CN115938997B - Wafer chuck and method for monitoring state of clamping piece - Google Patents

Abstract

The application provides a wafer chuck, including holder, chuck base member and monitoring piece, when the holder centre gripping wafer, the monitoring piece that sets up on the holder produces the load value signal, if the load value is less than first default, the monitoring piece sends first class alarm signal, avoid the wafer to drop on the holder, and then damage the wafer and cause the risk that cleaning equipment damaged, thereby improve the security and the reliability of wafer chuck and cleaning equipment, simultaneously, through the operating condition of monitoring piece real time monitoring holder, reduce the work load of mill inspection personnel.

Description

Wafer chuck and method for monitoring state of clamping piece

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a method for monitoring states of a wafer chuck and a clamping piece.

Background

The semiconductor manufacturing process generally includes photolithography, ion implantation, etching, and the like. After the related process, the wafer is generally fixed on a support table by a clamping member, the support table rotates, and a nozzle sprays cleaning agent to the surface of the wafer to be cleaned, so as to remove impurities on the surface of the wafer. In the long-term use process of the clamping piece, the clamping piece and the wafer are stressed mutually, so that abrasion can occur, the clamping piece is insufficient in clamping stress on the wafer, the clamping piece is generally inspected manually at regular intervals in the prior art, however, manual inspection does not have instantaneity, and unqualified clamping pieces are difficult to discover timely.

Disclosure of Invention

Accordingly, a primary object of the present application is to provide a wafer chuck, so as to solve the problem that it is difficult to find unqualified clamping members in time due to the fact that manual periodic inspection of the clamping members does not have real-time performance.

In order to achieve the above purpose, the technical scheme of the application is realized as follows:

the application discloses a wafer chuck includes:

the clamping piece is used for clamping the wafer;

the chuck base body is provided with a plurality of through holes, and each clamping piece is arranged in one through hole in a penetrating way;

the monitoring piece is fixed on the clamping piece and is used for monitoring the clamping force of the clamping piece on the wafer;

when the clamping piece clamps the wafer, and the load obtained by the monitoring piece is smaller than a first preset value, the monitoring piece sends out a first type of alarm signal.

Further, the wafer chuck further comprises a driving member for driving the clamping members to rotate synchronously, so that the clamping members and the wafer are in a clamping state or an unclamping state.

Further, the clamping piece is provided with a central hole, and the monitoring piece is positioned in the central hole.

Further, the monitoring piece is located between the inner wall of the through hole and the clamping piece, and the clamping piece is partially exposed out of the through hole.

Further, the clamping piece is provided with a clamping part and a base part, the axis of the clamping part is parallel to the axis of the base part and is spaced from the axis of the base part, and the outer column surface of the clamping part is connected with the outer column surface of the base part.

Further, the chuck base body is also formed with a plurality of gas channels circumferentially distributed, the gas channels are located at the inner sides of the through holes, and the gas channels are used for conveying gas to the surface of the wafer, which is close to one side of the chuck base body.

Further, the axial length of the clamping portion is greater than the thickness of the wafer.

Further, the clamping piece and the wafer are in a clamping state, and the distance between one side of the wafer, which is close to the chuck base body, and the chuck base body is within a preset distance range.

The present application also provides a method for monitoring a state of a chuck, which is applied to the wafer chuck according to any one of the preceding claims, and the method includes:

acquiring relative position parameters of the chuck base body and the clamping piece;

judging whether the wafer chuck clamps the wafer or not according to the relative position parameters;

when the judgment result is that the wafer chuck and the wafer are in a clamping state, acquiring a load value received by the monitoring piece;

and when the load value is smaller than a first preset value, the monitoring piece sends out a first type of alarm signal.

Further, the monitoring method further comprises:

and when the judgment result is that the wafer chuck and the wafer are in the unclamped state, the wafer is taken out by the manipulator.

The application provides a wafer chuck, including holder, chuck base member and monitoring piece, when the wafer is held to the holder, a plurality of holders receive the reaction force of wafer, the monitoring piece that sets up on the holder produces load value signal, for example, when the monitoring piece is piezoelectric sensor, load value signal is voltage value signal, if voltage value is less than first default, indicate that the holder is to the clamping force of wafer for a short time, the monitoring piece sends first type alarm signal, avoid the wafer to drop easily on the holder, and then damage the wafer and cause the risk of cleaning equipment damage, thereby improve the security and the reliability of wafer chuck and cleaning equipment, simultaneously, through the operating condition of monitoring piece real-time supervision holder, reduce the work load of mill inspection personnel.

Drawings

Fig. 1 is a schematic top view of a wafer chuck according to an embodiment of the present disclosure;

FIG. 2 is a cross-sectional view taken along the direction A in FIG. 1;

FIG. 3 is a schematic diagram illustrating an assembly of a driving member and a clamping member according to an embodiment of the present disclosure;

FIG. 4 is a schematic view illustrating an assembly of a driving member and a clamping member according to another embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustrating an assembly of a monitor and a clamping member according to an embodiment of the present disclosure;

FIG. 6 is a schematic view illustrating an assembly of a monitor and a clamping member according to another embodiment of the present disclosure;

fig. 7 is a flowchart of a method for monitoring a state of a clamping member according to an embodiment of the present application.

Description of the reference numerals

1. A wafer chuck; 11. a clamping member; 111. a clamping part; 112. a base; 12. a chuck base; 121. a gas channel; 13. a monitoring member; 14. a driving member; 141. a gear portion; 142. a drive gear; 15. and (3) a wafer.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

The individual features described in the specific embodiments can be combined in any suitable manner, without contradiction, for example by combination of different specific features, to form different embodiments and solutions. Various combinations of the specific features described herein are not presented in order to avoid unnecessarily obscuring the present invention.

In the following description, references to the term "first/second/are merely to distinguish between different objects and do not indicate that the objects have the same or a relationship therebetween. It should be understood that references to orientations of "above", "below", "outside" and "inside" are all orientations in normal use, and "left" and "right" directions refer to left and right directions illustrated in the specific corresponding schematic drawings, and may or may not be left and right directions in normal use.

It should be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element. The term "coupled," unless specifically indicated otherwise, includes both direct and indirect coupling.

In general, during use of the wafer chuck, because the clamping members on the wafer chuck are forced against the wafer, wear occurs, and sometimes bending or even breaking of the clamping members may occur due to other reasons. When one of the clamping pieces is damaged, other clamping pieces are abnormally stressed, so that chain reaction is triggered, other clamping pieces are damaged, and then the clamping pieces are insufficiently stressed to clamp the wafer, so that the wafer falls from the clamping pieces. When the wafer chuck rotates at high speed, the drop can also collide with other components in the wafer chuck, which can lead to wafer breakage and damage to other components in the wafer chuck.

The state detection of the clamping piece is currently checked by manual regular inspection, the use condition of the clamping piece is judged manually, the existence of contingency is judged manually, the state of the clamping piece can be observed after the machine is in a standby state in each inspection, and the quantity of the machines is large, so that the inspection workload is large each time. Meanwhile, the inspection result is not real-time, and there is no problem in inspection, but an emergency occurs later, which is not beneficial to the stability of the wafer chuck.

In view of this, as shown in fig. 1-2, the present application provides a wafer chuck 1, which includes a clamping member 11, a chuck base 12, and a monitoring member 13. The clamping piece 11 is used for clamping a wafer 15, the chuck base body 12 is provided with a plurality of through holes, each clamping piece 11 is arranged in a through hole in a penetrating mode, the monitoring piece 13 is fixed on the clamping piece 11, the monitoring piece 13 is used for monitoring the clamping force of the clamping piece 11 on the wafer 15, and when the clamping piece 11 clamps the wafer 15, the load obtained by the monitoring piece 13 is smaller than a first preset value, the monitoring piece 13 sends out a first type of alarm signal.

Specifically, the clamping member 11 includes a clamping portion 111 and a base portion 112, the clamping portion 111 is fixedly connected to the base portion 112, a welding process or an integral forming process can be adopted in the fixing connection process, a plurality of through holes are formed in the chuck base 12, the plurality of through holes are concentrically distributed along the circumferential direction of the chuck base 12 and along the axis of the chuck base, a corresponding number of clamping members 11 are disposed in the plurality of through holes, at least a portion of the base portion 112 of the clamping member 11 is disposed in the through holes, and the clamping portion 111 of the clamping member 11 is located above the through holes and is used for clamping the wafer 15. The wafer chuck 1 is further provided with a monitoring piece 13, the monitoring piece 13 is arranged on the clamping piece 11 and is used for acquiring a load signal generated by the clamping piece 11 when the wafer 15 is clamped, for example, when the monitoring piece 13 is a piezoresistive pressure sensor or a piezoelectric ceramic sensor, the load signal is a voltage value signal, if the voltage value generated by the action of the clamping force received by the monitoring piece 13 is smaller than a first preset value, the clamping force of the clamping piece 11 on the wafer 15 is smaller, the monitoring piece 13 sends out a first type alarm signal and is used for timely informing an equipment engineer of overhauling the working state of the clamping piece 11, the inspection workload of the equipment engineer is saved, and the wafer 15 is prevented from falling off from the clamping piece 11 to damage the wafer 15. It will be appreciated that the monitoring element 13 emits a first type of alarm signal when the plurality of clamping elements 11 clamp the wafer 15 and the load value generated by at least one clamping element 11 of the plurality of clamping elements 11 is less than a first predetermined value.

Specifically, the two connection modes of the monitoring piece 13 and the clamping piece 11 are provided, wherein the first connection mode is that the monitoring piece 13 is arranged in a clamping part 111 of the clamping piece 11, for example, the monitoring piece 13 is a piezoelectric ceramic sensor, the clamping part 111 is cylindrical, an installation groove is arranged in the clamping part 111 and is used for installing the piezoelectric ceramic sensor, the structure of the piezoelectric ceramic sensor is matched with the installation groove, when the clamping part 111 clamps a wafer 15 to generate clamping force, the piezoelectric ceramic sensor in the clamping part 111 is stressed, and thus, the piezoelectric ceramic sensor generates a voltage value signal; the second connection mode is to install the monitor 13 in the base 112 of the holder 11, for example, the base 112 is cylindrical, and an installation groove is provided in the base 112 of the holder 11 for installing the piezoceramic sensor, when the wafer 15 is clamped by the clamping portion 111, the clamping portion 111 and the base 112 are fixedly connected, so that the piezoceramic sensor in the base 112 will also generate a voltage signal under the action of the clamping force. The first preset value needs to be set according to the type of sensor selected by the monitor 13 and the connection mode of the monitor 13 and the clamping member 11, for example, the monitor 13 is a piezoelectric ceramic sensor, the connection mode of the monitor 13 and the clamping member 11 is that a central hole is formed in the clamping portion 111, the piezoelectric ceramic sensor is installed in the central hole, the clamping force of the clamping member 11 on the wafer 15 is gradually increased in a machine test, and meanwhile, a voltage value signal sent by the piezoelectric ceramic sensor is set to be the first preset value until the clamping force calculated by converting the voltage value signal is equal to the minimum value of the designed allowable clamping force range.

In an embodiment, when the clamping member 11 clamps the wafer 15 to be cleaned and the load obtained by the monitoring member 13 is greater than a second preset value, the monitoring member 13 sends out a second type of alarm signal. Specifically, the monitoring piece 13 is a piezoelectric ceramic sensor, the load is a voltage value, when the clamping piece 11 clamps the wafer 15, the clamping piece 11 is subjected to the clamping force, so that the piezoelectric ceramic sensor installed on the clamping piece 11 generates a voltage value signal, when the voltage value received by the monitoring piece 13 is larger than a second preset value, namely, the clamping force between the clamping piece 11 and the wafer 15 is larger, the monitoring piece 13 sends a second type alarm signal, and an equipment engineer is notified to check the outer end size of the wafer 15, so that the service life of the clamping piece 11 is prevented from being influenced by the overlarge outer end size of the wafer 15. In particular, the first type of alarm signal and the second type of alarm signal may be optical signals or voice signals, for example, the first type of alarm signal is a yellow flashing alarm, and the second type of alarm signal is a red flashing alarm. The second preset value is determined according to the type of the selected monitor 13 and the connection mode of the clamping member 11, the clamping force of the clamping member 11 to the wafer 15 is gradually increased in the machine test, and the voltage value signal sent by the piezoelectric ceramic sensor is set as the second preset value until the clamping force calculated by converting the voltage value signal is equal to the maximum value of the range of the design allowable clamping force. It should be further noted that, due to different machine tools or different processes, there is a difference in the rotation speed of the wafer chuck 1, so the stress between the clamping member 11 and the wafer 15 also varies. Therefore, the monitor 13 also needs to set different first preset values and second preset values according to different machines or different processes, i.e. the voltage fluctuation range of the wafer chuck 1 in normal operation.

In one embodiment, the wafer chuck 1 further includes a driving member 14 for driving the plurality of clamping members 11 to rotate synchronously, so that the clamping members 11 and the wafer 15 are in a clamping state or an unclamping state. For example, as shown in fig. 2 to 3, the driving member 14 includes a driving motor, each clamping member 11 is connected to one driving motor, the driving motor controls the base 112 of the clamping member 11 to rotate in the through hole of the chuck base 12, when the clamping portion 111 of the clamping member 11 approaches the axis of the chuck base 12 to the first position, the clamping member 11 and the wafer 15 are in a clamping state, so as to facilitate the subsequent cleaning process of the wafer 15, when the clamping portion 111 of the clamping member 11 is far from the axis of the chuck base 12 to the second position, the clamping member 11 is far from the wafer 15 and is not in contact with the wafer 15, and the clamping member 11 and the wafer 15 are in a clamping-released state; for example, as shown in fig. 4, the driving member 14 includes a gear portion 141 and a driving gear 142, the gear portion 141 is fixedly connected with the base 112 of the clamping member 11, when the position of the clamping member 11 needs to be changed, the driving gear 142 is engaged with the gear portion 141 through a lifting device, and the driving gear 142 drives the gear portion 141 to rotate by a predetermined angle, so that the clamping member 11 and the wafer 15 are in a clamping state or an unclamping state. It should be noted that, when the clamping member 11 rotates along its central axis, the installation space occupied by the clamping member 11 is small compared with the way of adopting the rotation movement of the clamping member 11, so that a larger clamping space is reserved for the manipulator, and interference with the manipulator is avoided.

In one embodiment, as shown in fig. 5, the clamping member 11 is provided with a central hole, and the monitoring member 13 is located in the central hole. Specifically, the clamping portion 111 of the clamping member 11 is cylindrical, a central hole is formed in the clamping portion 111, and the clamping force is generated when the clamping portion 111 clamps the wafer 15 in the same manner as the mounting of the monitoring member 13, so that the monitoring member 13 in the clamping portion 111 is stressed, a load value signal is generated by the monitoring member 13, the monitoring member 13 is arranged in the clamping portion 111, the monitoring member 13 is prevented from directly acting on the wafer 15, and the service life of the monitoring member 13 is prolonged.

In one embodiment, as shown in fig. 6, the monitoring member 13 is located between the inner wall of the through hole and the clamping member 11, and the clamping member 11 is partially exposed from the through hole. Specifically, the annular hollow monitor member 13 is mounted on the inner wall of the through hole of the chuck base 12, and then the base 112 of the clamping member 11 is mounted on the inner wall of the monitor member 13, that is, the monitor member 13 is disposed between the chuck base 12 and the base 112 of the clamping member 11, there is no contact area between the clamping member 11 and the chuck base 12, when the clamping portion 111 of the clamping member 11 clamps the wafer 15, the clamping portion 111 receives the clamping force from the wafer 15, and since the base 112 is fixedly connected with the clamping portion 111, the base 112 also receives the clamping force to act on the monitor member 13, so that the monitor member 13 generates a load signal, for example, when the monitor member 13 is a piezoelectric ceramic, the load signal is a voltage value signal. It should be noted that, since the clamping portion 111 wears during long-term use and needs to be replaced according to the use condition, the present embodiment installs the monitor 13 in the through hole of the chuck base 12, which is beneficial to prolonging the service life of the monitor 13.

In one embodiment, as shown in fig. 6, the clamping member 11 is provided with a clamping portion 111 and a base portion 112, wherein the axis of the clamping portion 111 is parallel to and spaced apart from the axis of the base portion 112, and the outer cylindrical surface of the clamping portion 111 is connected to the outer cylindrical surface of the base portion 112. Specifically, the clamping portion 111 and the base portion 112 are both cylindrical, the diameter of the clamping portion 111 is smaller than that of the base portion 112, the axes of the clamping portion 111 and the base portion 112 are parallel and are arranged at intervals, the clamping portion 111 is located above the base portion 112, the outer cylindrical surface of the clamping portion 111 is tangential to the outer cylindrical surface of the base portion 112, when the clamping portion 111 and the wafer 15 are in a clamping-releasing state, the distance between the clamping portion 111 and the wafer 15 is the farthest, and enough avoiding space is reserved for the manipulator to take out the wafer 15. In particular, the outer cylindrical surface of the clamping portion 111 is connected with the outer cylindrical surface of the base 112, the step width formed by the clamping portion 111 and the base 112 is the largest, so that the clamping member 11 is convenient for being applied to more wafers 15 with different outer diameter ranges, and meanwhile, the clamping portion 111 is located in the outer cylindrical surface of the base 112 in the vertical direction, thereby improving the space utilization rate.

In one embodiment, as shown in fig. 1, the chuck base 12 is further formed with a plurality of gas channels 121 circumferentially distributed around, the gas channels 121 being located inside the through holes, and the gas channels 121 being used to deliver gas to the surface of the wafer 15 on the side close to the chuck base 12. Specifically, the chuck base 12 is provided with a plurality of gas channels 121 circumferentially and annularly distributed, the plurality of gas channels 121 are uniformly distributed at intervals, the plurality of gas channels 121 can be switched to be introduced with a first flow or a second flow, and the first flow of gas is used for lifting the wafer 15 when the plurality of clamping members 11 and the wafer 15 are in a clamping-releasing state, so that the wafer 15 is lifted to be suspended, and a robot can conveniently take the wafer 15 out of the wafer chuck 1 for subsequent cleaning or drying and other processes. When the plurality of clamping members 11 and the wafer 15 are in the clamping state, the second flow of gas is introduced to purge the sputtered cleaning solution or particles, so that the cleaning solution or particles are prevented from entering between the wafer 15 and the chuck base. It should be noted that, for example, the first flow rate is 50L/min to 200L/min, the second flow rate is 200L/min to 250L/min, and the gas introduced may be compressed air, nitrogen or inert gas. It will be appreciated that the gas flow switching of the plurality of gas channels 121 may provide a flow valve on a line connected to the gas channels 121 for passing the first flow or the second flow of gas into the gas channels 121.

In one embodiment, as shown in fig. 2, the axial length of the clamping portion 111 is greater than the thickness of the wafer 15. Specifically, the clamping portion 111 is fixed above the base 112 and used for clamping the wafer 15, and the length of the clamping portion 111 is greater than the thickness of the wafer 15, for example, when the thickness of the wafer 15 is generally 0.3 mm-1 mm, the length of the clamping portion 111 is set to 2cm, so that the robot hand can place the wafer 15 on the clamping portion 111 in the vertical direction, the clamping space is reserved, and the design difficulty of the robot hand is reduced.

In one embodiment, as shown in fig. 2, the clamping member 11 and the wafer 15 are in a clamping state, and the distance between the side of the wafer 15, which is close to the chuck base 12, and the chuck base 12 is within a preset distance range. Specifically, the robot places the wafer 15 above the chuck base 12, the gas channel 121 of the chuck base 12 leads to gas toward the side of the wafer 15 close to the chuck base 12, so that the wafer 15 is in a floating state, and drives the clamping member 11 to clamp the wafer 15, wherein the floating height of the wafer 15 is equal to the height of the wafer 15 in the clamping state. Since the wafer chuck 1 can make the center portion of the clamped wafer 15 sink during the high-speed rotation process, the particles on the side of the chuck base body 12 close to the wafer 15 are very easy to touch, so the suspension height of the wafer 15 is controlled by controlling the flow of the gas, the distance between the side of the wafer 15 close to the chuck base body 12 and the chuck base body 12 is determined, so that the distance between the side of the wafer 15 close to the chuck base body 12 and the chuck base body 12 is within a preset distance range, for example, the preset distance range is set to 1-3 mm, and the height of the wafer 15 in the clamped state is set to 2 mm by controlling the flow of the gas. The upper limit value of the preset distance range is set to avoid that the flow rate of the gas is too large, so that the wafer 15 is located above the clamping portion 111, and the clamping portion 111 cannot clamp the wafer 15.

The application also provides a method for monitoring the state of the clamping piece, which is a schematic flow chart of the method for monitoring the state of the clamping piece according to the embodiment of the invention, as shown in fig. 7, and the method comprises the following steps:

s100, acquiring relative position parameters of the chuck base body and the clamping piece.

And S200, judging whether the wafer chuck clamps the wafer or not according to the relative position parameters.

And S300, when the judgment result is that the wafer chuck and the wafer are in a clamping state, acquiring a load value received by the monitoring piece.

And S400, if the load value is smaller than a first preset value, the monitoring part sends out a first type of alarm signal.

Specifically, forward and reverse rotation of the driving piece is controlled through bidirectional pulse current, time of forward pulse current is determined according to set clamping time of the clamping piece and the wafer, time of reverse pulse current is determined according to set clamping part and time of the wafer in a clamping-releasing state, namely time of the wafer in a suspension state, and accordingly time of one period of bidirectional pulse current is determined, wherein a forward pulse current value is larger than zero, a reverse pulse current value is smaller than zero, and the forward pulse current value and the reverse pulse current value are the same in size. For example, when the driving member is a driving motor, the driving motor drives the clamping member to rotate forward by a preset angle when the driving motor receives the forward pulse current, so that the clamping portion of the clamping member and the wafer form a clamping state, the clamping portion of the clamping member is close to the axis of the chuck base body, and the clamping member is at the first position. When the driving motor receives the reverse pulse current, the driving motor drives the clamping piece to reversely rotate by a preset angle, so that the clamping part of the clamping piece and the wafer are in a clamping state, namely the clamping piece and the wafer are in a separation state, the clamping part is far away from the axis of the chuck base body, and the clamping piece is at a second position. The relative positions of the axis of the chuck base body and the clamping part are different between the clamping state and the unclamping state of the wafer chuck and the wafer, so that the relative position parameters of the clamping piece and the chuck base body are obtained according to the set bidirectional pulse current. When the clamping member is at the first position, the wafer chuck and the wafer are in a clamping state, the monitoring member obtains a received load value, for example, the monitoring member is a piezoelectric ceramic sensor, the load value is a voltage value, and when the obtained voltage value is smaller than a first preset value, the monitoring member indicates that the clamping force of the clamping member on the wafer is smaller than the minimum value of the design range, so that the subsequent target process of the wafer chuck is stopped, and the target process can be a process of rotating the wafer chuck. If the clamping force of the wafer chuck is found to be smaller than the design value in the process of cleaning the wafer, the cleaning process should be stopped immediately at the moment, and the monitoring piece sends out a first type of alarm signal to inform the equipment engineer to overhaul the clamping piece, so that the wafer is prevented from falling off the clamping piece and being damaged and the wafer chuck are prevented from being damaged due to the fact that the clamping force of the clamping piece to the wafer is smaller. It can be appreciated that the monitoring member may further set a second preset value, where the second preset value is set to avoid that the clamping force between the clamping member and the wafer is greater than the maximum value of the allowable clamping force range, which results in a larger clamping force between the clamping member and the wafer, and affects the service life of the clamping member. When the obtained voltage value is larger than or equal to the first preset value and smaller than or equal to the second preset value, the wafer chuck is in a normal working state, and the subsequent target process is continued.

In one embodiment, the clamp condition monitoring method further comprises:

s500, when the judgment result is that the wafer chuck and the wafer are in the clamping-released state, the wafer is taken out by the manipulator.

Specifically, the driving member is a driving motor, the relative position parameters of the clamping member and the chuck base body are obtained according to the set bidirectional pulse current, when the driving motor receives the reverse pulse current, the driving motor drives the clamping member to reversely rotate by a preset angle, so that the clamping part of the clamping member and the wafer are in a clamping-releasing state, the clamping part of the driving member drives the clamping part to be far away from the axis of the chuck base body, the clamping member is at a second position, the wafer chuck and the wafer are in a clamping-releasing state, the clamping member is not in contact with the wafer, the wafer is kept in a suspension state through a gas channel on the chuck base body, and the manipulator takes out the wafer into the next process, for example, the next process is drying.

The above embodiments are only for illustrating the technical solution of the present application, and are not limiting; although the present application has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some of the technical features thereof; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (8)

1. A wafer chuck, comprising:

the clamping piece is used for clamping the wafer;

the chuck base body is provided with a plurality of through holes, and each clamping piece is arranged in one through hole in a penetrating way;

the monitoring piece is fixed on the clamping piece and is used for monitoring the clamping force of the clamping piece on the wafer;

when the clamping piece clamps the wafer, and the load obtained by the monitoring piece is smaller than a first preset value, the monitoring piece sends out a first type of alarm signal;

the clamping piece is provided with a central hole, and the monitoring piece is positioned in the central hole; or alternatively, the first and second heat exchangers may be,

the monitoring piece is located between the inner wall of the through hole and the clamping piece, and the clamping piece is partially exposed out of the through hole.

2. The wafer chuck as set forth in claim 1, further comprising a driving member for driving the plurality of clamping members to rotate in synchronization to place the clamping members in a clamped state or an undamped state with the wafer.

3. The wafer chuck as set forth in claim 1, wherein the clamping member is provided with a clamping portion and a base portion, an axis of the clamping portion being parallel to and spaced apart from an axis of the base portion, an outer cylindrical surface of the clamping portion being contiguous with an outer cylindrical surface of the base portion.

4. The wafer chuck as set forth in claim 1, wherein the chuck base is further formed with a plurality of gas passages circumferentially distributed around the circumference, the gas passages being located inside the through holes, the gas passages being for supplying gas to a surface of the wafer on a side close to the chuck base.

5. The wafer chuck as set forth in claim 3, wherein an axial length of said clamping portion is greater than a thickness of said wafer.

6. The wafer chuck as set forth in claim 1, wherein the clamping member is in a clamped state with the wafer, and a distance between a side of the wafer adjacent to the chuck base and the chuck base is within a predetermined distance range.

7. A method for monitoring the state of a clamping member, applied to the wafer chuck according to any one of claims 1 to 6, comprising:

acquiring relative position parameters of the chuck base body and the clamping piece;

judging whether the wafer chuck clamps the wafer or not according to the relative position parameters;

when the judgment result is that the wafer chuck and the wafer are in a clamping state, acquiring a load value received by the monitoring piece;

and when the load value is smaller than a first preset value, the monitoring piece sends out a first type of alarm signal.

8. The monitoring method of claim 7, wherein the monitoring method further comprises:

and when the judgment result is that the wafer chuck and the wafer are in the unclamped state, the wafer is taken out by the manipulator.

Images