CN217114355U

CN217114355U - Wafer alignment device and mounting structure

Info

Publication number: CN217114355U
Application number: CN202122966073.4U
Authority: CN
Inventors: 任瑞; 刘普然
Original assignee: Semiconductor Manufacturing Electronics Shaoxing Corp SMEC
Current assignee: Semiconductor Manufacturing Electronics Shaoxing Corp SMEC
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2022-08-02
Anticipated expiration: 2031-11-30

Abstract

The utility model relates to a wafer alignment device and an installation structure, wherein the alignment device comprises at least three centering adjusting mechanisms, each centering adjusting mechanism is arranged along the radius direction of the same circle center, and the included angles between two adjacent centering adjusting mechanisms in each group are the same; each centering adjusting mechanism comprises an air cylinder and a moving part which is pushed by the air cylinder to do reciprocating linear motion along the radius direction of the circle center, and each air cylinder is arranged on the bottom surface of the air cylinder fixing frame. When the aligning device is installed, the top surface of the cylinder fixing frame and the bottom surface of the chuck for fixing the wafer are attached and fixed, and the free end of each moving part moves along the radius direction of the circle center of the top of the chuck. The utility model discloses an aligning device simple structure and small, can paste the installation of wafer chuck, can not occupy the too much space influence operation of board, can effectively avoid wafer and chuck center to take place the skew, and the wafer size and the thickness scope that aligning device is suitable for the regulation are wider, are favorable to simplifying hardware mechanical structure.

Description

Wafer alignment device and mounting structure

Technical Field

The utility model relates to a semiconductor manufacturing installation specifically indicates a wafer aligning device and mounting structure.

Background

In the manufacturing process of a semiconductor device, wafers are often transferred and conveyed by a mechanical arm in different manufacturing processes, the wafers are placed on a wafer chuck in a process cavity by the mechanical arm in a plurality of process manufacturing processes to be positioned, the process processing is convenient, and the wafer chuck is fixed by adopting a vacuum adsorption mode, so that the center of circle of the wafer is required to be coincident with the center of circle of the chuck to avoid the wafer from deviating, otherwise, the vacuum value is influenced, and further, the product quality defect is caused. In order to avoid the occurrence of the above-mentioned offset, a wafer alignment device is usually required to be disposed, for example, an alignment device is disposed between a wafer cassette and a wafer chuck in a process chamber, when a robot arm picks up a wafer from the wafer cassette, the wafer is firstly ensured to be correctly positioned by the alignment device, and then the wafer is accurately placed on the chuck, and the alignment device usually occupies a certain operation space alone, and often has a complex structure and is high in cost.

Some processes do not separately set an alignment device, but realize that the wafer has no offset by precisely controlling the stroke coordinate of the mechanical arm, for example, a wafer film stripping machine, and the control mode is often complicated in mechanical hardware structure and control program. In a semiconductor manufacturing process, a plurality of processes need to carry out film sticking protection on a wafer, and after the manufacturing process is finished, the film needs to be peeled from the wafer, and a film peeling machine is a commonly used film peeling device at present. A wafer positioning table is arranged on the film stripping machine, the center of the wafer positioning table is a heating chassis, and the outer circumference of the heating chassis is a rubber ring. When the film is peeled, the wafer is transferred to the wafer positioning table through the mechanical arm, and the wafer is heated by the heating chassis, so that the viscosity between the wafer and the film is reduced, and the film peeling efficiency is improved; the rubber ring can increase the friction force in contact with the wafer, prevent the separation of the wafer and the wafer positioning table during film stripping, and also can play a role in preventing the wafer positioning table from being in hard contact with the wafer to cause wafer damage.

When the wafer is placed on the wafer positioning table, the center of the wafer and the center of the wafer need to be kept concentric, otherwise, the film stripping equipment is caused to have a voltage abnormity alarm shutdown fault, and the film stripping efficiency is reduced. The existing film stripping machine is controlled by adjusting the stroke coordinate from the mechanical arm to the circle center of the wafer positioning table, wafers with different sizes need to be adjusted and switched among different product coordinates, and the mechanical hardware structure is relatively complex. In addition, a device for aligning a wafer placed on a wafer positioning table is not arranged on a currently used film stripping machine, the wafer is fixed by a clamp on a mechanical arm in a transfer process, friction force exists between the clamp and the wafer, when the clamp places the wafer on the positioning table and then performs separation action, the wafer is prone to certain offset, and even if the mechanical arm achieves concentric circles with the positioning table through accurate stroke coordinate control in a moving process, the situation that the wafer finally placed on the positioning table is not offset cannot be completely avoided.

SUMMERY OF THE UTILITY MODEL

The utility model discloses at first disclose a wafer aligning device, simple structure and small in size secondly still disclose this aligning device's mounting structure, can directly laminate the wafer chuck fixed, can not occupy too much operating space, can effectively avoid putting into the wafer on the chuck and the skew takes place for the chuck.

In order to realize the above purpose, the utility model discloses the technical scheme who adopts is:

a wafer alignment device comprises at least three centering adjusting mechanisms, wherein each centering adjusting mechanism is arranged along the radius direction of the same circle center, and included angles between every two adjacent centering adjusting mechanisms in each group are the same; each centering adjusting mechanism comprises an air cylinder and a moving part which is pushed by the air cylinder to do reciprocating linear motion along the radius direction of the circle center.

Further, each centering adjustment mechanism is arranged on the circumference of the same circle, and the moving distance of the moving part in each centering adjustment mechanism is the same.

Furthermore, each centering adjusting mechanism also comprises a limiting screw for limiting the stroke of the moving part.

Further, each centering adjustment mechanism is not arranged on the circumference of the same circle, a pressure sensor is arranged at the free end of the moving part in each centering adjustment mechanism, and the stroke distance of each air cylinder is controlled by signals of the pressure sensor.

Further, the moving portion comprises a vertical surface and a horizontal surface, one end of the vertical surface is connected with the air cylinder, the other end of the vertical surface is connected with the horizontal surface, and the other end of the horizontal surface is a free end.

Further, the free end is provided with a circular or arc-shaped contact portion.

Further, the aligning device also comprises an air cylinder fixing frame, the air cylinder in each centering adjusting mechanism is arranged on the bottom surface of the air cylinder fixing frame, and the horizontal plane of each moving part is parallel to the top surface of the air cylinder fixing frame.

Further, the cylinder fixing frame is of a circular ring structure.

A mounting structure of a wafer alignment device comprises a chuck for placing a wafer and the wafer alignment device, wherein a cylinder of each centering and adjusting mechanism is arranged at the bottom of the chuck, and the free end of each moving part moves along the radius direction of the circle center at the top of the chuck.

Furthermore, each cylinder is installed on the bottom surface of the cylinder fixing frame, and the top surface of the cylinder fixing frame is attached and fixed to the bottom surface of the chuck.

The aligning device designed by the utility model has simple structure and small volume, is especially suitable for being installed and used on a film stripping machine, can be installed by being attached to a wafer chuck, does not occupy too much space of a machine table to influence the operation, and has wider range of applicable and adjustable wafer size and thickness; an alignment device is additionally arranged at a wafer chuck of the film stripping machine and used for adjusting the offset of a wafer placed on the chuck, so that the accurate control of the stroke coordinate of the mechanical arm is reduced, and the simplification of a hardware mechanical structure is facilitated; the alignment device can effectively prevent the wafer and the center of the chuck from deviating, can reduce the abnormal voltage alarm probability of the film stripping machine, and is beneficial to improving the film stripping efficiency.

Drawings

FIG. 1 is a front view of an alignment apparatus and a wafer chuck after assembly in an embodiment of the present invention;

fig. 2 is a schematic diagram of the back structure of fig. 1.

Detailed Description

The technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

The present embodiments respectively disclose a wafer alignment apparatus and a mounting structure of the wafer alignment apparatus, and the whole wafer alignment apparatus is designed based on the principle of simple structure, small size and small occupied operation space during mounting, except for the premise of solving the problem of no position offset of a wafer placed on a wafer chuck by a mechanical arm.

As shown in fig. 1 and fig. 2, the wafer alignment apparatus in this embodiment at least includes three centering adjustment mechanisms, each of which includes a cylinder 2 and a moving part 3 that is pushed by the cylinder 2 to reciprocate linearly along a radius direction of a same center, one end of the moving part 3 is connected to a piston rod of the cylinder 2, and the other end of the moving part 3 is a free end and is used to contact with an edge-side end surface of a wafer 5 and push the wafer 5 toward the center. The embodiment and the drawings only show three centering adjustment mechanisms as examples, and four or more centering adjustment mechanisms can be arranged according to actual needs. Taking three centering adjustment mechanisms as an example, taking a set target point as a circle center, arranging each centering adjustment mechanism along three radius directions of the circle center of the target point, and making included angles between two adjacent centering adjustment mechanisms in each group identical, if three, the included angle is 120 degrees. In this embodiment, it is recommended to provide three centering adjustment mechanisms, each centering adjustment mechanism is provided on the same circumference where the center of the target point is located, and the moving distances of the moving parts 3 in each centering adjustment mechanism are set to be the same. Under the structure, the strokes of the piston rods of the air cylinders in the three centering adjusting mechanisms are consistent, and the stroke distance of the air cylinder 2 for pushing the wafer 5 when the circle center of the wafer 5 is superposed with the circle center position of the target point from the initial state of the piston rod can be calculated according to the size of the wafer 5 to be adjusted. According to the type of the cylinder 2, the moving distance of the moving part 3 may be controlled by a predetermined method according to the calculated moving distance, or a stop screw (not shown) may be provided on the path of each moving part 3 moving toward the center of the circle, and the position of the stop screw is also calculated in advance according to the position where the center of the wafer 5 coincides with the center of the target point.

Of course, in addition to the above arrangement mode, the three centering adjustment mechanisms may not be arranged on the same circumference at the same time, and the arrangement mode is more flexible, but the requirement that the included angles between two adjacent centering adjustment mechanisms in each group are the same is still met. Under the structure, the distance from the initial point of the cylinder piston rod in each centering adjusting mechanism to the point when the piston rod moves to the position where the center of the wafer 5 coincides with the center of the target point is calculated respectively, and the moving distance of the cylinder piston rod of the centering adjusting mechanism arranged on the circumference with larger radius is also longest. In order to facilitate the control of the stroke, a pressure sensor can be installed at the free end of the moving part 3 in each centering adjustment mechanism, the stroke distance of each air cylinder 3 is controlled by the signal of the pressure sensor, and when the pressure values fed back by the three pressure sensors reach the maximum value and are equal, the piston rods of the three air cylinders 2 stop moving.

For simplification in structural design, the moving portion 3 of the centering adjustment mechanism of the present embodiment adopts an L-shaped structure, that is, is divided into a vertical surface 31 and a horizontal surface 32, the cylinder 2 is located below the horizontal surface 32 and is arranged in parallel with the horizontal surface, the bottom of the vertical surface 31 is fixedly connected with the end of the piston rod of the cylinder 2, the top of the vertical surface 31 is fixedly connected with the horizontal surface 32, and the other end of the horizontal surface 32 is a free end for pushing the wafer 5. When the piston rod moves in the direction away from the center of the target point, the free ends of the moving parts 3 are pushed to work on the wafer 5, and when the piston rod moves in the opposite direction, the centers of the wafers 5 can be just coincided with the center of the target point when the free ends of the three moving parts 3 contact the wafer 5. Considering that the wafer 5 is not moved when the free end of the moving part 3 is separated from the wafer 5 after the wafer 5 is aligned, the free end in this embodiment only contacts with the edge side end face of the wafer 5, so that the contact area can be reduced, and the friction influence caused by the contact can be reduced. Further, in order to achieve a smaller contact area, it is proposed that the contact portion 33 of the free end is designed in a circular configuration, or alternatively, in an arc shape (only a circular example is shown in the drawings).

When the alignment device is used for centering and adjusting the wafer 5 placed on the wafer chuck 4 by the mechanical arm, the mounting modes of the alignment device can be divided into the following two modes: firstly, three centering adjustment mechanism is independently fixed separately, and three cylinder 2 is fixed in the bottom of wafer chuck 4, makes the horizontal plane of every removal portion 3 be located wafer chuck 4 top, according to the size and the thickness of wafer 5 calculate the mounted position can, this kind of mounting structure is more nimble, can set up according to the board space, but need calculate the mounted position accuracy of three centering adjustment mechanism well, and the removal stroke of adjusting piston rod is troublesome relatively. Secondly, the cylinders 2 of the three centering adjusting mechanisms can be fixed on the bottom surface of the same cylinder fixing frame 1, the cylinders 2 are attached to the bottom surface of the cylinder fixing frame 1, the horizontal surface 32 of each moving part 3 is parallel to the top surface of the cylinder fixing frame 1, and then the top surfaces of the cylinder fixing frames 1 and the bottom surface of the wafer chuck 4 are attached and fixedly connected. Only the second mounting structure is shown in the attached drawings, and the second mode is also recommended to be adopted in the embodiment, so that the mounting is more convenient.

The wafer chuck 4 shown in fig. 1 is a structure on a film stripping machine, the lower part of the position of the wafer 5 is generally a heating chassis, a rubber ring 6 is arranged on the periphery of the heating chassis, and the wafer 5 is placed on the rubber ring 6 by a mechanical arm. Considering that most wafer chucks 4 all adopt the vacuum adsorption mode to fix wafer 5, consequently wafer chuck 4 bottom is equipped with the vacuum tube, for the installation that makes cylinder mount 1 can not cause the influence to wafer chuck 4's work, designs cylinder mount 1 for the ring structure in this embodiment, can avoid the setting of walking the line of vacuum tube just. After the alignment device in this embodiment is installed in the above manner, the cylinder piston rod of each centering adjustment mechanism is pushed to the maximum stroke, which can be adjusted according to actual needs without affecting the mechanical arm to place the wafer 5 on the chuck 4. After the wafer 5 is placed on the chuck 4, the vacuum equipment is not started, the air cylinders 2 are started to enable the piston rods to retract, the wafer 5 is gradually pushed to the center by the free ends of the three moving parts 3 under the driving of the three air cylinders 2, the center of the wafer 5 is overlapped with the center of the chuck 4, the vacuum equipment is started to adsorb the wafer 5 after the position is aligned, and then the moving parts 3 are controlled to be far away from the wafer 5, so that the wafer 5 is prevented from moving.

The structure of the alignment device provided by the embodiment can ensure the concentricity of the wafer 5 and the chuck 4, the stroke adjusting range of the moving part 3 is large, the alignment adjustment of the wafer with the outer diameter of 190-230 mm can be at least met, the thickness range of the wafer is wide, and the alignment device is suitable for the wafer with the thickness of 400-1600 microns.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A wafer alignment apparatus, comprising: the centering mechanism comprises at least three centering adjusting mechanisms, each centering adjusting mechanism is arranged along the radius direction of the same circle center, and the included angles between every two adjacent centering adjusting mechanisms in each group are the same; each centering adjusting mechanism comprises an air cylinder and a moving part which is pushed by the air cylinder to do reciprocating linear motion along the radius direction of the circle center.

2. The wafer alignment device of claim 1, wherein: each centering adjusting mechanism is arranged on the circumference of the same circle, and the moving distance of the moving part in each centering adjusting mechanism is the same.

3. The wafer alignment device of claim 2, wherein: each centering adjusting mechanism also comprises a limit screw for limiting the stroke of the moving part.

4. The wafer alignment device of claim 1, wherein: each centering adjusting mechanism is not arranged on the circumference of the same circle, a pressure sensor is arranged at the free end of a moving part in each centering adjusting mechanism, and the stroke distance of each air cylinder is controlled by the signal of the pressure sensor.

5. The wafer alignment device of claim 1, wherein: the moving part comprises a vertical surface and a horizontal surface, one end of the vertical surface is connected with the air cylinder, the other end of the vertical surface is connected with the horizontal surface, and the other end of the horizontal surface is a free end.

6. The wafer alignment device of claim 5, wherein: the free end is provided with a circular or arc-shaped contact part.

7. The wafer alignment device of claim 5, wherein: the aligning device also comprises an air cylinder fixing frame, an air cylinder in each centering adjusting mechanism is arranged on the bottom surface of the air cylinder fixing frame, and the horizontal plane of each moving part is parallel to the top surface of the air cylinder fixing frame.

8. The wafer alignment device of claim 7, wherein: the cylinder fixing frame is of a circular ring structure.

9. A wafer aligning device mounting structure, characterized in that: comprising a chuck for holding a wafer and a wafer alignment apparatus as claimed in any one of claims 1 to 8, wherein the cylinder of each centering adjustment mechanism is disposed at the bottom of the chuck, and the free end of each moving portion moves in the radial direction of the center of the top of the chuck.

10. The wafer alignment device mounting structure of claim 9, wherein: each cylinder is installed on the bottom surface of the cylinder fixing frame, and the top surface of the cylinder fixing frame is fixedly attached to the bottom surface of the chuck.