JP2005311063A - Cmp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a CMP (chemical mechanical polishing) device which polishes, based on the detection of a conditional changes during polishing work, by catching the changes in the abrasive which occurs during the polishing work. <P>SOLUTION: The CMP device (polishing unit 1 or the like) applies polishing work on a wafer 5 through the abrasive supplied between a polishing pad 3 and the wafer 5, by turning relatively the polishing pad 3 and the wafer 5. The device is constituted so as to have an abrasive supplier 11 for supplying the abrasive employed for the polishing work, a viscosity detector 14 for measuring the viscosity and the amount of shearing of the abrasive supplied by the abrasive supplier 11, and a condition-monitoring unit 16 for detecting the conditional changes of the abrasive during the polishing work, from the detected viscosity and amount of shearing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to ultra-precision processing of devices in a wafer manufacturing apparatus, and more particularly to a CMP apparatus that detects a change in the state of an abrasive in chemical mechanical polishing using an abrasive and performs polishing based on the change in the state.

  The polishing apparatus is used for polishing the surface of a member to be polished such as a glass, a quartz substrate, or a semiconductor wafer. For example, a chemical mechanical polishing method (CMP method) for a metal film on an interlayer insulating film in a semiconductor wafer is used. A polishing apparatus (referred to as a “CMP apparatus”) that precisely performs polishing is known. In order to polish the surface of the member to be polished by this CMP apparatus, the polishing pad is brought into close contact with the surface of the member to be polished, and an abrasive is supplied between the polishing pad and the surface of the member to be polished to This is performed by rotating the polishing member. For this reason, the polishing accuracy of the member to be polished needs to capture the state of the polishing agent being polished and reflect it in the polishing operation. However, as described above, depending on the processing principle and structure of the CMP apparatus, It is very difficult to capture and observe the state of the abrasive.

  For this reason, in the conventional CMP apparatus, the target value is determined based on the method of observing the state of the semiconductor wafer being polished by the position detector and the end point detector and feeding back to the processing control, or the result of polishing of the member to be polished. It is common to review the polishing conditions and polishing pad specifications as the processing conditions for the next polishing, and review the processing conditions such as pressurization, number of rotations, operating time, rotation direction, and oscillation. Met. Also known is a method for improving the processing accuracy in a CMP apparatus using this abrasive by observing the chemical and physical state of the abrasive before being used in the polishing operation and controlling the state of the abrasive. (For example, refer to Patent Document 1).

JP 2000-308957 A

  However, there has been a problem that it is difficult to establish chemical mechanical polishing accuracy because there is no technique to compensate for the inability to directly capture the change in state of the abrasive during polishing. For example, since no method has been developed to detect particle chemistry and physical property change characteristics in abrasive particle changes during polishing, stick-slip operation (chemical mechanical polishing using abrasives is performed, but instantaneously In the semiconductor wafer and polishing pad to be polished, it is difficult to grasp the polishing operation of the polishing processing part, including the operation in which the surface directly contacts without passing through the abrasive and the polishing state is repeated) It was hindering improvement.

  The present invention has been made in view of such a problem, and provides a CMP apparatus that performs polishing based on detecting a change in state during polishing processing by detecting a change in abrasive generated during polishing processing. For the purpose.

  In order to solve the above problems, a CMP apparatus according to the first aspect of the present invention (for example, the polishing unit 1 in the embodiment) rotates a polishing pad and a member to be polished (for example, the wafer 5 in the embodiment), Abrasive supplying means for polishing a member to be polished with an abrasive supplied between a polishing pad and a member to be polished, and supplying an abrasive used for polishing (for example, the abrasive in the embodiment) A supply unit 11), a detection unit (for example, a viscosity detector 14 in the embodiment) for measuring the viscosity and shear amount of the abrasive supplied by the abrasive supply unit, and polishing processing from the detected viscosity and shear amount And a state change detecting means (for example, the state monitoring unit 16 in the embodiment) for detecting the state change.

  The CMP apparatus according to the second aspect of the present invention rotates the polishing pad and the member to be polished, and polishes the member to be polished with the abrasive supplied between the polishing pad and the member to be polished. Abrasive supply means for supplying the abrasive used for polishing, a detection means for measuring the viscosity and shear amount of the abrasive supplied by the abrasive supply means, and polishing from the detected viscosity and shear amount And a state change detecting means for detecting a change in state during polishing by detecting a change in the characteristics of the agent or a change in the state of the abrasive.

  In the CMP apparatuses according to the first and second aspects of the present invention, it is preferable that the detection means is configured to detect the viscosity index value, shear rate, viscosity, shear stress, and rotational speed of the abrasive.

  Such a CMP apparatus has an abrasive compounding and supplying apparatus that mixes and supplies an abrasive, and the state detection means optimizes the compounding of the abrasive based on the detected state change, and the optimized compounding It is preferable that the abrasive is supplied by an abrasive compounding / supplying device.

  In addition, such a CMP apparatus has a drive device (for example, the polishing head drive control device 20 in the embodiment) that rotates, pressurizes, and swings the polishing pad, and the state change detection means detects the state change detected. Based on this, it is preferable that the driving device controls the rotation, pressurization and swinging of the polishing pad. And this drive device is a drive part (for example, servomotor 21 in the embodiment) for rotating the polishing pad, a drive control part for controlling this drive part, and a pressure for changing the pressure of the polishing pad against the member to be polished. A mechanism unit, a swing mechanism unit that swings the polishing pad, and a drive command unit (for example, servo control unit 23 in the embodiment) that issues a speed command to the drive control unit based on a position command to the drive unit. The state change detecting means outputs a position command, pressure command and swing command to the drive command unit based on the status change, and outputs a speed command to the drive control unit to rotate, pressurize and swing the polishing pad. Is preferably configured to control.

  Further, in such a CMP apparatus, the state conversion detecting means obtains the initial deviation amount of the abrasive amount of the polishing agent, confirms the start of the state change based on the initial deviation amount, and then determines the polishing condition from the subsequent shear rate and shear stress. It is preferable to be configured to arbitrarily start setting.

  In addition, the state change detection means obtains a minute change value of the viscosity from the viscosity, shear rate and shear stress, obtains a shear stress from the viscosity, confirms the state change of the abrasive, and determines the concentration of the abrasive from the viscosity. Accordingly, it is preferable that an abrasive blending command is output to the abrasive blending supply device, and a position command, a speed command, a pressure command, and a swing command are output to the driving device.

  In addition, the state change detection means obtains the yield value of the abrasive according to the Gapson flow equation from the shear stress and shear rate, monitors the particle structure destruction of the abrasive, and sends the abrasive flow control command to the abrasive compounding supply device. And a position command, a speed command, a pressure command, and a swing command are preferably output to the drive device.

  In addition, the state change detection means is configured to obtain the hysteresis of the abrasive from the viscosity and the amount of shear, to confirm the particle structure destruction of the abrasive, and to output an abrasive selection command to the abrasive compounding and supplying apparatus. Is preferred.

  Further, such a CMP apparatus has temperature detection means (for example, a liquid temperature detection point 9 in the embodiment) for detecting the temperature of the abrasive immediately before being supplied to the polishing process, It has a temperature adjusting means (for example, the cooling control mechanism 8 in the embodiment) for adjusting the temperature of the abrasive to be supplied, and the state change detecting means obtains the temperature of the abrasive being processed from the viscosity, and is detected by the temperature detecting means. It is preferable that a temperature command is output to the abrasive compounding / supplying device from the measured temperature and the temperature during processing, and the temperature of the polishing agent being processed is controlled to a predetermined value by the temperature adjusting means.

  At this time, the abrasive compounding / supplying apparatus includes a compounding unit for compounding the abrasive (for example, the abrasive compounding unit 44 in the embodiment) and a supply control unit for controlling the supply of the abrasive (for example, the emergency input switching in the embodiment). 49), and the state change detecting means is configured to output a temperature command based on the temperature detected by the temperature detecting means, the temperature of the abrasive in the blending means, and the temperature of the abrasive in the supply control means. It is preferable.

  When the CMP apparatus according to the present invention is configured as described above, the viscosity and shear amount of the abrasive used in the polishing process supplied by the abrasive supply means, in particular, the viscosity index value, shear rate, viscosity, shear stress. By detecting the rotation speed, it is possible to detect a change in state during the polishing process by detecting a change in the characteristics of the abrasive or a change in the state of the abrasive, which has been difficult to develop in the conventional apparatus.

  Further, the composition of the abrasive is optimized and supplied from the viscosity and shear amount detected in this way, and the structure is configured to control the rotation, pressurization and oscillation of the polishing head (polishing pad). Therefore, the CMP apparatus can be controlled in accordance with the detected characteristic change or state change of the abrasive, and the processing accuracy can be improved. In particular, in the rotation control of the polishing pad, not only the position command is output to the drive command unit but also the speed command is output to the drive control unit, so that the state of the polishing agent can be quickly controlled by the rotation of the polishing pad. In addition, the composition of the abrasive and the rotation, pressure and oscillation of the polishing head can be controlled using the initial deviation, shear stress and hysteresis from the viscosity and shear of the abrasive. And the processing accuracy can be further improved. Further, the processing accuracy can be improved by controlling the temperature of the abrasive supplied to the polishing process.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. First, a CMP apparatus will be described with reference to FIG. The CMP apparatus includes a cassette index unit, a wafer cleaning unit, a polishing unit, and the like according to the polishing process. In this embodiment, only the polishing unit will be described. The polishing unit 1 of this CMP apparatus includes a polishing head 2, a polishing pad 3, and a wafer chuck 4.

  The wafer chuck 4 is configured to suck and hold the wafer 5 from the back surface. The wafer chuck 4 is rotatably supported in a horizontal plane and is rotated by driving means such as an electric motor (not shown).

  The polishing head 2 is attached to a swinging end portion of a polishing arm configured to be swingable in the horizontal direction with respect to the wafer chuck 4 and to be vertically movable in the vertical direction. And a polishing pad 3 for polishing the surface of the wafer 5 flatly. The polishing pad 3 is replaceable with respect to the polishing head 2 and is held on the polishing head 2 by vacuum suction through a plate. The polishing head 2 is driven by a rotation driving mechanism (a polishing head drive control device 20 shown in FIG. 2), which will be described later, disposed in the polishing arm, and is attached so as to freely rotate at high speed in a horizontal plane. Further, the polishing arm is provided with a pressurizing mechanism that swings the polishing head 2 up and down to adjust the pressure of the polishing pad 3 against the wafer 5 and a swinging mechanism that swings the polishing head 2 (pressurization). The mechanism and swing mechanism will be described later). For this reason, when the polishing head 2 is rotationally driven in a direction opposite to the rotation direction of the wafer chuck 4 described above, the polishing pad 3 and the wafer 5 are rotated relative to each other, and are moved up and down to be pressurized, and the polishing arm is polished. The surface of the wafer 5 is polished by swinging the pad 3 (polishing head 2).

  In polishing the wafer 5, the chemical mechanical polishing belt 6 formed between the upper surface of the wafer 5 and the lower surface of the polishing pad 3 is supplied from an abrasive compounding supply device 40 (shown in FIG. 3) described later. An abrasive is supplied through the abrasive inlet 7 and used for polishing the wafer 5. That is, a chemical mechanical polishing process operation is performed on the surface of the wafer 5 using the polishing pad 3 by the polishing agent guided by the rotation, pressurization, and swinging of the polishing head 2.

  The polishing agent supplied from the polishing agent inlet 7 is adjusted to a predetermined temperature by a cooling / heating control mechanism 8 to be described later and supplied to the chemical mechanical polishing zone 6, but is supplied to the chemical mechanical polishing zone 6. The temperature of the polishing agent is detected at the liquid temperature detection point 9 immediately before the operation. Further, an end point detector (not shown) is provided above the wafer 5 sucked and held by the wafer chuck 4 so that the wafer 5 being polished is observed from above and reflected light of the light irradiated on the surface of the wafer 5 is reflected. The progress of polishing is monitored by measuring.

  Now, the state change detection mechanism 10 that detects the state change of the abrasive in the chemical mechanical polishing zone 6 will be described. As described above, in polishing the wafer 5, since the polishing head 2 and the wafer chuck 4 are rotated, the abrasive in the chemical mechanical polishing zone 6 is scattered to the side by the principle of centrifugal separation. At least one abrasive supply device 11 is provided around the wafer chuck 4 (a semicircular circle of the chemical mechanical polishing belt 6) (three locations in FIG. 1), the rotation of the polishing pad 3, Along with the rocking and pressurization, the polishing agent supply device 11 receives a polished abrasive in accordance with the rotation speed, pressurization and polishing time, and can be optimally supplied to the viscosity detector 14 described later. ing.

  Since the composition of the polished abrasive supplied by the abrasive supply device 11 changes when pressure is applied, it falls down through the collection tube 12a under its own weight and is collected in the abrasive collection box 13. . This polished polishing agent includes a surface exfoliation product of the wafer 5 and a section of the polishing pad 3, and a deterioration product due to aggregation, absorption, and dispersion of the polishing agent. Therefore, in the abrasive collection box 13, only the abrasive from which these deteriorated materials and the like have been settled and settled is dropped through the collection tube 12 b by its own weight and sent to the viscosity detector 14.

  The viscosity detector 14 is configured to perform a viscosity analysis of the abrasive flowing in from the collection tube 12b and output the viscosity and shear amount of the abrasive as a viscosity. If this viscosity detector 14 is, for example, a top-type viscosity detector, a test object (in the case of this embodiment, the above-mentioned abrasive) is put into a detection unit having a rotating top, and the top and the test object are detected. The frictional force is converted into torque, converted into a current signal, and output. The viscosity amount output from the viscosity detector 14 includes the viscosity index value (the index value indicating the viscosity in 100%), the shear rate, the viscosity, the shear stress, and the rotation speed of the piece. This amount of viscosity is transmitted to the state monitoring unit 16 by the transducer 15.

  The viscosity detector 14 is provided with a calibration abrasive inlet 18 so that the detected value of the viscosity detector 14 can be calibrated. Further, the viscosity detector 14 can be cleaned with pure water by the detector purification mechanism 19, and the abrasive whose viscosity has been detected, the calibration abrasive, and the pure water used for cleaning are discharged by the discharge valve 17. It is configured to be discharged to the outside.

  The state monitoring unit 16 analyzes each characteristic of the initial deviation amount, shear stress, viscosity, shear rate, shear stress, and hysteresis from the viscosity amount (viscosity and shear amount) detected as described above to determine the state of the abrasive. Monitor changes. The hysteresis is obtained from the viscosity index value obtained by the viscosity detector 14. When this state monitoring unit 16 detects a change in the state of the abrasive, an algorithm process is performed to control the driving of the polishing head 2.

  Here, a control system of a servo motor that rotationally drives the polishing head 2 will be described with reference to FIG. The polishing head drive control device 20 includes a servo motor 21 that drives the polishing head 2, an operation console 22 that performs setting of polishing processing including pressurization, rotation speed, rotation direction, rotation time, and the like, and polishing set by the operation console 22. A servo control unit 23 that outputs a speed command to the servomotor 21 according to the set value of machining, a drive control unit 24 that drives the servomotor 21 based on the speed command, and a position of the servomotor 21 that is detected and fed back to the drive control unit 24 And a control circuit 26 for confirming the difference between the current value and the target value in the time domain.

  The speed command output from the servo control unit 23 is added with position information by the position control unit 27 of the drive control unit 24, converted into a current command value by the speed control unit 28, and the current command value is converted by the drive current control unit 29. After being converted into a current value, the servo amplifier 21 is driven by the power amplifier unit 30. A current detector 31 is provided between the power amplifier unit 30 and the servo motor 21, and the current value detected by the current detector 31 is fed back to the current control unit 29. Has been. The position information detected by the position detector 25 is differentiated by the position control unit 28 and fed back to the speed control unit 29.

  As described above, the servo control unit 23 controls the servo motor 21 on the basis of the set value from the console 22, and control for the state change of the abrasive detected by the state monitoring unit 16 is performed in this control. Added. That is, the state monitoring unit 16 performs algorithm processing on the viscosity and the amount of shear as a speed command signal for controlling the rotation of the polishing head 2 and adds it as a current signal to the current control unit 29 of the drive control unit 24 in FIG. At the same time, the state monitoring unit 16 outputs a position command signal to the servo control unit 23 in order to respond to the response control of the polishing head 2. Here, if the state change of the abrasive is output only to the servo control unit 23 and the servo motor 21 is controlled, a secondary delay occurs and the state change of the abrasive cannot be appropriately reflected in the control of the servo motor 21. At the same time, the servo motor 21 is configured to be added to the current control unit 29 of the drive control unit 24 as a current command value. As described above, the state monitoring unit 16 adds the correction amount corresponding to the state change of the abrasive to the set value of the console 22, so that the unstable polishing process generated in the chemical mechanical polishing band 6 is performed. Can be incorporated into the control system of the polishing head 2.

  On the other hand, there is a control system using the signal of the state monitoring unit 16 in the pressurizing mechanism 59 and the swinging mechanism 63 shown in FIGS. 3 and 4, and the state change signal at the time of polishing is used by a system including them. Then, polishing is performed with optimized operations of rotation, pressurization, and swinging.

  FIG. 3 shows the pressurizing mechanism 59 in this embodiment. The pressurizing mechanism 59 is mounted on the head mechanism of the CMP apparatus, and includes a D / A (digital / analog) converter 60, an electropneumatic regulator 61, and a pressure sensor 62. A state change during polishing is transmitted as a pressure command signal to the servo control unit 23 by the state monitoring unit 16, and the height position of the polishing pad 3 is determined based on the command value, and a pressure value for the wafer 5 is determined. The pressurization of the polishing pad 3 against the wafer 5 is controlled by the command signal from the servo control unit 23 being transmitted to the electropneumatic regulator 61 via the D / A converter 60 and the polishing head 2 being moved up and down. . Note that the pressure value is monitored by the pressure sensor 62. In addition, the electropneumatic regulator 61 has an origin return (return reference) function and a limiter function to limit the upper and lower drive strokes, and starts at the origin position when the power is turned on. Move the up / down stroke and decide the pressure value. This stroke command signal is optimally controlled in cooperation with a swing mechanism 63, which will be described later, in the servo control unit 23.

  FIG. 4 shows the swing mechanism 63 in this embodiment. The swing mechanism 63 includes a control amplifier 64, a detector 65, and a motor 66. A swing command signal is received by the control amplifier 64 from the state monitoring unit 16 through the servo control unit 23 and the swing range set by the motor 66 is swung at a specified speed. In order to confirm the position in the swing section and achieve a constant operation speed (rate), a detector 65 is provided to perform feedback and monitoring of the above operation. When the power is turned on, the origin position monitored by the detector 65 is recognized, and then the swing range of the motor 66 is controlled through the control amplifier 64. The range of the swing stroke limit is a control range recognized by the detector 65.

  In the above embodiment, the case where the state monitoring unit 16 rotates, pressurizes and swings the polishing head 2 to control the processing according to the state change during the polishing processing has been described. The unit 16 can be configured to perform rotation control or pressure control of the wafer chuck 4, or to control both the polishing head 2 and the wafer chuck 4.

  The state change of the abrasive detected by the state change monitoring unit 16 is also used for selection and supply control of the abrasive used for the polishing process. Next, an abrasive blending and supplying apparatus 40 that supplies an abrasive to the polishing unit 1 according to the present embodiment will be described with reference to FIG. The abrasive blending and supplying apparatus 40 includes an abrasive blending tank 41, a pure water tank 42, an additive tank 43, and an abrasive blending unit 44 for blending abrasives, pure water and additives supplied from these tanks 41 to 43. , And a supply pipe 45 that supplies the blended abrasive to the abrasive inlet 7 of the polishing section 1. The abrasive supply tank 41 can be provided according to the type of abrasive used for the polishing process, and FIG. 5 shows a case where tanks 41a and 41b for two types of abrasive are provided. .

  In addition, the abrasive blending and supplying apparatus 40 has a blending carburetor 48 that adjusts the amount of pure water supplied from the auxiliary slurry tank 46, the pure water tank 47 for blending, and the pure water tank 47 for blending in the vicinity of the polishing unit 1. And an emergency loading mechanism 50 comprising an emergency loading switch 49. The polishing agent and pure water supplied from the polishing agent auxiliary tank 46 and the pure water tank 47 for blending are switched by an emergency charging switch 49 provided in the vicinity of the polishing unit 1 of the supply pipe 45 to flow the polishing agent. Supplied to the inlet 7.

  The abrasive blending and supplying apparatus 40 is controlled by an abrasive supply controller 51, and the blending control of the abrasive is performed by controlling the tanks 41 to 43, 46, and 47 and the blending carburetor 48 with control lines 52 and 53. . In a normal polishing process, a predetermined amount is supplied from the abrasive tank 41 (41 a, 41 b), the pure water tank 42 and the additive tank 43, mixed by the abrasive compounding unit 44 and supplied to the abrasive inlet 7. However, when response supply is difficult with this supply mechanism, the emergency charging mechanism 50 is operated for the purpose of emergency supply. Then, the abrasive and pure water are supplied to the abrasive inflow port 7 through the emergency charging switch 49.

  The cooling control mechanism 8 described above includes a cooling unit 8a that cools the abrasive that passes therethrough and a heating unit 8b that heats the abrasive, and includes a Peltier unit 54 and a spiral heater unit 55, respectively. Then, the temperature controller 56 of the abrasive distribution controller 51 controls the Peltier unit 54 and the spiral heater unit 55 with the control lines 57 and 58, and sets the abrasive passing through the cooling control mechanism 8 to a desired temperature. It can be supplied to the polishing band 6. The abrasive compounding / supplying device 40 receives a command signal (a compounding command, a flow rate control command, a selection command, and a temperature command, which will be described later) from the state change monitoring unit 16 by the abrasive distribution controller 51, Selection, blending and temperature control are performed.

  In the CMP apparatus according to the present embodiment, at the start of the polishing operation, polishing is performed using a value selected from the manufacturer's specification values and experience values for selecting and blending the abrasive. However, the response of the abrasive supply to the CMP apparatus has an apparatus function that can secure a direct feed from the abrasive compounding / supplying apparatus 40 to the polishing processing position in 1 second, so that it does not affect the state change during the polishing process. , Allowing re-selection and re-blending of abrasives.

  Then, based on the state change of the abrasive, the state change monitoring unit 16 analyzes the characteristics of the initial deviation amount, shear stress, viscosity, shear rate, shear stress, and hysteresis from the polishing head drive control device 20 and the abrasive blend supply device 40. A method for outputting a control command will be described.

  First, the viscosity change value of the abrasive is constantly monitored from the initial deviation value of the amount of deviation of the abrasive, and by checking the progress of this initial deviation amount, the line level “normal” and “state change start” are determined. I do. Based on the determination result, the polishing conditions of the CMP apparatus are arbitrarily set from the subsequent shear rate and shear stress.

  The start of state change is confirmed by grasping the minute change value of viscosity from the viscosity value, shear rate value, and shear stress, and the trend of shear stress value from the viscosity value. In addition, from the relationship between the linearity between the viscosity and the concentration of the abrasive, a characteristic that can confirm the increase in the concentration by increasing the viscosity is used. Then, by processing these values with an algorithm, a blending command for the abrasive is output to the abrasive distribution controller 51, a speed command is output to the drive control unit 24, and a position command, a pressure command and a swing command are output to the servo control unit. To 23. When the zeta potential of the abrasive becomes small, the attractive force between particles becomes large and the agglomeration phenomenon easily occurs. Therefore, it is necessary to control the pH value to be adjusted so as to obtain a zeta potential of a certain value or more. Therefore, it has been necessary to install a pH meter in the conventional CMP apparatus. However, since the concentration can be obtained from the viscosity value in this way, it is not necessary to separately install a pH meter in the CMP apparatus, and the time required for the measurement of the pH meter can be shortened, so that the response of the system is improved. Is planned.

  From the shear stress and the shear rate, the yield value of the abrasive according to the Gapson flow equation is grasped, the particle structure destruction of the abrasive is monitored, and the flow rate control command of the abrasive is output to the abrasive distribution controller 51. The command, position command, pressure command and swing command are output to the drive control unit 24 and the servo control unit 23.

  Further, the hysteresis is grasped from the viscosity index value, the particle structure destruction of the abrasive is confirmed, and an abrasive selection command is output to the abrasive delivery controller 51 to select the abrasive.

  Further, even when the temperature of the abrasive is increased, the fact that the viscosity and the temperature characteristic have a linear relationship is utilized, and a temperature command is output to the abrasive distribution controller 51 to set the temperature of the abrasive in the chemical mechanical polishing zone 6. Control. In the present embodiment, in addition to the temperature measurement at the liquid temperature detection point 9 described above, three points are measured by the abrasive blending unit 44 and the emergency charging switch 49, and the temperature control is performed by the cooling control mechanism 8. It is configured to be

  As described above, according to the CMP apparatus according to the present embodiment, the fluidity and chemical property change characteristics of the abrasive, which was difficult with the conventional apparatus, are determined, and the control system is polished by detecting the state change during the polishing process. Processing state variable feedback can be achieved. Therefore, it was possible to realize a method that can control the amount of change in the state of an unstable element for which the equation of state cannot be established, which could not be achieved by the development technology up to now.

  As a result, it is possible to establish deterioration management of the abrasive, and to review the selection of the optimum abrasive and to review the blending ratio in detecting the state change during the polishing process. Further, it is possible to determine the normality of the abrasive agent and the start of state change from the detection of the initial deviation amount value of the abrasive, and control commands to the polishing head drive control device 20 and the abrasive compounding / supplying device 40 from the viscosity and shear amount. Can be output. Then, the polishing pad specification suitable for the detection and evaluation function of the state change of the abrasive is established, and the dress structure is established accordingly, so that the processing accuracy in the CMP apparatus according to the present embodiment can be improved.

It is a block diagram which shows the grinding | polishing part and state change detection mechanism of the CMP apparatus which concern on this invention. It is a block diagram which shows the polishing head drive control apparatus of the CMP apparatus which concerns on this invention. It is a block diagram which shows the pressurization mechanism part of the CMP apparatus which concerns on this invention. It is a block diagram which shows the rocking | fluctuation mechanism part of the CMP apparatus which concerns on this invention. It is a block diagram which shows the abrasive | polishing agent compounding supply apparatus of the CMP apparatus which concerns on this invention.

Explanation of symbols

1 Polishing unit (CMP equipment)
3 Polishing pad 5 Wafer (member to be polished)
8 Cooling control mechanism (temperature adjustment means)
9 Liquid temperature detection point (temperature detection means)
11 Abrasive Supply Unit (Abrasive Supply Unit)
14 Viscosity detector (detection means)
16 State monitoring unit (state change detection means)
20 Polishing head drive control device (drive device)
21 Servo motor (drive unit)
23 Servo control unit (drive command section)
24 Drive control unit 40 Abrasive compound supply device 59 Pressure mechanism unit 63 Oscillation mechanism unit

Claims (12)

In a CMP apparatus that rotates a polishing pad and a member to be polished, and polishes the member to be polished with an abrasive supplied between the polishing pad and the member to be polished.
Abrasive supply means for supplying the abrasive used in the polishing process;
Detection means for measuring the viscosity and shear amount of the abrasive supplied by the abrasive supply means;
A CMP apparatus comprising: a state change detecting means for detecting a state change during the polishing process from the detected viscosity and the amount of shear. In a CMP apparatus that rotates a polishing pad and a member to be polished, and polishes the member to be polished with an abrasive supplied between the polishing pad and the member to be polished.
Abrasive supply means for supplying the abrasive used in the polishing process;
Detection means for measuring the viscosity and shear amount of the abrasive supplied by the abrasive supply means;
State change detecting means for detecting a state change during the polishing process by detecting a change in characteristics of the abrasive or a change in state of the abrasive from the detected viscosity and the amount of shear. CMP apparatus.   The CMP apparatus according to claim 1, wherein the detection unit is configured to detect a viscosity index value, a shear rate, a viscosity, a shear stress, and a rotation speed of the abrasive. It has an abrasive blending and supplying device that mixes and supplies abrasives,
The state change detecting means is configured to optimize the composition of the abrasive based on the detected state change and to supply the optimized composition with the abrasive composition supply device. The CMP apparatus according to claim 1, wherein the CMP apparatus is characterized. A driving device for rotating, pressing and swinging the polishing pad;
The said state change detection means is comprised so that rotation, pressurization, and rocking | fluctuation of the said polishing pad may be controlled by the said drive device based on the detected said state conversion. A CMP apparatus according to claim 1. The drive device rotates the polishing pad, a drive control unit that controls the drive unit, a pressurizing mechanism that changes the pressure of the polishing pad against the member to be polished, and swings the polishing pad Based on a position command to the drive unit, a speed command is output to the drive control unit, a pressure command is output to the pressurizing mechanism unit, and a swing command is sent to the swing mechanism unit And a drive command unit that outputs
The state change detection means outputs the position command, the pressure command and the swing command to the drive command unit based on the state change, and outputs the speed command to the drive control unit to output the polishing command. The CMP apparatus according to claim 5, wherein the CMP apparatus is configured to control rotation, pressurization, and swinging of the apparatus.   The state change detecting means obtains an initial deviation amount of the shear amount of the abrasive, confirms the start of state change based on the initial deviation amount, and arbitrarily sets polishing conditions based on the subsequent shear rate and shear stress. The CMP apparatus according to claim 1, wherein the CMP apparatus is configured to start.   The state change detecting means obtains a minute change value of the viscosity from the viscosity, the shear rate and the shear stress, obtains a shear stress from the viscosity, confirms a state change of the abrasive, and the viscosity The concentration of the abrasive is obtained from the output, and the abrasive compounding command is output to the abrasive compounding and supplying device, and the position command, the speed command, the pressure command, and the swing command are output to the driving device. The CMP apparatus according to claim 6, wherein the CMP apparatus is configured to do so.   The state change detecting means obtains a yield value of the abrasive according to the Gapson flow equation from the shear stress and the shear rate, monitors a particle structure destruction of the abrasive, and sends the polishing composition to the abrasive compounding apparatus. 9. The apparatus according to claim 6, wherein the flow rate control command of the agent is output and the position command, the speed command, the pressure command, and the swing command are output to the driving device. A CMP apparatus according to claim 1.   The state change detecting means obtains the hysteresis of the abrasive from the viscosity and the amount of shear, confirms the particle structure destruction of the abrasive, and outputs an abrasive selection command to the abrasive blending and supplying apparatus. 10. The CMP apparatus according to claim 4, wherein the CMP apparatus is configured. Temperature detecting means for detecting the temperature of the abrasive immediately before being supplied to the polishing process;
The abrasive blending and supplying apparatus has temperature adjusting means for adjusting the temperature of the abrasive to be supplied;
The state change detection means obtains the temperature of the abrasive during the processing from the viscosity,
A temperature command is output to the abrasive compounding / supplying device from the temperature detected by the temperature detecting means and the temperature during the processing, and the temperature of the abrasive being processed is set to a predetermined temperature by the temperature adjusting means. The CMP apparatus according to claim 4, wherein the CMP apparatus is configured to be controlled to a value. The abrasive blending and supplying apparatus has a blending unit that blends an abrasive and a supply control unit that controls the supply of the abrasive,
The state change detecting means is configured to output the temperature command based on the temperature detected by the temperature detecting means, the temperature of the abrasive in the blending means, and the temperature of the abrasive in the supply control means. The CMP apparatus according to claim 11, wherein

Images