Target changing mechanism and target changing method of ion implanter

Abstract

The invention discloses an ion implanter target-batch film changing mechanism and a target-batch film changing method.The target-batch film changing mechanism comprises a target table, a film storage chamber, a first conveying assembly and a steering conveying mechanism, the target table is rotatably installed in the target-batch film storage chamber, a plurality of target discs are evenly arranged on the target table in the circumferential direction, and the disc faces of the target discs are perpendicular to the target table; a plurality of wafers are horizontally placed in the wafer storage chamber, the steering conveying mechanism comprises a wafer changing disc and a second conveying assembly, the first conveying assembly is used for achieving wafer conveying between the wafer storage chamber and the wafer changing disc, and the wafer changing disc is used for clamping the wafers and achieving switching between the horizontal state and the vertical state of the wafers. The second conveying assembly is used for achieving wafer conveying between the wafer changing disc and the target disc. According to the batch target piece changing mechanism, the structure of the target disc in the whole target chamber can be greatly simplified, complex movement in the target chamber is avoided, then the granularity in the target chamber is reduced, and the product yield is improved. The batch target film changing method is simple in step, convenient to operate and stable and efficient in film changing.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor manufacturing equipment, and in particular relates to a batch target changing mechanism and a batch target changing method for an ion implanter. Background Art

[0002] As one of the key doping equipment in the manufacture of semiconductor devices, the ion implanter can accurately control the implantation angle and dosage, doping concentration and depth, improve the integration, yield and life of the circuit, and reduce costs and power consumption. When changing targets in batches, the existing ion implanter uses a robot to directly deliver the wafers to the target plate in the target chamber. Due to storage requirements, the wafers in the storage chamber are placed horizontally, but during the ion implantation process, the wafers need to be placed vertically to face the ion beam. The wafer handling robot has certain limitations and can only carry out wafer handling with three degrees of freedom: up and down, front and back, and horizontal rotation, and cannot flip the wafer. The existing solution is to separately set a rotating structure and a fixed-angle locking structure on each target position, and set a corresponding drive and control mechanism to realize the automatic flipping of each target plate relative to the target position to drive the wafer on the target plate to flip. Specifically, when loading the wafer, the manipulator moves the wafer into the target chamber, the target plate of the target chamber is switched from the injection position to the wafer pick-up position and locked, the target plate after the wafer is placed is switched from the wafer pick-up position to the injection position and locked, and when unloading the wafer, the locking mechanism is first opened, the target plate is switched from the injection position to the wafer pick-up position and locked, and then the wafer is taken away by the manipulator. Since there are multiple target positions in the batch target chamber, each target position needs to have clamping, flipping, locking, driving and control functions, which makes the target position structure of the entire target chamber complex. The inventors of this application found in practical research that the multiple complex target position structures in the batch target chamber are very likely to produce pollutants such as metal particles during their complex movement process, which will have an adverse effect on the process and reduce the product yield. At the same time, affected by the assembly accuracy and processing accuracy, the existing wafer changing mechanism has poor movement stability and large transmission friction, and it is more difficult to meet the requirements of high granularity. However, the semiconductor ion implantation process stage has higher and higher requirements for wafer granularity and target chamber cleanliness. Reducing the transmission granularity is an issue that cannot be ignored. In order to solve the granularity problem, it is necessary to simplify the target position structure in the target chamber and improve the movement stability and reliability of the structure. Therefore, there is an urgent need for a set of auxiliary transport mechanisms to achieve film transfer while effectively simplifying the structure of the target position in the target room. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an ion implanter batch target changing mechanism and a batch target changing method with simple structure, stable movement and high reliability in view of the deficiencies in the prior art.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A target batch changing mechanism for an ion implanter comprises a target table, a wafer storage chamber, a first conveying assembly and a steering conveying mechanism, wherein the target table is rotatably mounted in the target batch chamber, the target table is evenly provided with a plurality of target disks along the circumferential direction, the disk surface of the target disk is perpendicular to the target table, a plurality of wafers are horizontally placed in the wafer storage chamber, the steering conveying mechanism comprises a wafer changing disk and a second conveying assembly, the first conveying assembly is used for realizing wafer transfer between the wafer storage chamber and the wafer changing disk, the wafer changing disk is used for clamping wafers and realizing switching between the horizontal state and the vertical state of the wafers, and the second conveying assembly is used for realizing wafer transfer between the wafer changing disk and the target disk.

[0006] As a further improvement of the present invention, the second transmission assembly includes a swing arm and a translation assembly, the film changing disc can be installed on the free end of the swing arm so as to be flipped up and down, and the fixed end of the swing arm is located on the translation assembly, and the swing arm and translation assembly are used to make the film changing disc reach the film changing handover position, and the film changing handover position is the point where the circular motion trajectory of the center of the film changing disc is tangent to the circular motion trajectory of the center of the target disc, and the film changing disc to be changed is concentric with the target disc to be changed.

[0007] As a further improvement of the present invention, a rotating assembly and a locking assembly are provided at the free end of the swing arm, and the film changing plate is installed at the free end of the swing arm through the rotating assembly. The locking assembly is used to lock the angle of the film changing plate when it needs to be fixed.

[0008] As a further improvement of the present invention, the target plate is a mechanical chuck or an electrostatic chuck.

[0009] As a further improvement of the present invention, the disc changing disc is a mechanical chuck.

[0010] As a further improvement of the present invention, the first conveying component is a robot, and the robot is installed in the film storage chamber.

[0011] As a general technical concept, the present invention also provides a method for batch target replacement based on the above-mentioned ion implanter batch target replacement mechanism, comprising the following steps:

[0012] S1. Wafer loading and replacement before ion implantation process:

[0013] S1.1, the first conveyor assembly takes out the wafers in the wafer storage chamber and places them horizontally on the wafer exchange tray;

[0014] S1.2, flip the wafer tray to switch the wafer from a horizontal state to a vertical state;

[0015] S1.3, the second conveying assembly conveys the wafer in a vertical state to the target plate;

[0016] S1.4, the wafer changing plate is switched from the vertical position to the horizontal position, and the target stage is rotated at the same time, and steps S1.1 to S1.3 are repeated until the target plate to be loaded with the wafer in the target chamber is loaded;

[0017] S2. Unloading and replacing the wafer after ion implantation process:

[0018] S2.1, the second transfer assembly transfers the processed wafer from the vertical target plate to the vertical wafer change plate;

[0019] S2.2, flip the wafer tray to a horizontal position, so that the wafer after the process is switched from a vertical state to a horizontal state;

[0020] S2.3, the first conveying assembly conveys the processed wafers on the wafer changing tray to the wafer storage chamber;

[0021] S2.4, the wafer exchange plate is switched from the horizontal position to the vertical position, and the target stage is rotated to repeat steps S2.1 to S2.3 until the target plate of the wafer to be unloaded after the process in the target chamber is unloaded.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] (1) In view of the problem that each target plate in the current batch target chamber not only needs to clamp the wafer, but also needs to be flipped at a certain angle to cooperate with the robot to transfer the wafer, which leads to the complicated structure and complex movement of the batch target chamber, and is prone to the generation of metal particles, the present invention provides an ion implanter batch target wafer changing mechanism, which realizes the flipping of the wafer outside the target chamber by arranging a wafer changing plate outside the target chamber that can clamp and flip the wafer, and then uses a second transmission component to realize the wafer transfer between the wafer changing plate and the target plate, thereby eliminating the need to set a rotation, locking, driving and control structure for each target plate, and only needs to set a target plate that can vertically clamp the wafer at each target position to realize wafer changing, which can greatly simplify the structure of the target position and target plate in the entire target chamber, avoid complex movement in the target chamber, and thus greatly reduce the particle size in the target chamber, improve product yield, and improve movement reliability while maintaining the original wafer transfer efficiency.

[0024] (2) In the batch target wafer changing mechanism of the ion implanter of the present invention, the steering transmission mechanism composed of the wafer changing plate, the swing arm and the translation assembly is mainly based on the movement of the same horizontal plane, and the movement is stable and reliable during the whole wafer changing process. The swing arm drives the wafer changing plate to swing in an arc between the wafer picking and placing position of the first transmission assembly and the wafer changing handover position. When the circular motion trajectory of the wafer changing plate center is tangent to the target plate center and the wafer changing plate and the target plate are concentric, it is the wafer changing handover position. This position is important and unique. By setting the wafer changing handover position in advance and changing the wafer according to this position, it can ensure that the wafers between the wafer changing plate and the target plate are accurately and smoothly handed over.

[0025] (3) The batch target replacement method of the present invention has simple steps, convenient operation, and stable and efficient replacement. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structural principle of the target batch changing mechanism of the ion implanter in Example 1 of the present invention.

[0027] Legend: 1. Target stage; 11. Target plate; 2. Wafer storage chamber; 3. First conveying assembly; 4. Wafer; 5. Wafer changing plate; 6. Second conveying assembly; 61. Swing arm; 62. Translation assembly. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0029] Example 1

[0030] Figure 1 A specific implementation of the target batch changing mechanism of the ion implanter of the present invention is shown, comprising a target table 1, a wafer storage chamber 2, a first conveying assembly 3 and a steering conveying mechanism, wherein the target table 1 is rotatably mounted in the target batch chamber, a plurality of target disks 11 are evenly arranged along the circumference of the target table 1, the disk surface of the target disk 11 is perpendicular to the target table 1, a plurality of wafers 4 are horizontally placed in the wafer storage chamber 2, the steering conveying mechanism comprises a wafer changing disk 5 and a second conveying assembly 6, the first conveying assembly 3 is used for realizing the wafer 4 transfer between the wafer storage chamber 2 and the wafer changing disk 5, the wafer changing disk 5 is used for clamping the wafer 4 and realizing the switching between the horizontal state and the vertical state of the wafer 4, and the second conveying assembly 6 is used for realizing the wafer 4 transfer between the wafer changing disk 5 and the target disk 11. In this embodiment, a wafer changing plate 5 capable of clamping and flipping the wafer 4 is arranged outside the target chamber to realize flipping of the wafer 4 outside the target chamber, and then a second conveying assembly 6 is used to realize the transfer of the wafer 4 between the wafer changing plate 5 and the target plate 11. Therefore, there is no need to set a rotation, locking, driving and control structure for each target plate 11. Only a target plate 11 capable of vertically clamping the wafer 4 is required at each target position to realize wafer changing. This can greatly simplify the structure of the target position and the target plate 11 in the entire target chamber, avoid complex movements in the target chamber, and thus greatly reduce the particle size in the target chamber.

[0031] When loading and changing wafers in batch targets, the first conveying assembly 3 (such as a robot) places the wafer 4 in the wafer storage chamber 2 horizontally on the wafer changing plate 5, and the wafer changing plate 5 clamps the wafer 4 and flips it from the horizontal position to the vertical position, and then the second conveying assembly 6 conveys the vertical wafer 4 to the vertical target plate 11 for clamping, and the wafer changing plate 5 flips to the horizontal position for the next loading. When unloading and changing wafers in batch targets, the second conveying assembly 6 conveys the vertical post-process wafer from the vertical target plate 11 to the vertical wafer changing plate 5, and the wafer changing plate 5 flips to the horizontal position, and the first conveying assembly 3 transfers the post-process wafer on the wafer changing plate 5 to the wafer storage chamber 2, and the wafer changing plate 5 flips to the vertical position for the next unloading.

[0032] Further improved, in this embodiment, the second conveying assembly 6 includes a swing arm 61 and a translation assembly 62, the film changing plate 5 can be mounted on the free end of the swing arm 61 so as to be flipped up and down, the fixed end of the swing arm 61 is located on the translation assembly 62, the swing arm 61 and the translation assembly 62 are used to make the film changing plate 5 reach the film changing handover position, the film changing handover position is the point where the circular motion trajectory of the center of the film changing plate 5 is tangent to the circular motion trajectory of the center of the target plate 11, and the film changing plate 5 to be changed is concentric with the target plate 11 to be changed. The film changing plate 5 is driven by the swing arm 61 to be at the film taking and placing position ( Figure 1 A position shown) and the film change handover position ( Figure 1 When the circular motion trajectory of the center of the wafer changing plate 5 is tangent to the center of the target plate 11 and the concentric position of the wafer changing plate 5 and the target plate 11 is the wafer changing handover position, this position is important and unique. By setting the wafer changing handover position in advance and changing wafers according to this position, it can ensure that the wafer 4 between the wafer changing plate 5 and the target plate 11 is accurately and smoothly handed over. The steering transmission mechanism composed of the wafer changing plate 5, the swing arm 61 and the translation assembly 62 in this embodiment is mainly based on the movement of the same horizontal plane, and the movement is stable and reliable during the whole wafer changing process.

[0033] It can be understood that the steering transmission mechanism composed of the wafer changing plate 5, the swing arm 61 and the translation assembly 62 is equivalent to a handling robot with four degrees of freedom. Since the wafer 4 in the wafer storage chamber 2 is placed horizontally, the direction of the wafer 4 on the manipulator is also horizontal, and the direction of the wafer 4 on the target plate 11 in the target chamber is vertical (the crystal plane is facing the direction of beam injection), and the two directions are perpendicular. The steering transmission mechanism of this embodiment can not only clamp the wafer 4, but also drive the wafer 4 to rotate at a 90° angle to switch the wafer 4 to a vertical position, and then enter the target chamber by horizontally swinging a certain angle, and finally, the wafer changing plate 5 is moved back and forth in a straight line through the translation assembly 62 to reach the wafer changing handover position, and the vertical wafer 4 is handed over to the vertical target plate 11. The wafer changing plate 5 of this embodiment is a mechanical chuck, and the target plate 11 is a mechanical chuck or an electrostatic chuck. It only needs to clamp the wafer 4 moved by the wafer changing plate 5 through the target plate 11 to complete the wafer loading and changing, which can greatly simplify the movement structure of the target plate 11 in the target chamber and improve the cleanliness of the target chamber.

[0034] Of course, in other embodiments, the second conveying component 6 may also adopt other conveying structures as long as the purpose of the present invention can be achieved, such as using a horizontally rotating turntable or annular turntable in conjunction with a manipulator: a plurality of flippable film changing discs 5 are evenly arranged on the annular turntable, and a manipulator is fixed at the center of the annular turntable. The film changing disc 5 is first switched to a vertical position, and the annular turntable drives the film changing disc 5 to rotate, and the target table 1 drives the target disc 11 to rotate. When the line connecting the center of the film changing disc 5 and the center of the target disc 11 overlaps with the line connecting the center of the annular turntable and the center of the target table 1, a manipulator with up and down and front and back freedom is used to clamp the wafer 4 for translation, which can also achieve wafer change. However, compared with the present embodiment, the film changing disc 5 and the target disc 11 are directly connected, and the above-mentioned conveying structure has one more manipulator handover, which is not as simple as the present embodiment, and the running stability and reliability are not as good as the present embodiment.

[0035] As a further improvement, in this embodiment, a rotating assembly and a locking assembly are provided at the free end of the swing arm 61, and the wafer changing plate 5 is mounted on the free end of the swing arm 61 through the rotating assembly, and the locking assembly is used to lock the angle of the wafer changing plate 5 when it needs to be fixed. In this embodiment, the azimuth switching and fixed angle locking of the wafer changing plate 5 can be achieved accurately and smoothly through the cooperation of the rotating assembly and the locking assembly, so as to avoid the angular deviation of the wafer 4 during the swinging process of the swing arm 61, which affects the smooth handover between the wafer changing plate 5 and the target plate 11, and further improve the stability of the steering transmission.

[0036] The manipulator is installed in the film storage chamber 2. The rotating assembly and the locking assembly can adopt the rotating structure of the prior art, as long as the horizontal and vertical positions of the film changing disk 5 in this embodiment can be switched and locked. For example, two rotating shafts symmetrical with the center of the disk are arranged on the outer periphery of the film changing disk 5, and the two rotating shafts are respectively located on the extension lines of the same diameter of the film changing disk 5. A bracket is arranged at the free end of the swing arm 61 to make the rotating shaft cooperate with the top of the bracket, and the rotating shaft is controlled by the motor to rotate, thereby driving the film changing disk 5 to switch from 0° to 90°.

[0037] Example 2

[0038] A method for batch target replacement of an ion implanter batch target replacement mechanism based on embodiment 1 comprises the following steps:

[0039] S1. Wafer loading and replacement before ion implantation process:

[0040] S1.1, the first conveying assembly 3 takes out the wafer 4 in the wafer storage chamber 2 and places it horizontally on the wafer changing tray 5;

[0041] S1.2, the wafer changing plate 5 is turned over to switch the wafer 4 from a horizontal state to a vertical state;

[0042] S1.3, the second conveying assembly 6 conveys the wafer 4 in a vertical state to the target plate 11;

[0043] S1.4, the wafer changing plate 5 is switched from the vertical position to the horizontal position, and the target table 1 is rotated to repeat steps S1.1 to S1.3 until all the wafers 4 on the target plates 11 in the target chamber are loaded.

[0044] S2. Unloading and replacing the wafer after ion implantation process:

[0045] S2.1, the second transfer assembly 6 transfers the processed wafer from the vertical target plate 11 to the vertical wafer change plate 5;

[0046] S2.2, the wafer changing plate 5 is turned to a horizontal position, so that the wafer after the process is switched from a vertical state to a horizontal state;

[0047] S2.3, the first conveying assembly 3 conveys the processed wafers on the wafer changing tray 5 to the wafer storage chamber 2;

[0048] S2.4, the wafer changing plate 5 is switched from the horizontal position to the vertical position, and the target table 1 is rotated to repeat steps S2.1 to S2.3 until all the processed wafers on the target plates 11 in the target chamber are unloaded.

[0049] Specifically, before the ion implantation process, the wafer is loaded: the robot in the wafer storage chamber 2 moves the wafer 4 to the wafer changing plate 5, places the wafer 4 horizontally and clamps it on the wafer changing plate 5, and the steering conveying mechanism has four degrees of freedom, which respectively realizes the inclination rotation, angle swing, front and back translation and wafer 4 clamping through the rotating assembly, the swing arm 61, the translation assembly 62 and the wafer changing plate 5, and finally moves the wafer 4 into the target chamber, and hands it over with the target plate 11 of the target chamber at a specific handover position, completing a single loading and changing of wafers; in coordination with the rotation movement of the target stage 1 in the target chamber, the wafer changing mechanism goes back and forth for multiple times to complete all loading and changing of the target plate of the target batch in the target chamber. After the ion implantation process, the wafer is unloaded: the target plate 11 of the wafer that needs to be taken out after the process is rotated to the wafer changing handover position in turn by the rotation of the target stage 1, and is taken out in turn by the steering conveying mechanism and moved away by the robot. The batch target changing method of this embodiment has simple steps, convenient operation, and smooth and efficient wafer changing.

[0050] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solutions of the present invention without departing from the spirit and technical solutions of the present invention, or modify them into equivalent embodiments of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solutions of the present invention still fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A target batch changing mechanism for an ion implanter, characterized in that: The invention comprises a target platform (1), a wafer storage chamber (2), a first conveying assembly (3) and a steering conveying mechanism. The target platform (1) is rotatably mounted in the target batch chamber. The target platform (1) is evenly provided with a plurality of target disks (11) along the circumference. The disk surface of the target disk (11) is perpendicular to the target platform (1). A plurality of wafers (4) are horizontally placed in the wafer storage chamber (2). The steering conveying mechanism comprises a wafer changing disk (5) and a second conveying assembly (6). The first conveying assembly (3) is used to realize the wafer (4) transfer between the wafer storage chamber (2) and the wafer changing disk (5). The wafer changing disk (5) is used to clamp the wafer (4) and realize the switching of the wafer (4) between the horizontal state and the vertical state. The second conveying assembly (6) is used to realize the wafer (4) transfer between the wafer changing disk (5) and the target disk (11).

2. The target batch changing mechanism of the ion implanter according to claim 1, characterized in that: The second transmission assembly (6) comprises a swing arm (61) and a translation assembly (62); the film changing disc (5) is mounted on the free end of the swing arm (61) in an upside-down manner; the fixed end of the swing arm (61) is located on the translation assembly (62); the swing arm (61) and the translation assembly (62) are used to enable the film changing disc (5) to reach a film changing handover position; the film changing handover position is a position where a circular motion trajectory of the center of the film changing disc (5) is tangent to a circular motion trajectory of the center of the target disc (11); and the film changing disc (5) to be changed is concentric with the target disc (11) to be changed.

3. The target batch changing mechanism of the ion implanter according to claim 2, characterized in that: The free end of the swing arm (61) is provided with a rotating assembly and a locking assembly, the film changing disc (5) is mounted on the free end of the swing arm (61) via the rotating assembly, and the locking assembly is used to lock the angle of the film changing disc (5) when it needs to be fixed.

4. The target batch changing mechanism for an ion implanter according to any one of claims 1 to 3, characterized in that: The target plate (11) is a mechanical chuck or an electrostatic chuck.

5. The target batch changing mechanism for an ion implanter according to any one of claims 1 to 3, characterized in that: The film changing disc (5) is a mechanical chuck.

6. The target batch changing mechanism for an ion implanter according to any one of claims 1 to 3, characterized in that: The first conveying component (3) is a robot, and the robot is installed in the film storage chamber (2).

7. A method for batch target replacement of an ion implanter batch target replacement mechanism according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Wafer loading and replacement before ion implantation process: S1.1, the first conveying assembly (3) takes out the wafer (4) in the wafer storage chamber (2) and places it horizontally on the wafer changing plate (5); S1.2, the wafer changing plate (5) is turned over so that the wafer (4) is switched from a horizontal state to a vertical state; S1.3, the second conveying assembly (6) conveys the wafer (4) in a vertical state to the target plate (11); S1.4, the wafer changing plate (5) is switched from the vertical position to the horizontal position, and the target table (1) is rotated to repeat steps S1.1 to S1.3 until the target plate (11) to be loaded with the wafer (4) in the target chamber is loaded; S2. Unloading and replacing the wafer after ion implantation process: S2.1, the second transfer assembly (6) transfers the processed wafer from the vertical target plate (11) to the vertical wafer exchange plate (5); S2.2, the wafer changing plate (5) is turned to a horizontal position, so that the wafer after the process is switched from a vertical state to a horizontal state; S2.3, the first conveying assembly (3) conveys the processed wafers on the wafer changing tray (5) to the wafer storage chamber (2); S2.4, the wafer exchange plate (5) is switched from the horizontal position to the vertical position, and the target table (1) is rotated to repeat steps S2.1 to S2.3 until the target plate (11) of the wafer to be unloaded after the process in the target chamber is completely unloaded.

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