Wafer carrying device

Abstract

The utility model provides a wafer carrying device, comprising a wafer centering and orienting module, the wafer centering and orienting module comprises a pedestal, a rotation support mechanism arranged on the pedestal and capable of driving a wafer to rotate along a central shaft; the wafer jacking and traversing mechanism is arranged on the base and 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 each second wafer support is provided with a flexible pad at the position close to the edge of the wafer and the position close to the inner side of the wafer.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor equipment, 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: 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, wafers need to ensure a certain rigidity and strength when being transported and processed. Traditionally, wafers in 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, which means that the number of diodes in the chip is required to be further increased, and it is an increasing trend year by year. However, as Moore's Law approaches its 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. Emerging technologies including rewiring and chip stacking are constantly emerging, which effectively supports the development of high-end chips, further improves the computing power of chips, and lays 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 sag more, which places extremely stringent requirements on wafer transportation. 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 platforms, and a horizontal moving axis used with the robot. Generally, in order to ensure ultra-high cleanliness, wafers are stored in sealed wafer boxes. The factory will configure a crane system to automatically drive the wafer boxes to different process equipment for processing. The wafer box will be transported by the crane to the wafer box loading platform of the wafer handling system at the front end of the process equipment. The wafer box loading platform opens the sealed wafer box, and the robot takes out the wafer from the wafer box and moves it to the wafer centering and orientation module. After the wafer is centered and oriented, the robot takes the wafer away and places it on the loading port of the process equipment to complete the wafer handling task.

[0006] Traditional EFEMs use vacuum adsorption fingers to fix the wafers for transport, and the wafer centering and orientation module also uses vacuum adsorption to fix the wafers for centering and orientation. 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 a focus of those skilled in the art. Utility Model Content

[0008] The utility model aims to provide a wafer transport device, which can solve the problem of wafer deformation and damage caused during the transport process.

[0009] In order to achieve the above-mentioned object, the utility model provides a wafer transport device, comprising: a wafer centering and orientation module, the wafer centering and orientation module comprising:

[0010] base;

[0011] A rotating support mechanism, disposed on the base, capable of driving the wafer to rotate along its central axis;

[0012] The wafer lifting and transverse movement mechanism is arranged on the base and can move horizontally and up and down; when lifting, the wafer is lifted from the rotating support mechanism, and when lowering, the wafer is returned to the rotating support mechanism; after the wafer is lifted, the wafer lifting and transverse movement mechanism can drive the wafer to move in the horizontal plane;

[0013] The rotation support mechanism includes at least three first wafer supports, each of which has a flexible pad arranged near the edge of the wafer and near the inner side of the wafer;

[0014] The wafer lifting and transverse movement mechanism includes 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.

[0015] In an optional solution, the first wafer holder is in the shape of an elongated strip, one end of each first wafer holder 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.

[0016] 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.

[0017] In an optional solution, the wafer transport device includes a robot arm, and the robot arm is equipped with an end effector;

[0018] The end effector mechanism comprises at least one finger for carrying a wafer, wherein the finger has two forks, and flexible pads are provided at both ends and in the middle of the forks.

[0019] In an optional solution, the end effector mechanism is divided into two layers, an upper layer and an lower layer, and each layer is provided with one of the fingers.

[0020] In an optional solution, the flexible pad is a perfluororubber O-ring.

[0021] In an optional solution, the wafer transport device further includes a wafer box loading platform, which is used to unlock and lock the wafer box and scan the wafers in the wafer box after unlocking.

[0022] The beneficial effects of the present invention are:

[0023] This utility model incorporates multiple flexible pads on the rotating support mechanism and wafer lifting and traversing mechanism. These pads can support the edges and center of the wafer, effectively supporting ultra-thin wafers and preventing damage caused by deformation due to their own weight during transport. The flexible pads also provide a non-slip feature, preventing the wafer from slipping even without vacuum suction, thus preventing wafer breakage caused by vacuum suction.

[0024] Furthermore, flexible pads are provided at both ends and in the middle of the robotic fingers to effectively support the ultra-thin wafer, prevent damage to the wafer caused by deformation due to its own weight during transportation, and prevent the wafer from being broken due to vacuum adsorption. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] 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 the same reference numerals generally represent the same components.

[0026] Figure 1This 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 with the arm not extended.

[0027] Figure 2 It is a top view of the end effector mechanism in one embodiment of the present invention.

[0028] Figure 3 It is a side view of the end effector mechanism in one embodiment of the present invention.

[0029] Figure 4 This is a top view of a wafer centering and orienting module in one embodiment of the present invention.

[0030] Figure 5 It is a side view of a wafer centering and orienting module in one embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1-wafer transport device; 2-wafer loading platform; 2-1-wafer box; 3-robot arm; 4-travel axis; 5-end actuator; 6-wafer centering and orientation module; 7-first wafer holder; 8-second wafer holder; 9-wafer recognition sensor; 10-linear CCD sensor; 10-1-light curtain; 11-rotation axis; 12-finger; 13-presence detection sensor; 14-first finger connector; 15-second finger connector; 16-wafer; 17-flexible pad. DETAILED DESCRIPTION

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description and drawings. However, it should be noted that the technical solutions of the present invention can be implemented in a variety of different forms and are not limited to the specific embodiments described herein. The drawings are highly simplified and not to exact scale, and are intended solely to facilitate and clearly illustrate the embodiments of the present invention.

[0034] It should be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" another element or layer, it may be directly on, adjacent to, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" another element or layer, there are 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 merely 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.

[0035] Spatially relative terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein for convenience of description to describe the relationship of one element or feature shown in the figures to other elements or features. It should be understood that the spatially relative terms are intended to include different orientations of the device in use and operation in addition to the orientations shown in the figures. For example, if the device in the drawings is flipped, then the elements or features described as "under" or "beneath" or "beneath" the other elements will be oriented as "over" the other elements or features. Thus, the exemplary terms "under" and "under" may include both the upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or in other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0036] The purpose of the terms used herein is only to describe specific embodiments and is not intended to limit the present invention. When used herein, the singular forms "a", "an" and "the" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "comprising" and / or "including", 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.

[0037] Example 1

[0038] Reference Figures 1 to 5 This embodiment provides a wafer transport device 1, comprising: a wafer centering and orientation module 6, wherein the wafer centering and orientation module 6 comprises:

[0039] base;

[0040] A rotating support mechanism, provided on the base, capable of driving the wafer 16 to rotate along its central axis;

[0041] The wafer lifting and transverse movement mechanism is provided on the base and can be translated and raised and lowered; when lifting, the wafer 16 is lifted from the rotating support mechanism, and when lowering, the wafer 16 is returned to the rotating support mechanism; after the wafer 16 is lifted, the wafer lifting and transverse movement mechanism can drive the wafer 16 to move in the horizontal plane;

[0042] The rotation support mechanism includes at least three first wafer supports 7, each of which 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;

[0043] The wafer lifting and transverse movement mechanism includes 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.

[0044] Specifically, in this embodiment, the wafer handling device further includes a robot 3 and three wafer cassette loading platforms 2. The three wafer loading platforms 2 are used to operate respective wafer cassettes 2-1; the robot 3 is used to transfer wafers 16 between the wafer centering and orientation module 6 and the wafer cassette loading platforms 2. The robot 3 is equipped with an end effector 5, which is used to pick up and place wafers 16.

[0045] 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 of the wafer box, and scans how many wafers are in the wafer box 2-1 and which slots they are in. Then, the walking axis 4 that drives the robot 3 to move horizontally drives the robot 3 to move 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 then 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.

[0046] 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 manipulator 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 recognition 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 maximum light shielding 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 orientation module first transfers the XY eccentricity of the wafer to a single X-axis according to the rotation angle a. The wafer lifting and transverse movement mechanism 8 lifts the wafer 16 from the rotating support mechanism. The wafer lifting and transverse movement mechanism 8 then moves the wafer distance deviation value. After completion, the wafer lifting and transverse movement mechanism descends and puts the wafer 16 back on the rotating support mechanism. In this way, 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 orientation module 6, this notch will cause a sudden change in voltage. 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 orientation function of the wafer 16.

[0047] In this embodiment, the rotation support mechanism includes three first wafer supports 7. The first wafer supports 7 are long strips, with one end of each first wafer support 7 corresponding to the center of the wafer 16 and the other end corresponding to the edge of the wafer 16; the angle between any two adjacent first wafer supports 7 is the same (i.e., the three first wafer supports 7 are evenly distributed). Each first wafer support 7 is provided with a flexible pad 17 near the edge of the wafer and near the inner side of the wafer, with a total of six flexible pads evenly supporting the edge and 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 support the outer area of ​​the wafer 16; the second wafer supports are evenly distributed. Each second wafer support 8 is provided with a flexible pad 17 at the edge of the wafer and near the inner side, with a total of six flexible pads evenly supporting the edge and inner side of the wafer, effectively ensuring the stability of the wafer during rotation and preventing the wafer from sagging.

[0048] In this embodiment, the end effector 5 is divided into two layers, each containing a finger 12. The upper finger is connected to the robot 3 via a first finger connector 14, while the lower finger is connected to the robot 3 via a second finger connector 15. This allows the upper and lower fingers 12 to independently extend and retract to access and place wafers 16, improving productivity. A presence detection sensor 13 is also mounted on the finger 12 to detect whether a wafer 16 is 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, and 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, and a flexible pad 17 is installed at the front and rear end respectively. Considering that the wafer being transported is ultra-thin wafers, only supporting the edge of the wafer can significantly solve the problem of wafer transportation stability and wafer drop, 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.

[0049] In this embodiment, the flexible pad 17 is a perfluororubber O-ring.

[0050] The robotic arm in this wafer handling device is layered, with one finger installed on each upper and lower layer. Each finger has two O-rings installed in the front, back, and center positions, for a total of six O-rings. The O-rings are made of perfluoroelastomer and can accommodate processes such as thin film deposition and etching. The six O-rings are evenly supported at the edges and near the center of the wafer, effectively supporting ultra-thin wafers and preventing damage to the wafers due to deformation from their own weight. The rotating support mechanism and the lifting and traversing mechanism of the wafer centering and orienting module in this wafer handling device are each equipped with six O-rings, for a total of 12 O-rings. These 12 O-rings are evenly supported at the edges and near the center of the wafer, effectively supporting ultra-thin wafers during wafer centering and orienting, preventing damage to the wafers due to deformation from their own weight.

[0051] The multi-point O-ring solution provided in this embodiment covers all devices that contact the wafer (manipulator, rotation support mechanism, wafer lifting and transverse movement mechanism), and comprehensively and effectively solves the current transportation problem.

[0052] 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.

[0053] Traditionally, ultra-thin wafers are transported using a Bernoulli-style transport method. This method relies on the rapid ejection of positive-pressure gas from a special structure, creating a localized negative pressure through varying gas flow rates to absorb the wafer. This method has a fatal drawback: the large amount of positive-pressure gas ejected from the structure can carry with it a significant number of microscopic particles. Because high-end chip line widths can be under 28nm, even the 100nm particles measured in Class 1, the highest cleanliness level, are significantly larger than the chip circuit line width, causing significant contamination and significantly reducing wafer yield. This embodiment avoids the Bernoulli-style wafer transport method, thus avoiding particle contamination of ultra-thin wafers. This embodiment utilizes a perfluoroelastomer O-ring support method, which only provides linear contact and minimizes the contact area, reducing contamination risk.

[0054] The above description is only a description of the preferred embodiment of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians 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: A wafer centering and orientation module, comprising: base; A rotating support mechanism, disposed on the base, capable of driving the wafer to rotate along its central axis; The wafer lifting and transverse movement mechanism is arranged on the base and can move horizontally and up and down; when lifting, the wafer is lifted from the rotating support mechanism, and when lowering, the wafer is returned to the rotating support mechanism; after the wafer is lifted, the wafer lifting and transverse movement mechanism can drive the wafer to move in the horizontal plane; The rotation support mechanism includes at least three first wafer supports, each of which has a flexible pad arranged near the edge of the wafer and near the inner side of the wafer; The wafer lifting and transverse movement mechanism includes 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 first wafer holder 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 supports are arranged close to the periphery of the wafer and are used to support the peripheral area of ​​the wafer; the second wafer supports are evenly distributed.

4. The wafer transfer device according to claim 1, wherein: The wafer transport device includes a robot arm, and an end effector is installed on the robot arm; The end effector mechanism comprises at least one finger for carrying a wafer, wherein the finger has two forks, and flexible pads are provided at both ends and in the middle of the forks.

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

6. The wafer transfer device according to claim 1 or 4, wherein: The flexible pad is a perfluororubber O-ring.

7. The wafer transfer device according to claim 1, wherein: The wafer transport device further includes a wafer box loading platform, which is used to unlock and lock the wafer box and scan the wafers in the wafer box after unlocking.

Images