JP3439314B2 - Wafer polishing system - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer polishing apparatus system.

[0002]

2. Description of the Related Art Conventionally, when mirror-polishing a surface of a wafer such as a silicon wafer which is a raw material for semiconductor chips, a sticking device for sticking a plurality of wafers to a carrier plate and a carrier plate to which the wafers are stuck are provided. A polishing device (polishing device) for polishing the wafer by moving it relative to the polishing platen surface, a peeling device for peeling the polished wafer from the carrier plate, and a cleaning device for cleaning the plate from which the wafer has been peeled, They were provided as independent devices. By the way, in the surface polishing of a silicon wafer in particular, semiconductor devices have been highly integrated and miniaturized, and extremely high polishing accuracy is required. Fine particles in the air also cause a decrease in polishing accuracy, and as a countermeasure against this, polishing work of silicon wafers is performed in a clean room. In addition, the carrier plate has a gradually increasing outer diameter along with an increase in the diameter of the silicon wafer and is becoming a heavy object, which makes it difficult to handle it manually.

[0003]

However, conventionally, each device is provided independently, so that the carrier plate is manually transported between the devices and is supplied to and discharged from each device. Therefore, there is a problem that a lot of manpower is required and the cleanliness in the clean room is deteriorated due to the large number of people intervening, the sticking accuracy is lowered, and the polishing accuracy is lowered.

Therefore, an object of the present invention is to provide a wafer polishing apparatus system capable of improving work efficiency by reducing human intervention as much as possible, and reducing the dust generated by a person to improve wafer polishing accuracy. To provide.

[0005]

The present invention is provided with the following constitution to achieve the above object. That is, the present invention, in the step of polishing the surface of the wafer, a carrier plate having a surface which is formed in a plate shape for suitably transporting the wafer, and the wafer is attached by the surface tension of a liquid such as water, A sticking device for sticking a wafer to the carrier plate, and a wafer stuck to the carrier plate is brought into contact with a polishing platen surface, and the carrier plate and the polishing platen surface are relatively moved to move the wafer surface. At least one polishing device that polishes to a mirror surface, a polishing supply device that conveys and supplies the carrier plate to which the wafer is attached from the attachment device to the polishing device, and a wafer that is polished by the polishing device. A peeling device for peeling from the carrier plate, and a carrier plate to which the wafer is attached is discharged from the polishing device and peeled off. A polishing and discharging device for transporting the carrier plate to a place, a cleaning device for cleaning the carrier plate after the wafer is separated by the separating device, and a separating and discharging device for discharging the carrier plate from the separating device and conveying it to the cleaning device, A cleaning and discharging device for discharging the carrier plate from the cleaning device and transporting the carrier plate to the sticking device, wherein a closed loop is formed by each of the above devices, and a plurality of the carrier plates are circulated in the closed loop. Is characterized by.

[0006] Further, in the pasting device, the wafer placed on the surface of the carrier plate is pressed by a predetermined load, and the wafer is applied to the surface of the carrier plate by surface tension of liquid such as water. By providing the pressing means for sticking, the wafer can be surely stuck to the carrier plate, and the system can be preferably automated.

The pressing means presses the wafer placed on the surface of the carrier plate,
With the roller device having the pressing roller that rotates so as to pass through the carrier plate, the wafer can be reliably and strongly adhered, and the carrier plate can be continuously and suitably conveyed. Therefore, manufacturing efficiency can be improved.

The pressing means includes a pressing mechanism for pressing the wafer placed on the surface of the carrier plate,
By providing a rotating mechanism that slightly rotates the wafer while it is pressed by the pressing mechanism, the wafer can be firmly and firmly attached.

Also, an identification device for identifying each specification of the plurality of carrier plates, and an unloading means for unloading the carrier plate from the closed loop when the identification plate does not match the desired specifications. By providing the carrying-in means for carrying in the carrier plate having the desired specifications into the closed loop, the carrier plate can be exchanged reliably and appropriately for lot management and the like, and the system can be suitably automated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a plan view showing an embodiment of a polishing apparatus system for a silicon wafer (hereinafter simply referred to as “wafer”) according to the present invention. 12
Is a carrier plate, which is formed in a disc shape.
The carrier plate 12 has a surface to which the wafer 11 is attached via a liquid such as water in order to preferably convey the wafer 11 in the step of polishing the surface of the wafer 11. The carrier plate 12 of this embodiment has a diameter of 8
It is formed so that 4 inch wafers or 5 6 inch diameter wafers can be attached.

On the surface of the carrier plate 12, for example, a backing material, which is an elastic material and has a surface having an excellent adsorption property for adsorbing the wafer 11, is attached to the base material of the carrier plate 12 with an adhesive. Has been formed. As the backing material, for example, there is a microporous sheet made of a polymer material mainly composed of polyurethane. Due to its elasticity, this backing material is suitable to the surface of the wafer 11 and easily adheres thereto, and it is possible to obtain a suitable adsorbing property due to the action of the surface tension of water. The template 13 is attached to the surface of the backing material with an adhesive. The template 13 is the wafer 11
Is provided in a plate material having a thickness of about two-thirds of the thickness of the above, and a hole having a size into which the wafer 11 is fitted is hollowed out. The template 13 surrounds the periphery of the wafer 11 attached to the surface of the carrier plate 12 to prevent the wafer 11 from slipping sideways.

Reference numeral 15 denotes a sticking device for sticking the wafer 11 supplied from the wafer supply device 15a on the surface of the carrier plate 12 (on the backing material). The wafer supply device 15a is provided so as to pull out the wafer 11 from the cassette holding the plurality of wafers 11 and place the wafer 11 in the hole of the template 13 on the surface of the backing material. . As the wafer supply device 15a, an XY motion mechanism (2) is used as in the "wafer mounting method and mounting device" disclosed in Japanese Patent Laid-Open No. 5-318310 filed by the present applicant.
Dimensional motion mechanism), a rotary table, and a vertical motion mechanism can be used. The wafer supply device 15a may be provided with a wafer cleaning device for cleaning the wafer 11 so that the wafer 11 can be reliably attached.

Then, the sticking device 15 presses the wafer 11 placed on the surface of the carrier plate 12 with a predetermined load to bring the wafer 11 onto the surface of the carrier plate 12 and the surface of liquid such as water. A pressing means is provided which allows the sticking to be carried out by tension. As the pressing means, a roller device having a pressing roller 17 that presses the wafer 11 placed on the surface of the carrier plate 12 and rotates so as to pass the carrier plate 11 can be used. The pressing roller 17 of the present embodiment is rotatably provided around an axis, and the axis is movably supported in the vertical direction so as to press the wafer 11 by its own weight. A cushion material is wound around the outer periphery of the pressing roller 17 so as not to damage the surface of the wafer 11.

As another pressing means, as shown in FIG. 2, one having a rotating mechanism 93 for slightly rotating while pressing the wafer 11 onto the backing material by the pressing mechanism 92 may be used. Good. An air bag can be used as the pressing mechanism 92. According to this, since the fluid pressure is used, the entire surface of the wafer 11 can be pressed uniformly. By pressing the wafer 11 with the pressing means as described above, bubbles or excess water between the backing material and the wafer can be removed so as to be squeezed out. This allows
The wafer 11 can be reliably and strongly adhered to the surface of the backing material that forms the surface of the carrier plate 12.

Numeral 48 is a polishing apparatus row, in which the wafer 11 adhered to the carrier plate 12 is brought into contact with the surface of the polishing platen, and the carrier plate 12 and the surface of the polishing platen are moved relatively to each other, so that the surface of the wafer 11 is removed. In this embodiment, four polishing devices for polishing mirror surfaces (hereinafter referred to as "polishing devices") are arranged. The following is a polishing device 50
The configuration and operation of the polishing device row 48 will be described in detail. Reference numeral 52 is a surface plate, which has a polishing surface adhered to its upper surface to form a polishing surface plate, which is rotationally driven. A center roller 54 is rotatably provided at the center of the surface plate 52. 56 is a guide roller,
A plurality of rotatably arranged around the surface plate 52 at a predetermined interval and holding the wafer 11 on the lower surface of the carrier plate 12 are clamped on the surface plate 52 between the center roller 54 and the carrier plate 12. It is provided so as to be movable between the free position.

According to this polishing apparatus 50, the guide roller 56 at the innermost portion in the rotating direction of the surface plate 52 with respect to the supply position of the carrier plate 12 on the surface plate 52 is set to the carrier plate 12.
Move to the clamping position of. Then, the carrier plate 12 supplied to the supply position is conveyed to the position where it is sandwiched between the center roller 54 and the guide roller 56 by the rotation of the surface plate 52. Similarly, the carrier plate 12 is sandwiched between the guide roller 56 and the center roller 54 which are second from the innermost part in the same manner, so that the carrier plates 12 (four in this embodiment) are sequentially inserted from the back side of the surface plate 52. Is set between the center roller 54 and each of the plurality of guide rollers 56. Then, while the carrier plate 12 is pressed against the surface plate 52 by a top ring (not shown), the surface plate 52 is rotated to polish the wafer 11. The carrier plate 12 includes the center roller 54 and the guide roller 5.
6 and is rotated by the difference in peripheral speed between the center and the periphery of the surface plate 52. This allows
Each wafer 11 can be polished uniformly.

Reference numeral 51 denotes a polishing supply device, which is used for the wafer 11
The carrier plate 12 to which is attached is conveyed from the attaching device 15 to the polishing device 50 (polishing device row 48) and supplied.
The polishing supply device 51 includes a conveyor 53 and a rotating device 5.
5. The loading arm device 61 is a component. Conveyor 5
3 is a conveyor roller 5 that has a drive unit built therein and rotates about its own axis.
3a, or a roller row or the like composed of a plurality of rollers 53b rotatably and synchronously provided by a belt or the like. On the conveyor 53, the surface of the carrier plate 12 to which the wafer 11 is attached faces upward and is moved in that state. By appropriately setting the length of the conveyor 53, the number of carrier plates 12 that can stay can be adjusted appropriately. By thus retaining the carrier plate 12, the takt time of the system can be adjusted appropriately.

In the rotating device 55, a pair of the conveyor rollers 53a are arranged in parallel, and the carrier plate 12 is provided for each pair of the conveyor rollers 53a by 90.
It is equipped with a swivel mechanism that swivels. According to the rotating device 55, the sticking device 15 is formed by the pair of conveyor rollers 53a.
The carrier plate 12 can be introduced from the side, and after turning 90 degrees, the carrier plate 12 can be discharged to the polishing device row 48 side.

Reference numeral 61 denotes a supply arm device, which supplies the carrier plate 12 to the above-mentioned supply position of the carrier plate 12 on the surface plate 52 of the first polishing device 50. The supply arm device 61 is provided with a reversing / conveying device, and the carrier plate 12 is reversed so that the surface on which the wafer 11 is stuck becomes the lower surface, and the carrier plate 12
Stock position 53c provided at the end of the conveyor 53
Can be conveyed to a predetermined supply position on the surface plate 52. Reference numeral 83c denotes a plate carry-out device, which operates so as to discharge the carrier plate 12 determined to be discharged by the barcode detection unit 68 described later. When the carrier plate 12 does not operate so as to be carried out, it simply operates so as to send the carrier plate 12.

Reference numeral 60 denotes a transfer device in the polishing device row, which is arranged between the polishing devices 50 and 50, receives the carrier plate 12 from the discharge position of the carrier plate 12 of the upstream polishing device, and receives it from the downstream side. Of the carrier plate 1 at the supply position of the carrier plate 12 of the polishing device 50 of
2 are sequentially supplied.

If a brush (not shown) having bristles planted on the lower surface of a disk having the same diameter as the carrier plate 12 is supplied onto the surface plate 52 of each polishing device 50, the polishing device 50 is fixed. The clogging of the polishing cloth attached on the board 52 can be removed. The brush supplied onto the surface plate 52 is nipped by a center roller 54 and a guide roller 56 at a predetermined position, and the surface plate 50 is rotated while being pressed by a polishing cloth of the surface plate 50 by a top ring (not shown). By doing
The clogging of the polishing cloth can be removed. The method for removing the clogging of the polishing cloth is not limited to this method, and the platen 50
Alternatively, a brush or the like arranged so as to be able to move in and out from the adjacent position may be used.

Reference numeral 63 is a polishing discharge device, which is the polishing device 50 at the most downstream side of the carrier plate 12 to which the wafer is attached.
The carrier plate 12 operates as a discharging device that sequentially discharges the carrier plate 12 from the discharging position, and conveys the carrier plate 12 from the polishing device 50 to the peeling device 71 described later. The polishing and discharging device 63 includes a discharging arm device 63a, a plate stock portion 63b, a conveyor 63c, and a bar code detecting portion 68 as constituent elements. The discharge arm device 63a is provided adjacent to the most downstream polishing device 50 in the polishing device row 48. The discharge arm device 63a reverses the carrier plate 12 and discharges it to the plate stock portion 63b.

The plate stock portion 63b has 4
It has a structure with a shelf. The number of shelves is the same as the number of carrier plates 12 mounted on one polishing apparatus 50. This plate stock part 63b
The water tank is filled with clean water, and by immersing the carrier plate 12 to which the wafer is adhered in the clean water, the corrosive action due to the chemical action of the liquid polishing agent can be stopped and the surface of the wafer can be stopped. Can be washed.

Reference numeral 68 denotes a bar code detecting section, which is provided as a carrier plate identifying device. The carrier plate 12 placed on the shelf of the plate stock unit 63b is sent to the barcode detection unit 68 by the conveyor 63c. The barcode detecting section 68 is provided with a device for detecting the barcode on the lower surface of the carrier plate 12. The barcode detection unit 68 manages, for example, lot management, type according to the number of wafers stuck (difference in wafer size), or proper use of the carrier plate 12 due to difference in wafer type such as notch type or orientation flat type. Used for.

Reference numeral 71 denotes a peeling device, which is provided adjacent to the bar code detector 68 and peels the wafer 11 polished by the plurality of polishing devices 50 from the carrier plate 12. The separated wafer 11 is stored in the adjacent wafer storage portion 73. The peeling device 71 is provided with the carrier plate 12 conveyed from the bar code detecting section 68.
Is mounted and held in an inclined state, and is provided with a mounting table 71a capable of turning at a predetermined rotation angle. And the mounting table 71a
The carrier plate 12 held by the wafer 11
In order to peel off the water, a nozzle is provided for spraying clean water (pure water) onto the peripheral side surface of the wafer 11 while spraying it. After the wafer 11 is peeled off, this nozzle moves the wafer 11 on the carrier plate 12 so as to send the wafer 11 to the wafer storage 73 along the inclination of the mounting table 71a.
It is provided so that it can run toward 3. According to this peeling device 71, every time the wafer 11 is swung by a predetermined angle corresponding to the bonding position of the wafer 11, the nozzle travels while ejecting clean water, peels the wafers 11 one by one, and stores the wafers. It is discharged to the part 73.

The peeling device 71 has a pair of conveyor rollers 71b with a built-in driving device for pulling the carrier plate 12 into the peeling device 71, and the carrier plate 12 is sent from the peeling device 71 to a cleaning device to be described later. Therefore, it is provided with a pair of conveyor rollers 71c with a built-in drive device arranged in a direction orthogonal to the pair of conveyor rollers 71b. Therefore, the pair of conveyor rollers 71c operates as a peeling and discharging device. Reference numeral 73 denotes a wafer accommodating unit, which is used as a carrier plate 1 by the peeling device 71.
The wafer 11 separated from No. 2 is stored in the cassette while being immersed in pure water. The cassette fully loaded with the wafers 11 is unloaded by the cassette loading / unloading device 75. Further, the cassette loading / unloading device 75 supplies an empty cassette to the wafer storage portion 73. As the cassette loading / unloading device 75, for example, a versatile arm robot device can be used, and by providing such peripheral devices, the system can be fully automated.

Reference numeral 77 denotes a cleaning device, which is a carrier plate 1 after the wafer 11 is peeled by the peeling device 71.
2 Wash the surface. As the cleaning device 77, a mounting table 77a on which the carrier plate 12 is mounted is rotationally driven, and an upper plate 77b in which brushes are planted is rotationally driven and swingably driven. . As a result, the surface (upper surface) of the carrier plate 12 can be brushed and cleaned. Also, the cleaning device 77
A brush 77c, which is in contact with the peripheral side surface of the carrier plate 12 mounted on the mounting table 77a and brushes the peripheral side surface, is disposed on the side of the mounting table 77a. Further, 79 is a back surface brush portion, and a brush 79a formed in a roller shape brushes and cleans the back surface of the carrier plate 12. Reference numeral 79b denotes a line shower portion, which sprays clean water toward a portion where the roller-shaped brush 79a is brushing to spray the carrier plate 12
It is provided to wash away the dirt.

Reference numeral 81 is a cleaning / discharging device, which serves as a line for transporting the carrier plate 12 from the cleaning device 77 to the sticking device 15. This line includes a plate loading / unloading device 83a for loading / unloading a carrier plate for sticking five wafers, a plate loading / unloading device 83b for loading / unloading a carrier plate for sticking four wafers, and a bar code detector 68. It consists of According to the plate loading / unloading devices 83a and 83b, the carrier plates 12 are selected based on the data of the carrier plates 12 identified by the bar code detection unit 68, and those which do not meet the specifications for the next polishing process are selected. Be shipped. The carrier plate 12 thus carried out is provided with a multi-stage shelf for holding the carrier plate 12, and is received and carried out by the track carriage 85 which moves on a predetermined track. Further, it is a matter of course that the track car 85 is also used when carrying in a new carrier plate 12. That is, the plate loading / unloading devices 83a, 83
Reference numeral b is a carry-out means for carrying out the carrier plate 12 from the closed loop when the carrier plate 12 does not match the desired specifications by the barcode detection unit 68, and also carries the carrier plate 12 into the closed loop. Acts as a loading means.

The plate loading / unloading device 83b and the attaching portion 15
The barcode detection unit 68 is again provided between the two. The bar code detecting unit 68 has the same function as that of the constituent elements of the polishing and discharging device 63, performs the same identification, and counts the number of times each carrier plate 12 is used in the present embodiment, and the carrier plate Identification is also performed to manage the 12 lifespans (lifespan related to shape accuracy, etc.). By providing the barcode detection unit 68 in this manner, it is possible to reliably eliminate troubles such as lot mixing. It should be noted that these bar code detection units 68 can be installed not only at the installation positions of this embodiment but also at any positions in the closed loop system.

The respective devices described above are arranged in order as is clear from the figure, and a closed loop forming a wafer polishing device system is formed. According to this, the carrier plate 12 can be suitably circulated in the closed loop. Further, the conveyor 53 capable of accommodating the plurality of carry plates 12, the plate stock portion 63b capable of immersing the plurality of carry plates 12 in clean water, and the like can suitably adjust the time balance of each process, which is preferable. Since the tact time can be set, the wafer polishing apparatus can be preferably automated as a system.

Furthermore, in the above structure, the inspection means for inspecting the shape accuracy such as the flatness of the surface of the carrier plate 12 and the carrier plate 12 when the inspection means does not satisfy the reference accuracy. It may be provided with unloading means for unloading 12 from the closed loop of the system of the present invention, and loading means for loading the carrier plate 12 in place of the unloading carrier plate 12 into the closed loop. As the carry-out means and carry-in means, the plate carry-in / carry-out devices 83a and 83b and the plate carry-out device 83c can be preferably used. Thus, the defective carrier plate can be appropriately detected and automatically replaced, and the system according to the present invention can be preferably continuously operated. Although the present invention has been variously described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. That is.

[0032]

According to the present invention, in a system for polishing the surface of a wafer by using a carrier plate having a surface to which the wafer is attached by the surface tension of a liquid such as water, each process device and between the devices A closed loop is preferably formed by the supply / discharge device provided, and the carrier plate can be appropriately circulated in the closed loop. Therefore, the wafer polishing apparatus system can be favorably automated and human intervention can be significantly reduced, resulting in a remarkable effect that work efficiency can be improved. Then, by reducing manual intervention, it is possible to significantly reduce the fine dust generated by human activity, and it is possible to maintain a high cleanliness inside the clean room. As a result, there is a remarkable effect that the polishing accuracy of the wafer can be improved.

[Brief description of drawings]

FIG. 1 is a plan view showing an embodiment of a wafer polishing apparatus system according to the present invention.

FIG. 2 is a cross-sectional view illustrating an example of a pressing unit according to the present invention.

[Explanation of symbols]

11 wafers 12 Carrier plate 15 Sticking device 17 Pressing roller 50 polishing equipment 51 polishing supply device 63 Polishing and discharging device 68 Bar code detector 71 Peeling device 71c Conveyor roller 77 Cleaning device 81 Cleaning and discharging device 83a, 83b Plate loading / unloading device 92 Pressing mechanism 93 rotation mechanism

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiaki Seki 1650 Kiyono, Matsushiro-cho, Nagano-shi, Nagano Fujikoshi Machine Industry Co., Ltd. Machinery Industry Co., Ltd. (56) References JP-A-8-148451 (JP, A) JP-A-5-201535 (JP, A) Actual development: 5-80659 (JP, U) (58) Fields investigated ( Int.Cl. ⁷ , DB name) H01L 21/304 B24B 37/04

Claims (5)

(57) [Claims] 1. A carrier plate having a surface formed in a plate shape for transporting the wafer in the step of polishing the surface of the wafer and having the surface adhered by the surface tension of a liquid such as water, and the carrier plate. A sticking device for sticking the wafer to the wafer, and the wafer stuck to the carrier plate is brought into contact with the polishing platen surface, and the carrier plate and the polishing platen surface are relatively moved to polish the wafer surface to a mirror surface. At least one polishing device, a polishing supply device that conveys and supplies the carrier plate to which the wafer is attached from the attachment device to the polishing device, and a wafer that is polished by the polishing device from the carrier plate. A peeling device for peeling, and a carrier plate to which the wafer is attached is discharged from the polishing device and conveyed to the peeling device. A polishing and discharging device, a cleaning device for cleaning the carrier plate after the wafer is separated by the separating device, a separating and discharging device for discharging the carrier plate from the separating device and transporting it to the cleaning device, and the carrier plate And a cleaning / discharging device for discharging the cleaning liquid from the cleaning device to the sticking device, wherein a closed loop is formed by each of the above devices, and a plurality of the carrier plates are circulated in the closed loop. Wafer polishing system. 2. The sticking device presses a wafer placed on the surface of the carrier plate with a predetermined load to bring the wafer onto the surface of the carrier plate by surface tension of a liquid such as water. 2. The wafer polishing apparatus system according to claim 1, further comprising a pressing means for adhering the wafer. 3. The pressing device is a roller device that has a pressing roller that presses a wafer placed on the surface of the carrier plate and that rotates so as to pass the carrier plate. The wafer polishing apparatus system according to claim 2. 4. The pressing means comprises a pressing mechanism for pressing the wafer placed on the surface of the carrier plate, and a rotating mechanism for slightly rotating the wafer while the wafer is pressed by the pressing mechanism. The wafer polishing apparatus system according to claim 2. 5. An identification device for identifying each specification of a plurality of the carrier plates, and an unloading means for unloading the carrier plate from the closed loop when the carrier plate does not match a desired specification by the identification device. 2. The wafer polishing apparatus system according to claim 1, further comprising a carrying-in means for carrying in a carrier plate having a desired specification into the closed loop.