JP3583491B2 - Polishing apparatus and method - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a polishing apparatus and method , and more particularly, to a polishing apparatus and method for polishing a polishing target such as a semiconductor wafer in a flat and mirror-like manner .
[0002]
[Prior art]
In recent years, as the degree of integration of semiconductor devices has increased, circuit wiring has become finer, and the distance between wirings has become smaller. In particular, in the case of optical lithography of 0.5 μm or less, the depth of focus becomes shallow, so that the image plane of the stepper needs to be flat.
Therefore, it is necessary to planarize the surface of the semiconductor wafer. As one of the planarization methods, polishing is performed by a polishing apparatus.
[0003]
Conventionally, this type of polishing equipment can be roughly divided into a load / unload function for transferring a cassette containing wafers, a transfer function for moving wafers, a polishing function for polishing wafers, and recently cleaning a wafer after polishing. The apparatus is provided with a cleaning function for controlling the operation of the apparatus and a control function for controlling the operation of the apparatus, and the apparatus is configured by individually assembling a number of devices and members for attaching the devices in order to perform these functions.
[0004]
[Problems to be solved by the invention]
Conventional polishing equipment is
(1) Since there are many types of semiconductor wafers to be processed, and polishing process conditions differ depending on the type of wafer, the configuration of equipment to be used is also different, it is difficult to standardize the equipment, and the standardization reduces the cost and shortens the delivery time. Could not hope. (→ Productivity of Device Manufacturing) (2) The generation of semiconductor wafers is rapidly changed, and the function of the device needs to be advanced at the same time. However, the remodeling of the device is not easy and the cost of renewing the device is large.
(→ extensibility)
(3) Since the polishing apparatus is usually installed in a clean room, the disassembly of the apparatus in repair and the generation of dust when replacing parts must be suppressed as much as possible, but there is a limit in the assembly configuration of the apparatus. (→ Maintenance)
(4) Since the layout such as the size of the device, the position of loading / unloading the wafer cassette, and the position of the operation panel is fixed, access to the device is inconvenient depending on the location of use. (→ User compatibility)
[0005]
The present invention has been made in view of the above circumstances, and has as its object to provide a polishing apparatus and method excellent in productivity, expandability, maintainability, and user responsiveness.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a polishing apparatus for polishing a wafer, wherein the polishing apparatus includes a load / unload block for transferring a cassette containing wafers, and a transfer block for moving the wafer. A polishing block for polishing a wafer, a cleaning block for cleaning the polished wafer, a relative position of a cassette of the load / unload block and a robot of the transfer block, and a relative position of a robot of the cleaning block and the transfer block. the Ri control block and Tona for storing the teaching, each block is characterized in changeable der Rukoto independently of each other.
[0007]
Further, the load / unload block, the transport block, the polishing block, and the cleaning block do not have a dimensional relationship with each other .
Further, a subdivision or same function blocks the individual blocks and multiple bonds, characterized in that to match the change of the device configuration.
Further, the cleaning block has a drying tank for drying the wafer.
Further, in the loading and unloading block, characterized in that the wafer before processing wafers after drying process so that the return to the original cassette been paid.
Further, the wafer is returned to a shelf in the cassette where wafers before processing are stored.
The load / unload block includes a sensing sensor for measuring the number of wafers stored in the cassette and the position of the storage shelf.
Further, polishing how the present invention extracts the wafer from the cassette loading and unloading block, and transported to the polishing block to the wafer by conveying block of the robot, to polish the wafer in polishing block, the wafer after polishing and cleaning block A polishing method for cleaning and drying by using a computer in a control block for teaching a relative position between a cassette of the load / unload block and a robot of the transport block and a relative position of a robot of the cleaning block and the robot of the transport block. And the load / unload block, the transport block, the polishing block, the cleaning block, and the control block can be changed independently of each other .
Moreover, before starting polishing process, after the mapping of the number and location of the storage rack of the wafer in the cassette is measured by the sensing sensor, and stores the information into the computer of the control block, the polishing process of the wafer it said that you start.
Further, the wafer that has been polished, washed, and dried is returned to a cassette in which wafers before processing are stored.
The wafer is returned to a shelf in the cassette where wafers before processing are stored.
[0008]
[Action]
According to the present invention having the configuration of the functional blocks described above, standardization can be performed in block units, cost reduction and delivery time can be reduced, and the productivity of device manufacturing is improved.
Further, when the function of the device needs to be advanced in the future, the unit can be updated in units of blocks, so that the cost of remodeling is low and the device has expandability.
[0009]
Further, repair can be performed by replacing each block, and the degree of disassembly is limited, so that dust generation can be minimized, and maintenance is excellent.
Then, the layout such as the position of loading / unloading the wafer cassette and the position of the operation panel can be changed according to the request of the user, and an apparatus which can flexibly respond to the user can be provided.
[0010]
【Example】
Hereinafter, embodiments of a polishing apparatus according to the present invention will be described with reference to the drawings.
FIG. 1 is an external view of a polishing apparatus according to the present invention. A transfer port 3 is provided in an apparatus main body A. After a cassette 2 containing unpolished wafers 1 is inserted into the cassette transfer port 3, an operation panel is provided. When the switch 4 is turned on, the wafers 1 in the cassette 2 are automatically extracted one by one, polished, washed, returned to the original cassette 2, and stored. After the polishing of all the wafers 1 is completed, the cassette 2 is taken out and sent to the next step.
[0011]
FIG. 2 shows the inside of the apparatus main body A. A load / unload block 5 for transferring a cassette 2 accommodating the wafer 1, a transport block 6 for moving the wafer 1, and polishing for polishing the wafer 1 are shown. A block 7, a cleaning block 8 for cleaning the polished wafer 1, and a control block 9 for controlling each of these blocks are independently arranged on a common base 10.
[0012]
The load / unload block 5 includes a stage 11 on which the cassette 2 is placed, and a sensing sensor 12 that measures the number of stored wafers 1a to z and the positions of the storage shelves 13a to 13z (mapping of wafers). The information is stored in the computer 14 in the control block 9.
[0013]
The transfer block 6 has a robot 15 movably mounted on a rail 6a, and the fingers 16 transfer the wafer 1a between the blocks. The robot 15 functions as a unit, and a plurality of robots 15 can be installed on the rail 6a.
[0014]
The polishing block 7 has a rotary table 18 and a top ring 17 facing the rotary table 18. A polishing cloth is attached to the surface of the rotary table 18, and a device for supplying a polishing liquid on the polishing cloth surface is provided. Have been.
The cleaning block 8 includes a cleaning tank 19 for performing cleaning with pure water and a drying tank 20, and these tanks 19 and 20 are units constituting the cleaning block 8.
[0015]
As described above, these five blocks are not mutually interfered or affected by each other, that is, when individual blocks are replaced, added, or the configuration is changed. Therefore, in these blocks, since union is not particularly unified, the combination direction and position of the blocks are free.
[0016]
The operation of the polishing apparatus of the present invention thus configured will be described.
The cassette 2 inserted from the transfer port 3 in FIG. 1 is placed on the stage 11 of the load / unload block 5, and the number of stored wafers 1a to z and the positions of storage shelves 13a to z are measured by the sensing sensor 12. (Wafer mapping), and the information is stored in the computer 14 in the control block 9. When the mapping is completed, the fingers 16 of the robot 15 mounted on the transport block 6 take out the wafer 1a from the shelf 13a of the cassette 2.
[0017]
The relative position between the robot 15 and the cassette 2 is stored in the computer 14 in advance by teaching after each block is arranged. That is, the operation and the position setting of the robot 15 are performed according to a command from the computer 14, and the structure between the load / unload block 5 where the cassette 2 is placed and the transport block 6 where the robot 15 is mounted is set. It is not dictated by the constrained dimensions obtained by the constraint.
[0018]
The wafer 1 a taken out of the cassette 2 is mounted on the top ring 17 of the polishing block 7 by the robot 15 and polished on the turntable 18. A polishing cloth is stuck on the surface of the turntable 18 and is polished in a state where the abrasive liquid flows down.
[0019]
The polished wafer 1a is transferred to the cleaning block 8 by the robot 15, and is mounted in the cleaning tank 19 in the block. When the cleaning is completed, the wafer 1a is mounted on a drying tank 20 in the block and drained, and thereafter is taken out of the cleaning block 8 by the robot 15 and returned to the storage shelf 13a of the cassette 2. The relative positions of the robot 15 and the cleaning block are stored in the computer 14 in advance, as described above.
In this manner, polishing of one wafer 1a is completed, the remaining wafers 1b to 1z are polished, and the cassette is replaced when all the wafers have been processed.
[0020]
The process conditions for optimally polishing the wafer 1 include, in addition to the rotation speed and pressing force of the top ring 17 corresponding to the film to be polished on the surface of the wafer 1, the rotation speed of the turntable 18, and the type of cloth material on the surface. There are types of polishing liquids, and these are appropriately set and selected depending on the type of film on the wafer surface. Here, the chemical properties of the polishing liquid differ greatly depending on the type. For example, when the film of the wafer is SiO ₂ , the polishing liquid is nearly neutral, but when the film is a metal, the polishing liquid is acidic or alkaline. Therefore, a special material having corrosion resistance is used as a material of a polishing-related member that comes into contact with the abrasive liquid. Further, the mechanism of the cleaning device also differs depending on the film of the wafer in the post-process cleaning.
[0021]
Under these conditions, the present apparatus can completely standardize the three blocks of the loading / unloading block 5, the transport block 6, and the control block 9, and is stocked in blocks. Since some parts of the polishing block 7 and the cleaning block 8 are different depending on the type of the wafer 1, the polishing block 7 and the cleaning block 8 are assembled in a semi-finished product, and the parts are optionally stocked. Therefore, when manufacturing an apparatus suitable for use conditions, a unitized block may be assembled, and the amount of stock itself is small. As a result, the productivity of device manufacturing is high.
[0022]
FIG. 3 shows a usage mode utilizing the above-described features of the present invention. In order to improve the cleaning performance, one cleaning tank 19a is added to the cleaning block 8, and the transport block 6 increases the throughput. Therefore, one robot 15a is additionally provided. The load / unload block 5, polishing block 7, and control block 9 have not been updated. As for the relative position between the updated blocks, the memory of the computer is updated after the teaching. In this way, the device can be freely, easily, and inexpensively updated without any special arrangement between the blocks.
[0023]
FIG. 4 shows a state where the drying tank 20 of the cleaning block 8 is removed for repair. Since the work of disassembly and repair is carried out in a separate room while being mounted on the dedicated cart 21, dust generation at the installation location of the apparatus is minimized. Also, in the case of replacing with a substitute block, the relative position is determined by teaching.
[0024]
In FIG. 5, the positions of the cassette loading / unloading block 5 and the operation panel 4 are interchanged according to the user's request. As described above, according to the present invention, each block can be freely laid out since there is no restriction on the special arrangement.
[0025]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the apparatus is divided into blocks according to functions, it is possible to standardize in units of blocks, it is possible to reduce costs and shorten delivery times, and it is possible to increase the productivity of apparatus manufacturing. Is improved.
According to the second aspect of the present invention, since there is no special arrangement between the blocks, it is possible to easily update the block unit at a low cost when the function is required to be advanced, and it can be used for future expansion. High responsiveness.
[0026]
Further, repair can be performed by replacing each block, and the degree of disassembly work is limited, so that dust generation can be minimized and maintenance is good.
Since the layout of the device can be easily arranged according to the installation location, it is possible to provide a device that can flexibly respond to individual users.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the appearance of a polishing apparatus according to an embodiment of the present invention.
FIG. 2A is a perspective view showing the inside of a polishing apparatus according to an embodiment of the present invention;
(B) is a figure which shows the structure of a cassette.
FIG. 3 is a perspective view showing another use mode of the polishing apparatus according to the embodiment of the present invention.
FIG. 4 is a perspective view showing a cleaning block of the polishing apparatus according to one embodiment of the present invention.
FIG. 5 is a plan view showing another layout of the polishing apparatus according to one embodiment of the present invention.
[Explanation of symbols]
Reference Signs List 1 Wafer 4 Operation panel 5 Load / unload block 6 Transport block 7 Polishing block 8 Cleaning block 9 Control block 14 Computer 15, 15a Robot 19, 19a Cleaning tank 20 Drying tank

Claims (11)

A polishing apparatus for polishing a wafer,
The polishing apparatus comprises:
A loading / unloading block for transferring a cassette containing wafers,
A transfer block for moving the wafer,
A polishing block for polishing the wafer,
A cleaning block for cleaning the polished wafer;
The load and unloading Ri and load block of the cassette relative position and the cleaning block of the robot of the transport block and the control block for storing the teaching of the relative position of the robot of the transport block Tona,
The polishing apparatus according to claim changeable der Rukoto each block independently of each other. The polishing apparatus according to claim 1, wherein the load / unload block, the transport block, the polishing block, and the cleaning block do not have a dimensional relationship with each other . Before plurality combine subdivision or the same functional blocks Kiko 's block, polishing device according to claim 1, wherein characterized in that match the change of the device configuration. 4. The polishing apparatus according to claim 1, wherein said cleaning block has a drying tank for drying a wafer. 5. The polishing apparatus according to claim 4, wherein in the loading / unloading block, the wafer after the drying process is returned to the original cassette in which the wafer before the processing is stored. 6. The polishing apparatus according to claim 5 , wherein the wafer is returned to a shelf in the cassette where wafers before processing are stored. Wherein the load-unload block, polishing according to any one of claims 1 to 6, characterized in that it comprises a sensing sensor for measuring the position of the number and storage rack accommodating wafers in the cassette apparatus. A polishing method for extracting a wafer from a cassette of a load / unload block, transporting the wafer to a polishing block by a robot of a transport block , polishing the wafer in the polishing block, and cleaning and drying the polished wafer in a cleaning block. ,
In the computer in the control block, the cassette of the load / unload block and the relative position of the robot of the transfer block and the relative position of the cleaning block and the robot of the transfer block are stored by teaching,
The polishing method according to claim 1, wherein the load / unload block, the transport block, the polishing block, the cleaning block, and the control block can be changed independently of each other. Before Po Risshingu process starts, the number and location of the storage rack of the wafer in the cassette is measured by the sensing sensor, the information after the mapping stored in a computer in the control block, start the polishing process of the wafer The polishing method according to claim 8, wherein the polishing is performed. 9. The polishing method according to claim 8 , wherein the polished, cleaned, and dried wafer is returned to a cassette in which a wafer before processing is stored. 11. The polishing method according to claim 10 , wherein the wafer is returned to a shelf in the cassette where wafers before processing are stored.

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