CN210379012U - Wafer carrier - Google Patents

Abstract

The application relates to a wafer carrier, which comprises a wafer worktable and a driving module. The wafer worktable is provided with a plurality of wafer contact holes. The driving module comprises a plurality of drivers; each driver corresponds to each wafer contact hole one by one. The contact of the driver is used for passing through the corresponding wafer contact hole and contacting with the wafer; the driver is used for driving the contact area of the wafer to move along the axial direction of the wafer through the contact so as to enable the wafer to be flat. Based on the above, the driver can drive the corresponding wafer contact area to move along the axial direction of the wafer through the contact, so that the wafer tends to be flat, the influence caused by the defect point of the wafer carrier is effectively reduced, and the wafer yield and the yield are improved. Based on the structure, the defect points of the wafer carrier of the wafer can be reduced from more than 100 nanometers to 1 nanometer, so that the defect points of the wafer carrier are offset, and the influence on the critical dimension and the alignment error is reduced.

Description

Wafer carrier

Technical Field

The present application relates to the field of semiconductor manufacturing technologies, and more particularly, to a wafer carrier.

Background

In the production process of the wafer, factors such as pollution on the back surface of the wafer, wafer quality problems and wafer workbench (wafer) abrasion can cause wafer carrier defect points (Chuck spots) to cause wafer deformation, so that Critical Dimension (CD) and Overlay error (Overlay) of a wafer product are influenced, and the wafer yield is reduced.

Currently, there is no effective way to reduce the impact caused by wafer carrier defect points.

SUMMERY OF THE UTILITY MODEL

Accordingly, there is a need for a wafer carrier that can effectively reduce the influence of the defect points of the wafer carrier.

In order to achieve the above object, an embodiment of the present invention provides a wafer carrier, including:

the wafer worktable is used for bearing a wafer; the wafer worktable is provided with a plurality of wafer contact holes.

The driving module comprises a plurality of drivers; each driver corresponds to each wafer contact hole one by one; the contact of the driver is used for passing through the corresponding wafer contact hole and contacting with the wafer; the driver is used for driving the contact area of the wafer to move along the axial direction of the wafer through the contact so as to enable the wafer to be flat.

In one embodiment, the driver is a driver provided with a displacement feedback module.

In one embodiment, the displacement feedback module is a capacitive displacement feedback module. The capacitance displacement feedback modules are arranged around the corresponding contacts.

In one embodiment, the driving module further includes a signal processing module connected to the driver.

In one embodiment, the driving module further comprises an amplifying driving module. The amplification driving module is connected between the signal processing module and the driver.

In one embodiment, the displacement feedback module is connected with the signal processing module.

In one embodiment, the actuator is a piezoceramic actuator.

In one embodiment, the wafer contact holes are arranged in a honeycomb pattern.

The contact is a cylindrical contact; the height of the cylindrical contact ranges from 0.1 mm to 0.2 mm; the diameter of the cylindrical contact ranges from 0.3 mm to 0.4 mm.

In one embodiment, the wafer stage further defines vacuum pumping holes and wafer lifting holes.

In one embodiment, a cooling water circuit is arranged in the wafer workbench.

One of the above technical solutions has the following advantages and beneficial effects:

in the wafer carrier, a wafer worktable for bearing wafers is provided with a plurality of wafer contact holes; each driver in the driving module corresponds to each wafer contact hole one by one; the contact points of the driver are contacted with the wafer through the corresponding wafer contact holes. Based on the above, the driver can drive the corresponding wafer contact area to move along the axial direction of the wafer through the contact, so that the wafer tends to be flat, the influence caused by the defect point of the wafer carrier is effectively reduced, and the wafer yield and the yield are improved.

Drawings

The foregoing and other objects, features and advantages of the application will be apparent from the following more particular description of preferred embodiments of the application, as illustrated in the accompanying drawings. Like reference numerals refer to like parts throughout the drawings, and the drawings are not intended to be drawn to scale in actual dimensions, emphasis instead being placed upon illustrating the subject matter of the present application.

FIG. 1 is a schematic diagram of a wafer carrier in accordance with one embodiment;

FIG. 2 is a schematic view of an exemplary embodiment of a deboss bump for a wafer carrier;

FIG. 3 is a schematic view of an embodiment of a wafer carrier for eliminating pits;

FIG. 4 is a first schematic block diagram of a drive of a wafer carrier in accordance with one embodiment;

FIG. 5 is a schematic view of a drive module of the wafer carrier in one embodiment;

FIG. 6 is a schematic view of an embodiment of a wafer carrier with wafer contact hole distribution;

FIG. 7 is a second schematic block diagram of a drive for a wafer carrier in accordance with one embodiment;

fig. 8 is a schematic view of the internal structure of the wafer stage of the wafer carrier according to an embodiment.

Description of the reference symbols

100 wafer stages; 110 wafer contact holes; 120 vacuum pumping holes; 130 wafer lifting holes; 140 a cooling water circuit; 210 is a driver; 212 contact points; 213 cylindrical contacts; 214 a capacitance displacement feedback module; 300, a wafer; 310 salient points; 320 pits.

Detailed Description

To facilitate an understanding of the present application, the present application will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present application are shown in the drawings. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element and be integral therewith, or intervening elements may also be present.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In a wafer process, a wafer is required to be placed in a wafer carrier (chuck), and a wafer table (wafer) is used to carry the wafer and perform vacuum adsorption on the wafer. In this process, the wafer is prone to wafer carrier defect sites. For example, when particles are carried on the back surface of a wafer or a contact of a wafer carrier, the wafer may be deformed when placed on a vacuum wafer carrier, i.e., a bump (hotspot) is formed on the wafer, which may cause a focus error and an Overlay error, affect a critical dimension, and reduce a yield; in addition, in severe cases, the wafer needs to be reworked, which reduces the yield of the wafer. In addition, with the use of the machine, the contact of the wafer carrier is gradually worn, so that pits (Coldspot) appear on the wafer, Overlay errors and critical dimensions are affected, and the yield is reduced; in addition, when the wafer is seriously worn, the wafer worktable needs to be replaced, so that the downtime is caused, and the wafer yield is reduced.

Currently, there is no effective way to eliminate the error caused by the defect point of the wafer carrier. If the impact of a wafer carrier defect point on a wafer exceeds 3 device design areas, the wafer needs to be reworked, which results in a reduction in yield. Therefore, the embodiment of the application can be applied to semiconductor photoetching equipment, can reduce the influence of factors such as wafer back pollution, wafer quality problems and wafer working platform abrasion on products in the exposure process, and improves the yield.

In one embodiment, a wafer carrier is provided, as shown in fig. 1, comprising:

a wafer stage 100 for carrying a wafer 300; the wafer stage 100 defines a plurality of wafer contact holes 110.

A driving module including a plurality of drivers 210; each driver 210 corresponds to each wafer contact hole 110 one-to-one; the contacts 212 of the driver 210 are used to contact the wafer 300 through the corresponding wafer contact holes 110; the driver 210 is used for driving the contact area of the wafer 300 to move along the axial direction of the wafer through the contact 212, so as to flatten the wafer 300. The contacts 212 are disposed above the driver 210.

Specifically, the wafer carrier includes a wafer stage 100 and a driving module; the wafer stage 100 may have a disc-like or flat-plate-like wafer carrying shape, wherein the front surface of the wafer stage 100 may be used for carrying the wafer 300, i.e. a wafer carrying surface; the driving module may be disposed inside the wafer stage 100, or the driving module may be disposed outside the wafer stage 100 and near the back of the wafer stage 100. Further, a plurality of wafer contact holes 110 are formed on the wafer carrying surface of the wafer table 100, and the driving module is configured with a corresponding driver 210 for each wafer contact hole 110; the contacts 212 of the actuator 210 may pass through the corresponding wafer contact holes 110 for contacting the wafer 300, enabling support of the wafer 300 and movement of the corresponding wafer contact areas; that is, the driver 210 can move the contact 212 in a direction perpendicular to the plane of the wafer. Specifically, the wafer carrier has a plurality of wafer contact holes 110 and drivers 210, and the wafer is placed on the front surface of the wafer stage 100 and is carried by the contacts 212 of the respective drivers 210; the contact 212 may be located at the top end of the driver 210, and in particular, may be provided at the end of the displacement transmission mechanism of the driver 210; the contact area between the wafer 300 and the contact 212 is the contact area; the driver 210 may drive the corresponding contact area to move up and down through the contact 212 according to an external command, so as to keep the wafer 300 flat.

It should be noted that, the wafer flatness mentioned in the embodiments of the present application may be such that the axial height difference of the wafer 300 falls within a predetermined range, or the flatness of the wafer 300 falls within a predetermined range. The driver 210 is a precision displacement driving actuator, and can be used for error compensation, micro-feeding, precision adjustment and the like; specifically, the driver 210 may include two parts, a driving element (actuator) and a micro-displacement transmission mechanism; optionally, the micro-displacement driving element types include an electromechanical driving type, an electromagnetic driving type, a piezoelectric/electrostrictive driving type, a magnetostrictive driving type, and the like. The actuator 210 in the embodiment of the present application further includes a contact 212 provided at an end of the micro displacement transmission mechanism; illustratively, the driver 210 may be a piezoelectric ceramic driver, an electrostrictive ceramic driver, a giant magnetostrictive driver, or the like, which is not particularly limited herein.

The wafer contact hole 110 may be a circular hole, an elliptical hole, a square hole, a hexagonal hole, a polygonal hole, an irregular hole, or the like, and is not limited herein. Accordingly, the transmission mechanism of the driver 210 may be a cylinder, a rectangular parallelepiped, a polygonal cylinder, or the like, and is not particularly limited herein. Meanwhile, the contacts 212 may be configured as a cylinder, a hemisphere, a cuboid, a prism, or the like, as required. In the wafer process, the wafer carrier needs to vacuum-adsorb the wafer so as to perform the processes of exposure, development, deposition, etc. The wafer carrier may be provided with a certain density of wafer contact holes 110 and drivers 210, so that when the wafer back has particles and wafer quality problems or the wafer table 100 is worn, the corresponding driver 210 drives the corresponding contact area of the wafer to move up and down along the axial direction, so as to eliminate the convex points or concave points caused by defects. For example, as shown in fig. 2, when the wafer has a defect of the bump 310, the driver 210 contacting the bump 310 may be controlled to move downward to eliminate the defect of the bump 310, so as to flatten the wafer; as shown in FIG. 3, when the wafer has the pit 320 defect, the driver 210 contacting the pit 320 can be controlled to move upward to eliminate the pit 320 defect, so as to flatten the wafer.

It should be noted that, based on the above structure, a signal can be manually sent to the driving module to indicate the corresponding driver 210 to generate displacement, so as to achieve the purpose of manually eliminating the defect point of the wafer carrier; meanwhile, the wafer carrier defect points on the wafer can be automatically identified by computer equipment, and then signals are sent to the driving module to indicate the corresponding driver 210 to generate displacement, so that the equipment can automatically eliminate the wafer carrier defect points.

In the embodiment of the present application, the driver 210 can drive the corresponding wafer contact area to move along the axial direction of the wafer through the contact 212, so that the wafer tends to be flat, the influence caused by the defect point of the wafer carrier is effectively reduced, and the yield and the output of the wafer are improved. Based on the structure, the defect points of the wafer carrier of the wafer can be reduced from more than 100 nanometers to 1 nanometer, so that the defect points of the wafer carrier are offset, and the influence on the critical dimension and the alignment error is reduced.

In one example, the wafer contact hole 110 may be a through hole communicating the front and back sides of the wafer stage 100, each driver 210 may be disposed proximate the back side of the wafer stage 100, and the contacts 212 extend out of the wafer contact hole 110 through a transfer mechanism; based on this, replacement and maintenance of a single drive 210 may be facilitated, reducing maintenance costs and reducing downtime. In addition, the driving module can be disposed in the wafer stage 100 to form an integrated wafer carrier with the wafer stage 100, so that the matching degree between the wafer contact hole 110 and the driver 210 can be enhanced, the operation precision of the wafer carrier can be improved, and the influence caused by the defect point of the wafer carrier can be further reduced.

In one embodiment, the driver 210 is a driver provided with a displacement feedback module. The displacement feedback module is used for acquiring the displacement of the contact 212.

Specifically, each driver 210 in the driving module may be correspondingly provided with a displacement feedback module. When the driver 210 drives the corresponding contact region to move along the axial direction of the wafer through the contact 212, the displacement feedback module can acquire the displacement of the contact 212 so as to perform closed-loop control; for example, the closed loop control may further determine whether the driver 210 is to be further displaced or stopped from being displaced based on the amount of displacement of the contact 212. Based on the above structure, the embodiment of the present application can improve the moving precision of the driver 210, and further reduce the influence caused by the defect point of the wafer carrier. It should be noted that the displacement feedback module may be mainly composed of a displacement sensor; alternatively, the displacement sensor may be of the potentiometer type, inductive type, capacitive type, eddy current type, or hall type, etc. It should be noted that, depending on the sensing manner of the displacement feedback module, the displacement feedback module may be set at a suitable position so as to accurately acquire the displacement of the contact 212, and therefore, the position of the displacement feedback module is not limited herein.

In one embodiment, as shown in FIG. 4, the displacement feedback module is a capacitive displacement feedback module 214; the capacitive displacement feedback modules 214 are disposed around the corresponding contacts 212.

Specifically, the driver 210 may have a capacitive displacement feedback module 214 built therein, and the capacitive displacement feedback module 214 is disposed around the contact 212, so that the displacement of the contact 212 can be precisely acquired for precise closed-loop control.

In one embodiment, as shown in fig. 5, the driving module further includes a signal processing module connected to the driver 210.

Specifically, the signal processing module may be configured to convert the acquired movement parameter signal into a voltage signal, and send the voltage signal to the driver 210, so as to instruct the driver 210 to perform displacement output. Specifically, the signal processing module may be mainly composed of a single chip, a signal converter, a voltage conversion circuit, a digital-to-analog converter, a comparator, an amplifying circuit, or the like, which is not limited herein.

Specifically, the driving module may further include a signal processing module. Alternatively, the signal processing modules may be respectively connected to the drivers 210; meanwhile, one signal processing module may also be connected to a certain number of drivers 210, and at this time, a wafer carrier needs to be configured with a plurality of signal processing modules; in addition, one signal processing module may be correspondingly connected to one driver 210, and at this time, the number of drivers 210 of the wafer carrier, the number of signal processing modules, and the number of wafer contact holes 110 are the same. Specifically, the signal processing module may be configured to convert the externally transmitted movement parameter signal into a voltage signal, and then send the voltage signal to the driver 210, where the driver 210 performs corresponding displacement output based on the voltage signal. Based on the structure, the signal processing module of the wafer carrier can control the corresponding driver 210 according to the external moving parameters, so that the automatic control of the wafer carrier is convenient to realize, and the efficiency and the precision of eliminating the defect points of the wafer carrier are improved.

In one embodiment, as shown in fig. 5, the driving module further includes an amplifying driving module. The amplification driving module is connected between the signal processing module and the driver 210.

Specifically, in the driving module, the signal processing module and the corresponding driver 210 may be connected through the amplifying driving module. The amplification driving module may be configured to amplify the voltage signal transmitted by the signal processing module, and further transmit the amplified voltage signal to the driver 210, so as to improve the signal accuracy and the reliability of the control of the driver 210. It should be noted that, in the driving module, an amplification driving module may be respectively configured for each driver 210; in addition, the amplification driving module and the selection circuit may be used in cooperation to transmit signals to the plurality of drivers 210.

In one embodiment, as shown in FIG. 5, the displacement feedback module is connected to the signal processing module.

Specifically, the signal processing module can also be used for acquiring the displacement.

Specifically, the displacement feedback module is connected with the signal processing module, so that the collected displacement can be transmitted to the signal processing module; the signal processing module can perform closed-loop control based on the displacement amount, or further transmit the displacement amount to external computer equipment to complete the closed-loop control.

In one embodiment, the actuator 210 is a piezoceramic actuator 210.

Specifically, the actuator 210 is a piezoelectric ceramic actuator 210, which has the advantages of high displacement resolution, small volume, fast response, no heat generation, and the like; further, the driver 210 may also have a capacitance displacement feedback system built therein, which enables precise closed-loop control. The precision (up to 0.1 nm) and response rate of the pressure-sensitive ceramic driver 210 can be satisfied for the displacement requirement of the wafer carrier, and the size and volume of the device are suitable.

In one embodiment, as shown in FIG. 6, the wafer contact holes 110 are arranged in a honeycomb pattern.

Specifically, all the wafer contact holes 110 in the wafer stage 100 may be arranged in a honeycomb shape, so as to realize a dense contact hole arrangement, and it should be noted that the wafer contact holes 110 may be disposed at the center of the corresponding honeycomb unit. Illustratively, the center-to-center spacing of adjacent wafer contact holes 110 ranges from 3 mm to 5 mm, such as 3.5 mm, 4 mm, or 4.5 mm; the wafer contact hole 110 may be a circular hole with a diameter ranging from 0.5 mm to 1.5 mm, such as 0.8 mm, 1 mm, or 1.4 mm. It should be noted that the wafer contact holes 110 may be uniformly arranged in other structures, which is not illustrated here.

In one embodiment, as shown in FIG. 7, the contacts 212 may be cylindrical contacts 213. Specifically, the height of the cylindrical contact 213 ranges from 0.1 mm to 0.2 mm, such as 0.12 mm, 0.15 mm, or 0.18 mm. The diameter of the cylindrical contact 213 ranges from 0.3 mm to 0.4 mm, for example, 0.33 mm, 0.35 mm, or 0.37 mm. The drivers 210 may also be arranged in a honeycomb fashion to achieve a dense arrangement. In addition, the height of the transmission mechanism of the driver 210 may range from 5 mm to 5.5 mm, such as 5.15 mm, 5.35 mm, or 5.45 mm.

In one embodiment, as shown in fig. 8, the wafer stage 100 further defines vacuum pumping holes 120 and wafer lifting holes 130.

Specifically, the wafer stage 100 is further provided with vacuum suction holes 120 for vacuum suction, so that the wafer can be vacuum-sucked. Further, the wafer stage 100 may further include a wafer lift hole 130(E-pin hole), and based on this structure, the E-pin of the apparatus may pass through the wafer lift hole 130, and is used to lift the wafer when the wafer is placed and moved.

In one embodiment, as shown in fig. 8, a cooling water circuit 140 is provided in the wafer stage 100.

Specifically, a cooling water circuit 140(Lens circuit water, LCW circuit) may be used to absorb heat generated from the wafer stage 100. Optionally, the cooling water paths 140 are uniformly distributed inside the wafer stage 100, so that heat generated by driving can be better absorbed, and the influence of temperature on overlay error can be better controlled.

Illustratively, the wafer table is a disk-shaped table, and the cooling water path is provided in the disk-shaped table. Alternatively, the water inlet and the water outlet of the cooling water path may be disposed on the side wall of the disk-shaped worktable, and the pipeline of the cooling water path extends under the wafer bearing surface of the entire wafer worktable.

Alternatively, the cooling water path may be provided in a spiral shape in the wafer stage or in a serpentine shape in the wafer stage. In addition, on the basis of the wafer bearing surface, the wafer worktable can be divided into a plurality of units, and a cooling water channel is respectively arranged for each unit; specifically, the water inlet can be arranged at the side wall boundary of the unit, the pipeline starts from the water inlet, is spirally arranged along the unit boundary, gradually tends to the center of the unit, is spirally arranged along the direction gradually far away from the center of the unit by being close to the center of the unit, and is finally connected with the water outlet at the side wall boundary close to the water inlet to form a pipeline shape similar to the Fermat spiral, so that the area of the pipeline can be effectively increased by the design, and the heat dissipation capacity is enhanced. For example, the wafer table is divided into 6 units based on the wafer carrying surface, and the outline of each unit can be a sector of 60 degrees; aiming at the contour, a Fermat spiral pipeline with the periphery contour similar to an equilateral triangle can be arranged; based on this, the heat dissipation can be carried out through a plurality of cooling water routes, improves the radiating effect. It should be noted that there is no stagger inside the pipes, and at the same time, adjacent pipes are spaced apart.

Furthermore, the cooling water path can be provided with a heater which can be arranged close to the water inlet and can be used for heating cooling water, thereby avoiding the influence on the wafer manufacturing process due to overlarge temperature difference.

In one embodiment, the wafer carrier may further comprise a wafer inspection apparatus. The wafer detection equipment is connected with the signal processing module.

Specifically, the wafer detection device can be used for detecting defect points of a wafer carried by the wafer workbench, and can also be used for calculating position and height information of the defect points of the wafer carrier according to the defect points (or other wafer flatness problems) of the wafer carrier found by the Z-map detected by the wafer, so as to obtain a movement parameter signal, and sending the movement parameter signal to the signal control module. The signal control module converts the signal into a voltage signal, and after the drive circuit amplifies the signal, the driver realizes corresponding displacement according to the amplified signal. It should be noted that the wafer inspection apparatus may employ optical inspection and/or electrical inspection, and the like, and is not limited herein.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present application. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims (10)

1. A wafer carrier, comprising:

the wafer worktable is used for bearing a wafer; the wafer workbench is provided with a plurality of wafer contact holes;

the driving module comprises a plurality of drivers; each driver corresponds to each wafer contact hole one by one; the contact of the driver is used for passing through the corresponding wafer contact hole and contacting with the wafer; the driver is used for driving the contact area of the wafer to move along the axial direction of the wafer through the contact so as to enable the wafer to be flat.

2. The wafer carrier of claim 1,

the driver is provided with a displacement feedback module.

3. The wafer carrier of claim 2,

the displacement feedback module is a capacitance displacement feedback module;

the capacitance displacement feedback modules are arranged around the corresponding contacts.

4. The wafer carrier of claim 2, wherein the drive module further comprises a signal processing module connected to the driver.

5. The wafer carrier of claim 4, wherein the drive module further comprises an amplification drive module;

the amplification driving module is connected between the signal processing module and the driver.

6. The wafer carrier of claim 4,

the displacement feedback module is connected with the signal processing module.

7. A wafer carrier as claimed in any one of claims 1 to 6,

the driver is a piezoelectric ceramic driver.

8. A wafer carrier as claimed in any one of claims 1 to 6 wherein each wafer contact hole is arranged in a honeycomb pattern;

the contact is a cylindrical contact; the height of the cylindrical contact ranges from 0.1 mm to 0.2 mm; the diameter of the cylindrical contact ranges from 0.3 mm to 0.4 mm.

9. The wafer carrier of any of claims 1 to 6, wherein the wafer stage further defines vacuum pumping holes and wafer lifting holes.

10. A wafer carrier as claimed in any one of claims 1 to 6 wherein cooling water is provided within the wafer table.

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