KR100807254B1 - Defect inspection device - Google Patents

Abstract

Disclosed is a defect inspection apparatus capable of providing various images required for defect analysis and having a simple structure. The defect inspection apparatus of the present invention includes a stage for moving an inspected object to a desired position, a holder moving with the stage having a seating portion on which the inspected object is seated, and an upper surface of the inspected object seated on the holder. An optical microscope having a light source, an illumination device which is installed to move with the stage, irradiates light to the lower surface of the test subject seated on the holder, and an electron microscope which scans an electron beam on the test subject seated on the holder to generate an image. It is configured to include.

Description

Fault Inspector {DEFECT INSPECTING APPARATUS}

      1 is a configuration diagram schematically showing a configuration of a conventional defect inspection apparatus.

      2 is a configuration diagram showing the configuration of a defect inspection apparatus according to the present invention.

      Figure 3 is a plan view showing a holder and a lighting device for supporting the photomask in the present invention.

      * Description of symbols on the main parts of the drawings *

      10: vacuum chamber 20: stage

      30 holder 40 optical microscope

      50: electron microscope 60: control unit

      70: display device 80: lighting device

      The present invention relates to a defect inspection apparatus, and more particularly, to a defect inspection apparatus for generating an image for analyzing a defect of an inspected object.

      The semiconductor manufacturing process includes a photographic process of transferring the circuit pattern formed on the photomask to a wafer photoresist film applied on the wafer. Since the photoresist film pattern transferred to the wafer is a result of the circuit pattern formed on the photomask, the morphological characteristics of the wafer photoresist film pattern are essentially influenced by the characteristics of the photomask. Therefore, since defects generated during the manufacturing process of the photomask lead to defects in the wafer, it is essential to detect and confirm the defects of the photomask before using the photomask in the photolithography process.

      Defects of the photomask are inspected for their presence and position by the detection equipment, and the defects thus detected are confirmed by the review equipment. The review equipment receives data on defects from the detection equipment and generates an image for defect analysis. In general, since the photomask is made of quartz that transmits light, in order to analyze defects on the photomask, reflected light reflected by irradiating light on the upper surface of the photomask and light transmitted by irradiating light from the lower part of the photomask It is necessary to analyze the information.

      1 is a configuration diagram schematically showing the configuration of a conventional defect inspection apparatus. As shown in FIG. 1, a conventional defect inspection apparatus includes a holder 2 for fixing a photomask 1, which is an inspection object, a stage 3 for moving the photomask 1 to a desired observation position, An optical microscope 4 having a reflective illumination device 4a and an image sensor 4b, a transmission illumination device 5 for irradiating light from the lower part of the photomask 1, a control unit 6 and a display device ( 7). When data regarding defect information is input to the defect inspection apparatus, the control unit 6 moves the stage 3 so that the defect of the photomask 1 is located under the optical microscope. Then, the light is irradiated from the reflective illuminator 4a or the transmissive illuminator 5 according to the defect information, and the image sensor 4b transmits the reflected light reflected from the photomask 1 or the transmitted light transmitted through the photomask 1. Collect. The image sensed by the image sensor 4b is transmitted to the control unit 6 and displayed on the display device 7.

      In recent years, as the circuit line width decreases, the size of defects present in the photomask is also getting smaller and smaller. However, due to the characteristics of the optical microscope, the conventional defect inspection apparatus cannot obtain a high resolution image suitable for identifying fine defects.

      In the defect inspection apparatus as described above, the light irradiated from the transmission illumination device 5 must be detected by the image sensor 4b provided in the optical microscope 4 after passing through the photomask 1, and the transmission illumination device 5 is It is fixed to irradiate light with the image sensor 4b of the optical microscope 4, while the photomask 1 moves with the stage 3 according to the position of the defect, so that the transmission illuminator 5 and the stage The structure that (3) does not interfere with each other becomes complicated.

      SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to provide a defect inspection apparatus having a simple structure while providing various images required for defect analysis.

 The defect inspection apparatus according to the present invention for achieving this object has a stage for moving the inspected object to a desired position; and a holder on which the inspected object is mounted, the holder moving with the stage; and the inspected mounted on the holder. An optical microscope having a light source for irradiating light on the upper surface of the body; and an illumination device which is installed to move together with the stage and which irradiates light on the lower surface of the test subject mounted on the holder; and mounted on the holder. And an electron microscope for generating an image by scanning an electron beam onto the inspected object.

The lighting device is installed in the holder under the support.

The lighting device is provided in a flat shape so that light can be irradiated to the entire area of the lower surface of the test object.

In addition, the defect inspection apparatus according to the present invention is a defect inspection apparatus for generating an image to analyze the defect of the inspected object, a stage for moving the inspected object to a desired position; and supports the inspected object, together with the stage And a holder that moves, and a flat lighting device disposed between the stage and the test object to irradiate light to the lower surface of the test object.

      Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail. 2 is a block diagram showing a configuration of a defect inspection apparatus according to the present invention, Figure 3 is a plan view showing a holder and a lighting device for supporting a photomask in the present invention.

      As shown in FIG. 2, the defect inspection apparatus according to the present invention includes a vacuum chamber 10, a stage 20 movably installed in the vacuum chamber 10, and a photomask 100 that is a test object. Scanning electron beams to a holder 30 for supporting the light, an optical microscope 40 for providing an optical image through the window 11 installed in the vacuum chamber 10, and a photomask 100 fixed to the holder 30. An electron microscope 50, a control unit 60, and a display device 70.

      The stage 20 is for moving the photomask 100 to a desired position, and may be composed of an X-stage 21, a Y-stage 22, and a θ-stage 23. The X-stage 21 moves the photomask 100 in the X-axis direction, and the Y-stage 22 moves the photomask 100 in the Y-axis direction. The θ-stage 23 rotates the photomask 100 about the Z axis.

      The holder 30 is installed above the stage 20 and moves together with the stage 20. The holder 30 has a support 31 for fixing the photomask 100.

      The optical microscope 40 includes a light source 41 for irradiating light to the upper surface 101 of the photomask 100 supported by the holder 30, and a photomask 100 for light emitted from the light source 41. A beam splitter 42 for guiding the upper surface 101 of the lens, a lens 43 for focusing light emitted from the light source 41 to the photomask 100, and light or a photo reflected from the photomask 100. And an image sensor 44 for receiving light transmitted through the mask 100. Here, the image sensor 44 detects the reflected light and the transmitted light as described above, and converts the converted light into an electrical signal to provide the controller 60 with information about a defect present in the photomask 100. As the image sensor 44, a charge coupled device (CCD) may be used.

      2 and 3, the lighting device 80 is disposed under the photomask 100, more specifically, between the photomask 100 and the stage 20. The lighting device 80 is provided in a flat shape so as to cover the entire lower surface 102 of the photomask 100. At this time, the lighting device 80 is installed to move with the stage 20. In this embodiment, the lighting device 80 is shown to be installed in the holder 30, but alternatively, it is also possible to fix the lighting device 80 to the stage 20 through a separate structure. The lighting device 80 irradiates light from the lower surface 102 of the photomask 100, and the irradiated light passes through the photomask 100 to reach the image sensor 44, and the photomask 100. Information on defects. As such, when the flat lighting device 80 is used, the transmitted light may be irradiated with the image sensor 44 of the optical microscope 40 while simplifying the structures of the stage 20 and the lighting device 80.

      As shown in FIG. 2, the electron microscope 50 is a scanning electron microscope, which includes an electron gun 51 and an electron optical column 52 having a condenser lens (not shown) and an objective lens (not shown) therein. Has The electron gun 51 and the electron optical column 52 form a focused electron beam and irradiate the photomask 100, which generates secondary electrons from the surface of the photomask 100, and the detector 53 detects these two. The electrons are collected to provide the controller 60 with information necessary for forming an image.

     Hereinafter, a method of inspecting a defect of a photomask using a defect inspection apparatus according to the present invention will be described with reference to FIG. 2.

      First, the photomask 100 requiring the defect observation is introduced into the vacuum chamber 10. At this time, the photomask 100 is mounted on the support 31 of the holder 30 by an automatic transfer device (not shown). If data regarding defect information of the photomask and defect information obtained from a device (not shown) for detecting the position is input to the control unit 60, the control unit 60 moves the stage 20 to cause a defect of the photomask 100. It is located under the optical microscope 40. When the reflected light should be used according to the type of defect, the controller 60 controls the light source 41 of the optical microscope 40 to irradiate light onto the upper surface 101 of the photomask 100. Then, the reflected light reflected from the upper surface 101 of the photomask 100 is detected by the image sensor 44, and the control unit 60 controls the display device 70 based on the image information detected by the image sensor 44. Display the observed image. In addition, when the transmitted light is to be used according to the type of defect, the controller 60 controls the lighting device 80 to irradiate light to the lower surface 102 of the photomask 100. Then, the transmitted light passing through the photomask 100 is detected by the image sensor 44, and the controller 60 displays the observation image on the display device 70 based on the image information detected by the image sensor 44.

      On the other hand, when work such as high resolution defect analysis or component analysis is required, the control unit 60 moves the stage 20 so that the defects of the photomask 100 are positioned under the electron microscope 50. When the user inputs a desired magnification, the controller 60 controls the electron microscope to irradiate the focused electrons to the photomask 100. Then, secondary electrons generated in the photomask 100 are collected by the detector 53, and the controller 60 receives the observed image signal from the detector 53 and displays the image on the display device 70.

      As described above, according to the present invention for generating a transmitted light image

By installing the lighting device to move with the stage, the structure of the defect inspection device can be simplified.

      In addition, according to the present invention, since the reflected light image, the transmitted light image, and the electron microscope image can be provided by one device, the time required for defect analysis can be reduced, thereby improving productivity.

Claims (5)

A stage for moving the inspected object to a desired position; and A holder having a support on which the inspected object is mounted and moving together with the stage; and An optical microscope having a light source for irradiating light to the upper surface of the object under test mounted on the holder; and Is installed to move with the stage, the illumination device for irradiating light to the lower surface of the test subject mounted on the holder; And An electron microscope for generating an image by scanning an electron beam on an object under test mounted on the holder; Defect inspection apparatus comprising a. The method of claim 1, The lighting device is a defect inspection device, characterized in that installed in the holder under the support. The method of claim 1, The lighting device is a defect inspection device, characterized in that provided in the flat plate so that the light irradiated to the entire area of the lower surface of the object. In the defect inspection apparatus for generating an image to analyze the defect of the subject, A stage for moving the inspected object to a desired position; and A holder for supporting the test object and moving together with the stage; and A flat panel lighting device installed between the stage and the inspected object to irradiate light to the lower surface of the inspected object; Defect inspection apparatus comprising a.       The method of claim 4, wherein       The flat lighting device is a defect inspection device, characterized in that installed in the holder.

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