JP2005121438A - Substrate inspecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate inspecting apparatus that suppresses the occurrence of scattered light reflected by a stage pin, and preventing the misdetection of defects on the surface of a substrate. <P>SOLUTION: In the substrate inspecting apparatus for providing a stage pin for supporting the light-transmissive substrate on a stage, and detecting defects on the substrate by detecting the reflection light of laser beams applied to the substrate placed on the stage pin by a detector, a reflection preventing means for preventing the reflection of laser beams from the stage pin to the detector is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  In the present invention, a stage pin for supporting a substrate having light permeability is provided on a stage, and a defect of the substrate is detected by detecting reflected light of a laser beam irradiated on the substrate placed on the stage pin by a detector. The present invention relates to a substrate inspection apparatus to be detected.

  The circuit pattern formed in the semiconductor device has a very complicated and fine structure with the recent high integration of the semiconductor device.

  For this reason, if fine foreign matters or wrinkles are present on the substrate on which the circuit pattern is formed, there has been a problem that the circuit patterns are disconnected or short-circuited due to the foreign matters or wrinkles.

  In order to solve this problem, conventionally, a substrate inspection apparatus is used to detect defects such as foreign matter and wrinkles on the substrate surface, and a circuit pattern is formed only on a substrate having no defect to manufacture a product.

  As shown in FIG. 4, the substrate inspection apparatus 10 includes stage pins 12 that support a substrate 13 on a stage 11, and irradiates the substrate 13 placed on the stage pins 12 from vertically above. Using a detector 17 that scans with the laser light 14 and provides reflected light 16 (hereinafter referred to as “scattered light”) other than the predetermined reflected light 15 of the reflected light of the laser light 14 around the substrate 13. The presence or absence of defects on the surface of the substrate 13 is determined by detecting and determining the presence or absence of the scattered light 16.

That is, when there is no defect 18 such as a foreign substance or a flaw on the surface of the substrate 13, the scattered light 16 is not generated because the laser beam 14 is reflected only in the vertically upward direction, but there is a defect 18 on the surface of the substrate 13. The laser light 14 hits the defect 18 and generates scattered light 16 that is reflected in an irregular direction. And when this detector 17 detected this scattered light 16, it was discriminate | determined with the defect part 18 (for example, refer patent document 1).
JP 11-295233 A

  However, since the conventional substrate inspection apparatus 10 is originally used for inspection of a substrate that does not transmit light, such as a silicon substrate, the substrate inspection apparatus 10 has light transmission properties like a quartz substrate. When the high substrate 13 is inspected, as shown in FIG. 5, the laser light 14 is transmitted through the substrate 13 and reflected by the stage pins 12 to generate scattered light 16, which is detected by the detector 17. As a result, there is a possibility that the substrate 13 in which the defect portion 18 does not actually exist is erroneously determined as having the defect portion 18.

  Accordingly, in the present invention according to claim 1, a stage pin for supporting a light-transmitting substrate is provided on the stage, and the reflected light of the laser beam irradiated on the substrate placed on the stage pin is detected by the detector. Thus, the substrate inspection apparatus for detecting a defect in the substrate has an antireflection means for preventing the reflection of the laser light from the stage pin to the detector.

  Further, in the present invention according to claim 2, the antireflection means forms the stage pin with a material having a lower reflectance of the laser beam than the stage.

  According to the third aspect of the present invention, the antireflection means includes a low reflection layer made of a material having a lower laser beam reflectance than the stage on the upper surface of the stage pin.

  According to the first aspect of the present invention, a stage pin that supports a substrate having light transmittance is provided on the stage, and the reflected light of the laser beam irradiated on the substrate placed on the stage pin is detected by a detector. In the substrate inspection device that detects the defect of the substrate by using the anti-reflection means for preventing the reflection of the laser beam from the stage pin to the detector, the generation of scattered light due to the reflection of the laser beam on the stage pin Therefore, it is possible to prevent erroneous detection of defects.

  Further, in the present invention according to claim 2, since the antireflection means is formed of a material having a lower reflectivity of laser light than the stage, it is necessary to make a large capital investment only by replacing the stage pin. Thus, the inspection accuracy of the substrate inspection apparatus can be improved.

  Further, in the present invention according to claim 3, since the antireflection means is provided with a low reflection layer made of a material having a lower reflectivity of laser light than the stage on the upper surface of the stage pin, it is only necessary to process the stage pin. In addition, the inspection accuracy of the substrate inspection apparatus can be improved without making a great investment in equipment.

  A substrate inspection apparatus according to the present invention is a stage pin that is a substrate support that keeps a substrate horizontal on a stage on which a substrate that is an object to be inspected is placed and that can be easily detached after inspection. The substrate placed on the stage pin is irradiated with laser light from vertically above, and reflected light other than the predetermined reflected light (hereinafter referred to as “scattered light”) among the reflected light. This is a substrate inspection apparatus that detects defects such as foreign matter and wrinkles on the surface of a substrate by detecting using a detector provided around the substrate.

  The substrate inspection apparatus further includes an antireflection means for preventing the laser light transmitted through the substrate from being reflected from the stage pin toward the detector when inspecting the substrate having a high light transmittance. Yes.

  In this antireflection means, the stage pin is formed of a material having a laser beam reflectance lower than that of the stage, or a low reflection layer of a material having a laser beam reflectance lower than that of the stage is provided on the upper surface of the stage pin. It is formed by.

  As the material having a low reflectivity, a metal having a low spectral reflectivity with respect to the wavelength of the laser light applied to the substrate is used, so that the reflectivity of the stage pin is lower than that of the stage.

  In this way, by forming the stage pin or the upper surface of the stage pin with a material having a lower reflectance than the stage, the substrate can be used when inspecting a substrate having a high light transmittance such as a quartz substrate. Since it is possible to suppress generation of scattered light due to reflection of the transmitted laser light on the stage pin, it is possible to prevent erroneous detection of defects.

  Further, as described above, in order to provide a substrate inspection apparatus that can prevent erroneous detection of defects, the stage pin is formed of a low-reflectance material, or a low-reflectance material is used only for the stage pin. Therefore, since the conventional substrate inspection apparatus other than the stage pins can be used as it is, a highly reliable substrate inspection apparatus can be obtained without making a large capital investment.

  A substrate inspection apparatus according to the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the substrate inspection apparatus 1 includes a stage 2, a stage pin 4, a laser light irradiation device 5, and a detector 6.

  The stage 2 is a mounting table on which a substrate 3 that is an object to be inspected is mounted.

  A plurality of stage pins 4 are provided on the upper surface of the stage 2, and serve as a support for the substrate 3 that keeps the substrate 3 horizontal and allows the substrate 3 after inspection to be easily detached.

  The laser beam irradiation device 5 is a device that scans the surface of the substrate 3 while irradiating the laser beam 7 from vertically above the substrate 3 when inspecting the substrate 3.

  The detector 6 detects scattered light reflected by the laser beam 7 irradiated by the laser beam irradiation device 5 when it has a defect such as a foreign substance or a flaw on the surface of the substrate 3 and is reflected in a direction other than vertically above the defect. It is a device.

  In particular, the stage pin 4 described above is formed using a material having a lower reflectivity of the laser beam 7 than that of the stage 2 as shown in FIG. 2A, or as shown in FIG. By forming a low reflection layer made of a material having a lower reflectivity of the laser beam 7 than that of the stage 2 on the upper surface of the pin 4, antireflection means 8 is provided for preventing the reflection of the laser beam.

  Thus, by providing the antireflection means 8, as shown in FIG. 1, when inspecting a substrate 3 having a high light transmittance such as a quartz substrate, the laser beam 7 is transmitted through the substrate 3. Even if the light is reflected on the stage pin 4, the surface of the stage pin 4 has a low reflectance of the laser beam 7, so that the generation of scattered light can be suppressed. It is possible to prevent erroneous detection of defects such as erroneous recognition, and the substrate inspection apparatus 1 with high inspection accuracy can be obtained.

  Even if the laser beam 7 transmitted through the substrate 3 is reflected by the stage 2, a predetermined interval is provided between the stage 2 and the detector 6, so that the reflected light is transmitted through the substrate 3 again. And becomes difficult to be detected by the detector 6.

  In order to obtain the substrate inspection apparatus 1 with high inspection accuracy as described above, it is only necessary to provide the antireflection means 8 formed on the stage pin 4 using a material whose reflectivity of the laser beam 7 is lower than that of the stage 2. Since the conventional substrate inspection apparatus 10 other than the stage pins 4 can be used as it is, the substrate inspection apparatus 1 with high inspection accuracy can be obtained without making a large capital investment.

  Here, as the material having a low reflectance of the laser beam 7 used in the present embodiment, a metal having a low spectral reflectance with respect to the wavelength of the laser beam 7 irradiated onto the substrate 3 is used.

  As shown in FIG. 3, the spectral reflectance of the metal varies depending on the type of metal and the wavelength of the laser beam to be irradiated.

  Therefore, for example, in the substrate inspection apparatus 1 using the laser beam 7 having a wavelength of about 500 (nm), as shown in FIG. 3, Au (gold), which is the metal having the lowest spectral reflectance at this wavelength, can be selected. desirable.

  In particular, in the substrate inspection apparatus 1 using the laser beam 7 having a wavelength of about 300 (nm), when Ag (silver) is selected as the material used for the stage pin, the spectral reflectance of the laser beam 7 is changed as shown in FIG. Since it can be 10% or less, the scattered light 16 generated when the laser beam 7 transmitted through the substrate 3 is reflected by the stage pin 4 can be made so weak that it can be ignored, thereby detecting a defect erroneously. Can be completely prevented.

It is explanatory drawing which shows the board | substrate inspection apparatus which concerns on this invention. It is sectional drawing which shows an antireflection means. It is a graph which shows the spectral reflectance of the metal with respect to the wavelength of a laser beam. It is explanatory drawing which shows the conventional board | substrate inspection apparatus. It is explanatory drawing which shows the erroneous detection of a defect.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Board | substrate inspection apparatus 2 Stage 3 Board | substrate 4 Stage pin 5 Laser beam irradiation apparatus 6 Detector 7 Laser beam 8 Antireflection means

Claims (3)

A substrate for detecting defects in the substrate by providing a stage pin for supporting a substrate having light transparency on the stage and detecting reflected light of the laser beam irradiated on the substrate placed on the stage pin by a detector In inspection equipment,
A substrate inspection apparatus comprising antireflection means for preventing reflection of laser light from the stage pin to the detector.   The substrate inspection apparatus according to claim 1, wherein the antireflection means is formed of a material having a lower reflectivity of the laser beam than the stage.   The substrate inspection apparatus according to claim 1, wherein the antireflection means includes a low reflection layer made of a material having a lower reflectance of the laser beam than the stage on an upper surface of the stage pin.

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