Electrostatic adsorption device

Abstract

The utility model relates to the technical field of semiconductor integrated circuit manufacturing, in particular to an electrostatic adsorption device. The electrostatic adsorption device comprises an electrostatic chuck, the electrostatic chuck comprises a base body and a conductive film located on the upper surface of the base body, a high-voltage power supply is arranged below the electrostatic chuck, and the high-voltage power supply is electrically connected with the conductive film; an ejector pin channel is also formed in the electrostatic chuck, and the ejector pin channel longitudinally penetrates through the base body and the conductive film; the ejector pin can move up and down in the ejector pin channel; the ejector pin driving device is connected with the ejector pin and is used for driving the ejector pin to do lifting motion; and the electrostatic chuck is provided with a sensor for detecting the movement of the ejector pin. The electrostatic adsorption device can solve the problems that the wafer is difficult to jack up by the ejector pin due to residual charges between the wafer and the sucker in the related technology, and the wafer is easy to deviate if the wafer is forcibly jacked up by increasing the driving force, so that the risk of wafer breakage exists.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor integrated circuit manufacturing, and in particular to an electrostatic adsorption device. Background Art

[0002] Wafer back side processing technology is widely used in the field of semiconductor integrated circuit technology. The mainstream processes required to produce such devices include wafer back side thinning process, ion implantation process and thermal annealing process.

[0003] When performing the wafer backside processing process, an electrostatic adsorption device is required. The electrostatic adsorption device uses electrostatic attraction to adsorb the wafer to perform process processing on the wafer. Usually, the electrostatic adsorption device includes an electrostatic chuck, a DC power supply, a wafer lifting pin, and a mechanical drive device for driving the wafer lifting pin to rise and fall. After the DC power supply applies voltage, an electrostatic attraction is formed between the charge formed on the surface of the wafer and the charge generated on the surface of the electrostatic chuck. With the help of this attraction, the wafer can be adsorbed on the chuck for process operation. After the process operation is completed, the power supply is disconnected to release the static electricity and eliminate the electrostatic attraction. Then the pin rises and the wafer is retrieved by the robotic arm.

[0004] However, in the actual production process, it was found that the above-mentioned power-off process cannot completely eliminate the charge between the wafer and the suction cup. The residual charge between the wafer and the suction cup will make it difficult for the ejector pin to lift the wafer. If the driving force is increased to forcibly lift the wafer, it will easily cause the wafer position to shift, and there is a risk of wafer breakage. Summary of the invention

[0005] The present application provides an electrostatic adsorption device that can solve the problem in related technologies that the residual charge between the wafer and the suction cup makes it difficult for the ejector pin to lift the wafer. If the driving force is increased to forcibly lift the wafer, it is easy to cause the wafer position to shift, and there is a risk of wafer breakage.

[0006] In order to solve the technical problem in the background technology, the present application provides an electrostatic adsorption device, which includes:

[0007] An electrostatic chuck, the electrostatic chuck comprising a substrate and a conductive film on the upper surface of the substrate, a high voltage power supply is provided under the electrostatic chuck, and the high voltage power supply is electrically connected to the conductive film; an ejector pin channel is also formed in the electrostatic chuck, and the ejector pin channel longitudinally penetrates the substrate and the conductive film;

[0008] An ejector pin, the ejector pin being capable of moving up and down in the ejector pin channel;

[0009] An ejector drive device, the ejector drive device is connected to the ejector and is used to drive the ejector to perform lifting motion;

[0010] The electrostatic chuck is provided with a sensor for detecting the movement of the ejector pin.

[0011] Optionally, the ejector channel and the ejector are provided with corresponding displacement sensors, and the displacement sensors are sensors for detecting the movement of the ejector.

[0012] Optionally, a displacement signal receiving device is provided on the inner wall of the ejector channel, and a displacement signal transmitting device is provided on the outer wall of the ejector, and the displacement signal transmitting device transmits a signal toward the displacement signal receiving device.

[0013] Optionally, the displacement signal receiving device is on the inner wall of the ejector channel and extends along the direction of the ejector lifting movement.

[0014] Optionally, the electrostatic adsorption device further includes a signal processing unit, and the signal processing unit is electrically connected to the displacement sensor and the high voltage power supply.

[0015] Optionally, a distance sensor is provided on the upper surface of the electrostatic chuck, and the distance sensor is a sensor for detecting movement of the wafer driven by the ejector pin.

[0016] Optionally, the electrostatic adsorption device further includes a signal processing unit, and the signal processing unit is electrically connected to the distance sensor and the high voltage power supply.

[0017] The technical solution of the present application includes at least the following advantages: the electrostatic adsorption device provided by the present application can solve the problem that the residual charge between the wafer and the suction cup will make it difficult for the ejector pin to lift the wafer. If the driving force is increased to forcibly lift the wafer, it will easily cause the wafer position to shift, and there is a risk of wafer breakage. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A schematic diagram of the structure of an electrostatic adsorption device provided in one embodiment of the present application is shown;

[0020] Figure 2 An enlarged structural diagram of the ejector channel in one embodiment of the present application. DETAILED DESCRIPTION

[0021] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in this application. Obviously, the described embodiments are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0022] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0023] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0024] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0025] Figure 1 The schematic diagram of the structure of the electrostatic adsorption device provided in one embodiment of the present application is shown. Figure 1 It can be seen that the electrostatic adsorption device includes:

[0026] An electrostatic chuck 100 includes a substrate 110 and a conductive film 120 formed on the upper surface of the substrate 110, a high-voltage power supply 200 is provided under the substrate 100, and the high-voltage power supply 200 is electrically connected to the conductive film 120; a pin channel 130 is also formed in the electrostatic chuck 100, and the pin channel 130 vertically penetrates the substrate 110 and the conductive film 120.

[0027] The ejector pin 300 can move up and down in the ejector pin channel 130. When the ejector pin 200 is lifted, the wafer in contact with the ejector pin can be lifted up.

[0028] The ejector driving device 400 is connected to the ejector 300 and is used to drive the ejector 300 to perform lifting motion.

[0029] The electrostatic chuck 100 is provided with a sensor for detecting the movement of the ejector pin.

[0030] In this embodiment, a sensor for detecting the movement of the ejector pin is provided in the electrostatic chuck. When the electrostatic adsorption device is working, the sensor can collect the movement information of the ejector pin, so as to determine whether the wafer is lifted up. When the high-voltage power supply is turned off, the static charge between the wafer and the electrostatic chuck is completely released, so that the ejector pin can lift the wafer, that is, the ejector pin has a certain displacement. If the ejector pin fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it can be determined that the static charge has not been completely released, so the high-voltage power supply applies a reverse voltage to the conductive film to neutralize the residual charge. Then try to lift the wafer again. If the ejector pin still fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it is determined that the static charge has not been completely released, and the high-voltage power supply applies a reverse enhancement voltage to the conductive film to neutralize the residual charge.

[0031] From the above, it can be seen that the electrostatic adsorption device provided in this embodiment can solve the problem that the residual charge between the wafer and the suction cup will make it difficult for the ejector pin to lift the wafer. If the driving force is increased to forcibly lift the wafer, it will easily cause the wafer position to shift, and there is a risk of wafer breakage.

[0032] In one embodiment of the present application, a corresponding displacement sensor is provided on the ejector channel and the ejector, and the displacement sensor is a sensor for detecting the movement of the ejector. Figure 2 The enlarged structural diagram of the ejector channel in one embodiment of the present application is shown. Figure 2 It can be seen that a displacement signal receiving device 510 is provided on the inner wall of the ejector channel 130, and a displacement signal transmitting device is provided on the outer wall of the ejector 300, and the displacement signal transmitting device transmits a signal toward the displacement signal receiving device. Exemplarily, the displacement signal receiving device 510 is on the inner wall of the ejector channel 130 and extends along the direction of the lifting and lowering movement of the ejector 300 to improve the accuracy of obtaining the displacement signal of the ejector 300.

[0033] The electrostatic adsorption device further includes a signal processing unit 600 , and the signal processing unit 600 is electrically connected to the displacement sensor and the high voltage power supply 200 .

[0034] When in use, the signal processing unit 600 controls the displacement signal transmitting device of the displacement sensor to send a displacement signal, and the displacement signal receiving device 510 feeds back the received displacement signal to the signal processing unit 600. The signal processing unit 600 determines the displacement of the ejector pin 300 according to the received displacement signal to determine whether the wafer is lifted. When the high-voltage power supply is turned off, the static charge between the wafer and the electrostatic chuck is completely released, so that the ejector pin can lift the wafer, that is, the ejector pin has a certain displacement. If the ejector pin fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it can be determined that the static charge has not been completely released, so the high-voltage power supply applies a reverse voltage to the conductive film to neutralize the residual charge. Then try to lift the wafer again. If the ejector pin still fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it is determined that the static charge has not been completely released, and the high-voltage power supply applies a reverse enhancement voltage to the conductive film to neutralize the residual charge.

[0035] In other embodiments of the present application, a distance sensor is provided on the upper surface of the electrostatic chuck, and the distance sensor is a sensor for detecting the movement of the wafer driven by the ejector pin. The signal processing unit is electrically connected to the distance sensor and the high voltage power supply.

[0036] When in use, the signal processing unit 600 controls the distance sensor to send a signal to measure the distance between the wafer and the upper surface of the electrostatic chuck, so as to judge the displacement of the ejector pin to determine whether the wafer is lifted by the ejector pin. When the high-voltage power supply is turned off, the static charge between the wafer and the electrostatic chuck is completely released, so that the ejector pin can lift the wafer, that is, the ejector pin has a certain displacement. If the ejector pin fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it can be determined that the static charge has not been completely released, so the high-voltage power supply applies a reverse voltage to the conductive film to neutralize the residual charge. Then try to lift the wafer again. If the ejector pin still fails to lift the wafer, that is, the ejector pin has not been displaced to a certain extent, it is determined that the static charge has not been completely released, and the high-voltage power supply applies a reverse enhancement voltage to the conductive film to neutralize the residual charge.

[0037] The above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection created by this application.

Claims

1. An electrostatic adsorption device, characterized in that: The electrostatic adsorption device comprises: An electrostatic chuck, the electrostatic chuck comprising a substrate and a conductive film on the upper surface of the substrate, a high voltage power supply is provided under the electrostatic chuck, and the high voltage power supply is electrically connected to the conductive film; an ejector pin channel is also formed in the electrostatic chuck, and the ejector pin channel longitudinally penetrates the substrate and the conductive film; An ejector pin, the ejector pin being capable of moving up and down in the ejector pin channel; An ejector drive device, the ejector drive device is connected to the ejector and is used to drive the ejector to perform lifting motion; The electrostatic chuck is provided with a sensor for detecting the movement of the ejector pin.

2. The electrostatic adsorption device according to claim 1, characterized in that: The ejector channel and the ejector are provided with corresponding displacement sensors, and the displacement sensors are sensors used to detect the movement of the ejector.

3. The electrostatic adsorption device according to claim 2, characterized in that: A displacement signal receiving device is provided on the inner wall of the ejector channel, and a displacement signal transmitting device is provided on the outer wall of the ejector. The displacement signal transmitting device transmits a signal toward the displacement signal receiving device.

4. The electrostatic adsorption device according to claim 3, characterized in that: The displacement signal receiving device is on the inner wall of the ejector channel and extends along the direction of the ejector lifting movement.

5. The electrostatic adsorption device according to claim 2, characterized in that: The electrostatic adsorption device further includes a signal processing unit, and the signal processing unit is electrically connected to the displacement sensor and the high voltage power supply.

6. The electrostatic adsorption device according to claim 1, characterized in that: A distance sensor is provided on the upper surface of the electrostatic chuck, and the distance sensor is a sensor used to detect the movement of the wafer driven by the ejector pin.

7. The electrostatic adsorption device according to claim 6, characterized in that: The electrostatic adsorption device further includes a signal processing unit, and the signal processing unit is electrically connected to the distance sensor and the high voltage power supply.

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