being disposed below the semiconductor wafer. A strip-shaped cleaning liquid riding on high-frequency sound waves passing through the wafer is jetted from the elongated cleaning liquid discharge port of the bar-type high-frequency vibration nozzle toward the back surface of the semiconductor wafer. At this time, a cleaning liquid on high-frequency sound waves is jetted from the high-frequency vibration nozzle to the entire back surface of the semiconductor wafer. For this reason, the particles on the wafer surface are washed away together with the cleaning liquid, and re-adhesion of the particles is prevented, so that precision cleaning is performed.

Further, a cleaning liquid in the form of a strip riding on the high-frequency sound wave from the high-frequency vibration nozzle is jetted onto the back surface of the semiconductor wafer, and at the same time, the cleaning liquid is jetted from a second cleaning liquid jetting means disposed above the semiconductor wafer, for example, a shower nozzle. When sprayed toward the front surface of the semiconductor wafer, high-frequency sound waves pass through the semiconductor wafer from the back side, and the reflected high-frequency sound waves pass through the front surface, similarly to the above-described cleaning device in which a high-frequency vibration nozzle is disposed above and a shower nozzle is disposed below. By repeating the action of transmitting light from the side to the back side, the front side of the semiconductor wafer can be simultaneously precision-cleaned.

Therefore, according to another cleaning apparatus of the present invention, the front and back surfaces of the semiconductor wafer can be precisely cleaned at the same time. Further, when cleaning the semiconductor wafer with the high-frequency vibration nozzle, it is generally advantageous in terms of efficient cleaning to spray the cleaning liquid on the high-frequency sound wave in close proximity to the semiconductor wafer with the vibration nozzle. In the cleaning apparatus according to the present invention, the bar-type high-frequency vibration nozzle disposed below can be close to the back surface of the semiconductor wafer, and the second cleaning liquid ejecting means disposed above, such as a shower nozzle, is similar to the high-frequency vibration nozzle. They can be arranged at a certain distance without being close to the semiconductor wafer.
As a result, when the semiconductor wafer after cleaning is taken out from the holding means, the semiconductor wafer can be taken out without disturbing the vibrating nozzle as in the case where a high-frequency vibrating nozzle is arranged above, so that handling properties are improved. You.

Further, when a cylindrical high-frequency vibration nozzle is arranged above the semiconductor wafer and the driving member drives the vibration nozzle in the radial direction of the semiconductor wafer, particles fall from the driving member to contaminate the semiconductor wafer. There is fear. In still another cleaning apparatus according to the present invention, the bar-type high-frequency vibration nozzle is disposed below the semiconductor wafer, so that the swept cylindrical high-frequency vibration nozzle is disposed above the semiconductor wafer. Contamination can be avoided.

It is preferable that the frequency of the high-frequency sound wave passing through the wafer is adjusted so as to have a wavelength of 1 / 2λ of the resonance frequency of the wafer. Specifically, a 5-inch wafer (thickness: 0.55 mm) is used, and the sound speed is 8000.
In the case of m / sec, the frequency is a positive multiple of 7.27 MHz, and a 6-inch wafer (thickness: 0.65 mm) is used.
When the sound speed is 8000 m / sec, the frequency is 6.1.
8 inch wafer (thickness: 0.75m)
m), and when the sound speed is 8000 m / sec, the frequency is set to a positive multiple of 5.33 MHz.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a sectional view showing a cleaning apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a first view used in the cleaning apparatus of FIG.
FIG. 3 is a cross-sectional view illustrating a high-frequency vibration nozzle serving as a cleaning liquid injection unit.

A motor 2 having a drive shaft 1 extending vertically
Are housed in a cylindrical support member 3. The support plate 4
It is fixed on the cylindrical support member 3 by a plurality of screws 5. The support plate 4 is provided with holes 6 and 7 at locations corresponding to the drive shaft 1 and at portions extending leftward from the support member 3. A disk-shaped plate 10 having a hole 8 opened in the center and having an annular projection 9 around the hole 8 is provided with a plurality of screws screwed onto the support plate 4 from the lower surface of the support plate 4 toward the plate 9. It is fixed by screws 11.

The processing tank 12 is disposed above the disk-shaped plate 10. The processing tank 12 has a cylindrical shape with a bottom, and has a cylindrical portion 13 protruding upward at the center of the bottom. The discharge pipe 14 is connected to a bottom portion near the left side wall of the processing tank 12. The processing tank 12 is supported and fixed by a stand (not shown) such that the cylindrical portion 13 is positioned concentrically with the hole 8 of the disk-shaped plate 10.

A rotating disk 16 having a cylindrical body 15 projecting downward at the center thereof is disposed horizontally in the processing tank 12, and the cylindrical body 15 is concentric in the cylindrical portion 13 of the processing tank 12. And extends outside the processing tank 12. On the inner peripheral surface near the lower part of the cylindrical body 15,
An annular engaging portion 17 protrudes in the horizontal direction. For example, four support rods 18 whose upper and lower parts are threaded are inserted into the peripheral edge of the rotating disk 16 so as to extend in the vertical direction at an equal circumferential angle (90 °), respectively. A nut 19 is screwed into a screw portion below the support rod 18 protruding from the support rod 18 and is fixed to the rotating disk 16. The columnar support blocks 20 are respectively screwed to the threaded portions above the support rods 18 so as to be located on the same horizontal plane.

A cylindrical fixed shaft 22 having an annular flange 21 in the vicinity of the center and having a thread cut on the outer periphery of the lower part is concentrically formed in the cylindrical body 15 of the rotating disk 16 from the processing tank 12. And is inserted into the hole 8 of the disc-shaped plate 10. The cylindrical fixed shaft 22 is fixed to the plate 10 by screwing a nut 23 into a lower part protruding downward from the lower surface of the plate 10.
At the lower end opening of the fixed shaft 22, there is formed a junction 24 with the cleaning liquid supply pipe. A cleaning liquid supply pipe (not shown) is connected to the junction 24.
A shower nozzle 27, which is a second cleaning liquid ejecting means extending in the horizontal direction and having a plurality of ejection ports 26 communicating with the washing liquid flowing portion 25 formed at an upper portion thereof, is provided at a peripheral portion of the rotating disk 16. It is located in a space surrounded by the inserted and fixed four support rods 18, and is integrally formed at the tip of the fixed shaft 22 so that the hollow portion 28 and the flow portion 25 communicate with each other. Two bearings 29a, 2
9b is an inner surface of the cylindrical body 15, an outer peripheral surface of the fixed shaft 22, an annular flange 21 of the fixed shaft 22, and the plate 10
Annular spacer 3 in the space defined by annular projection 9
It is arranged at a desired interval up and down via 0.
The lower surface of the upper bearing 29a is formed on the inner peripheral surface near the lower portion of the cylindrical body 15 by the annular engaging portion 1a.
7, and the upper surface of the lower bearing 29 b is engaged with the lower surface of the annular engaging portion 17. Rubber V
The ring 31 is interposed between the upper inner peripheral surface of the cylindrical body 15 of the rotating disk 16 and the fixed shaft 22, and the washing liquid from a shower nozzle described later is used to wash the bearings 29a, 29b.
Is disposed on the inner peripheral surface of the cylindrical body 15 and the fixed shaft 22.
To prevent inflow.

The driven-side timing pulley 32 is fitted around the lower part of the cylindrical body 15 and is fixed to the cylindrical body 15 by a plurality of screws 33. The drive-side timing pulley 34 is fitted to the drive shaft 1 of the motor 2 and is fixed to the drive shaft 1 by a locking member 35 attached therebetween. The timing belt 36 is pivotally supported between the timing pulleys 32 and 34. Therefore, by rotating the drive shaft 1 of the motor 2 and rotating the drive timing pulley 34 fixed to the drive shaft 1, the rotational force is transmitted to the driven timing pulley via the timing belt 36. 32 and the cylindrical body 1 to which the timing pulley 32 is attached.
5 is rotated about the fixed shaft 22.

A plurality of support rods 18 vertically fixed to the rotating disk 16 and the support blocks 20 attached to the upper ends of the support rods 18 hold the substrate to be cleaned horizontally. Means. Further, the drive shaft 1, the motor 2, the rotating disk 16, the fixed shaft 22, the bearings 29a, 29
b, a rotating means for rotating the holding means by the timing pulleys 32 and 34 and the timing belt 36.

A cylindrical high-frequency vibration nozzle 41, which is a first cleaning liquid injection means, is disposed above the rotating disk 16,
The reciprocating operation is performed as shown by an arrow A within a range corresponding to the radius of the rotating disk 16. As shown in FIG. 2, the cylindrical high-frequency vibration nozzle 41 has a cylindrical main body 43 in which the inner peripheral surfaces of the upper and lower portions are threaded, and which has a cleaning liquid introduction hole 42 in a side wall near the lower portion. On the inner peripheral surface near the lower portion of the cylindrical main body 43, an annular engaging portion 44 projects in the horizontal direction. A nozzle housing 46 having a circular cleaning liquid discharge port 45 at a lower end is screwed to a lower portion of the cylindrical main body 43. The cleaning liquid introduction pipe 47 is inserted into the cleaning liquid introduction hole 42 of the cylindrical main body 43, and the main body 4 is brazed.
It is fixed to 3. The disk-shaped vibrator 48 is disposed in the cylindrical main body 43 with a ring-shaped liquid-tight packing 49 locked by the annular engaging portion 44 interposed therebetween. The annular collar 50 also serving as a presser and ground is provided with the vibrator 4.
8 are arranged in contact with the periphery. A holding metal member 51 whose outer peripheral surface is subjected to thread cutting is abutted on the upper surface of the annular collar 50 by being screwed into the cylindrical main body 43 from the upper end thereof. A cable fitting member 54 having a through hole 52 at the center and a screw portion 53 on the upper side is in contact with the holding member 51 via a ring-shaped copper plate 55 in the tubular main body 43. An inverted conical groove 56 is formed at the upper end of the screw portion 53 of the fitting member 54. For example, an inverted conical ferrule 58 having a hole 57 at a central portion made of a fluororesin is fitted in an inverted conical groove 56 at the upper end of the screw portion 53 of the fitting member 54. A cap 60 having a hole 59 at the center is screwed to the screw portion 53 of the fitting member 54. The distal end of the coaxial cable 61 is inserted through the hole 59 of the cap 60, the hole 57 of the ferrule 58, and the through hole 52 of the fitting member 54 into the holding member 51. In addition,
The ferrule 58 is inserted into the groove 56 by rotating the cap 60 downward, and the coaxial cable 61 is fixed to the fitting member 54 by the wedge effect. The center cable (positive side cable) 62 of the coaxial cable 61 is
And the vibrator 4 through the inside of the annular collar 60.
8 is connected to the upper surface. A peripheral cable (ground side cable) 63 of the coaxial cable 61 is connected to the copper plate 55.
Are connected by solder or the like. That is, the peripheral cable (ground side cable) 63 is connected to the periphery of the vibrator 48 through the copper plate 55, the holding metal member 51 located below the copper plate 55, and the annular collar 50. The coaxial cable 61 is connected to a high-frequency oscillator (not shown).

Next, the operation of the cleaning apparatus according to the first embodiment of the present invention will be described. Substrate to be cleaned, for example, semiconductor wafer 6
4 is horizontally placed on a support block 20 attached to four support rods 18 provided on the rotating disk 16. When the motor 2 is driven to rotate the drive shaft 1 and the drive-side timing pulley 34 fixed to the drive shaft 1 is rotated, the rotational force is transmitted to the driven-side timing pulley 32 via the timing belt 36. The rotating disk 16 having the cylindrical body 15 to which the timing pulley 32 is attached is rotated about the fixed shaft 22. As a result, the semiconductor wafer 64 mounted on the support block 20 at the upper end of the four support rods 18 fixed to the rotating disk 16 is rotated.

When the cleaning liquid, for example, pure water is supplied to the cleaning liquid supply pipe (not shown) connected to the junction 24 of the cylindrical fixed shaft 22 in a state where the semiconductor wafer 64 is rotated as described above, the pure water becomes Through the cavity 28 of the fixed shaft 22, it is introduced into the circulation part 25 of the shower nozzle 27 communicating therewith, and the plurality of injection ports 2 on the nozzle 27
6 is injected upward. The shower nozzle 2
7 is located in a space surrounded by the four support rods 18 inserted and fixed to the periphery of the rotating disk 16,
Pure water is sprayed from the shower nozzle 27 onto the back surface of the semiconductor wafer 60 which is mounted on the support block 20 of the support rod 18 and rotated. A cleaning liquid, for example, pure water is introduced into the cleaning liquid introduction pipe 47 of the cylindrical high frequency vibration nozzle 41, and the pure water is supplied into the cylindrical main body 43 through the cleaning liquid introduction hole 42. When high-frequency power is applied from a high-frequency oscillator (not shown) to the vibrator 48 disposed above the cleaning liquid introduction hole 42 of the cylindrical main body 43 through the coaxial cable 61, the vibrator 48 vibrates at a desired frequency. From the circular discharge port 45 of the nozzle housing 46 attached to the lower portion of the cylindrical body 43, pure water riding on high-frequency sound waves is sprayed onto the surface of the rotating semiconductor wafer 64, and the high-frequency sound waves are
Through. At the same time, when the high-frequency vibration nozzle 41 reciprocates as shown by the arrow A within a range corresponding to the radius of the rotating disk 16, that is, the radius of the semiconductor wafer 64, the circular discharge port 45 of the nozzle housing 46 A cleaning liquid on high-frequency sound waves is sprayed on the entire surface of the semiconductor wafer 64. The pure water jetted from the nozzles 27 and 41 and after cleaning the front and back surfaces of the semiconductor wafer 64 is stored in the processing tank 12 and discharged to the outside through the discharge pipe 14.

As described above, while holding and rotating the semiconductor wafer 64 in a horizontal state by the holding means and the rotating means, the high-frequency sound wave passing through the wafer 64 from the high-frequency vibration nozzle 41 disposed above the semiconductor wafer 64. By spraying pure water on the surface of the semiconductor wafer 64 toward the surface of the semiconductor wafer 64 and reciprocating the high-frequency vibration nozzle 41 within a range corresponding to the radius of the semiconductor wafer 64 as shown by an arrow A. Wafer 6
Pure water on high frequency sound waves is jetted from the high frequency vibration nozzle 41 to the entire surface of 4. Therefore, the wafer 6
Particles on the four surfaces can be washed away together with pure water, and precise cleaning can be performed while preventing particles from re-adhering.

Pure water on which high-frequency sound waves from the high-frequency vibration nozzle 41 are jetted toward the surface of the semiconductor wafer 64 to be swept in the direction of arrow A, and at the same time, the shower nozzle 27 disposed below the semiconductor wafer 64. When pure water is sprayed toward the back surface of the semiconductor wafer 64, the high-frequency sound waves from the high-frequency vibration nozzle 41 pass through the semiconductor wafer 64 and also act on particles existing on the back surface, and the shower nozzle 27 The particles can be washed away by the sprayed pure water liquid film. The high-frequency sound wave that has reached the liquid film is reflected by an air layer having a significantly different acoustic impedance, and acts on particles on the back surface of the wafer 64 while acting on particles on the back surface of the wafer 64.
Passing inside and returning to the front side. The high-frequency sound wave returned to the front surface side is reflected at the interface between the liquid film and the air layer on the surface of the wafer 64, and thereafter attenuates while repeating the same reflection as described above. In this manner, pure water is sprayed from the shower nozzle 29 onto the back surface of the semiconductor wafer 64 to form a liquid film, so that the semiconductor wafer 64 can be disposed below the semiconductor wafer 64, that is, without disposing a high-frequency vibration nozzle on the back surface side. The entire back surface can be simultaneously precision cleaned.

In fact, the following experiment using the cleaning apparatus of Example 1 confirmed that the front and back surfaces of the semiconductor wafer could be precisely cleaned. (Experimental Example) First, both sides of an 8-inch silicon wafer polished on both sides were forcibly contaminated with silicon powder of 0.2 μm or more. The silicon wafer 64 was horizontally placed on a support block 20 attached to four support rods 18 provided on the rotating disk 16. By driving the motor 2 to rotate the drive shaft 1 and rotating the drive-side timing pulley 34 fixed to the drive shaft 1, the rotational force is applied to the driven-side timing pulley 32 via the timing belt 36. The rotating disk 16 having the cylindrical body 15 to which the timing pulley 32 was attached was rotated about the cylindrical fixed shaft 22. As a result, the silicon wafer 6 placed on the support block 20 at the upper end of the four support rods 18 into which the rotating disk 16 is inserted and fixed.
4 was rotated at a speed of 1500 rpm. In a state where the silicon wafer 64 is rotated, pure water is supplied to a cleaning liquid supply pipe (not shown) connected to the junction 24 of the cylindrical fixed shaft 22, and the pure water is supplied to the cavity of the fixed shaft 22. Pure water is introduced at a flow rate of 2.4 liters / minute onto the back surface of the silicon wafer 64 rotating from the plurality of injection ports 26 above the nozzle 27 by introducing the pure water to the flow portion 25 of the shower nozzle 27 communicating with the shower nozzle 27 through the portion 28. Sprayed. Further, pure water is introduced into the cleaning liquid introduction pipe 47 of the cylindrical high frequency vibration nozzle 41, and the pure water is supplied into the cylindrical main body 43 through the cleaning liquid introduction hole 42. At the same time, a high frequency power is applied from a high frequency oscillator (not shown) to the vibrator 48 disposed above the cleaning liquid introduction hole 42 of the cylindrical main body 43 through the coaxial cable 61 to thereby make the vibrator 48
Vibrates at a frequency of 1.5 kHz and generates a high frequency of 1.5 kHz from the circular discharge port 45 of the nozzle housing 46 attached to the lower part of the cylindrical main body 43. The high-frequency sound wave is sprayed onto the surface of the rotating silicon wafer 64 at a flow rate of 0.8 liter / min for 30 seconds while the high-frequency vibration nozzle 41 is set at a distance of 3.0 m within a radius range of the silicon wafer 64. The silicon wafer 64 was cleaned by reciprocating at a speed of / min.

Comparative Example In the cleaning apparatus of FIG. 1 described above, an elongated shower nozzle was used in place of the high-frequency vibration nozzle, and pure water was supplied from the shower nozzle to the rotating silicon wafer at a flow rate of 0.8 liter / min. The silicon wafer was cleaned in the same manner as in the experimental example, except that the injection was performed. The number of particles and the removal rate of the particles on the front and back surfaces of the silicon wafer cleaned by the experimental example and the comparative example were measured.
The results are shown in Table 1 below.

[0040]

[Table 1]

As is clear from Table 1, the cleaning apparatus according to Embodiment 1 of the present invention can remove particles on the front and back surfaces of the silicon wafer satisfactorily and can perform precision cleaning. If the particle removal rate on the back surface of the silicon wafer is about 70%, it is possible to manufacture a semiconductor device having good characteristics without contamination caused by particles on the back side from this wafer.

After the above-described cleaning of the silicon wafer 64, the injection of pure water from the shower nozzle 27 and the injection of pure water on the high-frequency sound wave from the high-frequency vibration nozzle 41 are stopped, and the motor 2 By increasing the rotation speed and rotating the rotary disk 16 at a high speed of, for example, 3000 rpm, the silicon wafer 64 placed on the support block 20 of the support rod 18 of the rotary disk 16 can be continuously spin-dried. .

In the first embodiment, the high-frequency vibration nozzle is of a cylindrical type and is swept within the radius of the substrate to be cleaned (for example, a silicon wafer).
It is not limited to this. For example, a similar effect can be obtained by using a bar-type high-frequency vibration nozzle having a rectangular main body having an elongated cleaning liquid discharge port instead of the cylindrical high-frequency vibration nozzle.

(Embodiment 2) FIG. 3 is a sectional view showing a cleaning apparatus according to Embodiment 2 of the present invention, and FIG. 4 is a bar-type high-frequency vibration nozzle which is a first cleaning liquid injection means incorporated in the cleaning apparatus of FIG. FIG. 5 is a sectional view taken along line VV in FIG.

A motor 102 having a drive shaft 101 extending in the vertical direction is housed in a cylindrical support member 103.
The support plate 104 is fixed on the cylindrical support member 103 by a plurality of screws 105. Further, the support plate 1
Reference numerals 04 denote holes 10 at positions corresponding to the drive shaft 101 and at portions extending leftward from the support member 103, respectively.
6, 107 are opened. A disc-shaped plate 110 having a hole 108 opened in the center and having an annular projection 109 around the hole 108 has a plurality of screws screwed onto the support plate 104 from the lower surface of the support plate 104 toward the plate 109. It is fixed by screws 111.

The processing tank 112 contains the disk-shaped plate 11.
0. The processing tank 112 has a cylindrical shape with a bottom, and has a cylindrical portion 113 projecting upward at the center of the bottom. The discharge pipe 114 is connected to a bottom portion of the processing tank 112 adjacent to the left side wall. The processing tank 112 is supported and fixed by a stand (not shown) such that the cylindrical portion 113 is positioned concentrically with the hole 108 of the disk-shaped plate 110.

A cylindrical body 11 protruding downward at the center.
The rotating disk 116 having the number 5 is disposed horizontally in the processing tank 112. The cylindrical body 115 extends concentrically through the inside of the cylindrical portion 113 of the processing tank 112 and extends outside the processing tank 112. The cylindrical body 115
An annular engaging portion 117 protrudes in the horizontal direction from the inner peripheral surface near the lower portion of the housing. For example, four support rods 118 whose upper and lower portions are threaded are inserted into the peripheral edge of the rotating disk 116 so as to extend vertically at an equal circumferential angle (90 °), respectively, and the lower surface of the rotating disk 116 is A nut 119 is screwed into a screw portion below the support rod 118 protruding from the support rod 118 and is fixed to the rotating disk 116. The columnar support blocks 120 are screwed into the threaded portions above the support rods 118 so as to be located on the same horizontal plane.

A cylindrical fixed shaft 122 having an annular flange 121 near the center and having a thread cut on the outer periphery of the lower part is
The disk-shaped plate 1 passes through the cylindrical body 115 of the rotating disk 116 concentrically from the processing tank 112.
It is inserted into ten holes 108. The cylindrical fixed shaft 12
2 is fixed to the plate 110 by screwing a nut 123 into a lower part protruding downward from the lower surface of the plate 110. Two bearings 124a,
124b is an inner surface of the cylindrical body 115, the cylindrical fixed shaft 1
22, an outer peripheral surface, an annular flange 121 of the fixed shaft 122,
Also, they are arranged at a desired interval vertically in the space defined by the annular projection 109 of the plate 110 via an annular spacer 125. The lower surface of the upper bearing 124a is engaged with the upper surface of the annular engaging portion 117 formed on the inner peripheral surface near the lower portion of the cylindrical body 115. The upper surface of the lower bearing 124b is engaged with the lower surface of the annular engaging portion 117. A rubber V-ring 126 is interposed between the upper inner peripheral surface of the cylindrical body 115 of the rotating disk 116 and the fixed shaft 22, and a cleaning liquid from a bar-type high-frequency vibration nozzle described later
4a and 124b are prevented from flowing between the inner peripheral surface of the cylinder 115 and the fixed shaft 122.

The driven-side timing pulley 127 is fitted on the outer periphery of the lower part of the cylindrical body 115 and has a plurality of screws 128.
Is fixed to the cylindrical body 115. The drive-side timing pulley 129 is connected to the drive shaft 10 of the motor 102.
1 and is fixed to the drive shaft 101 by a locking member 130 attached between them. The timing belt 131 is pivotally supported between the timing pulleys 127 and 129. Accordingly, by rotating the drive shaft 101 of the motor 102 and rotating the drive-side timing pulley 129 fixed to the drive shaft 101, the rotational force is applied to the driven-side timing pulley via the timing belt 131. 127 and the cylindrical body 1 to which the timing pulley 127 is attached.
The rotating disk 116 having the reference numeral 15 is rotated about the cylindrical fixed shaft 122.

The plurality of support rods 118 fixed vertically to the rotating disk 116 and these support rods 118
The support blocks 12 respectively attached to the upper ends of
0 constitutes holding means for holding the substrate to be cleaned horizontally. The drive shaft 101 and the motor 1
02, the rotating disk 116, the fixed shaft 122, the bearings 124a and 124b, the timing pulley 1
27, 129 and the timing belt 131 constitute rotating means for rotating the holding means.

The bar type high frequency vibration nozzle 132 is fixed to the upper end of the cylindrical fixed shaft 122. The bar-type high-frequency vibration nozzle 132 includes a rectangular lower block 134 having a horizontally long recess 133 as shown in FIGS.
A rectangular upper block 137 having an elongated cleaning liquid discharge port 135 on the upper surface and a horizontally long nozzle hole 136 having a lower surface having an area smaller than the opening area of the upper surface of the recess 133 is provided. The upper block 136 is provided with the nozzle hole 13 of the upper block 137 in the lower block 134.
6 is fixed with the packing 138 therebetween so as to face the recess 133 of the lower block 134.
By fixing the upper block 137 to the lower block 134 in this manner, the upper block 137 at the periphery of the nozzle hole 136 protrudes from the upper surface of the recess 133 in an eaves-like manner. The rectangular vibration plate 139 is provided on the upper block 137 protruding like an eave on the upper surface of the recess 133.
It is arranged on the packing 138 on the lower surface. The rectangular frame-shaped cap 140 is disposed on the lower surface of the vibration plate 139, and a screw (not shown) is screwed from the cap 140 side to the eave portion of the upper block 137 so that the vibration plate 139 is attached to the lower block 137. It is fixed between the recess 133 and the nozzle hole 136 of the upper block 137. The rectangular vibrator 141 is fixed to the lower surface of the vibration plate 139. The power supply cable 142 is inserted from the lower end of the cylindrical fixed shaft 122 and is connected to the lower block 1.
34 Cable fitting member 1 attached to lower surface
Through the lower block 134, the lower block 134 extends into the recess 133. The power supply cable 142
The main terminal 144 has a tip connected to the vibrator 141. The ground terminal 145 coaxially attached to the power supply cable 142 is connected to the cap 140.
Through the diaphragm 139. The power supply cable 142 is connected to a high-frequency oscillator (not shown). The first flow path 145 of the cleaning liquid is counterbored in the lower block 134 so as to open on the upper and lower surfaces thereof. The second flow path 146 of the cleaning liquid is counterbored in the upper block 137. The second flow path 146
Is opened at the lower surface of the upper block 137 to open the first block.
A rising hole 147 communicating with the flow path 145; a cylindrical hole 148 formed in the longitudinal direction of the upper block 137 and communicating with the hole 147; And a plurality of cleaning liquid outflow holes 149 opened. Cleaning liquid supply pipe 1
50 is inserted from the lower end of the cylindrical fixed shaft 122 and communicates with the first flow passage 145 of the lower block 134 through a fitting member 151 attached to the lower surface of the lower block 134.

The bar-shaped shower nozzle 152 having an L-shaped cross section, which is the second cleaning liquid injection means, is provided with the rotating disk 116.
It is arranged above. The shower nozzle 152
A cleaning liquid supply member 153, a horizontally elongated nozzle body 154 connected to the supply member 153, and extending in the horizontal direction;
The cleaning liquid flowing portion 155 formed inside the main body 154
And a plurality of injection ports 156 communicating with the circulation part 155 and opened on the lower surface of the main body 154.

Next, the operation of the cleaning apparatus according to the second embodiment of the present invention will be described. Substrate to be cleaned, for example, semiconductor wafer 1
37, four support rods 118 provided on the rotating disk 116
And is horizontally mounted on the support block 120. The motor 10
When the drive shaft 2 is driven to rotate the drive shaft 101 and the drive-side timing pulley 129 fixed to the drive shaft 101 is rotated, the rotational force is transmitted to the driven-side timing pulley 127 via the timing belt 131. Then, the rotating disk 116 having the cylindrical body 115 to which the timing pulley 127 is attached is rotated about the cylindrical fixed shaft 122. As a result, the semiconductor wafer 137 mounted on the support block 120 at the upper end of the four support rods 118 fixed to the rotating disk 116 is rotated.

When the cleaning liquid, for example, pure water is supplied to the cleaning liquid supply pipe 150 inserted into the cylindrical fixed shaft 122 while the semiconductor wafer 137 is rotated as described above, the pure water passes through the fitting member 151. The first flow path 1 of the bar-type high-frequency vibration nozzle 132 communicating therewith
45, introduced into the second flow path 146,
6 from the plurality of injection holes 149.
The liquid is injected toward the vibration plate 139 in the 37 rectangular nozzle holes 136, and the inside of the nozzle 136 is filled with pure water. In this state, the lower and upper blocks 13 are passed through the power supply cable 142 from a high-frequency oscillator (not shown).
Vibrator 1 attached to the lower surface of diaphragm 139 between 4, 137
When high-frequency power is applied to 41, the vibrator 141 vibrates at a desired frequency. For this reason, a high-frequency sound wave is generated from the vibration plate 139 to which the vibrator 141 is attached to the elongated discharge port 135 on the upper surface of the rectangular nozzle hole 136 of the upper block 137. As a result, as shown in FIGS. 3 and 5, the elongated discharge port 1 of the upper block 137 is formed.
From 35, pure water riding on high-frequency sound waves is sprayed in a belt shape on the surface of the rotating semiconductor wafer 157. At this time, the high-frequency sound wave passes through the semiconductor wafer 157. At the same time, the cleaning liquid is supplied to the cleaning liquid supply unit 153 of the shower nozzle 152 disposed above the semiconductor wafer 157,
For example, when pure water is supplied, the horizontally long nozzle body 154 is formed.
Of the nozzle body 154
Pure water is sprayed in a strip shape from the plurality of lower spray ports 156 onto the surface of the rotating semiconductor wafer 157. The pure water sprayed from each of the nozzles 132 and 152 and after cleaning the back and front surfaces of the semiconductor wafer 157 is supplied to the processing tank 1.
12 and discharged to the outside through a discharge pipe 114.

As described above, the semiconductor wafer 157 passes through the wafer 157 from the bar-type high-frequency vibration nozzle 132 disposed below the semiconductor wafer 157 while holding and rotating the semiconductor wafer 157 in a horizontal state by the holding means and the rotating means. Pure water on high-frequency sound waves is applied to the semiconductor wafer 1
By spraying the particles toward the front surface of the semiconductor wafer 157, particles on the entire back surface of the semiconductor wafer 157 can be washed out together with pure water, and precision cleaning can be performed while preventing particles from re-adhering.

Pure water carrying high-frequency sound waves from the bar-type high-frequency vibration nozzle 132 is jetted in a band shape toward the surface of the semiconductor wafer 157, and at the same time, the semiconductor wafer 157
When pure water is jetted from the shower nozzle 152 disposed above the semiconductor wafer 157 toward the surface of the semiconductor wafer 157,
The high-frequency sound wave from the high-frequency vibration nozzle 132 transmits through the semiconductor wafer 157 and also acts on particles existing on the surface thereof, so that the particles can be washed away by the pure water liquid film sprayed from the shower nozzle 152. . The high-frequency sound wave that has reached the liquid film is reflected by an air layer having a significantly different acoustic impedance, passes through the inside of the wafer 157 and returns to the back side while acting on particles on the surface of the wafer 157. The high-frequency sound wave returned to the back surface side is reflected at the interface between the liquid film and the air layer on the back surface of the wafer 157, and thereafter attenuates while repeating the same reflection as described above. In this manner, pure water is sprayed from the shower nozzle 152 onto the surface of the semiconductor wafer 157 to form a liquid film, thereby forming the semiconductor wafer 157.
, That is, the entire surface of the semiconductor wafer 157 can be simultaneously precision cleaned without disposing the high-frequency vibration nozzle.

Therefore, according to the cleaning apparatus of the second embodiment described above, the front and back surfaces of the semiconductor wafer 157 can be simultaneously precision cleaned. Further, according to the cleaning apparatus of the second embodiment, the shower nozzle 152 is disposed above the semiconductor wafer 157, so that the high-frequency vibration nozzle disposed above the semiconductor wafer as in the first embodiment is provided on the surface of the semiconductor wafer. A sufficient distance from the surface of the wafer 157 can be provided without bringing them close to each other. As a result, the semiconductor wafer 157 after the cleaning can be easily taken out from the holding means, and the handling property can be improved.

Further, according to the cleaning apparatus of the second embodiment, since there is no driving member for reciprocating the high-frequency vibration nozzle above the semiconductor wafer as in the first embodiment, particles are generated from the driving member. Contamination of the semiconductor wafer 157 due to the falling of the semiconductor wafer 157 can be avoided.

Further, the bar type high frequency vibration nozzle 13
2, the plurality of injection holes 149 of the second flow path 146 in the upper block
By injecting the gas toward the vibration plate 139 in 36, it is possible to prevent bubbles from being taken into the surface of the vibration plate 139. As a result, the vibrating plate 139 can be efficiently vibrated when the vibrating member 141 vibrates, and a high-frequency sound wave traveling toward the elongated discharge port 135 can be generated. In the first and second embodiments, a semiconductor wafer is used as a substrate to be cleaned. However, the present invention can be similarly applied to a liquid crystal glass substrate, a semiconductor wafer, a magnetic disk, and the like.

[0060]

As described above, according to the present invention, the front and back surfaces of a substrate to be cleaned such as a semiconductor wafer can be simultaneously precision cleaned, and contamination from the rear side of the substrate to be cleaned can be prevented. In addition, it is possible to provide a cleaning apparatus that can be effectively used for manufacturing a high-density semiconductor device, a liquid crystal glass substrate, a magnetic disk, and the like.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a cleaning apparatus according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a high-frequency vibration nozzle (first cleaning liquid ejecting means) used in the cleaning apparatus of FIG.

FIG. 3 is a sectional view showing a cleaning apparatus according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing a bar-type high-frequency vibration nozzle serving as a first cleaning liquid injection unit incorporated in the cleaning apparatus of FIG. 5;

FIG. 5 is a sectional view taken along the line VV in FIG. 4;

[Explanation of symbols]

 2, 102: motor, 12, 112: processing tank, 15, 115: cylindrical body, 16, 116: rotating disk, 18, 118: support rod, 20, 120: support block, 22, 122: cylindrical fixed shaft 27, 152: Shower nozzle, 29a, 29b, 14a, 124b: Bearing, 32, 34, 127, 129: Timing pulley, 36, 131: Timing belt, 41: Cylindrical high frequency vibration nozzle, 64, 157: Silicon wafer 132 ... Bar type high frequency nozzle.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 21/304 643 B08B 3/02

Claims (9)

(57) [Claims] 1. A rotation for holding a substrate to be cleaned in a horizontal state.
Holding means having a support member ; a cylindrical fixed shaft also serving as a cleaning liquid supply section, and the rotation support section
Drive mechanism for rotating the material about the fixed axis
Rotating means for rotating said holding means having bets; disposed above the holding means, for injecting cleaning liquid riding high frequency sound waves toward the supported rotary support member surface of the substrate to be cleaned A first cleaning liquid spraying means; and a second cleaning liquid spraying means disposed below the holding means for spraying a cleaning liquid toward a back surface of the substrate supported by the rotation support member. Cleaning equipment. 2. The cleaning apparatus according to claim 1, wherein the first cleaning liquid ejecting unit has a cylindrical shape and is reciprocated in a radial direction from a rotation center of the substrate. 3. The first cleaning liquid ejecting means includes a rectangular main body having a nozzle hole having an elongated cleaning liquid discharge port on a lower surface, and a vibrator disposed in the main body so as to face the discharge port. The cleaning device according to claim 1, further comprising: 4. The driving mechanism includes a driven-side timing pulley attached to the rotation support member, a driving-side timing pulley, a timing belt pivotally supported between the respective pulleys, and the driving-side timing pulley. The cleaning device according to claim 1, further comprising a motor for rotating the cleaning device. 5. The cleaning liquid ejecting means has a cleaning liquid flowing part which is integrally connected in a horizontal direction to an upper end of the cylindrical fixed shaft also serving as a supply part of a cleaning liquid and communicates with a cavity of the fixed shaft. 2. The cleaning apparatus according to claim 1, wherein a plurality of cleaning liquid injection holes communicating with the circulation part are shower nozzles opened at an upper part. 6. A rotation for holding a substrate to be cleaned in a horizontal state.
Holding means having a support member ; a cylindrical fixed shaft also serving as a cleaning liquid supply section, and the rotation support section
Drive mechanism for rotating the material about the fixed axis
Rotating means for rotating the holding means having : a cleaning liquid, which is disposed below the holding means and is placed on the back surface of the substrate to be cleaned supported by the rotation supporting member , in which a cleaning liquid on which high frequency sound waves are applied is jetted in a band shape; first cleaning solution spray means for; disposed above and of the holding means, said rotating supporting
A second cleaning liquid ejecting means for injecting the cleaning liquid toward the surface of the substrate supported by the holding member ; 7. The driving mechanism includes a driven-side timing pulley attached to the rotation support member, a driving-side timing pulley, a timing belt pivotally supported between the respective pulleys, and the driving-side timing pulley. The cleaning device according to claim 6, further comprising a motor for rotating the cleaning device. 8. A rectangular block having a rectangular nozzle hole fixed at one end to an upper end of the cylindrical fixed shaft and having an elongated cleaning liquid discharge port on an upper surface, wherein the first cleaning liquid ejecting means is provided in the block. A vibrator arranged on the bottom side of the nozzle hole so as to face the discharge port and connected to a power supply cable introduced through the inside of the cylindrical fixed shaft,
The cleaning according to claim 6 , further comprising a cleaning liquid flow path formed in the block so as to communicate with the nozzle hole and connected to a cleaning liquid supply pipe introduced through the inside of the cylindrical fixed shaft. apparatus. 9. A cleaning liquid supply member, a horizontally elongated nozzle body connected to a lower end of the supply member and having a cleaning liquid flow part, and a second cleaning liquid injection means communicating with the cleaning liquid flow part at the bottom of the main body. 7. The cleaning apparatus according to claim 6 , wherein the cleaning apparatus includes a shower nozzle having a plurality of cleaning liquid injection ports that are opened.