JP6715078B2 - Wafer holding mechanism and method for rotary table and wafer rotary holding device - Google Patents

Description

The present invention relates to a wafer holding mechanism and method for a rotary table in a wafer rotary holding device, and a wafer rotary holding device.

2. Description of the Related Art Conventionally, in a semiconductor manufacturing process, a process (also referred to as a spin process) for performing various kinds of processing while rotating a semiconductor wafer such as silicon, such as spin etching, spin drying, and spin coating, has been increasing. As a specific device, a wafer rotation holding device such as a spin etching device, a spin drying device, and a spin coating device is known. In addition, as the wafer surface treatment in the device manufacturing process, in addition to the etching treatment for removing the damaged layer after back grinding, the developer is applied to the wafer and the circuit surface is exposed to the developer. Examples of the method include developing treatment of a semiconductor circuit printed on a wafer coated with, and cleaning of the wafer surface. As a wafer rotation holding device and method for spin-processing such a wafer, there are devices and methods described in Patent Documents 1 to 4, for example.

As shown in FIGS. 8 and 9, in these wafer rotation holding devices, when performing the spin processing, the wafer is set on the rotation table 106 and the wafer is held by using the plurality of outer peripheral guide pins 108. .. The rotary table 106 is rotated by rotating the rotary shaft 104 with the drive motor 105. The plurality of outer circumference guide pins 108 guide the outer circumference of the wafer W and are configured so that the wafer W is placed at a predetermined position on the rotary table 106. Reference numeral 116 is a plurality of lower surface pins that support the lower surface of the wafer W.

The outer peripheral guide pin 108 is composed of a plurality of pieces. For example, the outer peripheral guide pin 108 is held by three outer peripheral guide pins, but one of the three outer peripheral guide pins has a hinge structure 115 that tilts forward and backward (FIG. 8). ). That is, two of the three are fixed guide pins 110 that are fixed, and one is a movable guide pin 112 that is movable. During rotation of the rotary table 106, the lower end of the movable guide pin 112 is pressed by the force of the spring 114 from the opposite side of the hinge structure 115, so that the tip of the movable guide pin 112 approaches the outer peripheral side of the wafer W. The wafer W is tilted and held in contact with it. When the rotary table 106 is stopped, the cylinder body 118, which is below the rotary table 106 and is provided outside, is lifted to press the lower end 120 of the hinge portion of the hinge structure 115, and the tip of the movable guide pin 112 is fixed. By tilting away from the outer periphery of the wafer W, the contact holding of the wafer W is released, and the wafer W is taken in and out. Therefore, the wafer W is held by pressing the wafer W with the force of the spring 114. A vane 122 is provided on the rotary table 106, and a baffle 124 is also formed.

On the other hand, since various semiconductors are used in electronic devices and electronic parts and the types of wafers are diversifying, there are various wafers having different thicknesses, sizes, shapes, materials and the like. In addition, the thickness of wafers is becoming thinner year by year. As described above, in the method of pressing the lower end of the movable guide pin with the force of the spring 114, the wafer W placed on the rotary table 106 may have excessively high pressing force of the outer peripheral guide pin depending on the type of the wafer W. As a result, the wafer W is bent and the wafer W is damaged.

Patent No. 4625495 Patent No. 4111479 Patent No. 4257816 Patent No. 4364242

The present invention has been made in view of the above-mentioned prior art, and can deal with various wafers having different thicknesses, sizes, shapes, materials, etc., and prevents the wafers from bending or being damaged and stably rotates the wafers. An object of the present invention is to provide a wafer holding mechanism and method for a rotary table and a wafer rotary holding device that can hold the wafer.

In order to solve the above problems, a rotary table wafer holding mechanism of the present invention is a rotary table wafer holding mechanism of a wafer rotary holding device, wherein the rotary table is mounted on the rotary shaft and the tip of the rotary shaft, and A rotary table that holds the wafer, a drive motor that supplies power to the rotary shaft, a plurality of outer peripheral fixing pins installed upright on the rotary table, and a fixed pin pressure sensor attached to the outer peripheral fixing pins,
At least one outer peripheral movable pin erected on the rotary table corresponding to the outer peripheral fixed pin, and a movable pin pressure control unit attached to the outer peripheral movable pin,
And a wafer holding mechanism for a rotary table, wherein the movable pin pressure control unit tilts the outer peripheral movable pin according to pressure data from the fixed pin pressure sensor to perform wafer holding force control. Is.

The control by the movable pin pressure control unit is preferably motor control or solenoid control.

The wafer holding method for a rotary table of the present invention is a wafer holding method for a rotary table, which holds the wafer by using the wafer holding mechanism for a rotary table.

A wafer rotation holding device of the present invention is a wafer rotation holding device including the wafer holding mechanism for a rotary table.

It is preferable that the wafer rotation holding device includes a spin processing mechanism.

According to the present invention, it is possible to deal with various wafers having different thicknesses, sizes, shapes, materials, etc., so that the wafer can be stably rotated and held by preventing the wafer from being bent or damaged. It is possible to provide a wafer holding mechanism and method for a rotary table and a wafer rotation holding device, which is a significant effect.

It is a schematic diagram showing one embodiment of a wafer rotation holding device provided with a wafer holding mechanism for a turntable of the present invention. It is a top view of the wafer rotation holding device provided with the wafer holding mechanism for rotary tables of this invention. It is a principal part enlarged view of the wafer rotation holding device provided with the wafer holding mechanism for rotary tables of this invention. It is a principal part enlarged view of the wafer rotation holding device provided with the wafer holding mechanism for rotary tables of this invention. It is a flowchart which shows the control flow used for the wafer holding mechanism for rotary tables of this invention. It is a block diagram of control used for a wafer holding mechanism for a turntable of the present invention. It is a schematic diagram showing one embodiment of a power supply mechanism which can be used for a wafer holding mechanism for a turntable of the present invention. It is a schematic diagram showing one embodiment of a wafer rotation maintenance device provided with a conventional wafer maintenance mechanism for rotary tables. It is a principal part sectional view which shows one embodiment of the wafer rotation holding device provided with the conventional wafer holding mechanism for rotary tables.

Embodiments of the present invention will be described below, but it goes without saying that these embodiments are shown as examples and various modifications can be made without departing from the technical idea of the present invention. In the figure, the same members are denoted by the same reference numerals.

1 to 4, reference numeral 10 indicates a wafer holding mechanism for a rotary table of the present invention. The rotary table wafer holding mechanism 10 is a rotary table wafer holding mechanism of the wafer rotary holding device 12, and includes a rotary shaft 14 and a rotary table mounted on the tip of the rotary shaft 14 and holding the wafer W on the upper surface thereof. 16, a drive motor 18 for supplying power to the rotary shaft 14, a plurality of outer peripheral fixing pins 20 provided upright on the rotary table 16, and a fixed pin pressure sensor 22 attached to the outer peripheral fixing pins 20. At least one outer peripheral movable pin 24 provided upright on the rotary table 16 corresponding to the outer peripheral fixed pin 20 and a movable pin pressure control unit 26 attached to the outer peripheral movable pin 24, the fixed This is a wafer holding mechanism for a rotary table in which the outer peripheral movable pin 24 is tilted by the movable pin pressure control unit 26 according to the pressure data from the pin pressure sensor 22 and the holding force of the wafer W is controlled. .. As the wafer W, a semiconductor wafer such as a silicon wafer is used.

In the illustrated example, the rotary shaft 14 is made of SUS (stainless steel), and the rotary table 16 is made of synthetic resin such as industrial plastic.

As shown in FIG. 2, the rotary table 16 is provided with a vane plate 28 to form a medium flow path 30. Reference numeral 32 is a baffle plate formed on the rotary table 16. In the illustrated example shown in FIG. 2, two fixed outer peripheral pins 20 and one outer movable pin 24 are provided.

In addition, lower surface pins 34 for supporting the lower surface of the wafer W are erected on the rotary table 16, and the wafer W is supported by the lower surface pins 34.

As well shown in FIG. 3, a fixing pin pressure sensor 22 is attached to the outer peripheral fixing pin 20 so that the pressure due to the wafer W coming into contact with the outer peripheral fixing pin 20 can be detected. As the fixed pin pressure sensor 22, various known pressure sensors can be used. Reference numeral 36 is a lower frame of the turntable 16.

As shown in FIG. 4, a movable pin pressure control unit 26 is attached to the outer peripheral fixed pin 20, and the movable pin pressure control unit 26 controls the movable pin pressure controller 26 in accordance with pressure data from the fixed pin pressure sensor 22. The outer peripheral movable pin 24 is tilted. In the tilting operation of the outer peripheral movable pin 24, the tip 38 of the outer peripheral movable pin 24 can be tilted toward the wafer W side (tilted inward) as shown by the phantom line in FIG. You can also tilt to the other side (tilt outward).

In this way, the tip 38 of the outer peripheral movable pin 24 is tilted toward the wafer W side or tilted toward the side opposite to the wafer W so that the wafer W is prevented from falling off the rotary table 16. It is possible to adjust the force.

The movable pin pressure control unit 26 may be controlled by a mechanical driving unit or may be controlled by an electromagnetic driving unit. As the mechanical driving means, for example, motor control for controlling with a motor can be applied. As the electromagnetic driving means, for example, solenoid control of controlling with a solenoid can be applied. The illustrated example shows an example of motor control. In the motor control, as shown in FIG. 4, the movable pin motor 40 is configured to freely retract the cylinder body 42, and by pushing or pulling the connecting portion 44, the outer peripheral movable pin 24 is tilted. be able to.

Further, instead of the movable pin motor 40, the outer peripheral movable pin 24 can be tilted by an electromagnetic driving means such as a solenoid to control the wafer pressing pressure. The electromagnetic drive means such as a solenoid can be controlled to maintain a constant pressure by voltage control.

Next, a control flow used in the rotary table wafer holding mechanism of the present invention will be described with reference to FIGS. In the example of FIG. 5, an example of motor control is shown. FIG. 6 is a block diagram of the main part 47 of the control flow according to the pressure data of FIG.

In the loading state before loading the wafer W, the tip 38 of the outer peripheral movable pin 24 is tilted outward. When the control flow starts, the wafer W is loaded, supported by the lower surface pins 34, and placed on the rotary table 16 (step 50 in FIG. 5).

In order to hold the wafer W stably, the movable pin motor is normally rotated so that the outer peripheral movable pin 24 is located at a predetermined position to tilt the outer peripheral movable pin 24 (step 52 in FIG. 5). An operation for rotating the movable pin motor 40 in the forward direction is issued by an external computer 49 different from the wafer rotation holding device (substep 60 in FIG. 5). The instruction from the external computer 49 can be performed by various data communications. For example, data communication based on the short-range wireless communication standard for digital devices such as Bluetooth (registered trademark) can be performed.

Pressure data is detected from the fixed pin pressure sensor 22 (step 54 in FIG. 5 and FIG. 6). At this time, the external computer 49 receives the pressure data from the fixed pin pressure sensor 22 and transmits the set pressure value (substep 62 in FIG. 5).

When the pressure data detected by the fixed pin pressure sensor 22 is larger than the set value (step 56 in FIG. 5), it means that the pressing force with which the wafer W is in contact with the outer peripheral fixed pin 20 is too large. The movable pin motor 40 is rotated in the reverse direction. When the movable pin motor 40 is rotated in the reverse direction, the cylinder body 42 is pulled (retracted), the base end 48 of the outer peripheral movable pin 24 is pulled to the wafer W side, and the tip 38 of the outer peripheral movable pin 24 is placed on the opposite side of the wafer W. Tilt (tilt outward) and tilting operation is performed (substep 64 of FIG. 5 and FIG. 6).

On the other hand, when the pressure data detected by the fixed pin pressure sensor 22 is smaller than the set value (step 58 in FIG. 5), the pressing force with which the wafer W contacts the outer peripheral fixed pin 20 is too small. Therefore, the movable pin motor 40 is normally rotated. When the movable pin motor 40 is rotated in the forward direction, the cylinder body 42 is pushed (advanced), the base end 48 of the outer peripheral movable pin 24 is pushed to the side opposite to the wafer W, and the tip 38 of the outer peripheral movable pin 24 is moved to the wafer W. Tilt to the side (tilt inward), and the tilting operation is performed (substep 66 of FIG. 5 and FIG. 6).

The comparator 45 compares the detected pressure data with the set value. The comparator 45 may be attached to the rotary table 16, or the external computer 49 may be used to compare the detected pressure data with the set value. The value to be set is set according to the thickness, size, shape and material of the wafer. It is also possible to transfer the detected pressure data to the external computer 49, calculate the pressing force from the data according to the type of wafer, and control the pressing force of the outer peripheral movable pin 24.

When the pressure data detected by the fixed pin pressure sensor 22 is controlled as described above and reaches the set value, the spin process is started (step 60 in FIG. 5). Examples of spin treatment include spin etching treatment, spin drying treatment, and spin coating treatment. In addition, as the wafer surface treatment in the device manufacturing process, etching treatment for removing the damaged layer after back grinding, wafer coating treatment with a developing solution, and developing solution coating on the wafer surface after exposing the circuit pattern Examples of the developing process include a process of baking a semiconductor circuit on the formed wafer and a cleaning process of the wafer surface.

The start of the spin process is also instructed by the external computer 49 (substep 68 in FIG. 5).

When the spin process is completed (step 62 in FIG. 5), the movable pin motor 40 is reversely rotated and the holding of the wafer W is released (step 64 in FIG. 5). The external computer 49 also gives an instruction to release the holding of the wafer W (substep 70 in FIG. 5). By repeating the control flow in this manner, the wafer W can be continuously processed.

The rotation speed of the rotary table 16 is preferably about 100 to 1000 rpm. The outer peripheral fixed pin 20 and the outer peripheral movable pin 24 preferably have a cylindrical shape. Further, it is preferable that the outer peripheral fixed pin 20 is two and the outer peripheral movable pin 24 is one, and it is more preferable that they are evenly arranged at equal intervals.

Power can be supplied to the data transfer devices such as the fixed pin pressure sensor 22 and the external computer 49, and also to the movable pin motor 40 and the solenoid by various means. For example, a method using a battery, a method using a slip ring, a method using electromagnetic induction and the like can be mentioned. In the method using a battery, the battery may be embedded in the turntable 16. In the method using the slip ring, it is possible to transmit electric power or a signal through a metal ring and a brush arranged on the rotary shaft 14, for example.

An electric power supply mechanism 70 is shown in FIG. 7 as one embodiment using the above-mentioned electromagnetic induction method. In FIG. 7, a power supply mechanism 70 includes a rotary shaft 14, a rotary table 16 mounted on the tip of the rotary shaft 14 and holding a wafer W on the upper surface, and a drive motor 18 for supplying power to the rotary shaft 14. A fixed side primary coil 72 wound around the rotary shaft 14, a power supply source 74 connected to the fixed side primary coil 72, and a fixed side corresponding to the fixed side primary coil 72. A rotary table side secondary coil 76, which is provided at a distance and is attached to the rotary table 16, and a load 78 connected to the rotary table side secondary coil 76 via an electric wire 80, By induction, electric power is supplied to the load 78 via the secondary coil 76. Examples of the load 78 include the fixed pin pressure sensor 22 and the data transfer device such as the external computer 49, and the movable pin motor 40 and the solenoid.

As described above, according to the wafer holding mechanism 10 for a rotary table of the present invention, it is possible to deal with various wafers W having different thicknesses, sizes, shapes, materials, etc., and it is possible to prevent the wafers from being bent or damaged. The wafer can be stably rotated and held. The method of holding a wafer for a rotary table of the present invention is a method of holding the wafer W using the wafer holding mechanism 10 for a rotary table. The wafer rotation holding device 12 is a device provided with the wafer holding mechanism 10 for the rotary table.

10: Wafer holding mechanism for rotary table of the present invention, 12: Wafer rotary holding device of the present invention, 14, 104: rotary shaft, 16, 106: rotary table, 18, 105: drive motor, 20: outer peripheral fixing pin, 22 : Fixed pin pressure sensor, 24: outer peripheral movable pin, 26: movable pin pressure control unit, 28, 122: blade plate, 30: medium flow path, 32, 124: baffle plate, 34: lower surface pin, 36: lower frame, 38: tip of outer peripheral movable pin, 40: movable pin motor, 42: cylinder body, 44: connecting part, 45: comparator, 47: main part of control flow, 48: base end of outer peripheral movable pin, 49: external computer, 70: Power supply mechanism, 72: fixed side primary coil, 74: power supply source, 76: rotary table side secondary coil, 78: load, 80: electric wire, 108: outer peripheral guide pin, 110: fixed guide pin, 112: movable Guide pins, 114: spring, 115: hinge structure, 116: lower surface pin, 118: cylinder body, 120: lower end, W: wafer.

Claims (5)

A wafer holding mechanism for a rotary table of a wafer rotary holding device,
A rotation axis,
A rotary table mounted on the tip of the rotary shaft and holding a wafer on the upper surface;
A drive motor for supplying power to the rotating shaft,
A plurality of cylindrical outer peripheral fixing pins for holding the outer periphery of the wafer, which are erected on the rotary table,
A fixed pin pressure sensor provided in the rotary table and attached to the outer peripheral fixed pin;
At least one column-shaped outer peripheral movable pin for holding the outer periphery of the wafer, which is provided upright on the rotary table corresponding to the outer peripheral fixed pin,
A movable pin pressure control unit attached to the outer peripheral movable pin,
Have
Wherein the outer peripheral movable pin is tilting operation by the movable pin pressure control unit according to the pressure data from the fixed pin pressure sensor, it is adapted retention control of the wafer is performed,
Further comprising a power supply mechanism for supplying power to the fixed pin pressure sensor,
The power supply mechanism has a fixed-side primary coil wound around the rotation shaft, a power supply source connected to the fixed-side primary coil, and a predetermined distance corresponding to the fixed-side primary coil. A rotary table side secondary coil provided separately and attached to the rotary table, and electric power is supplied to the fixed pin pressure sensor via the secondary coil by electromagnetic induction. Table wafer holding mechanism. The wafer holding mechanism for a rotary table according to claim 1, wherein the control by the movable pin pressure control unit is motor control or solenoid control. A wafer holding method for a rotary table, comprising holding the wafer using the wafer holding mechanism for a rotary table according to claim 1. A wafer rotation holding device comprising the wafer holding mechanism for a rotary table according to claim 1. The wafer rotation holding device according to claim 4, wherein the wafer rotation holding device includes a spin processing mechanism.

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