High-precision wafer flatness measuring device

Abstract

The utility model discloses a high-precision wafer flatness measuring device. The device comprises a shell, an opening is formed in one side face of the shell, a wafer supporting device is installed at the bottom in the shell, a plurality of grooves extending side by side are formed in the wafer supporting device, and a vertical light source is installed on the inner side face of the opposite side of the opening of the shell through two vertical installation strips. An inclined semi-transparent and semi-reflective mirror is mounted in the middle of the shell through a plurality of pressing plates and a plurality of cushion blocks, and four cameras are mounted on the bottom side surface of the top of the shell; wherein the light source is close to the bottom surface of the semi-transparent and semi-reflective mirror, and the included angle between the semi-transparent and semi-reflective mirror and the wafer supporting device is 45 degrees. The high-precision wafer flatness measuring device provided by the utility model can realize on-line and rapid measurement of three-dimensional morphology of the surface of the wafer, is small in size, can be additionally arranged on any wafer processing equipment, and can rapidly adapt to various wafers, so that the equipment adjusting time is shortened, and the production continuity is improved.

Description

Technical Field

[0001] The utility model relates to the field of optical measuring devices, in particular to a high-precision wafer flatness measuring device. Background Art

[0002] In the field of semiconductor manufacturing, the flatness of the wafer surface directly affects the accuracy of the lithography process and the performance of the chip. Therefore, accurately measuring the surface flatness of the wafer is extremely important for improving product quality and production efficiency. However, the existing wafer surface flatness measurement technology has many limitations, and these limitations are particularly prominent in a fast production environment.

[0003] First of all, traditional flatness measurement technology relies on bulky equipment systems, which not only take up significant production space, but are also complex to operate and take a long time to set up and adjust, which significantly reduces the overall efficiency of the production line.

[0004] Second, existing equipment is poor at adapting to wafers of different sizes and shapes. Adjusting equipment to accommodate various wafer diameters often requires physical modification or replacement of parts, which increases operational complexity and may cause production delays, thus affecting the continuity of the production cycle.

[0005] In addition, the use of current contact and non-contact sensors can also provide certain surface flatness data, but the resolution and acquisition speed of this data often cannot meet the high-precision and high-speed production requirements. Especially in application scenarios that require rapid generation of high-density point cloud data, the limitations of existing technologies are particularly obvious.

[0006] Therefore, given the bulky size, lack of adaptability and limited data output capacity of existing measurement technologies, they are clearly insufficient in their ability to meet the dual demands of efficiency and accuracy in the modern semiconductor manufacturing industry. Utility Model Content

[0007] To solve the above problems, the utility model provides a high-precision wafer flatness measurement device, which can realize online and rapid measurement of the three-dimensional morphology of the wafer surface. It has a compact size and can be installed on any wafer processing equipment. It can quickly adapt to various wafers without physical modification or replacement of parts, thereby reducing equipment adjustment time and improving production continuity.

[0008] According to one aspect of the utility model, a high-precision wafer flatness measuring device is provided, comprising a shell, one of the side surfaces of the shell is open, a wafer supporting device is installed at the bottom of the inside of the shell, a plurality of grooves extending side by side are formed on the wafer supporting device, a vertical light source is installed on the inner side surface on the opposite side of the shell opening via two vertical mounting bars, an inclined semi-transparent and semi-reflective mirror is installed in the middle of the shell via a plurality of pressure plates and a plurality of pads, and four cameras are installed on the bottom side surface of the top of the shell; wherein the light source is close to the bottom surface of the semi-transparent and semi-reflective mirror, and the angle between the semi-transparent and semi-reflective mirror and the wafer supporting device is 45°.

[0009] In some embodiments, a plurality of ceramic pillars are mounted on the wafer support device. It is beneficial that another optional structure of the wafer support device is described.

[0010] In some embodiments, the wafer support device is in the shape of a disk, and a plurality of electric lifting support columns are arranged on the disk. The benefit of this is that another optional structure of the wafer support device is described.

[0011] In some embodiments, the computer controls the light source to project sine fringes, cosine fringes or Gray codes. It is beneficial that the types of patterns projected by the computer-controlled light source are described.

[0012] In some embodiments, the housing has two mounting rods extending side by side on the bottom side of the top of the housing, and the four cameras are respectively mounted on the two ends of the two mounting rods. The benefit is that the specific mounting method of each camera is described.

[0013] In some embodiments, a plurality of the wafer support devices are placed on a conveyor line and can pass under the semi-transparent and semi-reflective mirrors in sequence. The invention is beneficial in that another arrangement of a precision wafer flatness measurement device is described. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A schematic structural diagram of a high-precision wafer flatness measurement device according to an embodiment of the utility model;

[0015] Figure 2 for Figure 1 A schematic diagram of the structure of a high-precision wafer flatness measurement device after removing the semi-transparent and semi-reflective mirror;

[0016] Figure 3 for Figure 1 Schematic diagram of the structure of the wafer support device shown.

[0017] In the figure: housing 1, wafer support device 2, light source 3, semi-transparent and semi-reflective mirror 4, camera 5, groove 21, mounting bar 31, pressure plate 41, pad 42, mounting rod 51, DETAILED DESCRIPTION

[0018] The utility model is further described in detail below in conjunction with the accompanying drawings.

[0019] like Figure 1-3 As shown, the device includes a shell 1, which is roughly in the shape of a rectangular parallelepiped and has an opening on one side, while other main structures, including a wafer support device 2, a light source 3, a semi-transparent and semi-reflective mirror 4 and four cameras 5, are all installed inside the shell 1.

[0020] Preferably, the housing 1 is light-proof, thereby effectively avoiding interference from ambient light.

[0021] The wafer support device 2 is circular, and is formed with a plurality of grooves 21 extending side by side. The wafer support device 2 is used to support the wafer to be tested transported by the mounting robot, and the shape of each groove 21 is designed according to the front end of the robot.

[0022] Preferably, a plurality of ceramic columns (not shown in the diagram) may be densely installed on the wafer support device 2, so that the wafer can be prevented from being deformed due to its own gravity and abrasion.

[0023] Further preferably, the wafer support device 2 can be disc-shaped, and a plurality of electric lifting support columns (not shown in the scheme diagram) can be arranged on it. After the electric lifting support columns are raised, the robotic arm transports the wafer to be tested to the testing position, and then the electric lifting support columns are lowered, and the wafer to be tested can be supported in a plane to complete the measurement.

[0024] The light source 3 is vertically arranged and mounted on the inner side surface opposite to the opening of the housing 1. The two sides of the light source 3 are mounted by two vertical mounting strips 31 respectively.

[0025] Preferably, the computer-controlled light source 3 is capable of projecting sine fringes, cosine fringes or Gray codes.

[0026] The semi-transparent and semi-reflective mirror 4 is arranged in the middle of the shell 1, wherein the semi-transparent and semi-reflective mirror 4 is arranged to be inclined, and its two sides are respectively installed by multiple pressure plates 41 and multiple pads 42, and each side edge of the semi-transparent and semi-reflective mirror 4 is respectively located between each pressure plate 41 and each pad 42.

[0027] In addition, the included angle between the semi-transparent and semi-reflective mirror 4 and the wafer supporting device 2 is 45°, and the light source 3 is close to the bottom surface of the semi-transparent and semi-reflective mirror 4 .

[0028] The pattern projected by the light source 3 is reflected by the semi-transparent and semi-reflective mirror 4 and then projected onto the surface of the wafer to be measured, and the horizontal projection of the semi-transparent and semi-reflective mirror 4 is slightly larger than the object to be measured, thereby ensuring that its reflected image can completely cover the object to be measured.

[0029] The four cameras 5 are respectively slidably mounted on the bottom side of the top of the housing 1. Specifically, there are two mounting rods 51 extending side by side on the bottom side of the top of the housing 1, and the four cameras 5 are respectively mounted on the two ends of the two mounting rods 51.

[0030] Each camera 5 can be used to capture the deformed image reflected by the surface of the wafer to be tested, and each camera 5 can obtain a quarter of the wafer surface flatness distribution. The results are merged to obtain the complete wafer surface flatness distribution. Then, the relationship between the height and phase shift of the surface to be tested can be established by calculation, thereby realizing the measurement of the three-dimensional morphology of the wafer surface to guide the real-time adjustment of production parameters.

[0031] Preferably, the number of cameras 5 can be appropriately increased or decreased according to the size of the object to be measured, the resolution requirement, and the size requirement. At the minimum, one camera 5 can be used to achieve wafer flatness measurement.

[0032] In addition, multiple wafer support devices 2 can be placed on a conveyor line (not shown in the scheme diagram), and carry the wafers to be measured to pass under the semi-transparent and semi-reflective mirrors 4 of the flatness measuring device in sequence, thereby achieving continuous measurement.

[0033] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A high-precision wafer flatness measurement device, characterized in that: The invention comprises a shell (1), one of the side surfaces of the shell (1) is open, a wafer support device (2) is installed at the bottom of the shell (1), a plurality of grooves (21) extending side by side are formed on the wafer support device (2), a vertical light source (3) is installed on the inner side surface of the shell (1) opposite to the opening via two vertical mounting bars (31), an inclined semi-transparent and semi-reflective mirror (4) is installed in the middle of the shell (1) via a plurality of pressure plates (41) and a plurality of pads (42), and four cameras (5) are installed on the bottom side surface of the top of the shell (1); wherein the light source (3) is close to the bottom surface of the semi-transparent and semi-reflective mirror (4), and the angle between the semi-transparent and semi-reflective mirror (4) and the wafer support device (2) is 45°.

2. A high-precision wafer flatness measurement device according to claim 1, characterized in that: A plurality of ceramic columns are installed on the wafer supporting device (2).

3. The high-precision wafer flatness measurement device according to claim 1, characterized in that: The wafer supporting device (2) is disc-shaped, and a plurality of electric lifting supporting columns are arranged on it.

4. The high-precision wafer flatness measurement device according to claim 1, characterized in that: The computer controls the light source (3) to project sine fringes, cosine fringes or Gray codes.

5. The high-precision wafer flatness measurement device according to claim 1, characterized in that: The housing (1) has two mounting rods (51) extending side by side on the bottom side of the top of the housing, and the four cameras (5) are respectively mounted on the two ends of the two mounting rods (51).

6. The high-precision wafer flatness measurement device according to claim 1, characterized in that: A plurality of the wafer supporting devices (2) are placed on a conveying line and can pass through under the semi-transparent and semi-reflective mirrors (4) in sequence.

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