Photoetching machine suction cup and photoetching machine

Abstract

The utility model discloses a photoetching machine suction cup and a photoetching machine, the photoetching machine suction cup is used for adsorbing a wafer to be processed, the wafer is placed on the photoetching machine suction cup, the wafer comprises a central area and an edge area, and the photoetching machine suction cup comprises a base, a plurality of suction cups and a plurality of suction cups, the inner disc is fixedly mounted on the base, and the inner disc is in contact with the central area; the outer disc is movably connected with the base, the outer disc is in contact with the edge area, and the outer disc is arranged outside the inner disc in a sleeving mode, so that the outer disc is tightly attached to the inner disc; and the driving assembly is installed in the base, the driving assembly is connected with the outer disc, and the driving assembly is used for driving the outer disc to move relative to the inner disc. According to the utility model, the warping degree of the wafer can be effectively adjusted, and the method is simple and easy to implement, thereby avoiding the defocusing phenomenon and reducing the overlay error.

Description

TECHNICAL FIELD

[0001] The utility model relates to a semiconductor technical field especially relates to a photolithography machine sucking disc and photolithography machine. BACKGROUND

[0002] In the semiconductor process, with the formation of various material layers and various semiconductor device structures on the wafer surface, various stresses are generated on the wafer surface, causing the wafer to warp during the process. After the wafer that has warped is adsorbed to the chuck, the edge of the wafer will appear imaging focus shift phenomenon in the subsequent photolithography process, resulting in reduced edge overlay accuracy of the wafer, leading to reduced yield.

[0003] In the prior art, the compensation amount is constantly updated to compensate for different areas of the wafer through the correction per field (CPE) method, thereby improving the wafer overlay accuracy, but the severe warping cannot be compensated.

[0004] Therefore, it is necessary to provide a photolithography machine chuck and a photolithography machine to solve the above problems existing in the prior art. SUMMARY

[0005] The utility model aims at providing a photolithography machine chuck and a photolithography machine to solve the problem of wafer edge warping.

[0006] To achieve the above-mentioned purpose, the technical scheme of the utility model is as follows:

[0007] The utility model provides a photolithography machine chuck for adsorbing a wafer to be processed, the wafer is placed on the photolithography machine chuck, the wafer includes a center area and an edge area, and the photolithography machine chuck includes:

[0008] A base;

[0009] An inner disc fixedly installed on the base, the inner disc being in contact with the center area;

[0010] An outer disc movably connected with the base, the outer disc being in contact with the edge area, and the outer disc being sleeved outside the inner disc so that the outer disc and the inner disc are tightly attached;

[0011] A driving assembly installed in the base, the driving assembly being connected with the outer disc, and the driving assembly being used to drive the outer disc to move relative to the inner disc.

[0012] The photolithography machine suction disc has the advantages that: the warped wafer is placed on the photolithography machine suction disc, specifically, the center region of the wafer is located on the inner disc, and the edge region of the wafer is located on the outer disc; the inner disc and the outer disc are tightly attached during work; under the premise that the wafer is adsorbed on the photolithography machine suction disc, the driving assembly is started, the driving assembly drives the outer disc connected therewith to move relative to the inner disc, so that the outer disc drives the edge region of the wafer adsorbed therewith to move relative to the center region of the wafer, and the wafer is stopped working after being in a flat state, thereby overcoming the warping problem of the edge region relative to the center region, that is, the warped wafer is adjusted by using a mechanical force physical method, and the method is more simple and efficient.

[0013] Further, the surfaces of the inner disc and the outer disc are provided with first adsorption holes, and the first adsorption holes are connected with the first vacuum equipment.

[0014] Further, the sidewalls of the inner disc and the outer disc are provided with second adsorption holes, and the second adsorption holes are connected with the second vacuum equipment.

[0015] Further, the driving assembly comprises a first driving unit, a second driving unit and a third driving unit, the first driving unit, the second driving unit and the third driving unit are connected with the outer disc, the first driving unit is used for driving the outer disc to rotate around a first direction, the second driving unit is used for driving the outer disc to rotate around a second direction, and the third driving unit is used for driving the outer disc to move along a third direction.

[0016] Further, the first driving unit, the second driving unit and the third driving unit all comprise motors with encoders.

[0017] Further, the motor is a direct current motor or an alternating current motor.

[0018] Furthermore, the third drive unit also includes a ball screw, one end of which is connected to the motor in the third drive unit, and the other end is connected to the outer disk.

[0019] This utility model also provides a photolithography machine, including:

[0020] The lithography machine chuck is used to adjust the warpage of the wafer to a preset value;

[0021] A wafer warpage detection device is used to detect the warpage of the wafer.

[0022] A feedback system is used to provide real-time feedback on the warpage of the wafer.

[0023] The beneficial effects of the lithography machine provided by this utility model are as follows: Before exposure, the lithography machine uses a wafer warpage detection device to detect the morphology data of the wafer surface. If the obtained wafer warpage is greater than a preset value, the position of the wafer with warpage greater than the preset value is adjusted by the lithography machine chuck according to the surface morphology of the wafer. The feedback system provides real-time feedback on the wafer warpage achieved by the lithography machine chuck until the wafer warpage reaches the preset value, that is, the wafer surface reaches a certain flatness, and then the lithography machine chuck stops working. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the lithography machine chuck according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the first state of the photolithography machine chuck correcting a downwardly warped wafer according to an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the second state of the photolithography machine chuck correcting a downwardly warped wafer according to an embodiment of the present invention.

[0027] Figure 4 This is a schematic diagram of the photolithography machine chuck after correcting a warped wafer according to an embodiment of the present invention;

[0028] Figure 5 This is a schematic diagram of the first state of the photolithography machine chuck correcting an upwardly warped wafer according to an embodiment of the present invention.

[0029] Figure 6 This is a schematic diagram of the second state of the photolithography machine chuck correcting an upwardly warped wafer according to an embodiment of the present invention.

[0030] In the figure: 1. Inner disk; 11. First adsorption hole; 2. Outer disk; 3. Wafer; 4. Driving assembly; 41. First driving unit; 42. Second driving unit; 43. Third driving unit. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this utility model pertains. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed following the word and its equivalents, but does not exclude other elements or objects.

[0032] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings.

[0033] like Figures 1-6 As shown, an embodiment of this utility model provides a lithography machine chuck for adsorbing wafers to be processed. The wafers are placed on the lithography machine chuck, meaning the chuck simultaneously supports and fixes the wafers. The lithography machine chuck includes: a base, an inner disk 1, an outer disk 2, and a driving assembly 4. The inner disk 1 is fixedly mounted on the base, the outer disk is movably connected to the base, and the driving assembly is installed in the base. That is, the base serves as the support for the inner disk 1, the outer disk 2, and the driving assembly 4. The inner disk 1 and the outer disk 2 are designed as a split structure, which allows for both supporting and fixing the wafer 3, and also enables the adjustment of warped wafers 3, thereby eliminating defocusing and reducing overlay errors. The driving assembly 4 provides the driving force to drive the outer disk 2 relative to the inner disk 1.

[0034] Wafer 3 includes a central region and an edge region. The central region is circular, and the edge region surrounds the central region in a ring. Inner disk 1 is in contact with the central region, and outer disk 2 is in contact with the edge region. It should be noted that the dimensions of inner disk 1 and outer disk 2 are not limited in actual manufacturing. The size ratio between inner disk 1 and outer disk 2 can be specifically set according to the actual size of wafer 3. For example, for a wafer with a diameter of 150mm, the center of the wafer is used as the center, the 145mm diameter circular part is divided into the central region, and the remaining part is divided into the edge region. Inner disk 1 and outer disk 2 are set accordingly.

[0035] The outer disk 2 is fitted over the inner disk 1, and during operation, the outer disk 2 and the inner disk 1 are in contact. The drive assembly 4 is connected to the outer disk 2, causing the outer disk 2 to move the edge region of the wafer 3 relative to the center region. When the edge region of the wafer 3 warps, the drive assembly 4 drives the outer disk 2 to move the edge region it adheres to relative to the center region until the warpage of the wafer 3 is adjusted to a preset value, thus making the wafer 3 flat.

[0036] like Figures 2-4 As shown and in conjunction with reference Figure 1 The warped shape of wafer 3 is umbrella-shaped (downward warping), meaning the height of the edge region of wafer 3 (height refers to the height of the center and edge regions of wafer 3 relative to the inner disk 1) is lower than that of the center region of wafer 3 (Note: To clearly show the height difference between the center and edge regions of the wafer, the center region in the illustration is far from the inner disk 1, but in reality, the inner disk 1 is in contact with the center region). At this point, the edge region of wafer 3 needs to be lifted upwards to achieve a certain flatness. Specifically, under the action of the vacuum equipment, the inner disk 1 adsorbs the center region of wafer 3, and the edge region of wafer 3 is adsorbed and fixed to the outer disk 2. The drive component 4 connected to the outer disk 2 drives the outer disk 2 to move upwards until wafer 3 achieves flatness, at which point the movement of the outer disk 2 stops. The drive component 4 is then activated, causing the outer disk 2 to move downwards and reset, and wafer 3 is moved synchronously to reset, thus obtaining a flat wafer 3 on the inner disk 1 and outer disk 2.

[0037] like Figures 5-6 As shown and in conjunction with reference Figure 1 and Figure 4 The warped shape of wafer 3 is bowl-shaped (upwardly warped), meaning the height of the edge region of wafer 3 (height refers to the height of the center and edge regions of wafer 3 relative to the inner disk 1) is higher than that of the center region of wafer 3. Therefore, the edge region of wafer 3 needs to be pulled downwards to achieve a certain degree of flatness. Specifically, under the action of a vacuum device, the inner disk 1 adheres to the center region of wafer 3, and the drive assembly 4 drives the outer disk 2 to move upwards relative to the inner disk 1 until the outer disk 2 adheres and is fixed to the edge region of wafer 3. Then, the drive assembly 4 drives the outer disk 2 to move downwards relative to the inner disk 1, and the outer disk 2 drives the wafer 3 it adheres to to move downwards synchronously until wafer 3 is flat, thus obtaining a flat wafer 3 supported on the inner disk 1 and the outer disk 2.

[0038] like Figure 1As shown in the utility model some embodiments, the inner disc 1 and the outer disc 2 are provided with first suction hole 11. First suction hole 11 is communicated with first vacuum equipment, to this adsorption wafer 3. Utilize first suction hole 11 to adsorb wafer 3, the inner disc 1 adsorbs the central region of wafer 3, and the outer disc 2 adsorbs the edge region of wafer 3. Thereby under the premise of the inner disc 1 and the outer disc 2 adsorbing wafer 3, drive the outer disc 2 to exert mechanical force on the edge of wafer 3, make it bend, to adjust the warping of the edge region of wafer 3.

[0039] As Figure 1 As shown in the utility model some embodiments, the side wall of the inner disc 1 and the outer disc 2 is provided with second suction hole. Second suction hole is communicated with second vacuum equipment. To this, in working, the inner disc 1 and the outer disc 2 are adsorbed together by second vacuum equipment, so that the inner disc 1 and the outer disc 2 are close, ensure that the gap between them is very small.

[0040] It should be noted that the first vacuum equipment and the second vacuum equipment can be the same vacuum equipment. First suction hole 11 and second suction hole are at least one. Preferably, first suction hole 11 and second suction hole are uniformly provided with multiple. By first suction hole 11, the inner disc 1 and the outer disc 2 are uniformly distributed on the surface, so that wafer 3 is more uniform when being adsorbed. By connecting with first vacuum equipment, starting vacuum suction, so that negative pressure is generated in the photolithography chuck, thereby adsorbing wafer 3. Specifically, in the process of adsorbing wafer 3, under the action of vacuum equipment, first suction hole 11 generates vacuum pressure, so that wafer 3 is sucked; when wafer 3 needs to be released, vacuum equipment stops generating vacuum pressure, and blows air with certain pressure and flow into first suction hole 11, so as to break the vacuum, so as to facilitate the better separation of wafer 3 and the bearing surface of photolithography chuck. The process of adsorbing the inner disc 1 and the outer disc 2 by second suction hole is the same, and is not repeated here.

[0041] As Figure 1 As shown in the utility model some embodiments, drive assembly 4 includes first drive unit 41, second drive unit 42 and third drive unit 43. First drive unit 41, second drive unit 42 and third drive unit 43 are connected with outer disc 2. First drive unit 41 is used for driving outer disc 2 to rotate around first direction. Second drive unit 42 is used for driving outer disc 2 to rotate around second direction. Third drive unit 43 is used for driving outer disc 2 to reciprocate linearly along third direction. First direction, second direction and third direction are perpendicular to each other. For example, the first direction is X axis direction, the second direction is Y axis direction, and the third direction is Z axis direction, and the Z axis direction is perpendicular to the base.

[0042] According to the corresponding three-dimensional warping measurement, the first driving unit is arranged to realize the rotating movement of the outer disc around the X axis, so as to rotate the warped edge region by a certain angle relative to the X axis; the second driving unit is arranged to realize the rotating movement of the outer disc around the Y axis, so as to rotate the warped edge region by a certain angle relative to the Y axis; and the third driving unit is arranged to realize the up-down reciprocating linear movement of the outer disc in the Z axis direction, so as to adjust the edge region of the wafer up and down, and thus the adaptive adjustment can be realized according to the actual warping direction, which is helpful to the adjustment of various warping forms. That is, through the adjustment of the warping degree of the wafer 3 in the three-dimensional coordinate system, the effect of accurately adjusting the warping degree of the wafer 3 in the Rx, Ry and z directions can be realized.

[0043] As shown in Figure 1 some embodiments of the utility model, the first driving unit 41, the second driving unit 42 and the third driving unit 43 all include the motor with the encoder, that is, the encoder is arranged in the motor and is used integrally. The motor serves as the driving force and provides the driving force for the movement of the outer disc 2. The motor with the encoder is arranged, the working space is saved, and the working efficiency is improved. The encoder is used to record the position and speed information of the motor in real time, can feed back the information of the movement state of the motor to the controller, thereby realizing the accurate control. The controller adjusts the operation of the motor according to these data, and then can accurately control the position and speed of the movement of the outer disc 2 in the three-dimensional coordinate system, realizes the accurate control to the edge region of the wafer 3. It should be noted that the first driving unit 41, the second driving unit 42 and the third driving unit 43 can also be the motor without the encoder, but the encoder is externally connected for use, that is, the encoder and the motor are used separately.

[0044] As shown in Figure 1 some embodiments of the utility model, the third driving unit 43 further includes the ball screw. One end of the ball screw is connected with the motor in the third driving unit 43, and the other end is connected with the outer disc 2. The ball screw includes the screw rod, the nut and the ball. The ball screw converts the rotating movement of the motor into the linear movement, so that the outer disc 2 moves with the edge region of the wafer 3 on the Z axis, and the transmission efficiency is improved.

[0045] As shown in Figure 1As shown, in some embodiments of the present application, the motor is a DC motor or an AC motor. That is, any driving device that can drive the outer disc 2 to move can be used, and the motor can be selected flexibly according to actual use. For example, the motor is an AC motor, and the AC motor includes a permanent magnet and an electromagnet. This structure is simple, efficient, and can effectively drive the outer disc 2 to move. The rotor is rotated by the magnetic force of the permanent magnet and the magnetic force generated by the electromagnet. The magnetic force generated between the permanent magnet and the electromagnet is repulsive force by intermittent energization of each electromagnet, and the electromagnet is rotated by the repulsive force. According to the obtained warping data, different directions and different sizes of current are supplied to the electromagnet, so that the electromagnet moves and drives the outer disc 2 to move synchronously. The composition of the motor is not limited to this embodiment, and any motor structure that can drive the outer disc 2 can be used.

[0046] For example, the encoder includes a reading head and a grating ruler. The reading head is connected to the electromagnet, and the grating ruler is connected to the permanent magnet. The displacement information of the permanent magnet relative to the electromagnet is obtained by the relative movement between the reading head and the grating ruler. The data is read by the reading head, and the movement of the motor is accurately controlled according to the data.

[0047] The embodiment of the present application provides a photoetching machine, which comprises a photoetching machine suction disc, a wafer warping detection device and a feedback system. The photoetching machine suction disc is used for adjusting the warping degree of the wafer to a preset value. The wafer warping detection device is used for detecting the warping degree of the wafer. The feedback system is used for feeding back the warping degree of the wafer in real time.

[0048] The photoetching machine detects the topographic data of the wafer surface by the wafer warping detection device before exposure. If the obtained wafer warping degree is greater than the preset value, the wafer surface topography is adjusted by the photoetching machine suction disc in the three-dimensional coordinate system, and the feedback system feeds back the wafer warping degree adjusted by the photoetching machine suction disc in real time until the wafer warping degree reaches the preset value, that is, the wafer surface reaches a certain flatness, and the photoetching machine suction disc stops working. The other components of the photoetching machine are not described here.

[0049] In summary, the inner disc 1 and the outer disc 2 are provided in a split structure, which can not only carry and adsorb and fix the wafer, but also adjust the warping degree of the wafer by using the split structure. Specifically, when the edge region of the wafer is warped, the wafer that is warped needs to be adjusted. The wafer that is warped is placed on the photoetching machine suction disc, and the center region of the wafer is located on the inner disc to carry the center region by the inner disc. The driving assembly drives the outer disc to move relative to the inner disc, the outer disc acts on the edge region, and drives the edge region to move relative to the center region, so that the wafer is in a flat state, thereby overcoming the warping problem of the edge region relative to the center region, and effectively avoiding the defocus phenomenon and reducing the overlay error.

[0050] Although the embodiments of the present application have been described in detail above, it is obvious to those skilled in the art that various modifications and changes can be made to the embodiments. However, it should be understood that such modifications and changes are within the scope and spirit of the present application as described in the claims. Moreover, the present application described herein can have other embodiments and be practiced or implemented in various ways.

Claims

1. A photolithography chuck for holding a wafer to be processed, said wafer being placed on said photolithography chuck, said wafer comprising a central region and a peripheral region, characterized in that, The photolithography chuck comprises: a base; an inner disc fixedly installed on the base, the inner disc being in contact with the central region; an outer disc movably connected with the base, the outer disc being in contact with the edge region, the outer disc being sleeved outside the inner disc so that the outer disc and the inner disc are tightly attached; a driving assembly installed in the base, the driving assembly being connected with the outer disc, the driving assembly being used to drive the outer disc to move relative to the inner disc.

2. The photolithography chuck of claim 1, wherein, The surface of the inner disc and the surface of the outer disc are both provided with first suction holes, the first suction holes being in communication with a first vacuum device.

3. The photolithography chuck of claim 1, wherein, The sidewall of the inner disc and the sidewall of the outer disc are both provided with second suction holes, the second suction holes being in communication with a second vacuum device.

4. The photolithography chuck of claim 1, wherein, The driving assembly comprises a first driving unit, a second driving unit and a third driving unit, the first driving unit, the second driving unit and the third driving unit all being connected with the outer disc, the first driving unit being used to drive the outer disc to rotate around a first direction, the second driving unit being used to drive the outer disc to rotate around a second direction, and the third driving unit being used to drive the outer disc to make reciprocating linear motion along a third direction.

5. A photolithography chuck as claimed in claim 4, characterized in that The first driving unit, the second driving unit and the third driving unit all comprise motors with encoders.

6. A photolithography chuck as claimed in claim 5, characterized in that The motor is a direct current motor or an alternating current motor.

7. The photolithography chuck of claim 5, wherein, The third driving unit further comprises a ball screw, one end of the ball screw being connected with the motor in the third driving unit, and the other end of the ball screw being connected with the outer disc.

8. A lithographic machine characterized by, The photolithography chuck comprises: The photolithography chuck according to any one of claims 1-7, used to adjust the warping degree of the wafer to a preset value; a wafer warping detection device used to detect the warping degree of the wafer; a feedback system used to feed back the warping degree of the wafer in real time.

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