JP2007030118A - Dresser inspecting device, dresser inspecting method, cmp device and cmp device inspecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dresser inspecting device and dresser inspecting method for surely evaluating and inspecting the state of diamond buried into mechanical equipment in the dresser, and also to provide a CMP device employing the device and method, and a CMP device inspecting method. <P>SOLUTION: This dresser inspecting device inspects an abnormality of the dresser by burying diamond particles in a surface of a base material. The device is provided with: a light source means 11 for irradiating light in a direction substantially horizontal to a surface buried with the diamond particles in relation to the surface buried with the diamond particles in the dresser; a reflected image acquiring means 13 for acquiring images of the surface buried with the diamond particles by collecting reflected light reflecting on the surface buried with the diamond particles by irradiation light from the light source means 11; an image processing means 15 for forming a composite image by performing a combining processing of the plurality of images acquired by the reflected image acquiring means 13; and an abnormality detection means 17 for detecting an abnormality of the dresser based on the composite image. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dresser inspection apparatus and a dresser inspection method used in a CMP (Chemical Mechanical Polishing) apparatus which is a kind of semiconductor manufacturing apparatus, and a CMP apparatus and a CMP apparatus inspection method to which these are applied. In particular, a dresser inspection apparatus and a dresser inspection method for determining the state of the dresser by determining the state of diamond particles embedded in a substrate in a dresser used in the CMP apparatus, and a CMP apparatus and CMP to which these are applied The present invention relates to an apparatus inspection method.

  In recent years, in an LSI (Large Scale Integrated Circuit), with the miniaturization of design rules and the increase in the number of wiring layers, flattening techniques for interlayer insulating films and the like have become very important. At present, the most noticeable flattening technique is a chemical mechanical polishing (CMP) technique and a CMP apparatus.

  In a CMP apparatus using this CMP technique, the interlayer insulating film is planarized with a polishing cloth. Here, since the polishing cloth becomes dull as the flattening process is repeated, in order to perform a high-quality flattening process, the polishing cloth is polished by appropriately dressing (dressing) the polishing cloth. It is essential to maintain the property, that is, maintain an appropriate polishing state. Such dressing is performed using a member called a dresser in which diamond particles are embedded in the surface of a substrate.

  However, in the above conventional technique, there may be a situation in which diamond particles embedded in the dresser fall off from the substrate due to crushing or peeling during dressing. When diamond particles fall off from the dresser during dressing in this way, the diamond particles remain on the polishing cloth, and as a result, the surface of the object to be polished (semiconductor substrate) is visually confirmed during the flattening process. As a result, there is a problem that a scratch (big scratch) that is large enough to occur is generated, and the polished object (semiconductor substrate) in which such a scratch is generated cannot be used as a product, resulting in a defective product and a decrease in manufacturing yield. is there.

  Therefore, in order to prevent the occurrence of scratches due to diamond particles falling off from the dresser during dressing, a dresser that may cause diamonds to fall off by inspecting the dresser before polishing is used in advance. It is necessary not to. Therefore, conventionally, the dresser is inspected by observing the surface of the dresser with an optical microscope.

  However, the method of observing the surface of the dresser with an optical microscope has a problem that the reflection of light from the dresser substrate is large and it is difficult to determine the state of the diamond particles. Therefore, the present situation is that a technique for inspecting the dresser to reliably evaluate and inspect the possibility of the diamond falling off from the dresser to inspect the abnormality of the dresser has not yet been established.

  The present invention has been made in view of the above, and a dresser inspection apparatus and a dresser inspection method capable of reliably evaluating and inspecting the state of diamond embedded in equipment in a dresser, and CMP using the same An object is to obtain an inspection method for an apparatus and a CMP apparatus.

  In order to solve the above-described problems and achieve the object, a dresser inspection apparatus according to the present invention is a dresser inspection apparatus that inspects a dresser abnormality in which diamond particles are embedded in a surface of a base material. Light source means for irradiating light in a direction substantially parallel to the surface where the diamond particles are embedded, and light irradiated from the light source means reflected on the surface where the diamond particles are embedded. Reflected image acquisition means for collecting reflected light and acquiring an image of a surface embedded with diamond particles; and image processing means for generating a composite image by performing a combination process of a plurality of images acquired by the reflected image acquisition means. And an abnormality detecting means for detecting an abnormality of the dresser based on the composite image.

  According to the present invention, the surface of the dresser with the diamond particles embedded is irradiated with light in a direction substantially horizontal to the surface with the diamond particles embedded, and the light is irradiated on the surface with the diamond particles embedded. The reflected reflected light is collected to obtain an image of the surface in which the diamond particles are embedded, and a composite image is generated by combining the acquired images, and a dresser abnormality is detected based on the composite image. In order to detect, it is possible to reliably evaluate and inspect the diamond embedding state and the presence or absence of cracks in the base material of the dresser to detect an abnormality of the dresser.

  Hereinafter, a dresser inspection apparatus and a dresser inspection method according to the present invention, a CMP apparatus to which these are applied, and a CMP apparatus inspection method will be described in detail with reference to the drawings. In addition, this invention is not limited to the following description, In the range which does not deviate from the summary of this invention, it can change suitably.

  First, the basic concept of the present invention will be described. FIG. 1 is a diagram showing a schematic configuration of a dresser inspection apparatus according to the present invention. As shown in FIG. 1, the dresser inspection apparatus according to the present invention includes a light source unit 11 capable of adjusting an irradiation angle for irradiating light on the surface (diamond surface) of the dresser, and irradiation light from the light source unit 11. A reflected image acquisition unit 13 that collects reflected light reflected on the surface (diamond surface) of the lens to acquire an image of the diamond surface, and image data acquired by the reflected image acquisition unit 13 is transferred, and image processing of the data is performed. The image processing unit 15 that performs (multiplication processing) to generate a composite image, and the abnormality detection unit 17 that detects a dresser abnormality based on the composite image generated by the image processing unit 15 are configured.

  In the present invention, the light source unit 11 irradiates light onto a surface (hereinafter referred to as a diamond surface) in which diamond particles are embedded in a dresser in which diamond particles are embedded on the surface of the substrate. Here, the light irradiation with respect to the diamond surface is performed in the lateral direction, that is, at an angle substantially horizontal with or close to the horizontal of the diamond surface of the dresser. By applying light from the lateral direction, reflection of the irradiated light on the substrate can be eliminated. Then, the reflected light (scattered light) reflected by the diamond surface is collected to acquire an image of the diamond surface. For example, an image is taken using an optical microscope. As a result, an image in which diamond particles emerge can be obtained.

  Next, the light irradiation direction is changed by changing the position of the light source in the horizontal direction or changing (rotating) the position of the dresser in the horizontal direction, and an image is obtained in the same manner as described above. In this case, each time the direction of light irradiation to the dresser changes, the diamond particles that shine, that is, the diamond particles that emit reflected light, change. Thereby, for example, images as shown in FIGS. 2-1 to 2-3 can be obtained. FIGS. 2-1 to 2-3 are photomicrographs when the diamond surface of the dresser is irradiated with light from different lateral directions.

  After obtaining a plurality of images, the image processing unit 15 performs image processing (multiplication processing) of the captured images to synthesize the plurality of images to generate a composite image. Thereby, for example, a composite image as shown in FIG. 3 is obtained, and specific diamond particles can be recognized as bright spots. Here, all of the images are displayed in black except for the portion that is shining in common.

  Since the scattered light (reflected light) from the surface of the diamond particles is observed only by light irradiation from one direction, it is removed in this synthesis process. For this reason, the scattered light (reflected light) from the surface of the diamond particle is not recognized in the synthesized image after the synthesis process (FIG. 3). Therefore, the bright spot recognized on the synthesized screen after the synthesis process is an image of diamond particles that scatter light no matter which direction the light is applied.

  Next, the abnormality detection unit 17 detects the abnormality of the dresser based on the composite image generated by the image processing unit 15. When the diamond corresponding to the luminescent spot is observed in the composite image obtained as described above, the luminescent spot has a different color tone depending on the state of the diamond. For example, the luminescent spot having a color tone of yellow, white, blue, etc. Exists. This color difference reflects the light scattering state in the diamond particles. Thus, by determining the color tone of the bright spot, it is possible to determine diamond particles that are cracked and easily broken or diamond particles that float from the substrate and easily peel off. Therefore, in the present invention, the abnormality detecting unit 17 can detect the abnormal tone among the diamond particles embedded in the surface of the base material by determining the color tone of the bright spot of the composite image described above. It is possible to detect abnormalities of the dresser.

  In addition, in the diamond particle | grains applicable to the luminescent point recognized as said different color tone, light reflection as shown to FIGS. 4-1 to FIGS. 4-3 is performed. FIGS. 4-1 to 4-3 are cross-sectional views schematically showing the reflection state of irradiation light in diamond particles recognized as bright spots in the composite image.

  For example, FIG. 4A is a cross-sectional view schematically showing a reflection state of irradiation light on diamond particles recognized as yellow bright spots. The diamond particles recognized as yellow luminescent spots correspond to the diamond particles 23 that are not embedded at a predetermined depth from the base material 21 of the dresser but are floating from the predetermined depth. And this yellow luminescent spot originates in the light L1 in which the incident light L was reflected in the bottom face of the diamond particle which floated from the predetermined depth of the base material, and a part of it was absorbed inside the diamond particle. ing. In addition, the higher the brightness, the more the diamond particles lift from the substrate.

  FIG. 4B is a cross-sectional view schematically showing a reflection state of irradiation light on diamond particles recognized as white bright spots. The diamond particles recognized as white luminescent spots correspond to diamond particles 27 having cracks 25. The white bright spot is caused by the total reflected light L2 of the incident light L from the diamond particles 27 having the cracks 25. In particular, the higher the brightness, the greater the number of cracks 25 in the diamond particles, or the larger the cracks 25, and the higher the risk that the diamond particles will break during dressing.

  FIG. 4C is a cross-sectional view schematically showing the reflection state of the irradiation light on the diamond particles recognized as blue bright spots with low luminance. The diamond particles recognized as blue luminescent spots correspond to diamond particles 29 embedded in close contact with the base material 21 of the dresser, and are diamond particles normally embedded in the base material 21 without any problem. The blue bright spot with low luminance is caused by the reflected light L3 of the incident light L at the interface between the base material (nickel) and the diamond particles in the base material 21.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1 FIG.
FIG. 5 is a diagram illustrating a schematic configuration of the dresser inspection device according to the first embodiment of the present invention. As shown in FIG. 5, the dresser inspection apparatus according to the present embodiment includes a white light source 31 that is a light source unit capable of adjusting an irradiation angle for irradiating light on the surface (diamond surface) of the dresser, and a white light source 31. The CCD camera 33 which is a reflected image acquisition unit that collects the reflected light reflected by the surface of the dresser (diamond surface) and acquires the image of the diamond surface, and the image data acquired by the CCD camera 33 are An image processing unit that generates a composite image by performing image processing (composition processing) of the transferred data, and an abnormality detection unit that detects an abnormality of the dresser based on the composite image generated by the image processing unit It is configured. Here, in the present embodiment, a normal personal computer (PC) 35 having a display device for displaying an image is installed and a program for realizing functions as an image processing unit and an abnormality detection unit is used. The dresser D is fixed by a fixing portion 37.

  Next, the operation of the dresser inspection apparatus according to the present embodiment configured as described above, that is, a dresser inspection method using the dresser inspection apparatus according to the present embodiment will be described.

  First, for example, the dresser D is fixed with the surface in which the diamond particles are embedded in the dresser D (hereinafter referred to as diamond surface) facing upward. Next, the white light source 31 is used to irradiate the diamond surface of the dresser D with white light. Here, when white light is irradiated from the white light source 31 to the diamond surface of the dresser D, the white light is irradiated at an angle substantially horizontal or close to the horizontal of the diamond surface of the dresser D.

  Then, the CCD camera 33 photographs the diamond surface of the dresser D. That is, the reflection on the diamond surface of the dresser D is collected. As a result, reflection of the substrate of the dresser D can be suppressed, and an image in which diamond particles have emerged can be obtained.

  Next, the irradiation direction of white light on the diamond surface is changed by changing the position of the white light source 31 in the horizontal direction or changing (rotating) the dresser D position in the horizontal direction. Get the image.

  After obtaining a plurality of images, the captured image is subjected to image processing (multiplication processing) by a personal computer (PC) 35 (function as an image processing unit) to generate a composite image. In the synthesized image thus obtained, specific diamond particles can be recognized as bright spots.

  In the synthesized image, the portion other than the portion that is shining in all the images is displayed in black, and the scattered light (reflected light) from the surface of the diamond particles is removed in this synthesis process. For this reason, scattered light (reflected light) from the surface of the diamond particles is not recognized in the synthesized image after the synthesis process, and the bright spot recognized in the synthesized screen after the synthesis process is irradiated from any direction. It is an image of diamond particles scattering light.

  Next, an abnormality of the dresser D is detected in a personal computer (PC) 35 (function as an abnormality detection unit) based on the generated composite image. By judging the color tone of the bright spot in the composite image obtained as described above in the personal computer (PC) 35, it is possible to detect abnormal diamond particles among the diamond particles embedded in the surface of the substrate. It is possible to detect the abnormality of the dresser.

Embodiment 2. FIG.
FIG. 6 is a cross-sectional view showing the main configuration of the CMP apparatus according to the present embodiment. In FIG. 6, the polishing head 101, the rotatable polishing table 103, and the polishing installed on the upper surface of the polishing table 103 are shown. A pad (polishing cloth) 105, a slurry 107 that is a chemical abrasive, and a slurry supply means 109 are provided. The polishing head 101 is a polishing head (polishing head) in which a semiconductor wafer 113 to be polished is mounted on a polishing surface, and the polishing head 101 is configured to be rotatable. In this CMP apparatus, the slurry 107 is supplied to the polishing pad (polishing cloth) 105, and the polishing head 101 with the semiconductor wafer 113 mounted on the polishing surface is pressed against the polishing pad (polishing cloth) 105 and the polishing head 101 and The polishing process of the semiconductor wafer 113 is performed by rotating the polishing table 103.

  In addition, this CMP apparatus includes a dressing apparatus (not shown) for dressing the polishing pad (polishing cloth) 105 using a dresser in which diamond particles are embedded in the surface of a base material, and a dresser for inspecting an abnormality of the dresser. The dresser inspection apparatus 111 described in Embodiment 1 is provided as an inspection unit. In this CMP apparatus, the dresser inspection apparatus 111 inspects the dresser before polishing the individual semiconductor wafers. If an abnormality is detected in the dresser, the polishing pad 105 is polished. Stop dressing and polishing of the semiconductor wafer in advance.

  As a result, in this CMP apparatus, it is possible to reliably prevent the occurrence of scratches during the polishing process due to the abnormality of the dresser. Therefore, according to this CMP apparatus, it is possible to prevent the generation of defective products due to the abnormality of the dresser and the decrease in manufacturing yield, and to perform high-quality polishing with high yield.

Embodiment 3 FIG.
In the second embodiment described above, a case has been described in which the CMP apparatus includes the dresser inspection apparatus according to the present invention, and the dresser inspection apparatus performs the dresser inspection before the polishing process of each semiconductor wafer. It is also possible to adopt a configuration provided with an automatic dresser changing device that automatically changes the dresser.

  That is, in the CMP apparatus according to the present embodiment, a dresser inspection apparatus is provided as in the case of the second embodiment, and the dresser inspection apparatus inspects the dresser before performing polishing processing of individual semiconductor wafers. When an abnormality is detected in the dresser, the dressing of the polishing pad (polishing cloth) 105 and the polishing process of the semiconductor wafer are stopped in advance. Further, in a state where the polishing process is stopped, the automatic dresser exchange device replaces the dresser in which an abnormality is found with another normal dresser. Then, after performing dressing with a normal dresser, a polishing process is performed.

  As a result, in this CMP apparatus, as with the CMP apparatus according to the second embodiment described above, it is possible to reliably prevent the occurrence of scratches during the polishing process due to the abnormality of the dresser. Therefore, according to this CMP apparatus, it is possible to prevent the generation of defective products due to the abnormality of the dresser and the decrease in manufacturing yield, and to perform high-quality polishing with high yield.

  In addition, since the CMP apparatus according to this embodiment includes a dresser automatic changer, the dresser in which an abnormality is detected is automatically replaced, so that the polishing process can be efficiently performed without bothering humans. is there.

  As described above, the dresser inspection apparatus according to the present invention is useful for manufacturing a semiconductor device, and is particularly suitable for manufacturing a semiconductor device in which design rules are miniaturized.

It is a figure which shows schematic structure of the dresser inspection apparatus concerning this invention. It is a figure which shows an example of the microscope picture at the time of irradiating light to the diamond surface of a dresser from a different horizontal direction. It is a figure which shows an example of the microscope picture at the time of irradiating light to the diamond surface of a dresser from a different horizontal direction. It is a figure which shows an example of the microscope picture at the time of irradiating light to the diamond surface of a dresser from a different horizontal direction. It is a composite image figure which shows an example of the composite image produced | generated by performing the image process (multiplication process) of a some image. It is sectional drawing which showed typically the reflective state of irradiation light in the diamond particle recognized as a yellow luminescent spot in a synthesized image. It is sectional drawing which showed typically the reflective state of irradiation light in the diamond particle recognized as a white luminescent spot in a synthesized image. It is sectional drawing which showed typically the reflective state of the irradiation light in the diamond particle recognized as a blue luminescent spot in a synthesized image. It is a figure explaining schematic structure of the dresser inspection device concerning Embodiment 1 of the present invention. It is sectional drawing explaining the principal part structure of the CMP apparatus concerning Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Light source part 13 Reflected image acquisition part 15 Image processing part 17 Anomaly detection part 21 Base material 23 Diamond particle 25 Crack 27 Diamond particle 29 Diamond particle 31 White light source 33 Camera 37 Fixing part 101 Polishing head 103 Polishing table 105 Polishing pad (Polishing cloth) )
107 Slurry 109 Slurry Supply Unit 111 Dresser Inspection Device 113 Semiconductor Wafer D Dresser L Incident Light L1 Light L2 Total Reflected Light L3 Reflected Light

Claims (11)

A dresser inspection device for inspecting an abnormality of a dresser in which diamond particles are embedded in the surface of a base material,
Light source means for irradiating light in a direction substantially parallel to the surface embedded with the diamond particles with respect to the surface embedded with the diamond particles in the dresser;
Reflected image acquisition means for collecting the reflected light reflected from the surface embedded with the diamond particles by the irradiation light from the light source means to acquire an image of the surface embedded with the diamond particles;
Image processing means for generating a composite image by performing composite processing of a plurality of images acquired by the reflected image acquisition means;
An anomaly detecting means for detecting an anomaly of the dresser based on the composite image;
A dresser inspection device comprising: The abnormality detection unit detects an abnormality of the dresser by determining whether or not the diamond particles are embedded in the base material and the presence or absence of cracks in the diamond particles based on a color tone of the composite image. The dresser inspection apparatus according to 1. The dresser inspection apparatus according to claim 1, wherein the light source unit is capable of adjusting an irradiation angle of light applied to the surface in which the diamond particles are embedded. A CMP apparatus for performing chemical mechanical polishing of an object to be polished using an abrasive cloth,
Dressing means for performing dressing of the polishing cloth using a dresser in which diamond particles are embedded in the surface of the substrate;
Dresser inspection means for inspecting abnormality of the dresser;
Have
The dresser inspection means includes:
A light source unit that irradiates light in a direction substantially horizontal to the surface embedded with the diamond particles with respect to the surface embedded with the diamond particles in the dresser;
A reflected image acquisition unit that collects the reflected light reflected from the surface embedded with the diamond particles as the irradiation light from the light source unit, and acquires an image of the surface embedded with the diamond particles;
An image processing unit that generates a composite image by performing a composite process of a plurality of images acquired by the reflected image acquisition unit;
An anomaly detector that detects an anomaly of the dresser based on the composite image;
Providing
CMP apparatus characterized by the above. The abnormality detection unit detects an abnormality of the dresser by determining whether or not the diamond particles are embedded in the base material and the presence or absence of cracks in the diamond particles based on the color tone of the composite image. 5. The CMP apparatus according to 4. The CMP apparatus according to claim 4, wherein the light source unit is capable of adjusting an irradiation angle of light applied to a surface in which the diamond particles are embedded. The CMP apparatus according to claim 4, further comprising: a dresser automatic changing unit that automatically changes a dresser that performs dressing of the polishing cloth to a normal dresser. A dresser inspection method for inspecting an abnormality of a dresser in which diamond particles are embedded in the surface of a substrate,
A light irradiation step of irradiating light in a direction substantially horizontal to the surface embedded with the diamond particles with respect to the surface embedded with the diamond particles in the dresser;
A reflected image acquiring step of collecting the reflected light reflected on the surface of the dresser embedded with the diamond particles and acquiring an image of the surface embedded with the diamond particles;
An image processing step of generating a composite image by performing a composite processing of a plurality of images acquired in the reflected image acquisition step;
An abnormality detection step of detecting an abnormality of the dresser based on the composite image;
A dresser inspection method comprising the steps of: The abnormality detection step detects the abnormality of the dresser by judging whether the diamond particles are embedded in the base material and the presence or absence of cracks in the diamond particles based on the color tone of the composite image. The dresser inspection method according to claim 8. A method for inspecting a CMP apparatus for performing chemical mechanical polishing of an object to be polished using an abrasive cloth,
A dressing step of performing dressing of the polishing cloth using a dresser in which diamond particles are embedded in the surface of the substrate;
A dresser inspection process for inspecting abnormality of the dresser;
Including
The dresser inspection process includes:
A light irradiation step of irradiating light in a direction substantially horizontal to the surface embedded with the diamond particles with respect to the surface embedded with the diamond particles in the dresser;
A reflected image acquiring step of collecting the reflected light reflected on the surface of the dresser embedded with the diamond particles and acquiring an image of the surface embedded with the diamond particles;
An image processing step of generating a composite image by performing a composite processing of a plurality of images acquired in the reflected image acquisition step;
An abnormality detection step of detecting an abnormality of the dresser based on the composite image;
A method for inspecting a CMP apparatus, comprising: The abnormality detection step detects the abnormality of the dresser by judging whether the diamond particles are embedded in the base material and the presence or absence of cracks in the diamond particles based on the color tone of the composite image. The inspection method for the CMP apparatus according to 10.