Wafer carrying device

Abstract

The invention provides a wafer carrying device. The wafer carrying device comprises a manipulator, a wafer centering and orienting module and a wafer box loading table, the wafer loading table is used for operating the wafer box; the manipulator is used for conveying the wafer between the wafer centering and orienting module and the wafer box loading table; the wafer centering and orienting module comprises a rotary supporting mechanism which can drive a wafer to rotate; the wafer jacking and traversing mechanism can translate and lift up and down; the wafer is jacked up from the rotary supporting mechanism during lifting, and the wafer falls back to the rotary supporting mechanism during descending; after the wafer is jacked up, the wafer jacking and transverse moving mechanism can drive the wafer to move in a horizontal plane; the rotary supporting mechanism comprises at least three first wafer supports, and each first wafer support is provided with a flexible pad at the position close to the edge of a wafer and the position close to the inner side of the wafer. The wafer jacking and transverse moving mechanism comprises at least three second wafer supports, and the positions, close to the edge of the wafer and the inner side of the wafer, of each second wafer support are each provided with a flexible pad.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment, and in particular to a wafer conveying device. Background Art

[0002] Traditional semiconductor chip processing technology is divided into front-end and back-end processes, among which the front-end process is the main one and the back-end is only chip packaging and testing. The front-end process includes: glue coating, photolithography, development, etching, ion implantation, thin film deposition, cleaning, chemical mechanical polishing, furnace heat treatment, testing, etc. The front-end process is difficult and requires high production capacity. Generally, the wafer needs to ensure a certain rigidity and strength during transportation and processing. Traditionally, the wafers of the front-end process have a certain thickness. For example, the standard thickness of 12-inch wafers is 0.775 mm, and the thickness of 8-inch wafers is 0.725 mm. During the back-end packaging, the wafer will be thinned to 1 / 3 of the thickness before cutting and packaging. The reason is that a wafer that is too thick will affect the heat dissipation of the chip.

[0003] After entering 2020, consumer electronics such as mobile phones and computer chips, AI chips, supercomputer chips, etc. have higher requirements for chip computing power, that is, the number of chip diodes is required to be further improved, and it is an increasing trend year by year. However, as Moore's Law approaches the physical limit, it is difficult to make the lithography exposure line width narrower. Another important technical route has begun to gain popularity. This technical route is advanced packaging technology, including emerging technologies such as rewiring and chip stacking, which have continuously emerged, effectively supporting the development of high-end chips, further improving the computing power of chips, and laying the foundation for the development of modern human science and technology.

[0004] Advanced packaging technology actually involves welding multiple wafers or chips together through contact points, so the wafers need to be thinned during the front-end process. The thinned wafers are softer and have greater sag, which places extremely stringent requirements on wafer handling. It is necessary to ensure that the wafers do not have large deformation stress during transportation, which may cause damage to the internal chip microcircuits.

[0005] Generally, a wafer handling equipment (EFEM, equipment front end module) is configured at the front end of the front-end process equipment, including a robot, a wafer centering and orientation module, multiple wafer box loading tables, and a horizontal moving axis used with the robot. Generally, in order to store ultra-high cleanliness wafers in a closed wafer box, the factory will configure a crane system to automatically drive the wafer box to different process equipment for processing. The wafer box will be transported by the crane to the wafer box loading table of the wafer handling system at the front end of the process equipment. The wafer box loading table opens the closed wafer box, and the robot takes out the wafer from the wafer box and transports it to the wafer centering and orientation module. After the wafer is centered and oriented, the robot takes the wafer and puts it at the loading port of the process equipment to complete the wafer transportation task.

[0006] The traditional EFEM uses vacuum adsorption fingers to fix the wafers for transport, and the wafer centering and orienting module also uses vacuum adsorption to fix the wafers for centering and orienting. The vacuum adsorption method can easily adsorb and break ultra-thin wafers, or the internal microscopic circuits can be damaged due to adsorption stress.

[0007] Therefore, how to solve the problem of wafer deformation and damage during transportation has become the focus of technical personnel in this field. Summary of the invention

[0008] The purpose of the present invention is to provide a wafer transport device which can solve the problem of wafer deformation and damage caused during the wafer transport process.

[0009] In order to achieve the above object, the present invention provides a wafer transport device, comprising:

[0010] Robot, wafer centering and orientation module and wafer box loading station;

[0011] The wafer loading station is used to operate the wafer box;

[0012] The robot is used to transfer wafers between the wafer centering and orientation module and the wafer box loading platform;

[0013] The wafer centering and orientation module comprises:

[0014] Base,

[0015] A rotating support mechanism, disposed on the base, capable of driving the wafer to rotate along its central axis;

[0016] The wafer lifting and lateral movement mechanism is arranged on the base and can be translated and lifted up and down; when lifting, the wafer is lifted from the rotating support mechanism, and when lowering, the wafer is dropped back onto the rotating support mechanism; after the wafer is lifted, the wafer lifting and lateral movement mechanism can drive the wafer to move in a horizontal plane;

[0017] The rotating support mechanism comprises at least three first wafer supports, each of which has a flexible pad arranged at a position close to the edge of the wafer and close to the inner side of the wafer;

[0018] The wafer lifting and transverse movement mechanism comprises at least three second wafer supports, and each of the second wafer supports is provided with a flexible pad at a position close to the edge of the wafer and close to the inner side of the wafer.

[0019] In an optional solution, the first wafer holder is in the shape of an elongated strip, one end of each of the first wafer holders corresponds to the center of the wafer, and the other end corresponds to the edge of the wafer; the included angle between any two adjacent first wafer holders is the same.

[0020] In an optional solution, the second wafer holder is arranged close to the periphery of the wafer to support the peripheral area of ​​the wafer; the second wafer holder is evenly distributed.

[0021] In an optional solution, an end effector is installed on the robot; the end effector includes at least one finger for carrying a wafer, the finger has two forks, and flexible pads are provided at both ends and in the middle of the fork.

[0022] In an optional solution, the end effector mechanism is divided into two layers, an upper layer and a lower layer, and each layer is provided with one of the fingers.

[0023] In an optional solution, the flexible pad is a rubber O-ring.

[0024] The beneficial effects of the present invention are:

[0025] The present invention arranges a plurality of flexible pads on the rotating support mechanism and the wafer lifting and lateral movement mechanism. The flexible pads can bear the edge and central area of ​​the wafer, can effectively support the ultra-thin wafer, and prevent the problem of the wafer being damaged due to deformation of the ultra-thin wafer's own weight during transportation. The flexible pads have an anti-slip function, and the wafer will not slide down without vacuum adsorption, thereby preventing the wafer from being broken due to vacuum adsorption. Flexible pads are also arranged at both ends and in the middle of the mechanical finger to effectively support the ultra-thin wafer, and prevent the wafer from being damaged due to deformation of the ultra-thin wafer's own weight during transportation, and prevent the problem of the wafer being broken due to vacuum adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, in which like reference numerals generally represent like components.

[0027] Figure 1It is a top view of a wafer transfer device in one embodiment of the present invention, in which the robot is in an initial position and the arm is not extended.

[0028] Figure 2 FIG. 4 is a top view of an end effector mechanism in one embodiment of the present invention.

[0029] Figure 3 It is a side view of the end effector in one embodiment of the present invention.

[0030] Figure 4 FIG. 4 is a top view of a wafer centering and orienting module in one embodiment of the present invention.

[0031] Figure 5 FIG. 4 is a side view of a wafer centering and orienting module in one embodiment of the present invention.

[0032] Description of reference numerals:

[0033] 1-wafer transport device; 2-wafer loading platform; 2-1-wafer box; 3-robot; 4-travel axis; 5-end actuator; 6-wafer centering and orienting module; 7-first wafer holder; 8-second wafer holder; 9-wafer identification sensor; 10-linear CCD sensor; 10-1-light curtain; 11-rotation axis; 12-finger; 13-presence detection sensor; 14-first finger connecting piece; 15-second finger connecting piece; 16-wafer; 17-flexible pad. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description and drawings, the advantages and features of the present invention will become clearer. However, it should be noted that the concept of the technical solution of the present invention can be implemented in a variety of different forms and is not limited to the specific embodiments described herein. The drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0035] It should be understood that when an element or layer is referred to as being "on, adjacent to, connected to or coupled to other elements or layers, it may be directly on, adjacent to, connected to or coupled to other elements or layers, or there may be intervening elements or layers. In contrast, when an element is referred to as being "directly on, directly adjacent to, directly connected to or directly coupled to other elements or layers, there may be no intervening elements or layers. It should be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present invention, the first element, component, region, layer or part discussed below may be represented as a second element, component, region, layer or part.

[0036] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0037] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0038] Example 1

[0039] Reference Figures 1 to 5 This embodiment provides a wafer transport device 1, comprising:

[0040] Robot 3, wafer centering and orientation module 6 and wafer box loading station 2;

[0041] The wafer loading station 2 is used to operate the wafer box 2-1;

[0042] The robot 3 is used to transfer the wafer 16 between the wafer centering and orientation module 6 and the wafer box loading platform 2;

[0043] The wafer centering and orientation module 6 comprises:

[0044] Base;

[0045] A rotating support mechanism, disposed on the base, capable of driving the wafer 16 to rotate along its central axis;

[0046] The wafer lifting and lateral movement mechanism is arranged on the base and can be translated and lifted up and down; when lifting, the wafer 16 is lifted from the rotating support mechanism, and when lowering, the wafer 16 is dropped back onto the rotating support mechanism; after the wafer 16 is lifted, the wafer lifting and lateral movement mechanism can drive the wafer 16 to move in a horizontal plane;

[0047] The rotating support mechanism comprises at least three first wafer supports 7, each of which has a flexible pad 17 arranged at a position close to the edge of the wafer and close to the inner side of the wafer;

[0048] The wafer lifting and transverse movement mechanism comprises at least three second wafer supports 8 , and each of the second wafer supports 8 is provided with a flexible pad 17 at a position close to the edge of the wafer and close to the inner side of the wafer.

[0049] Specifically, in this embodiment, the wafer transport device includes three wafer box loading tables 2. The three wafer loading tables 2 are used to operate their respective wafer boxes 2-1 (unlock and lock the wafer boxes 2-1); the robot 3 is equipped with an end effector 5, which is used to take and place the wafer 16.

[0050] The general wafer transport process of the wafer transport device 1 is as follows: the wafer box 2-1 is transported to the wafer loading platform 2 through the factory overhead crane system, the wafer loading platform 2 unlocks the wafer box 2-1, opens the front cover door of the wafer box, and scans how many wafers are in the wafer box 2-1 and in which slots they are respectively, and then drives the walking shaft 4 of the robot 3 to move horizontally to the front of the wafer loading platform 2, the robot 3 extends the end effector 5 to take out the wafer 16 from the unlocked wafer box 2-1, the robot 3 retracts the end effector 5, the robot 3 moves to the front of the wafer centering and orientation module 6, and hands over the wafer 16 to the wafer. On the centering and orienting module 6, the wafer centering and orienting module 6 rotates the wafer 16 and calculates the center position offset and angular position offset of the wafer 16 through the linear CCD sensor 10, and performs center position compensation and angular position compensation of the wafer. After completing the centering and orienting function, the robot 3 takes the wafer 16 out of the wafer centering and orienting module 6 and places it on the back-end process module. After the process is completed, the robot 3 puts the wafer 16 back into the wafer box 2-1, and so on to complete the process processing of all wafers. The wafer loading table 2 then locks the opened front cover door of the wafer box 2-1, and finally sends the wafer box 2-1 away through the factory overhead crane system to complete a cycle.

[0051] The basic centering and orientation logic of the wafer centering and orientation module 6 is the existing technology. Specifically, the linear CCD sensor 10 is a detection device. The light curtain 10-1 that blocks the linear CCD sensor 10 will cause the amount of light cast above to change. The light receiving sensor below will output a voltage signal of a certain proportion according to the strength of the incoming light. The robot 3 places the wafer 16 on the rotating support mechanism of the wafer centering and orientation module 6, and determines whether the handover is successful through the wafer identification sensor 9. After the handover is successful, the rotating shaft 11 of the rotating support mechanism rotates the wafer 16 for one circle. The position with the largest light shielding amount is the position where the sensor outputs the minimum voltage. The rotation angle a at this time is recorded. By comparing the standard light shielding amount of the standard non-eccentric wafer, the light shielding amount difference can be obtained, and then the light shielding amount is changed according to the light shielding amount. After calculating the distance deviation value, the wafer centering and orienting module first transfers the XY eccentricity of the wafer to a single X-axis according to the rotation angle a, and the wafer lifting and transverse shifting mechanism 8 lifts the wafer 16 from the rotating support mechanism, and the wafer lifting and transverse shifting mechanism 8 then moves the wafer distance deviation value. After completion, the wafer lifting and transverse shifting mechanism descends and puts the wafer 16 back on the rotating support mechanism, so that the centering of the wafer 16 is completed. Generally, there will be a Notch on the edge of the wafer 16. When the wafer 16 rotates on the wafer centering and orienting module 6, this notch will cause a sudden change in voltage, and the rotation angle b at this time is recorded. After the wafer is centered, the rotating shaft drives the wafer to rotate by angle b to complete the orientation function of the wafer 16. The above as a whole completes the centering and orienting function of the wafer 16.

[0052] In this embodiment, the rotating support mechanism includes three first wafer supports 7. The first wafer supports 7 are long strips, one end of each of the first wafer supports 7 corresponds to the center of the wafer 16, and the other end corresponds to the edge of the wafer 16; the angle between any two adjacent first wafer supports 7 is the same (that is, the three first wafer supports 7 are evenly distributed). Each first wafer support 7 is arranged with a flexible pad 17 near the edge of the wafer and near the inner side of the wafer, and a total of 6 flexible pads evenly support the edge and the inner side of the wafer, effectively ensuring the stability of the wafer during rotation and preventing the wafer from sagging. The wafer lifting and transverse movement mechanism includes three second wafer supports 8, which are arranged near the periphery of the wafer and are used to carry the peripheral area of ​​the wafer 16; the second wafer supports are evenly distributed. Each second wafer support 8 is arranged with a flexible pad 17 at the edge and the inner side of the wafer, and a total of 6 flexible pads evenly support the edge and the inner side of the wafer, effectively ensuring the stability of the wafer during rotation and preventing the wafer from sagging.

[0053] In this embodiment, the end effector 5 is divided into two layers, upper and lower, each with a finger 12, the upper finger is connected to the robot 3 through a first finger connector 14, and the lower finger is connected to the robot 3 through a second finger connector 15, so that the upper and lower fingers 12 can be extended and retracted separately to pick up and place the wafer 16, with high production capacity. The finger 12 is also equipped with a presence detection sensor 13 for detecting whether there is a wafer 16 on the finger 12. A flexible pad 17 is installed on the finger 12 to support the wafer 16. Considering that the movement of the manipulator 3 involves rotational acceleration and deceleration, as well as linear acceleration and deceleration, and the wafer is only placed on the flexible pad 17, it is necessary to consider the vibration stability and slippage of the wafer on the finger 12. The unit price of mid-to-high-end processed wafers ranges from more than 100,000 yuan. If the wafer slips or is damaged by vibration, it will cause great losses. Therefore, the finger 12 is designed to have a fork on each side, with a flexible pad 17 installed at the front and rear ends respectively. Considering that ultra-thin wafers are being transported, only supporting the edge of the wafer can significantly solve the stability and wafer drop problems of wafer transportation, but it cannot solve the problem of the wafer sagging due to its own weight near the center. In order to solve this problem, a flexible pad is also installed between the left and right forks, for a total of 6 flexible pads, which effectively solves the current technical problems.

[0054] In this embodiment, the flexible pad 17 is a perfluoro rubber O-ring.

[0055] The manipulator in this wafer handling device is divided into upper and lower layers, each with a finger installed. Two O-rings are installed in the front, back and middle of each finger, for a total of 6 O-rings. The O-rings are made of perfluororubber and can correspond to processes such as thin film deposition and etching. The 6 O-rings are evenly supported on the edge of the wafer and near the center, which can effectively support ultra-thin wafers and prevent the wafer from being damaged due to deformation due to its own weight. The rotating support mechanism and the lifting and lateral movement mechanism of the wafer centering and orientation module in this wafer handling device are each equipped with 6 O-rings, for a total of 12 O-rings. These 12 O-rings are evenly supported on the edge of the wafer and near the center. When performing the wafer centering and orientation action, they can effectively support ultra-thin wafers and prevent the wafer from being damaged due to deformation due to its own weight.

[0056] The multi-point O-ring solution provided in this embodiment covers all devices that contact the wafer (manipulator, rotation support mechanism, wafer lifting and lateral movement mechanism), and comprehensively and effectively solves the current transportation problem.

[0057] The flexible pad of this embodiment has an anti-slip function. When vacuum adsorption is not used, the wafer will not slide off, thereby preventing the wafer from being broken due to vacuum adsorption.

[0058] Traditionally, ultra-thin wafers are transported using the Bernoulli method. The principle is that positive pressure gas is quickly ejected from a special structure, and local negative pressure is formed through different local gas flow rates to adsorb the wafer. This method has a fatal disadvantage, that is, a large amount of positive pressure gas ejected from the structure will bring out a lot of microscopic particles. Because the line width of high-end chips can be less than 28nm, even the 100nm particles of the highest cleanliness level Class 1 are much larger than the chip circuit line width, which can cause a big pollution problem and significantly reduce the yield of the wafer. The wafer transport of this embodiment does not use the Bernoulli method, avoiding particle contamination of ultra-thin wafers. This embodiment uses a perfluororubber O-ring support method, which has only line contact and a small contact area, reducing the risk of pollution.

[0059] The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims

1. A wafer transport device, characterized in that: include: Robot, wafer centering and orientation module and wafer box loading station; The wafer loading station is used to operate the wafer box; The robot is used to transfer wafers between the wafer centering and orientation module and the wafer box loading platform; The wafer centering and orientation module comprises: Base, A rotating support mechanism, disposed on the base, capable of driving the wafer to rotate along its central axis; The wafer lifting and lateral movement mechanism is arranged on the base and can be translated and lifted up and down; when lifting, the wafer is lifted from the rotating support mechanism, and when lowering, the wafer is dropped back onto the rotating support mechanism; after the wafer is lifted, the wafer lifting and lateral movement mechanism can drive the wafer to move in a horizontal plane; The rotating support mechanism comprises at least three first wafer supports, each of which has a flexible pad arranged at a position close to the edge of the wafer and close to the inner side of the wafer; The wafer lifting and transverse movement mechanism comprises at least three second wafer supports, and each of the second wafer supports is provided with a flexible pad at a position close to the edge of the wafer and close to the inner side of the wafer.

2. The wafer transfer device according to claim 1, wherein: The first wafer holder is in the shape of an elongated strip, one end of each of the first wafer holders corresponds to the center of the wafer, and the other end corresponds to the edge of the wafer; the included angle between any two adjacent first wafer holders is the same.

3. The wafer transfer device according to claim 1, wherein: The second wafer holder is arranged close to the periphery of the wafer and is used to support the peripheral area of ​​the wafer; the second wafer holder is evenly distributed.

4. The wafer transfer device according to claim 1, wherein: The manipulator is equipped with an end effector; The end effector mechanism comprises at least one finger for carrying a wafer, wherein the finger has two forks, and flexible pads are arranged at both ends and in the middle of the forks.

5. The wafer transfer device according to claim 4, wherein: The end effector is divided into two layers, an upper layer and a lower layer, and each layer is provided with one finger.

6. The wafer transfer device according to claim 1 or 4, characterized in that: The flexible pad is a rubber O-ring.

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