Stress monitoring device and method for wafer vacuum chuck

Abstract

The invention provides a stress monitoring device and method for a wafer vacuum chuck, and the stress monitoring device comprises a stress sensor, a signal processing unit, a logic judgment unit, a motion control unit and an alarm device, carries out the real-time stress monitoring of the motion of an adsorption pin, and effectively prevents the occurrence of an event that the adsorption pin is snapped due to the overlarge tensile stress.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, specifically to a stress monitoring device and method for a wafer vacuum chuck. Background Technology

[0002] In various semiconductor device manufacturing processes, photolithography is the central step in silicon wafer fabrication. Its essence is to replicate temporary circuit structures onto the silicon wafer that requires etching and ion implantation. This step utilizes exposure and development to etch feature patterns onto photoresist, and then transfers the patterns from the photomask to the substrate through etching. For photolithography equipment, immersion lithography machines are the core equipment in a critical layer of photolithography. The wafer stage, serving as the exposure stage, is used to place the wafer for exposure. Figure 1A As shown, the wafer is first placed on the adsorption pin (Epin) column of the carrier stage by the transfer robot. Then, after the transfer robot retracts, the adsorption pin column moves downward to the top surface of the carrier stage, so that the wafer is adsorbed on the carrier stage.

[0003] After the adsorption pin is worn down, its surface becomes smooth, which easily generates van der Waals intermolecular forces when adsorbing onto the wafer back, resulting in a significant increase in adsorption force. When the adsorption pin column moves downwards to the top surface of the support platform, it cannot release quickly enough and is prone to breakage during movement. Figure 2 The connection between the adsorption pin and the column shown in the figure results in the following: Figure 2 The fracture phenomenon is shown. The wafer carrier stage contains numerous components and complex wiring, therefore existing lithography machines lack real-time stress monitoring of the movement of the adsorption pins within the wafer carrier stage. Summary of the Invention

[0004] In view of the shortcomings of the prior art described above, the purpose of this application is to provide a stress monitoring device and method for a wafer vacuum chuck, which solves the problem of no real-time stress monitoring of the movement of the adsorption pin in the prior art.

[0005] To achieve the above and other related objectives, this application provides a stress monitoring device and method for a wafer vacuum chuck. The technical solution is as follows:

[0006] On one hand, embodiments of this application provide a stress monitoring device for a wafer vacuum chuck, comprising:

[0007] Stress sensor is used to measure the safe stress value of the adsorption pin column in the wafer vacuum chuck and the real-time stress of the adsorption pin column when it moves inside the wafer carrier stage.

[0008] The signal processing unit is used to receive feedback signals from the stress sensor based on the safety stress value and real-time stress of the adsorption pin column, and to process the signals and send them to the logic judgment unit.

[0009] The logic judgment unit is used to receive signals from the signal processing unit and make judgments to determine whether to send a stop signal to the motion control unit.

[0010] Upon receiving a stop signal from the logic judgment unit, the motion control unit instructs the motor device controlling the movement of the adsorption pin column to stop operating and triggers the alarm device; and

[0011] Alarm device.

[0012] Preferably, the adsorption pin is inserted into the stress sensor from the top hole of the stress sensor, and the adsorption pin does not detach from the stress sensor when it moves inside the wafer carrier stage.

[0013] Preferably, the wafer carrier stage has at least three vacuum chuck holes arranged in a ring at equal intervals, each vacuum chuck hole containing an adsorption pin post, and each adsorption pin post being equipped with a stress sensor.

[0014] Preferably, the stress sensor is fixed to the bottom of the wafer carrier through its bottom hole.

[0015] On the other hand, embodiments of this application provide a stress monitoring method for a wafer vacuum chuck, including:

[0016] Step 1: Measure the safe stress value of the adsorption pin column inside the wafer vacuum chuck and the real-time stress of the adsorption pin column when it moves inside the wafer carrier stage.

[0017] Step 2: Determine whether the real-time stress is greater than the safe stress value. If so, stop the movement of the adsorption pin column and trigger an alarm.

[0018] Preferably, when the adsorption pin column is in a moving state, if the signal from the signal processing unit is the same as the signal corresponding to the pre-stored safe stress value of the adsorption pin column, the logic judgment unit determines that the real-time stress is greater than the safe stress value.

[0019] As described above, the stress monitoring device and method for wafer vacuum chucks provided in this application have the following beneficial effects: real-time stress monitoring of the movement of the adsorption pin effectively prevents the adsorption pin from being pulled apart due to excessive tensile stress. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1A This diagram illustrates the process of a wafer being adsorbed onto the wafer carrier stage of a lithography machine.

[0022] Figure 1B Displayed as Figure 1A The top view of the adsorption pin column is shown in the figure;

[0023] Figure 2 The image shows a broken adsorption pin.

[0024] Figure 3 The diagram shown is a schematic diagram of a stress monitoring device for a wafer vacuum chuck provided in an embodiment of this application;

[0025] Figure 4 The diagram shows a cross-sectional view of the stress sensor in the stress monitoring device of the wafer vacuum chuck provided in the embodiment of this application and a schematic diagram of the positional relationship between the stress sensor and the adsorption pin.

[0026] Figure 5 The flowchart shown is a stress monitoring method for a wafer vacuum chuck provided in an embodiment of this application. Detailed Implementation

[0027] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this invention.

[0028] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0032] Please see Figure 3 The diagram shows a stress monitoring device for a wafer vacuum chuck provided in an embodiment of this application.

[0033] like Figure 3 As shown, the stress monitoring device of the wafer vacuum chuck includes a stress sensor, a signal processing unit, a logic judgment unit, a motion control unit, and an alarm device.

[0034] Stress sensors are used to measure the safe stress value of the adsorption pin pillars inside the wafer vacuum chuck and the real-time stress of the adsorption pin pillars as they move within the wafer carrier stage. For example... Figure 4 As shown, the adsorption pin is inserted into the stress sensor through the top hole of the stress sensor. When the adsorption pin moves inside the wafer carrier, it does not detach from the stress sensor. The stress sensor is fixed to the bottom of the wafer carrier through its bottom hole.

[0035] like Figure 1B As shown, the wafer carrier stage has at least three vacuum chuck holes arranged in a ring at equal intervals. Each vacuum chuck hole contains an adsorption pin column, and each adsorption pin column is equipped with a stress sensor.

[0036] The signal processing unit is used to receive feedback signals from the stress sensor based on the safety stress value and real-time stress of the adsorption pin column, and then send the processed signals to the logic judgment unit.

[0037] The signal processing unit sends the signal corresponding to the safety stress value +1 of the adsorption pin column and the signal showing the relationship between the real-time stress and the safety stress value of the adsorption pin column to the logic judgment unit. For example, the signal corresponding to the safety stress value +1 of the adsorption pin column is 1, the signal when the real-time stress is greater than the safety stress value of the adsorption pin column is also 1, and the signal when the real-time stress is not greater than the safety stress value of the adsorption pin column is 0.

[0038] The logic judgment unit is used to receive signals from the signal processing unit, judge the signals to determine whether to send a stop signal to the motion control unit.

[0039] When the adsorption pin column is in a moving state, if the signal from the signal processing unit is the same as the signal corresponding to the pre-stored safety stress value of the adsorption pin column, the logic judgment unit sends a stop signal to the motion control unit.

[0040] After receiving a stop signal from the logic judgment unit, the motion control unit instructs the motor device used to control the movement of the adsorption pin column to stop working and triggers the alarm device, so that the lithography machine stops operating in time.

[0041] Please see Figure 5 The flowchart illustrates the stress monitoring method for a wafer vacuum chuck provided in this embodiment of the application.

[0042] like Figure 5 As shown, the stress monitoring method for this wafer vacuum chuck includes the following steps:

[0043] Step 1: Measure the safe stress value of the adsorption pin column inside the wafer vacuum chuck and the real-time stress of the adsorption pin column when it moves inside the wafer carrier stage.

[0044] Step 2: Determine whether the real-time stress is greater than the safe stress value. If so, stop the movement of the adsorption pin column and trigger an alarm.

[0045] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this application. Therefore, the drawings only show the components related to this invention and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0046] In summary, the stress monitoring device and method for wafer vacuum chucks provided in this application monitor the movement of the adsorption pin in real time, effectively preventing the adsorption pin from breaking due to excessive tensile stress. Therefore, this application effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0047] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this application.

Claims

1. A stress monitoring device for a wafer vacuum chuck, characterized in that, The stress monitoring device includes: A stress sensor is used to measure the safe stress value of the adsorption pin column in the wafer vacuum chuck and the real-time stress of the adsorption pin column when it moves inside the wafer carrier stage. The signal processing unit is used to receive feedback signals from the stress sensor based on the safety stress value and real-time stress of the adsorption pin column, and to process the signals and send them to the logic judgment unit. A logic judgment unit is used to receive signals from the signal processing unit and make judgments to determine whether to send a stop signal to the motion control unit; Upon receiving a stop signal from the logic judgment unit, the motion control unit instructs the motor device controlling the movement of the adsorption pin column to stop operating and triggers the alarm device; and Alarm device.

2. The stress monitoring device according to claim 1, characterized in that, The adsorption pin is inserted into the stress sensor through the top hole of the stress sensor, and the adsorption pin does not detach from the stress sensor when it moves inside the wafer carrier stage.

3. The stress monitoring device according to claim 1, characterized in that, The wafer carrier stage has at least three vacuum suction cup holes arranged in a ring at equal intervals. Each vacuum suction cup hole contains an adsorption pin column, and each adsorption pin column is equipped with a stress sensor.

4. The stress monitoring device according to claim 1, characterized in that, The stress sensor is fixed to the bottom of the wafer carrier through its bottom hole.

5. A method for stress monitoring of a wafer vacuum chuck implemented by a stress monitoring device according to any one of claims 1-4, comprising: Step 1: Measure the safety stress value of the adsorption pin column inside the wafer vacuum chuck and the real-time stress of the adsorption pin column when it moves inside the wafer carrier stage. Step 2: Determine whether the real-time stress is greater than the safe stress value. If so, terminate the movement of the adsorption pin column and trigger an alarm.

6. The method according to claim 5, characterized in that, When the wafer vacuum chuck's adsorption pin column is in a moving state, if the signal from the wafer vacuum chuck signal processing unit is the same as the signal corresponding to the pre-stored safe stress value of the wafer vacuum chuck's adsorption pin column, the wafer vacuum chuck logic judgment unit determines that the real-time stress of the wafer vacuum chuck is greater than the safe stress value of the wafer vacuum chuck.

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