TW418476B - Apparatus and method for measuring the pressure distribution on the wafer surface - Google Patents

Abstract

An apparatus and method for measuring the pressure distribution on the wafer surface. The method comprises: firstly, defining the test pattern on the wafer surface and attaching the pressure sensing film on the surface of test pattern; then, applying pressure on the pressure sensing film to get the corresponding pressure pattern; and based on the pressure pattern, comparing the color density distribution to get the pressure distribution on the wafer surface. Further, the apparatus comprises: a chemical mechanical polishing apparatus used to allocate the wafer, apply pressure on the pressure sensing film and deduce corresponding pressure pattern; an image capturing device and an image processing device used to capture the pressure pattern and conduct a comparison of the pressure pattern, respectively, so as to deduce the pressure distribution on the wafer surface.

Description

418476 V. Description of the invention (i) The present invention relates to a device and method for measuring the pressure distribution on the surface of a wafer. Hole, line, block), and adjust the circuit layout to increase the flatness of the chemical mechanical polishing method. During the CMP process, the chip or wafer level pressure distribution is an important factor affecting the flatness of the wafer surface. With regard to the chemical mechanical polishing method, 'the wafer surface has a faster polishing speed in a region subjected to a larger pressure', and a region subjected to a smaller pressure has a slower polishing speed. Therefore, when the pressure on the surface of the wafer is extremely uneven due to the density of the integrated circuit layout, the polishing rate may be different and excessive polishing or insufficient polishing may occur. In other words, as the pressure distribution on the wafer or wafer surface becomes more even, the flatness of the wafer or wafer surface will be more uniform, so that the process quality will become uniform. However, the semiconductor industry has never proposed any method to numerically describe the pressure distribution on the wafer surface. In view of this, the main object of the present invention is to provide a method for measuring the pressure distribution on the wafer surface, which uses a pressure sensing film to push the pressure distribution on the wafer surface and adjust the circuit pattern on the wafer surface to have The most even pressure distribution is used to increase the flatness of the wafer surface and the uniformity of the polishing rate. Another object of the present invention is to provide a method for measuring the pressure distribution on a wafer surface. The method defines a test pattern on the wafer surface in advance, and the test pattern has holes, lines, blocks, or any combination thereof with various densities and sizes.

f 418A76 5. Description of the invention (2). In this way, the relationship between various circuit patterns and pressure distribution can be established, and the circuit pattern design can also refer to this relationship to improve the flatness of the chemical mechanical polishing method. Another object of the present invention is to provide a device for measuring a pressure distribution on a wafer surface, which uses an existing chemical mechanical polishing device to set a wafer and a pressure sensing film that presses the wafer surface, and uses image capture Devices (such as scanners or digital cameras) and image processing devices (such as analog processors or analog programs) to capture the pressure image of the pressure sensing film and estimate the pressure distribution on the wafer surface. In addition, because image capture devices (such as scanners or digital cameras) and image processing devices (such as analog processors or analog programs) can be provided by general computer systems and their peripheral devices, there is no need for large costs. Another object of the present invention is to provide a database for measuring the pressure distribution on the surface of a wafer, which stores various circuit patterns (holes, lines, blocks, or combinations of different densities and sizes) related to the pressure distribution. Libraries' guidelines for circuit design. In order to achieve the above and other objectives, the present invention provides a method for measuring the pressure distribution of the wafer table 2. The steps are as follows. First, a wafer surface is covered with a layer of a pressure sensing film; When pressure is applied, this pressure film has different color differences with different pressures, so as to obtain a corresponding, pressure 1 image. Then, 'the buzz based on the color density distribution of the pressure image' is used to derive the pressure distribution on the wafer surface. In this measurement method, the pressure-sensing film can be formed by joining two polymer films, and the surface is covered with a color-developing material layer and a color-sensitive material, respectively.

7 6 Layer 5. Description of the invention ⑶ The two polymer films are composed of two layers covered with a color-developing material layer and a color-sensitive material, and the two surfaces are bonded to each other. 'The surface is sequentially covered with a color-sensitive material layer and a color-developing layer. In this measurement method, the color-developing material layer can be composed of microfoam. In this measurement method, the pressure sensing film is covered on the surface of the wafer ^-¾ kinds of electrical w 'can be predefined test patterns On the wafer surface. In this way, various basic patterns (such as holes with different densities and sizes, such as straight lines, blocks, or relationships with pressure distribution can be completely established and the circuit adjusted to increase the flatness of the chemical mechanical polishing method. The surface is up to For the above and other purposes, the present invention also provides a device for measuring the disk force distribution of a wafer meter, wherein the wafer surface is covered with a pressure sensing film, and the measurement device is a chemical mechanical polishing device and an image capture device. And image processing device. The chemical mechanical polishing device is used to place the wafer and press the pressure sensing film to obtain the corresponding pressure image. The β image capture device is used to capture the pressure image. And the image processing The device compares the pressure distribution on the wafer surface based on the color density distribution of the pressure image.-In this measurement device, the 'image capture device can be a scanner, digital camera, or other device. Used to capture the pressure image of the pressure sensor film. In this measuring device, the 'image processing device can be an analog processor, an analog program, or other devices. Set to darken the color based on the pressure image

Page 6 41B4T6 V. Description of the invention (4) The degree of contrast is compared to estimate the pressure distribution on the wafer surface. In this measuring device, the relationship of various circuit patterns (holes, lines, blocks, or any combination of different densities and sizes) and pressure distributions can be stored in the database, so that the circuit design guidelines can be used to Provide better die and wafer level planarization process results. Among them, various circuit patterns can be defined in the test pattern, and the test pattern can be defined in advance on the wafer surface. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings to make a detailed description as follows: The first illustration of the drawings is the present invention The flowchart of the method for measuring the pressure distribution on the wafer surface; FIG. 2 is a block diagram of the device for measuring the pressure distribution on the wafer surface according to the present invention; and FIG. 3A is the pressure distribution of the wafer surface for measuring the pressure distribution. In the device and method, a schematic cross-sectional view of a pressure-sensing film; and FIG. 3B is a schematic cross-sectional view of another pressure-sensing film in the device and method for measuring a pressure distribution on a wafer surface according to the present invention. Explanation of symbols-10 chemical mechanical polishing device; 2 image acquisition device; _ 30 image processing device; PSF1, PSF2 pressure sensing film; G1 pressure image;

1Π wafer;

Ai, A2, Cl polymer films; B1, B2 color-developing material layers; and D1, D2 color-sensitive material layers. EXAMPLES In order to improve the flatness of the chemical mechanical polishing method, the present invention intends to build the relationship between various circuit patterns and pressure distributions into a database 'so as to be used by a circuit designer or a circuit analyst. Please refer to FIG. 1, which is a flowchart of a method for measuring a pressure distribution on a wafer surface according to the present invention. First ', in step S1, a test pattern is provided? 1. Holes (Lines), lines (Rectangular), or any combination thereof with different densities and sizes are defined in the test pattern ρι. Generally, holes are used to simulate Contacts, Vias, and trenches; straight lines are used to simulate Gates and metal interconnects; blocks are used to simulate Simulate memory cells and contact pads. In addition, various densities and sizes are used to simulate various practical circuits. Next, in step S2, the test pattern P1 of step S1 is defined on the surface of the wafer W1. In this way, the surface of the wafer W1 will have various circuit patterns to simulate various actual circuits. Then, in step S3, a surface of the wafer W1 defined with various circuit patterns is covered with a layer of a pressure sensing film PSF. Figures 3A and 3B are schematic cross-sectional views of two types of pressure sensing films, which are pressure sensing films (FUJI PRESCALE FILM) disclosed by Fujitsu. In Figure 3A, the pressure sensing film PSF1 is formed by joining two polymer films (p0iyester base) Al and C1.

Page 8 4184J6 V. Description of the Invention 1c. The surface of the polymer film A1 is covered with a color developing material layer ^ = ° ^ ~ ί〇Γη〇ίη8 layer) B1. The surface of the polymer film C1 is covered with the A1 and Clt material layers (Coroll-de Veloping Uyer) D1. The polymer films 2 are covered with the color-developing material layer B1 and the surface film A2 of the color material layer M: ° In the rule, the 'pressure-sensing film PSF2 is composed of a polymer ^, and its surfaces are sequentially covered In the example, the color-sensitive material layer D2 and the color-developing material layer "color-developing material layers M and B2 are composed of a plurality of membrane-bearing color cells (MlCrOCaPSUU). When the pressure sensor is thin, the micro-color cells of the 'color-developing material layer B1, B2 will rupture and release ::: = color material. The released color-developing material produces a different concentration of color with the color-sensitive material ❹′ΛΛΓ. The use of particle size control microchromosomes can be designed to release different concentrations of color materials depending on the pressure they are subjected to. Because of the pressure knife cloth of the pressure sensing film psfi, psf2, the color or density distribution can be directly read. Medium 'will cover the crystal covered with the pressure-sensing film psf =: = polishing, and, in step s5, the "polishing device" is used to moderately pressure the surface of the wafer? A pressure image will appear, the color or concentration distribution of which represents the pressure distribution on the surface of the wafer W1, as described above, '" Next, in step S6, use the image to extract cracks (such as a scanner, a digital camera) In the pressure step S7 of grasping the pressure sensing film PSF, the color or density of the pressure image obtained in step S6 is compared by using an image processing device (such as Ting Xia, such as analog processing 5 |) to deduct the device. Your pressure distribution. Morning "cloth, wrong to judge the surface of the crystal

V. Description of the Invention Next, in step S8, the mapping results (relationships of various circuit patterns and pressure distributions) obtained in the above steps are stored in a database for use by circuit designers or circuit analysts. In addition, 'to achieve the above and other objects', the present invention does not require a high cost. Please refer to FIG. 2 'This is a block diagram of an apparatus for measuring a pressure distribution on a wafer surface according to the present invention. As shown in FIG. 2 ', the measurement device of the present invention is composed of a chemical mechanical polishing device 10, a shirt image manipulation device 20, and an image processing device 30. Among them, the chemical mechanical polishing device 10 is used to place the wafer W1, and pressure is appropriately applied to the pressure sensing film PSF to obtain a pressure image G1 related to the pressure distribution; the image capture device 20 is used to capture The pressure image G1; and the image processing device 30 judges the pressure distribution on the surface of the wafer ff1 according to the color or density distribution of the pressure image G1. A test pattern p 1 is defined on the surface of the wafer 1, which has holes, lines, blocks, or any combination thereof of different densities and sizes to simulate various actual circuits, as described above. In this embodiment, the image capturing device may be a scanner or a digital camera. The image processing device may be an analog processor. In addition, a database can be set in the measuring device to store the relationship between various circuit patterns and pressure distribution. In this way, circuit designers and circuit analysts can adjust circuit patterns based on the established database, thereby improving the flatness of the chemical mechanical polishing method and reducing the degradation of process quality due to uneven polishing speed. As mentioned above, the method for measuring the dust force distribution on the wafer surface according to the present invention is to use a pressure sensing film to derive the pressure distribution on the wafer surface and adjust the crystal

Page 10 V. Description of the invention (8) The circuit pattern of the round surface has the most even pressure distribution, thereby increasing the flatness of the crystal. The round surface. In addition, the method for measuring the pressure distribution on the wafer surface of the present invention is to define a test pattern on the wafer surface in advance, which has holes, lines, blocks, or any combination thereof with various densities and sizes. In this way, the relationship between various circuit patterns and pressure distribution can be established, and the circuit pattern design can also refer to this relationship to improve the flatness of the chemical mechanical polishing method. Furthermore, the device for measuring the pressure distribution on the wafer surface of the present invention is to use an existing chemical mechanical polishing device to set the wafer and pressure the pressure sensing film on the wafer surface, and use an image capture device (such as a scanner) Or digital cameras) and image processing devices (such as analog processors or analog programs) to capture the pressure image of the pressure sensing film and estimate the pressure distribution on the wafer surface. In addition, because image capture devices (such as scanners or digital cameras) and image processing devices (#such as analog processors or analog programs) can be provided by general computer systems and their peripherals, so there is no need for large costs . ^ Furthermore, the device for measuring the pressure distribution on the wafer surface of the present invention stores various circuit patterns (the relationship between different densities and pressure distributions in a database, and borrows the "tit." Guidelines for circuit design or circuit analysis to To produce a circuit layout with better manufacturing quality. Limitation ... Although the present invention has been disclosed in the preferred embodiment as described above, it is not intended to be used in conjunction with the present invention. Anyone skilled in the art will not depart from the spirit of the present invention. As it can be modified and retouched, the scope of protection of the present invention shall be defined by the scope of the attached patent application.

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Claims (1)

六 '申 谙 Patents Scope 4184 T 6 1. A method for measuring the pressure distribution on a wafer surface, the measuring method includes: covering a pressure and applying pressure according to the pressure 2. If applying pressure sensing film color material The layer and a cover surface are connected to each other. 3. If applying a pressure sensing film color material layer and a 4 if the color developing material. 5. If covering the pressure, it must be 6 as the test pattern intended. 7. — Apply for material layer to apply force sense-Apply for force sensing thin force sensing thin force image with patent range with two poly color sensing materials combined 0 patent range with one poly color developing material patent range is measured by multiple patent ranges The film has different densities in the test pattern patent on the wafer surface; the film obtains a pressure image; and the pressure distribution on the wafer surface is derived. The method according to item 1, wherein the surface of the compound film is covered with a display layer, and the two polymer films are covered by the two layers. The method, wherein the film is sequentially covered with a compound film and a layer as described in the first item. Keys containing color-developing materials as described in item 2 or 3 1¾ Method, in which cells are composed. The measurement method according to item 1, further comprising a step on the surface of the wafer before the step of the surface of the wafer. The method according to item 5, wherein the surface of the hole of the size, the block, or any amount of the wafer is covered with a chemical mechanical force sensing film for distributing the surface pressure, and wherein The thin film measuring device includes: a mechanical polishing device for placing the wafer and applying the pressure to obtain a dust image; measuring a wafer and a pressure sensor Page 12 4 184 76 (ii) Patent application scope An image capture device to capture the pressure image; and an image processing device to derive the pressure distribution on the wafer surface based on the pressure image. Device, where the force image. Xiang Zhi, where the force image. Device, wherein the image capture device described in item 7 of the scope of patent application is a scanner for scanning 9. the image capture device described in item 7 of the scope of patent application is a digital camera, 10. The image processing device described in item 7 of the scope of patent application is an analog processor, and the pressure distribution of the wafer surface is estimated based on the pressure image. Ii. The device according to item 7 of the scope of patent application, wherein the wafer surface further defines a test pattern having holes, lines, blocks, or any combination thereof with different densities and sizes. 1 2. The device as described in item 11 of the scope of patent application, further comprising a database for establishing the relationship between the holes, lines, blocks, or any combination thereof of different densities and sizes in the test pattern and the pressure distribution. In order to use the integrated circuit layout as a guideline for designing the pressure distribution uniformly before designing the circuit layout. Page 13