JPS6211495B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cleaning and drying device for wafers (plate-shaped objects), and is mainly directed to a semiconductor wafer cleaning and drying device (rinser and dryer) that cleans semiconductor wafers and dries them by centrifugal drying. .

In the manufacturing process of semiconductor devices, in order to obtain semiconductor devices with good characteristics, the surface of a semiconductor wafer must be thoroughly cleaned and then dried before heat treatment such as oxidation, impurity diffusion, and vapor phase chemical growth.

Conventional semiconductor wafer cleaning and drying equipment for cleaning and drying the surface of semiconductor wafers has a nozzle installed in the center of the equipment body consisting of a cylindrical container (bell jar) to spray water radially from the ceiling. On the other hand, a rotating plate rotated by an external motor is installed in the lower part of the apparatus main body, and four wafer storage units supported by this rotating plate are arranged around the nozzle. Then, a plurality of semiconductor wafers to be processed are placed in an alignment jig (cartridge), stored in the wafer storage section, and the semiconductor wafers are divided into four blocks around the nozzle.
A plurality of semiconductor wafers are arranged horizontally and vertically, and the rotating plate is rotated to rotate the storage section in which the semiconductor wafers to be processed are stored around the nozzle. The surface of the wafer is cleaned by spraying water on it, then the water spray is stopped and the centrifugal action of high-speed rotation is used to dry the wafer, resulting in a semiconductor wafer with a clean surface. I have to.

Incidentally, semiconductor manufacturing processes have recently been automated in response to demands for labor savings and faster processing. As part of this automation, automation of the etching process was developed, and automatic etching equipment was introduced. It would be advantageous if a washing and drying device, which is closely related to this etching process, could also be incorporated into the automatic etching device. However, most commercially available devices, including the wafer cleaning/drying device described above, are of the manual type and cannot meet the above requirements. The reason why commercially available devices are not suitable for automation is as follows.

(1) Stopping the rotary table after rotational drying is affected by the rotation of the motor with inertia, so it cannot be stopped at a fixed position. When it comes to automation, for example, it is necessary to use robots to replace cartridges.
The rotary table must always be stopped at a fixed position so that the wafer storage section is always positioned within reach of the robot, but commercially available devices do not meet this requirement.

(2) The wafer storage section that stores the cartridges must be raised and lowered manually. In the case of automation, it is preferable that the wafer storage section be raised to the surface of the top plate in order to have a robot replace the cartridge, but commercially available devices do not meet this requirement.

(3) Opening and closing of the top plate is done manually. For automation, it must be able to open and close automatically, but commercially available devices do not meet this requirement.

Therefore, an object of the present invention is to provide a wafer cleaning and drying apparatus suitable for automation.

The gist of the present invention to achieve the above object is that a hole for wafer replacement is provided at a suitable location on the top plate, a door is provided in the hole that is driven by an opening/closing mechanism, and the wafer is placed close to the wafer storage section. A lifting device for the storage section was provided, and a fixed position stop device was installed on the rotary table section to allow the wafer storage section to stop at a position facing the wafer exchange hole, and these devices were operated in synchronization. It is characterized by this.

The present invention will be specifically explained below using Examples.

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

In the figure, reference numeral 1 indicates a cylindrical bell gear, the bottom plate 4 of which is inclined, and drain ports 2a on both sides of the bottom plate.
2b, and an exhaust port 3a, on the side of the bell gear.
3b is provided. The dirty water being washed is drained from the drain ports 2a and 2b, and the exhaust ports 3a and
Dirty air inside the container can be exhausted from 3b.

In the figure, reference numeral 10 denotes a disk-shaped top plate mounted on the bell gear 1, in the center of which a nozzle 11 having an injection port 15 is protruded from the outside into the bell gear. There are two holes 12a and 12b for wafer replacement in the periphery of the nozzle 11.
This hole is provided with doors 13a and 13b of a size that covers this hole. The wafer replacement holes 12a and 12b have a size that allows a rectangular cartridge in which a wafer is stored to be easily inserted and removed, and are used for cartridge replacement. Therefore, the number of holes is provided in accordance with the number of wafer storage sections provided on the rotary plate, which will be described later, and is not limited to two as described above. Therefore, the number of doors provided corresponding to this hole is not limited either. The doors 13a, 13b have drive shafts 14a, 14 at one end.
b, and these drive shafts 14a, 14b
is connected to the opening/closing mechanism. Specifically, this opening/closing mechanism is as shown in FIG. That is, one end of a link 37 is pivotally attached to the distal end of the drive shaft 14a, and the other end of the link 37 is rotatably attached to the distal end of a piston 38 extending from an air cylinder 39 via a pivot 36. supported. At the side of the air cylinder 39, an air introduction pipe 40 extending from the piston drive mechanism 72,
41 are provided. This piston drive mechanism 7
2 is a limit switch 6 provided on the left and right sides of a pusher 61 of a fixed position stop device (Fig. 4), which will be described later.
It is controlled by output signals V ₈ and V ₀ of 5 and 66. In other words, the output V ₀ of the limit switch 66
so that the piston 38 is retracted by
The output _V8 of the limit switch 65 causes the piston to move forward. This opens and closes the door. That is, for example, when air A ₂ is introduced into the air introduction pipe 40, the piston 38 moves forward, and when air A ₃ is introduced into the introduction pipe 41, the piston 38 moves backward. The rotary motion is transmitted to the drive shaft 14a via the link 37, and the door 13a is opened and closed. Therefore, if the supply of air to the air cylinder is controlled by the above control signals V ₀ and V ₈ ,
The door can be opened and closed automatically. In addition, 45 in the figure is a lower limit switch, and 4
6 is an upper limit switch. Drive shaft 14a
2 so that it touches this limit switch.
Two discs 42 and 43 are pivoted. This disc has grooves 4 at different angles that engage with the ball at the tip of the contact of the limit switch.
4,47 are provided. The output signals V ₄ and V ₅ of each limit switch are supplied to the drive mechanism 72.
is applied to Here, for example, when the ball of the limit switch 46 engages with the groove of the disk 43 as shown in the figure, the limit switch 46 is turned on and a signal _V5 is applied to the piston drive mechanism. As a result, the drive mechanism 72 moves the piston 38
It operates to stop the sending operation of air _A3 that is causing the air to retreat. Therefore, the door 13a is prevented from opening any further. On the contrary, door 13a
When the is closed (the state indicated by the chain line in the figure), the lower limit switch 45 is turned on, and the output signal _V4 is input to the drive mechanism 72, which stops the delivery operation of the air _A2 that is moving the piston 38 forward. This will prevent you from putting too much stress on the door.

In the figure, reference numeral 5 denotes a rotating plate provided at the bottom of the bell gear, and is fitted onto the upper end of a rotating shaft 6 which is inserted into the center of the bell gear bottom plate 4 via a bearing 7. A pulley 8 having pleats on its circumferential surface is rotatably attached to the lower part of the rotating shaft 6, and this pulley 8 is connected to a rotating mechanism 48. This rotation mechanism 48 is
Specifically, a motor shown at 48a in FIG. 4, a pulley 48b provided at the tip of the rotating shaft of this motor and having pleats on its circumferential surface, and a timing belt suspended between this pulley 48b and the above-mentioned pulley 8. Consists of 9. The motor 48a is connected to the motor control circuit 4
9's output signal _V3 . The rotating plate 5 is rotationally driven by such a rotating mechanism. Note that two further bearings 53 and 54 are provided below the bearing 7 provided between the rotating shaft 6 and the bottom plate 4 of the bell gear. The bearings 53 and 54 are supported by two fixed plates 51 and 52, respectively. The reason for using such a large number of bearings is to securely fix the rotating shaft 6 and prevent it from rolling.

In the figure, reference numerals 17a and 17b are support frames disposed on the rotary plate 5, and in the upper part of this support frame, as shown by broken lines, wafer storage sections 16a and 16b are connected to a pivot 18a.
It is rotatably provided via the. Specifically, as shown in FIG. 2, two rectangular support frames 17a ₁ and 17a ₂ are arranged side by side on the rotary plate 5 with a predetermined interval maintained between them _. ,17
A box-shaped wafer storage portion 16a sandwiched between a ₂ in a sandwich-like manner is rotatably provided via a pivot shaft 18a passing through support frames 17a ₁ and 17a ₂ . In FIG. 2, 24 is a cartridge stored in the wafer storage section 16a, and a plurality of wafers 25 (for example, 25 wafers) are stored in parallel in this cartridge. In addition, in FIG. 4, a ring 79 attached to the upper part of the support frames 17a and 17b is for ensuring secure fixation.

In the figure, reference numerals 19a and 19b indicate passive pulleys, and lifting arms 20a and 20b projecting downward are pivotally attached to shaft portions of the passive pulleys.
In addition, a roller 21 is attached to the tip of this lifting arm.
a and 21b are rotatably supported. 22
a and 22b are driving pulleys, and this pulley 2
Timing belts 23a, 23b are suspended between 2a, 22b and the pulleys 19a, 19b. The shaft 5 of this driving pulley 22a, 22b
0 is connected to a drive mechanism described later. Specifically, the passive pulley 19a is as shown in FIG.
The lower end of the support plate 27 is located at the upper center of the support frames 17a ₁ , 17a ₂ for supporting the wafer storage portion fixed on the rotating disk 5 and is fixed to the top plate 10 with screws 26. It is pivoted on. Further, the above-mentioned drive mechanism specifically has a configuration as shown in FIG. 2. That is, a worm gear 33 is pivotally attached to the tip of the drive shaft 50, and the worm gear 33 meshes with a worm 34 provided at the tip of the rotating shaft of the drive motor 35. Note that this drive motor 35 is driven by a control circuit 73. This control circuit 73 receives output signals V ₈ ,
Controlled by V ₀ . That is, when the output V ₀ of the limit switch 66 is applied, the motor 35 is rotated in the forward direction, and when the output V ₈ of the limit switch 65 is applied, the motor 35 is rotated in the reverse direction. Reference numerals 28 and 29 are discs provided corresponding to this limit switch, and have grooves 30a and 30b. limit switch 3
The outputs V ₈ and V ₇ of 1 and 32 are applied to the control circuit 73. The specific configuration and functions of these are shown in FIG. 3 above (limit switches 45, 4).
6, disks 42, 43), so a detailed explanation thereof will be omitted, but in short, this controls the upper and lower limits of the elevation of the wafer storage section. According to such a drive mechanism, it is possible to move up and down by rotating the drive motor 35 in forward and reverse directions. For example, the forward rotation of the drive motor 35 is transmitted to the drive pulley 2 through the worm 34 and the worm gear 33.
2a, and the rotation of this drive pulley 22a is transmitted to the passive pulley 19a via the timing belt 23a. Therefore, the lifting arm 20a connected to the shaft of the passive pulley 19a,
The shaft of the passive pulley 19a is used as a fulcrum to move upward in an arc. Therefore, this operation causes the wafer storage sections 16a and 16b to be pushed upward as shown by the chain lines in the corresponding portions of FIG. Note that FIG. 2 shows the state in which the wafer storage section is pushed upward in this manner. At this time, the lifting arms 20a, 20b
Since the rollers 21a and 21b are provided at the tips of the rollers 21a and 21b, the above-mentioned pushing-up operation is performed smoothly. Conversely, when lowering the wafer storage section, the drive motor may be rotated in the opposite direction. In such a rotation mechanism, the control circuit 73 controls the forward and reverse rotation of the drive motor by controlling the limit switch signal.
By controlling V ₀ and V ₈ electrically, the wafer storage section can be raised and lowered automatically.

Below the rotating shaft 6, there is a 2
slit disks 55, 56, photoelectronic switches 57, 58 provided close to the slit disks 55, 56, a positioning disk 59 pivotally attached to the lower end of the rotating shaft 6, this positioning circle. A fixed position stop mechanism is provided consisting of a pusher 61 located adjacent to the side of plate 59. Specifically, this fixed position stopping mechanism is shown in the perspective view of FIG. 4. That is, slit holes 63 and 64 are provided in a part of the slit disks 55 and 56, respectively, and each photoelectronic switch 57 is positioned so that the slit disks 55 and 56 are located in the recessed portions of the photoelectronic switches 57 and 58. , 58 are arranged facing each other. Of these photoelectronic switches, as shown in _FIG .
The output V ₂ is applied to the motor control circuit 49 mentioned above. Further, a power supply voltage is applied to the photoelectronic switches 57 and 58 based on an output signal from a rotation detection mechanism (not shown). In other words, the rotation of the rotating plate is, for example,
When the rotation speed becomes 5 rpm or less, a signal is issued from the rotation detection mechanism to enable the photoelectronic switches 57 and 58 to operate. A notch 60 is provided in a part of the positioning disk 59. The pusher 61 is constituted by an elongated crankshaft, and one end thereof is rotatably supported by a crankshaft 71 on a fixed plate (not shown). Approximately in the middle of this pusher 61 is the positioning disk 5.
A cylindrical protrusion 62 having a diameter that engages with the notch 60 of 9 is provided, and this cylindrical protrusion 6
2 is a notch 6 of the positioning disk due to the movement of the pusher based on the drive mechanism of the pusher, which will be described later.
0 can be engaged or disengaged. A tension spring 68 is attached to the tip of the pusher 61.
b is provided, and the other end of this spring 68b is connected to the fixed part 6
It is fixed at 7. A reciprocating mechanism 68 for reciprocating the pusher is provided approximately in the middle between the spring 68b and the cylindrical projection. This reciprocating mechanism specifically includes an air cylinder 68a, a piston 68c, and the spring 68b. This air cylinder 68a is connected to the drive mechanism 6
9, the piston 68c is controlled by the air _A1 sent from the introduction pipe 70, and operates to push out the piston 68c. The movement of the pusher 61 is controlled by this piston and the spring. That is,
Normally, air A ₁ is sent out from the drive mechanism 69, and therefore the piston 6 of the air cylinder 68a
8c projects forward and forcibly pushes the pusher 61 against the force of the spring 68b. Therefore, as shown by the chain line in the figure, the pusher cylindrical protrusion 62 is removed from the notch 60 of the positioning disk. The drive mechanism of the air cylinder 68a is connected to the output signal V ₁ of the upper photoelectronic switch 57.
is applied, and in response to this signal _V1 , the drive mechanism 69 operates to bleed air from the air cylinder 68a. Therefore, due to this air bleeding, the piston 68c becomes in a floating state, and the pusher 61 is pulled back by the force of the spring 68b, and the cylindrical protrusion 62 engages with the notch 60 of the positioning disk. made possible. After the above operation is completed, the drive mechanism 69 is reset by a reset signal R to return to its original state. Note that two limit switches 65 and 66 are provided on the left and right sides of the pusher 61. Among these, the limit switch 65 on the left side of the figure is for generating a rotation signal, and is turned on when the pusher 61 is separated from the positioning disc 59 and the contact piece comes into contact with its side, as shown by the chain line in the figure, and outputs an output signal. The limit switch ₆₆ on the right side is for generating a stop signal, and is turned on when the cylindrical protrusion 62 of the pusher 61 engages with the notch 60 of the positioning disk, as shown by the solid line in the figure. , is adapted to generate an output signal V ₀ . Therefore, based on these signal states, it is possible to know when the rotary plate has stopped rotating, and, for example, the stop signal V ₀ can be sent to the drive mechanism 72 in the door opening/closing mechanism and the motor control circuit 73 in the wafer storage lifting device. By applying this voltage, these can be driven synchronously.

By the way, the slit holes 63 and 64 of the slit disks 55 and 56 and the notch 6 of the positioning disk
The positional relationship with 0 is set as follows. That is, for example, assuming that the rotating shaft 6 makes one rotation counterclockwise, the slit hole 63 of the upper slit disk 55 is first passed through the upper photoelectronic switch 57, and then the cylinder of the pusher is pulled back. The protrusions 62 are arranged so as to engage with the notches 60 of the positioning disc, and the slit holes 64 of the lower slit disc 56 pass through the lower optoelectronic switch 58 almost at the same time. . When the projection 62 of the pusher engages with the notch 60 of the positioning disk and the rotary plate stops, the wafer storage section on the rotary plate faces directly below the door of the top plate.

According to the fixed position stop mechanism configured as described above, when the rotary plate drive motor 48 enters the stop stage and the rotation of the rotary shaft reaches 5 rpm, the rotation detection mechanism operates;
This output signal applies a power supply voltage to the optoelectronic switches 57 and 58, and these optoelectronic switches become operable. At this stage, first, when the upper slit hole 63 passes through the upper optoelectronic switch 57, the optoelectronic switch 57 is turned on and transmits the output signal _V1 to the drive mechanism 69 of the air cylinder 68a. This causes the drive mechanism 69 to work to remove air from the air cylinder 68a. Therefore, the pusher 61 is pulled back by the force of the spring 68b. Therefore, the projection 62 of the pusher is engaged with the cutout 60 of the positioning disk. In this way, the rotating shaft will be stopped at a fixed position, but
Furthermore, since the slit hole 64 of the lower slit disk passes through the lower photoelectronic switch 58 along with the above-mentioned stopping operation, the output signal of this photoelectronic switch is
_V2 is applied to motor control circuit 49 to lock the stopped state. That is, the photoelectronic switch 5
The control circuit 49 is operated by the output signal V ₂ of 8.
A control signal V ₃ is applied to the motor 48 . For this reason,
The motor is forced to stop. Therefore, the inertial movement of the motor is suppressed, and accurate positioning and stopping can be performed. After this series of operations is completed and the cartridge is replaced as described above, the drive mechanism 69 is returned to its original state by the reset signal R. That is, air is introduced into the air cylinder 68a, the piston comes to protrude, and the pusher 61 is separated from the positioning disk.

In FIG. 1, a net 74 existing inside the bell gear is a net stretched around the inner peripheral surface of the bell gear to prevent splashes from returning to the wafer section by hitting the peripheral wall of the bell gear during cleaning and drying operations. This is to prevent wax sewage, etc. Specifically, as shown in FIG. 4, this net 74 has support frames 7
5, 76, and this support frame has fixed pieces 77, 78
is fixed to the side wall of the bell gear.

The embodiment device described above is used in the following manner.

(1) First, when the cleaning and drying of the wafer is completed, turn off the power switch of the rotary drive motor 48a. As a result, the number of rotations of the rotating plate 5 decreases.

(2) When the rotation speed reaches 5 rpm, the output signal from the rotation detection mechanism activates the photoelectronic switch 5 of the fixed position stop mechanism.
7 and 58 become operational.

(3) At this stage, first, the upper photoelectronic switch 57 is turned on, and the drive mechanism 69 is operated by its output signal _V1 . For this reason, Pushya 61
approaches the positioning disc 59, and the projection 62 of the pusher engages with the notch 60 of the positioning disc. This causes the rotating plate to stop at a fixed position.

(4) At the same time as the rotating plate stops, the lower photoelectronic switch 58 is turned on, and the output signal _V2 brakes the motor, locking the rotation of the motor and ensuring positioning.

(5) Due to the above stopping operation, the limit switch 66 provided on the right side of the pusher 61 is turned on.
Generates an output signal V ₀ . This output signal V ₀ drives the drive mechanism 72 of the door opening/closing device and the motor control circuit 73 of the wafer storage unit lifting/lowering device.

(6) By the operation of the wafer storage unit elevating device, the wafer storage unit is raised to a position where it contacts the door surface, and the door is opened by the door opening/closing mechanism.

(7) In this state, the cartridge in the wafer storage section is replaced with a new cartridge by, for example, a robot.

(8) If the drive mechanism 69 of the fixed position stop mechanism is reset when all cartridges have been replaced, air is sent to the air cylinder 68a, the piston 68c moves forward, and the pusher 61
push forward. Therefore, the limit switch 65 provided on the left side of the pusher 61 is turned on and generates the signal _V8 . By applying this signal _V8 to the control circuit 73 of the elevating device of the wafer storage section and the drive mechanism 72 of the door opening/closing device, the respective states return to their initial states through each operation, and the cleaning and drying work is continued again. can be done.

Since such an apparatus can automatically stop at a fixed position, raise and lower the wafer storage section, and open and close the door, it can be incorporated into an automatic etching apparatus and is suitable for complete automation.

The invention is not limited to the above embodiments. That is, any specific configuration of the fixed position stopping device, the wafer storage unit elevating device, and the door opening/closing device may be used as long as it is within the scope of their operating principles.

[Brief explanation of the drawing]

FIG. 1 is a structural sectional view including a block diagram showing one embodiment of the present invention, and FIG. 2 is a perspective view including a block diagram showing an example of the lifting device used in the present invention. FIG. 3 is a perspective view including a block diagram showing an example of a door opening/closing device used in the present invention, and FIG. 4 is a partially cutaway perspective view showing the main part of FIG. 1. 1... Belgear, 2a, 2b... Drain port, 3
a, 3b... Exhaust port, 4... Bottom plate, 5... Rotating plate, 6... Rotating shaft, 7, 53, 54... Bearing, 8... Pulley, 9... Timing belt, 1
0...Top plate, 11...Nozzle, 12a, 12b...
...Wafer replacement hole, 13a, 13b...Door, 14
a, 14b... Drive shaft, 15... Injection port, 16
a, 16b...wafer storage section, 17a, 17b,
17a ₁ , 17a ₂ ... support frame, 18a, 18b ...
Axis, 19a, 19b...Passive pulley, 20a,
20b... Lifting arm, 21a, 21b... Roller, 22a, 22b, 48b... Driving pulley, 23a, 23b... Timing belt, 24
... Cartridge, 25 ... Wafer, 26 ... Screw, 27 ... Support plate, 28, 29, 42, 43 ...
...Disc, 30a, 30b, 44, 47...Groove, 3
1, 32, 45, 46...Limit switch, 3
3... Worm gear, 34... Worm, 35,
48a... Drive motor, 36... Axis, 37...
Link, 38... Piston, 39... Air cylinder, 40, 41... Air introduction pipe, 47... Sphere,
49, 73...control circuit, 50...drive shaft, 5
1, 52... Fixed plate, 55, 56... Slit disk, 57, 58... Photoelectronic switch, 59... Positioning disk, 60... Notch, 61... Pusher, 62... Projection, 63, 64...slit hole, 65, 66...limit switch, 67...
Fixed part, 68...Reciprocating mechanism, 68a...Air cylinder, 68b...Spring, 68c...Piston, 6
9... Drive mechanism, 70... Air introduction pipe, 71...
Crankshaft, 74... Net, 75, 76... Support frame, 77, 78... Fixed piece.

Claims (1)

[Claims] 1 A bell gear having a top plate, a rotary plate provided in the bell gear, a nozzle extending to the upper surface of the center of the rotary plate through the center of the top plate, and a nozzle disposed around the nozzle. and a wafer storage section supported on the rotating plate, the apparatus cleaning and drying wafers by rotating the rotating plate, the top plate having a hole for replacing the wafer and an opening/closing mechanism. A door is provided to cover the hole, which is driven by a door, and a lifting device for the wafer storage is provided in close proximity to the wafer storage.
A fixed position stopping device is provided in the rotary plate section, and the fixed position stopping device stops the rotating plate at a position such that the wafer storage section faces the wafer exchange hole, and the wafer stopped at this fixed position is A wafer cleaning and drying apparatus, characterized in that the storage section is raised by the wafer storage section lifting device until it approaches the wafer exchange hole, and the door is opened by the door opening/closing mechanism.