JP2003117811A - Wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributed control type wafer polishing device capable of reducing a load on the host computer of a wafer polishing device, eliminating the need of a cable for transfer raw data from an operating part, and controlling utilities such as air, vacuum and water at the use end thereof without using a centralized control by the host computer. SOLUTION: Control equipment for controlling the utilities such as air, vacuum, and water for pressing a wafer 50 against a polishing pad 20 and a microcomputer 46 having a data storage means, calculation means, and input/output means, sending and receiving signals from an external part, and controlling the control equipment are incorporated in a holding head 14 for holding the wafer 50. The microcomputer 46 communicates with the host computer, and controls the utilities at the use end thereof.

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 using a chemical mechanical polishing (CMP) method.

[0002]

2. Description of the Related Art A wafer polishing apparatus using CMP has a single or a plurality of operating units that are centrally controlled (process control, management, measurement, etc.) by a host computer installed separately from a processing stage. This operation unit holds or processes the wafer and observes and controls the processing state. Specific operation parts include a holding head that holds the wafer and presses it against the polishing pad, and a platen with a polishing pad. In more detail, air control equipment that supplies air to the holding head to press the wafer against the polishing pad. , A cleaning water control device for supplying cleaning water to the holding head.

FIG. 5 is a schematic view showing the structure of a conventional wafer polishing apparatus 1. This wafer polishing apparatus 1 includes a holding head 2 that holds a wafer, a spindle 3 that transmits a rotational force to the holding head 2, a platen 5 to which a polishing pad 4 is attached, a host computer 6, and an air vacuum that is supplied to an operating unit. The utility box 7 has a built-in control device for controlling water and the like.

According to this wafer polishing apparatus 1, signals from all the sensors are processed by the host computer, calculations are performed, and then individual control signals are output to the utility box 7 and the drive section of the operating section. After the utility box 7 receives the signal, air, vacuum, water, and the like are supplied to the operation unit, and the supply amount is feedback-controlled by controlling the regulator and the like based on the information from the supply amount detection sensor.

[0005]

However, in the conventional wafer polishing apparatus 1, even if the closed loop control as shown in FIG. 5 is performed, the supply amounts of air, vacuum, water, etc. are different from each other in the utility box 7. Since only the state immediately after the control device can be confirmed, there is a drawback that it is difficult to confirm if a change occurs between the utility box 7 and the operation unit for some reason.

That is, in the conventional wafer polishing apparatus 1, it is very difficult to know the state of air pressure at the end of use. In addition, since all raw data such as information obtained from sensors during process control / observation that occurs during a process in the operation unit and information obtained from endpoint sensors are sent to the host computer 6, it is related to information transmission. Problems and information processing problems occur. The former is
Related to noise and drive design. As the amount of raw signal increases, the number of cables increases, which makes it easier for noise to be transmitted. In addition, the air provided on the spindle 3
There is a problem that the rotary joint connecting the pipes for vacuum and water becomes complicated and expensive. On the other hand, in the latter, the processing time is delayed because it is necessary to simultaneously handle information of a plurality of operating units, and the configuration of the host computer 6 becomes complicated. Further, it is difficult to directly observe the emergency situation of the operation unit, and it is only possible to observe the signal processing through observation, so there is a problem that it takes time at the time of emergency stop.

Further, since the process control, response observation, and control calculation are all performed by the host computer 6,
There was also a problem of insufficient computing performance (extension of calculation time).

Further, since the utility box 7 is installed away from the operating part, it is difficult to accurately control the air pressure and the like.

The present invention has been made in view of such circumstances, and in order to solve the above-mentioned drawbacks of the conventional apparatus, utilities such as air, vacuum, and water are not used for centralized management by the host computer, but at the end of use. An object of the present invention is to provide a controllable distributed management type wafer polishing apparatus.

[0010]

In order to achieve the above-mentioned object, the present invention holds a wafer by a holding head, and the wafer is polished by pressing the wafer against a polishing pad via the holding head. In the polishing apparatus, the holding head is provided with a control device for controlling utilities such as air, vacuum, and water for pressing the wafer against the polishing pad, and data storage, calculation, and input / output means for external signals. A microcomputer for transmitting and receiving and controlling the control device is incorporated.

According to the first aspect of the present invention, since the holding head for holding the wafer has the control device for controlling the utility and the microcomputer built therein, it is possible to manage the dispersion in the holding head.

The present invention further provides, as in claim 2,
The wafer polishing apparatus has a host computer installed outside the holding head and is connected to the utility. The microcomputer communicates with the host computer and controls the utility at its end of use. It is characterized by that.

According to a third aspect of the present invention, the microcomputer is
A signal input / output unit connected to the host computer via a signal interface, a data input / output unit connected to the host computer via a data interface, and the signal input / output unit and the data input / output unit from the host computer. A storage unit that stores a plurality of control programs and signals and data for controlling the control device input via the storage unit, and the data stored in the storage unit is calculated, and a control signal is output to the control device. And an arithmetic circuit section that operates.

Further, according to a fourth aspect of the present invention, the host computer outputs a process start signal to the microcomputer contained in the holding head, and the microcomputer stores the process start signal in the storage unit based on the process start signal. The control program is controlled by using a plurality of control programs stored therein, and a process completion signal is output to the host computer when the process is completed, and the control program is as set forth in claim 5. To
It is possible to change or modify each time the program is executed, and if the same change or modification is made a preset number of times, the modified or modified control program is registered as a regular control program. I am trying.

Further, as described in claim 6, when an abnormality occurs in the holding head, the microcomputer can output an abnormality detection signal.

As described above, according to the present invention, the holding head has the built-in microcomputer including the storage unit for storing the data for distributed management, the arithmetic circuit unit, and the data input / output unit. Therefore, it is not necessary to exchange a large amount of data with the host computer during polishing, and data can be transferred via the input / output unit in the offline mode as needed.
The load on the host computer is reduced, the number of cables for transferring data from the holding head to the host computer is reduced, and since only the completion signal is exchanged, the design burden on the wafer polishing apparatus is reduced. Further, since it is not necessary to transmit the raw data signal through a long cable having a large number of cables, the configuration is resistant to noise. Further, since the utility and the like are controlled within the holding head, the control of the utility and the like becomes accurate.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION A preferred embodiment of a wafer polishing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a perspective view showing the overall structure of the wafer polishing apparatus 10. Wafer polishing apparatus 10 shown in FIG.
Is mainly composed of a platen 12 and a wafer holding head 14.

The platen 12 is formed in a disk shape, and a rotating shaft 16 is connected to the center of the lower surface of the platen 12. The platen 12 is
It rotates by driving a motor 18 connected to the rotary shaft 16. A polishing pad 20 is attached to the upper surface of the platen 12, and slurry is supplied onto the polishing pad 20 from a nozzle (not shown).

As shown in FIG. 2, the wafer holding head 14 is mainly composed of a carrier mount table 22 and a carrier plate 24. Carrier mount table 2
2 is formed in a disk shape, and the rotating shaft 22A shown in FIGS. 1 and 2 is connected to the center of the upper surface thereof. The carrier mount table 22 is rotated by driving a motor (not shown) connected to the rotary shaft 22A.

The carrier plate 24 is detachably attached to the lower surface of the carrier mount table 22. Further, when the carrier plate 24 is attached to the carrier mount table 22, the plurality of air flow paths 26, 28, 30 ... Formed in the carrier plate 24 become the plurality of air flow paths formed in the carrier mount table 22. 32, 34, 36 ...

.. extend from the carrier mount table 22 to the rotary shaft 22A and are connected to an air pump via a rotary joint (not shown) that connects the rotary shaft 22A and the fixed side. Has been done. When the air flow paths 32, 34, 36 are used as suction flow paths, a suction pump is connected instead of the air pump.

The air flow path 26 is formed by the carrier plate 24.
Are branched into a plurality of flow paths, and the air injection holes 26A, 26A ... Which are the respective outlets are evenly or unevenly distributed on a concentric circle centered on the central axis P of the carrier plate 24, and the carrier plate It is formed outside the lower surface of 24. Similarly, the air flow path 28 also has the carrier plate 2
4 are branched into a plurality of flow paths, and the air injection holes 28A, 28A ... Which are the respective outlets are evenly or unevenly distributed on a concentric circle centered on the central axis P of the carrier plate 24, and It is formed inside the lower surface of the plate 24. Similarly, the air flow path 30 is branched into a plurality of flow paths in the carrier plate 24, and the air injection holes 30A, 30A ...
Of the air injection holes 28A, 28A ... And the air injection holes 26 on the lower surface of the carrier plate 24.
A, 26A ...

On the other hand, the carrier mount table 22 has a regulator 3 as a control device for controlling the supply air.
8, 40, 42, ... and regulators 38, 40, 42
... and flowmeters 44, 44 corresponding to ...
Regulators 38, 4 based on measured data by
A microcomputer 46 for feedback controlling 0, 42, etc. is built in.

The regulator 38 is attached to the air flow path 32, and its opening / closing amount is controlled by the microcomputer 46.
As a result, the flow rate of the compressed air injected from the air injection holes 26A, 26A ... Is controlled. Also, the air flow path 3
The flow rate of the air supplied from 2 to the air flow path 26 is measured by the flow meter 44, and this measurement data is used by the microcomputer 4
It is output to 6. The microcomputer 46 feedback-controls the regulator 38 based on previously stored reference data, and controls the flow rate of the air to a flow rate corresponding to the reference data.

The regulator 40 is attached to the air flow path 34, and its opening / closing amount is controlled by the microcomputer 46.
As a result, the flow rate of the compressed air injected from the air injection holes 28A, 28A ... Is controlled. Also, the air flow path 3
The flow rate of the air supplied from 4 to the air flow path 28 is measured by another flow meter 44, and this measurement data is output to the microcomputer 46. The microcomputer 46 feedback-controls the regulator 40 based on the reference data stored in advance, and controls the flow rate of the air to a flow rate corresponding to the reference data.

The regulator 42 is attached to the air flow path 36, and its opening / closing amount is controlled by the microcomputer 46.
As a result, the flow rate of the compressed air injected from the air injection holes 30A, 30A ... Is controlled. Also, the air flow path 3
The flow rate of the air supplied from 6 to the air flow path 30 is measured by another flow meter 44, and this measurement data is output to the microcomputer 46. The microcomputer 46 feedback-controls the regulator 42 based on previously stored reference data, and controls the flow rate of the air to a flow rate corresponding to the reference data.

Further, the microcomputer 46 not only controls the regulator 40 and the regulator 42 so that the flow rate of the air corresponds to the reference data, but also processes the data relating to the processing state obtained from, for example, endpoint sensors, If the polishing rate is observed to be slower than expected, take action such as quickly increasing the flow rate to control the process.

In this way, the air injection holes 26A, 28A,
If the flow rate of the compressed air jetted from 30A is controlled, the pressing force of the wafer 50 facing the air jet holes 26A, 28A, and 30A against the polishing pad 20 can be controlled according to the part of the wafer 50. You can zone control the amount.

The signal cable 43 arranged from the carrier mount table 22 via the rotary shaft 22A is
It is connected to the host computer 52 of FIG. 3 via the rotary joint described above. The control program and reference data stored in the microcomputer 46 are created by the host computer 52 and then transmitted from the host computer 52 to the microcomputer 46 via the signal cable 43 in the idle mode. A data interface is provided for transferring a large amount of data.

Next, the operation of the wafer polishing apparatus 10 configured as described above will be described.

As shown in FIG. 3, the host computer 52 outputs a comprehensive control signal for starting the process to the microcomputer 46 of the holding head 14. Upon receiving the comprehensive signal, the microcomputer 46 makes full use of a plurality of control programs to start control. The contents of this control include opening / closing / output adjustment of the regulators 38, 40, 42, ... Which control the utility 55, and sucking up raw information of a sensor in another operation unit to calculate / store / process. As the sensor in another operation unit, the endpoint sensor 54 of FIG. 4 incorporated in the holding head 14 can be exemplified. The control program used here can be changed or modified as needed each time the program is executed.When the same change or modification is made a preset number of times, the learning function works and the change is automatically made. The modified program is registered as a regular control program and stored in the ROM.

When the wafer polishing state by the holding head 14 reaches the programmed processing result by the signal from the end point sensor 54 or when the time control reaches the set time, the microcomputer 46 as shown in FIG. Outputs a completion signal to the host computer 52. This completion signal is a signal for the overall control signal from the host computer 52.

In the microcomputer 46, the regulators 38, 4
All the information on the operating units such as 0 and 42 is managed. Therefore, an emergency situation can be sensed quickly, and an emergency stop or the like can be executed only for the operating unit. Therefore, the influence on other operating units can be extremely small. Naturally, the recovery time is also shortened. Further, in order to enable a large amount of data to be exchanged in an idle state where the device is not performing a process, a data input / output unit 56 is provided in the microcomputer 46, and various devised data transfer methods are adopted. There is.

FIG. 4 is a block diagram of the microcomputer 46. The microcomputer 46 includes a data input / output unit 56, a microprocessor unit (arithmetic circuit unit) 58, a ROM 6
0, RAM 62, signal input / output unit 64 and the like.

The microprocessor 58 calculates, controls,
ROM that stores and executes input / output programs
60 stores a data list such as an initial or improved control pattern of the process, and can write and rewrite data via a data interface.

The RAM 62 temporarily stores real-time data while the process is running, and transmits information to the ROM 60 as needed. The ROM 60 stores this information and retains this information even when the power is off.

The data input / output unit 56 exchanges data with the outside through a data interface, and
It functions as a buffer when exchanging measurement and control data in the holding head.

The signal input / output unit 64 is a buffer for exchanging control signals with the host computer 52.

Data input / output unit 56 and signal input / output unit 64
Are means for exchanging information of the microcomputer 46. The signal input / output unit 64 is always connected to the device in the apparatus such as the host computer 52, while the data input / output unit 56 is connected.
Is active only at fixed times. This is because a large amount of data is exchanged.

By thus incorporating the microcomputer 46 in the holding head, the maintenance of the entire wafer polishing apparatus becomes easy. In addition, data management such as data log becomes easy. Further, since a plurality of complicated host computer configurations are eliminated and a compact computing device is housed in the operation part of the apparatus, the floor area of the wafer polishing apparatus is reduced. Also,
Enables fine control of emergency situations and control of equipment during emergency situations. Further, since the error processing can be individually performed, the downtime is small and the time required for the restoration work of the device can be shortened.

In the present invention, the control device for controlling utilities such as air, vacuum and water and the microcomputer for distributed management are built in the holding head, but not limited to the internal organs, one or both of them is provided near the holding head. It may be configured to perform distributed management.

[0043]

As described above, according to the wafer polishing apparatus of the present invention, the holding head for holding the wafer, the control device for controlling the utilities such as air, vacuum, and water, the data storage, the calculation, and the input. It has output means and sends and receives signals to and from the outside, and it also has a built-in microcomputer that controls the control equipment, which enables decentralized management and control of air, vacuum, water, etc. ), Easy and accurate control is possible.

Further, the load on the host computer is reduced,
Maintenance is also easy. In addition, data management such as data log becomes easy. Further, since the complicated host computer configuration is eliminated and the utility box that centrally stores the control equipment for controlling the utility is unnecessary, the floor area of the wafer polishing apparatus is reduced.

Further, since a cable for transferring raw data from the control operation unit is not required and the number of air flow paths is reduced, the cost of expensive parts such as a rotary joint is reduced. In addition, since it is not necessary to transmit the raw data signal with a long cable, the configuration is resistant to noise.

Furthermore, since error processing can be performed individually,
There is little downtime, and the time required to restore the device can be shortened.

[Brief description of drawings]

FIG. 1 is an overall perspective view of a wafer polishing apparatus according to an embodiment.

2 is a schematic diagram of a holding head of the wafer polishing apparatus shown in FIG.

FIG. 3 is a block diagram showing a circuit configuration of the holding head shown in FIG.

FIG. 4 is a block diagram showing the configuration of the microcomputer shown in FIG.

FIG. 5 is a block diagram showing the configuration of a conventional wafer polishing apparatus.

[Explanation of symbols]

10 ... Wafer polishing apparatus, 12 ... Platen, 14 ... Wafer holding head, 20 ... Polishing pad, 22 ... Carrier mount table, 24 ... Carrier plate, 26, 2
8, 30, 32, 34, 36 ... Air flow paths, 38, 4
0, 42 ... Regulator (control device), 44 ... Flowmeter,
46 ... Microcomputer, 50 ... Wafer, 52 ... Host computer, 54 ... Endpoint sensor, 55 ... Utility, 56 ... Data input / output section, 58 ... Microprocessor (arithmetic circuit section), 60 ... ROM (storage section), 62 ...
RAM (storage unit), 64 ... Signal input / output unit

Claims (6)

[Claims] 1. A wafer polishing apparatus for holding a wafer by a holding head, and pressing the wafer against a polishing pad via the holding head to polish the wafer, wherein the holding head includes an air for pressing the wafer against the polishing pad. , A control device for controlling utilities such as vacuum, water, etc., and a microcomputer for controlling the control device while transmitting / receiving signals to / from the outside, including data storage, calculation, and input / output means are incorporated. Wafer polishing machine. 2. The wafer polishing apparatus has a host computer installed outside the holding head and is connected to the utility, wherein the microcomputer communicates with the host computer and executes the utility. The wafer polishing apparatus according to claim 1, wherein the wafer polishing apparatus is controlled at a use end. 3. The microcomputer includes a signal input / output unit connected to the host computer via a signal interface; a data input / output unit connected to the host computer via a data interface; A storage unit that stores a plurality of control programs or signals and data for controlling the control device input via the signal input / output unit and the data input / output unit, and calculates the data stored in the storage unit. The wafer polishing apparatus according to claim 2, further comprising: an arithmetic circuit unit that outputs a control signal to the control device. 4. The host computer outputs a process start signal to the microcomputer contained in the holding head, and the microcomputer outputs a plurality of control programs stored in the storage unit based on the process start signal. 4. The wafer polishing apparatus according to claim 2, wherein the controller is used to control the control device, and when the process is completed, a process completion signal is output to the host computer. 5. The control program can be changed or modified each time the program is executed, and when the same change or modification is performed a preset number of times,
The wafer polishing apparatus according to claim 4, wherein the changed or modified control program is registered as a regular control program. 6. The wafer polishing apparatus according to claim 4, wherein when an abnormality occurs in the holding head, the abnormality detection signal can be output from the microcomputer.