TW202241644A - Chemical mechanical polishing apparatus and the wafer buffering device and method therein - Google Patents

Abstract

A chemical mechanical polishing device as well as a wafer caching apparatus and a wafer caching method thereof. The wafer caching apparatus is arranged between a polishing unit and a cleaning unit of the chemical mechanical polishing device, and the wafer caching apparatus comprises a caching box body, a driving assembly provided on the caching box body, and a wafer storage assembly connected to the driving assembly and provided in the caching box body. The driving assembly drives the wafer storage assembly to rise from the internal of the caching box body, and a wafer holder leaves a water environment in the caching box body; a wafer is placed into the wafer holder by a manipulator, or the wafer is grabbed from the wafer holder by the manipulator; and the driving assembly drives the wafer storage assembly to be lowered into the caching box body, and the wafer holder enters the water environment in the caching box body. According to the present invention, the time at which the wafer is exposed to air without cleaning and drying is reduced, and the quality and yield of the wafer are improved.

Description

Chemical mechanical polishing equipment, wafer caching device and wafer caching method thereof

The invention relates to semiconductor manufacturing equipment, in particular to chemical mechanical polishing equipment, a wafer buffering device and a wafer buffering method thereof.

Existing CMP (Chemical Mechanical Planarization), chemical mechanical polishing equipment usually includes a front-end module EFEM, a polishing unit and a cleaning unit. With the continuous development of semiconductor manufacturing process, higher requirements are put forward for the precision and cleanliness of wafer production. In the process of chemical mechanical polishing planarization, when the wafer passes through the polishing unit, the polishing liquid is attached to the surface of the wafer. If the time for transferring the wafer to the cleaning unit is too long, the polishing liquid will dry and adhere to the wafer, which will affect the Wafer quality and yield. If the cleaning unit or polishing unit breaks down or is blocked during the process of recycling wafers after the operation is completed, the wafers that have entered the polishing unit cannot keep the surface in a wet state, which will affect the quality and yield of the wafers.

The object of the present invention is to provide a chemical mechanical polishing device, a wafer buffering device and a wafer buffering method, which reduce the time for the wafer to be exposed to the air without cleaning, and improve the quality and yield of the wafer.

In order to achieve the above object, the present invention provides a wafer buffer device, which includes: a buffer box, a driving element arranged on the buffer box, and a The wafer storage element in the box; the drive element drives the wafer storage element to move up and down in the buffer box, so that the wafers on the wafer storage element leave or enter the water environment in the buffer box .

The driving element is arranged outside or inside the buffer box.

The wafer storage element includes: a wafer holder fixedly connected to the drive element, and at least two wafer holders fixedly connected to the wafer holder.

The wafer seats are arranged in parallel and spaced up and down.

The wafer buffer device further includes a case cover, which is fixedly connected to the driving element and located above the wafer seat, and the size of the case cover matches the opening size of the buffer case.

A water supply and drainage port and an overflow port are arranged on the buffer box.

The wafer buffering device further includes a manipulator to cooperate with the buffering device, and the manipulator includes at least two degrees of freedom of lifting and horizontal movement.

The wafer seat includes a notch, and the notch is in line with the direction of the manipulator.

The present invention also provides a chemical mechanical polishing equipment, comprising: a polishing unit, which is used to polish the wafer; A cleaning unit, which is used to clean the polished wafer; At least one wafer buffering device, which is arranged between the polishing unit and the cleaning unit, is used for buffering wafers, so that the wafers are protected by water environment for a long time.

The wafer buffer device further includes a transfer manipulator for performing wafer grabbing and placing operations on the wafer buffer device.

The transfer manipulator includes: a rotating shaft, a mechanical arm, and a gripper. The gripper is mounted on the rotating shaft through the robotic arm. The rotating shaft provides two functions: rotation around the Z axis and Z-direction lifting. degree of freedom, the mechanical arm drives the gripper to move in the horizontal X direction.

The present invention also provides a wafer caching method. The driving element drives the wafer storage element to rise from the buffer box, and the wafer seat leaves the water environment in the buffer box; the wafer is placed into the wafer seat by a manipulator, or mechanical The hand grabs the wafer from the wafer seat; the driving element drives the wafer storage element to drop into the buffer box, and the wafer seat enters the water environment in the buffer box.

The manipulator is a manipulator in the cleaning area, or a manipulator in the polishing area, or a transfer manipulator.

Grab the wafers from the wafer holders of the wafer buffer device in order from top to bottom, first grab the wafers in the uppermost wafer holders, and the lower wafer holders that have not been grabbed wafers are still in the cache In the water environment in the box.

Place the wafers into the wafer holders of the wafer buffering device in the order from bottom to top, the wafers are first placed into the lowermost wafer holders, and the wafer holders that have already placed the wafers are lowered into the water in the buffer box. environment.

The present invention has the following beneficial effects: 1. The wafer buffer device is arranged between the polishing unit and the cleaning unit. The positions of the manipulator and the wafer buffer device are flexibly arranged, so that the manipulator can transfer the wafer from the polishing unit and the cleaning unit to the wafer buffer device respectively, reducing the number of wafers. The time the circle is exposed to air without cleaning. 2. The buffer box is designed with a water tank to protect the wafers in the water environment for a long time. 3. The driving components are arranged outside the buffer box to isolate the power mechanism from the water environment. 4. Wafer seats are arranged in parallel and spaced up and down, which realizes the stacking and storage of wafers up and down, saving space. 5. The wafer buffer device has a lifting function, which can realize the functions of picking and placing wafer positioning, opening and closing the buffer box, etc., reducing the stroke requirements of the transmission wafer manipulator, and placing the wafer on the wafer support of the buffer box. The order is from bottom to top. When the wafer holder rises and cooperates with the manipulator to pick and place the wafer, other wafers are still in the water environment, which can make full use of the space, increase the number of wafers that can be stored, and reduce the number of wafers due to transportation. and exposure time in air.

A preferred embodiment of the present invention will be specifically described below with reference to FIGS. 1 to 7 .

FIG. 1 is a schematic diagram of the arrangement method of the wafer buffer device 100. The transfer manipulator 501 and the wafer buffer device 100 can be arranged between the polishing unit 400 and the cleaning unit 200, wherein the transfer manipulator 501 realizes the EFEM front-end module 600 . Wafer transfer between the cleaning unit 200 and the polishing unit 400 . When the machine breaks down, causing the wafers to be unable to complete all the polishing, cleaning, and drying processes and to be recycled to the EFEM front-end module 600, the uniformity of the wafers being cleaned, wafers that have entered the contaminated area to be polished, and wafers being polished It can be transferred to the wafer buffer device 100 by the transfer manipulator 501, so that the wafer is protected by the wafer water environment for a long time, so that the wafer can be safely stored during the maintenance process of the unit, so that the wafer is not protected from chemical liquid crystallization on it. Waiting for pollution, when the standby station resumes normal operation, the wafers stored in the wafer buffer device 100 can be restored to the operation state before the failure in sequence.

As shown in FIG. 2 , it is a structural diagram of a wafer buffer device 100 provided in this embodiment. The wafer buffer device 100 includes: a buffer box 105, a driving element arranged on the buffer box 105, and a wafer storage element connected to the driving element and arranged in the buffer box 105, the The driving element can drive the wafer storage element to move up and down in the buffer box 105 , so that the wafers on the wafer storage element leave or enter the water environment in the buffer box 105 .

The drive assembly includes: a linear drive mechanism 111 disposed outside the buffer box 105 , a guide rail 101 connected to the linear drive mechanism 111 , and a slider 104 movable along the guide rail 101 . The drive element is arranged outside the buffer box 105, which is beneficial to improve the lifespan and anti-corrosion performance of the linear drive mechanism 111 .

The wafer storage element includes: a wafer holder 102 fixedly connected to the slider 104 , a plurality of wafer holders 106 fixedly connected to the wafer holder 102 , and the wafer holders 106 are arranged in parallel and spaced up and down.

In this embodiment, the wafer buffer device 100 further includes a case cover 103, which is fixedly arranged on the slider 104 and located above the wafer seat 106. The size of the case cover 103 is the same as that of the The size of the opening of the buffer box 105 matches, and when the linear drive mechanism 111 drives the slider 104 to drive a plurality of wafer seats 106 all down into the buffer box 105, the box cover 103 can completely close the buffer box The opening of the body 105.

The buffer tank 105 is provided with a water supply and drainage port 110 and an overflow port 112 .

As shown in Figure 2, the transfer manipulator 501 includes: a rotating shaft 107, a mechanical arm 108, and a gripper 109, the gripper 109 is installed on the rotating shaft 107 through the mechanical arm 108, and the rotating The shaft 107 provides two degrees of freedom of rotation around the Z axis and lifting in the Z direction, and the mechanical arm 108 can drive the gripper 109 to move in the horizontal X direction and Y direction. When the slider 104 drives the wafer holder 106 away from the upper edge of the buffer box 105 , the clamping claws 109 move to the wafer holder 106 to realize wafer grabbing and placement operations.

3A and 3B are schematic diagrams of the process of wafers entering the wafer buffering device. As shown in Figure 3A, the gripper 109 on the transfer manipulator 501 grips the wafer to be buffered, and the rotating shaft 107 drives the wafer to align with the wafer seat 106 in the buffer box 105; the water supply and drainage port at the bottom of the buffer box 105 110 is connected to the two-position three-way pipeline, and the operation of filling deionized water can be controlled according to the needs, until the deionized water covers the overflow port 112, and the water depth is enough to cover all the wafer holders 106; the linear drive mechanism 111 pushes the slider 104 Drive the wafer holder 102 to rise until the height of the bottom empty wafer holder 106 exceeds the buffer box 105; the rotating shaft 107 on the transfer manipulator 501 descends, driving the wafer to move to align with the bottom empty wafer holder 106 (1) The height between it and the upper wafer seat 106 (2); the horizontal movement of the mechanical arm 108 drives the wafer to move to the bottom of the empty wafer seat 106 (1); the rotation axis 107 descends to drive the wafer to move to the wafer On the round seat 106(1), the wafer falls into the wafer seat 106(1) after the gripper 109 is opened; the mechanical arm 108 and the rotating shaft 107 drive the gripper 109 in reverse stroke to pick up the second wafer to be buffered . After the wafer holder 106(1) receives the wafer, the slider 104 drives the wafer holder 102 down until the wafer is completely covered by the deionized water in the buffer box 105, and at the same time, the empty wafer holder 106(2) on the upper layer At the height beyond the top edge of the buffer box 105 , the second wafer arrives after being transported by the gripper 109 . By analogy, as shown in FIG. 3B , when all the wafers to be cached are in the deionized water protection state in the buffer box 105 , the slider 104 drives the box cover 103 down to the state of closing the buffer box 105 . When it is necessary to resume the previous operation of the wafer, the slider 104 drives the wafer support 102 to rise, so that the wafer on the top layer reaches a height beyond the buffer box 105, while the wafer on the lower layer is still in the water protection state; the transfer manipulator 501 presses the Similar to the previous process of placing the wafer, the wafer is grabbed to the position before the cache; the slider 104 drives the wafer holder 102 to move up, and so on, all the wafers rise above the water surface and are transported by the gripper 109 to the state before the cache. When all the wafers in the buffer box 105 are taken away, the slider 104 descends to drive the box cover 103 to close the buffer box 105, so that the interior is not polluted by external particles, which is beneficial to keep the interior clean when not in use for a long time. Simultaneously, the water outlet 110 at the bottom of the buffer box 105 opens the drain valve to drain all the deionized water in the buffer box 105 .

As shown in FIGS. 4-6 , the wafer buffer device 100 is arranged between the polishing unit 400 and the cleaning unit 200 , and the buffer box 105 is placed under the polishing turntable 302 to save space. When the wafers in the polishing unit 400 need to be buffered, the polishing platform 401 first transfers the wafers to the loading stage 301, and then the polishing area manipulator 502 transfers the wafers 601, 602 from the loading table 301 to the transfer table 302; After the wafer holder 106 is lifted beyond the buffer box 105 , the transfer manipulator 501 sequentially transfers the wafers from the transfer table 302 to the wafer holder 106 . When the wafers in the cleaning units 201 , 202 , 203 , 204 need to be buffered, the transfer robot 501 transfers the wafers from the cleaning unit 200 to the wafer seat 106 . The wafer buffer box 105 can be arranged in the area between the polishing unit 200 and the cleaning unit, and the location is flexible. When the transfer robot 501 is used as a transfer robot for multiple units at the same time, the buffer box 105 needs to be arranged at a position where the transfer robot 501 can pick up the wafer. At the same time, a configuration in which a single manipulator is paired with multiple buffer boxes 105 can be realized. As shown in FIG. 6 , the buffer box 105 is arranged on the lower stage of the polishing transfer table 302 and on the other side of the transfer robot 501 at the same time, which increases the number of wafers that can be buffered.

In one embodiment of the present invention, the drive element can be replaced by: ball screw, electric cylinder, pneumatic/hydraulic and other linear motion mechanisms, the drive element can be arranged inside the wafer buffer box 105, but Anti-corrosion measures are required. Adopting screw drive, it has self-locking ability, that is, it can keep the height positioning of the wafer seat 106 stable and unchanged when the motor is powered off.

In another embodiment of the present invention, the lifting drive of the linear drive mechanism 111 is driven by a servo motor, and the height of each wafer is precisely controlled and positioned to be away from the water surface, so that the wafer placed on the wafer support 102 can be as far as possible. The circle is in a state of water environmental protection. An alternative solution is a single positioning drive such as an air cylinder, so that the entire wafer needs to be exposed to the air every time the wafer is picked and placed, which increases the risk of wafer drying and crystallization.

In another embodiment of the present invention, the wafer holder 106 is fixed on the wafer holder 102 in parallel, and the distance between each other is preferably 10-60 mm, so that the claw clips 109 can be picked and placed without interfering with the wafer holder 106, and the lower wafer The wafers on the round seat 106 can just be in a water-protected state, that is, the space can be fully utilized to increase the number of wafers that can be stored, and at the same time reduce the time that the wafers are exposed to the air due to transportation.

In another embodiment of the present invention, the overflow port 112 and the water supply and drainage port 110 on the buffer box 105 are used to adjust the water volume in the buffer box 105. Preferably, the water supply and drainage port 110 is set at the bottom of the buffer box 105, and the top The overflow port is set, and the bottom water supply and drainage port 110 is used as the main water inlet. At the same time, the bottom drainage can be adjusted by the control valve, which is convenient for the installation and feedback of the water level sensor. 112 discharge. As an alternative, the water inlet and outlet can be added, exchanged or changed according to actual control needs.

In another embodiment of the present invention, the buffer box 105 may not be docked with the transfer manipulator 501 , and the manipulator in the cleaning area (not shown in the figure) or the manipulator 502 in the polishing area may directly pick and place the wafers.

In another embodiment of the present invention, the wafer seat 106 on the wafer holder 102 has a directionality, that is, the wafer seat 106 has a notch to avoid the gripper of the manipulator, so as to facilitate picking and placing the wafer. The notch on the wafer seat 106 should be in the same direction as the jaws of the manipulator, so as to support the wafer while avoiding the manipulator for picking and placing the wafer. When the transfer manipulator 501 is used to pick and place the wafer, the wafer seat 106 is preferentially paired with the gripper 109 that moves in the X direction. The wafer seat 106 is adjusted to match the jaws 109 that move in the Y direction.

As shown in FIG. 7 , in another embodiment of the present invention, according to actual conditions, the wafer buffer device may not have a box cover.

The present invention has the following beneficial effects: 1. The wafer buffer device is arranged between the polishing unit and the cleaning unit. The positions of the manipulator and the wafer buffer device are flexibly arranged, so that the manipulator can transfer the wafer from the polishing unit and the cleaning unit to the wafer buffer device respectively, reducing the number of wafers. The time the circle is exposed to air without cleaning. 2. The buffer box is designed with a water tank to protect the wafers in the water environment for a long time. 3. The driving components are arranged outside the buffer box to isolate the power mechanism from the water environment. 4. Wafer seats are arranged in parallel and spaced up and down, which realizes the stacking and storage of wafers up and down, saving space. 5. The wafer buffer device has a lifting function, which can realize the functions of picking and placing wafer positioning, opening and closing the buffer box, etc., reducing the stroke requirements of the transmission wafer manipulator, and placing the wafer on the wafer support of the buffer box. The order is from bottom to top. When the wafer holder rises and cooperates with the manipulator to pick and place the wafer, other wafers are still in the water environment, which can make full use of the space, increase the number of wafers that can be stored, and reduce the number of wafers due to transportation. and exposure time in air.

It should be noted that, in the embodiments of the present invention, the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "Back", "Left", "Right", "Vertical", "Horizontal", "Top", "Bottom", "Inner", "Outer", "Clockwise", "Counterclockwise", "Axial" , "radial", "circumferential" and other indicated orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments, rather than indicating or implying that the referred device or element must have Certain orientations, constructed and operative in certain orientations, therefore are not to be construed as limitations on the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In the present invention, unless otherwise clearly specified and limited, terms such as "installation", "connection", "connection" and "fixation" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection , or integrated; it can be mechanically connected or electrically connected; it can be directly connected or indirectly connected through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention according to specific situations.

Although the content of the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as limiting the present invention. Various modifications and alterations to the present invention will become apparent to those skilled in the art upon reading the above disclosure. Therefore, the protection scope of the present invention should be limited by the scope of the appended patent application.

100: Wafer cache device 101: guide rail 102: wafer support 103: box cover 104:Slider 105: Cache box 106, 106 (1), 106 (2), 106 (3): wafer holder 107:Rotary axis 110: drain 108: Mechanical arm 109: Gripper 110: drain 111: Linear drive mechanism 112: overflow port 200, 201, 202, 203, 204: cleaning unit 301: slide table 302: Repeater 400: polishing unit 401: Polishing platform 501: Transit manipulator 502: Manipulator in polishing area 600:EFEM front-end module 601, 602: Wafer X, Y, Z: direction/direction

FIG. 1 is a schematic diagram of a method for arranging a wafer buffer device provided in an embodiment of the present invention. FIG. 2 is a schematic structural diagram of a wafer buffer device provided in an embodiment of the present invention. 3A and 3B are schematic diagrams of the process of wafers entering the wafer buffering device. FIG. 4 is a layout diagram of a wafer buffer device arranged between a polishing unit and a cleaning unit in an embodiment of the present invention. FIG. 5 is a side view of FIG. 4 . FIG. 6 is a top view of FIG. 4 . FIG. 7 is a schematic structural diagram of a wafer buffer device without a case cover provided in an embodiment of the present invention.

100: Wafer cache device

101: guide rail

102: wafer support

103: box cover

104:Slider

105: Cache box

106(1), 106(2), 106(3): wafer holder

107:Rotary axis

108: Mechanical arm

109: Gripper

110: drain

111: Linear drive mechanism

112: overflow port

501: Transit manipulator

601, 602: Wafer

X, Y, Z: direction/direction

Claims (15)

A wafer buffering device, the wafer buffering device comprising: a buffering box, a driving element arranged on the buffering box, and a wafer storage element connected to the driving element and arranged in the buffering box; The driving element drives the wafer storage element to move up and down in the buffer box, so that the wafers on the wafer storage element leave or enter the water environment in the buffer box. The wafer buffer device according to claim 1, wherein the drive assembly is arranged outside or inside the buffer box. The wafer buffer device according to claim 1, wherein the wafer storage element comprises: a wafer holder fixedly connected to the drive element, and at least two wafer holders fixedly connected to the wafer holder. The wafer buffer device according to claim 3, wherein the wafer seats are arranged in parallel and spaced up and down. The wafer buffer device according to claim 3, wherein the wafer buffer device further includes a case cover, which is fixedly connected to the driving element and located above the wafer seat, and the size of the case cover is the same as the Match the opening size of the buffer box described above. The wafer buffer device according to claim 1, wherein the buffer box is provided with water supply and drainage ports and overflow ports. The wafer buffering device according to claim 1, wherein the wafer buffering device further includes a manipulator for use with the buffering device, and the manipulator includes at least two degrees of freedom of lifting and horizontal movement. The wafer buffer device as claimed in claim 7, wherein the wafer seat includes a notch, and the notch is in line with the direction of the manipulator. A chemical mechanical polishing device comprising: a polishing unit, which is used to polish the wafer; A cleaning unit, which is used to clean the polished wafer; At least one wafer buffering device as described in any one of claim 1 to claim 8, which is arranged between the polishing unit and the cleaning unit, and is used for buffering the wafer so that the wafer is kept in a long-term Water environment protection. The chemical mechanical polishing equipment as claimed in claim 9, wherein the wafer buffer device further includes a transfer manipulator, which is used to carry out wafer grabbing and placing operations on the wafer buffer device. The chemical mechanical polishing equipment according to claim 10, wherein the transfer manipulator comprises: a rotating shaft, a mechanical arm, and a gripper, the gripper is mounted on the rotating shaft through the mechanical arm, the The rotation axis provides two degrees of freedom of rotation around the Z axis and lifting in the Z direction, and the mechanical arm drives the gripper to move in the horizontal X direction. A wafer buffering method for chemical mechanical polishing equipment as described in any one of claim 9 to claim 11, the driving element drives the wafer storage element to rise from the buffer box, and the wafer seat leaves the buffer box Water environment; use the manipulator to place the wafer into the wafer seat, or use the manipulator to grab the wafer from the wafer seat; the driving element drives the wafer storage element to drop into the buffer box, and the wafer seat enters the water in the buffer box environment. The wafer caching method according to claim 12, wherein the manipulator is a manipulator in the cleaning area, or a manipulator in the polishing area, or a transfer manipulator. The wafer caching method as described in claim 12, wherein the wafers are grabbed from the wafer seats of the wafer buffer device in order from top to bottom, and the wafers in the uppermost wafer seats are grabbed first, and the lower layer Wafer pads with unpicked wafers remain in the water environment within the buffer tank. The wafer caching method as described in claim 12, wherein the wafers are placed in the wafer holders of the wafer buffering device in order from bottom to top, and the wafers are first placed in the lowermost wafer holders, and the wafers have been placed The wafer holder for the wafer is lowered into the aqueous environment within the buffer tank.

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