JP4019901B2 - Polishing pad, polishing apparatus and polishing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polishing pad, a polishing apparatus, and a polishing method, and more particularly, to a polishing pad having an optical path secured by optical end point detection, a polishing apparatus using the polishing pad, and a polishing method using the polishing pad.
[0002]
[Prior art]
A polishing pad used in a polishing apparatus having an optical end point detector irradiates a workpiece (for example, a wafer) on the polishing pad with detection light from a polishing plate on which the polishing pad is attached, and reflects the reflected light. In order to secure an optical path for sensing light with a detector, the following has been developed.
[0003]
Japanese Patent Laid-Open No. 7-235520 discloses an optical end point detector and a polishing apparatus having the same, and FIG. 3 of the same publication shows a polishing pad 66, which is shown on page 5 of the same publication. The right column paragraph 0017 describes that a view window 72 is provided on the polishing board 62, and the left column paragraph 0020 on page 6 of the publication discloses viewing at the position of the polishing pad 66 corresponding to the position of the view window 72. There is a description that an aperture 73 is provided (see Patent Document 1).
[0004]
Japanese Laid-Open Patent Publication No. 2001-284298 discloses a polishing state monitoring method using a plurality of optical monitors and a polishing apparatus having the monitors. The fourth column, left column, paragraph 0019 of the publication describes that a plurality of places where light passes through the polishing pad are provided. Further, in the right column, paragraph 0055, page 6 of the same publication, a transparent window for polishing monitoring was formed by placing transparent resin slightly lower than the polishing pad surface in three cuts provided on the pad surface. (See Patent Document 2).
[0005]
In Japanese Patent Laid-Open No. 10-83977, an opening is provided in the polishing surface in FIG. 3A of the same publication and its related explanation place, and a substantially transparent quartz plug (window) is provided in the opening. It is disclosed to form. That is, as shown in FIG. 9 of the present application, a rectangular opening 72 is formed in the polishing pad 71, and a transparent window 73 is formed in the opening 72. In addition, as described in Paragraph 0012 on page 4, left column of the same publication, it is described that the upper surface of the plug is not in contact with the wafer and the layout is intended to minimize the gap. Has been. Further, as described in FIG. 3B of the same publication and the right column paragraph 0014 of page 4 of the same publication, an opening is provided in the polishing surface, and the polyurethane does not contain a substantially transparent nylon microsphere. It is disclosed to form a plug (window). The plug and the wafer are in contact with each other (see Patent Document 3).
[0006]
[Patent Document 1]
JP-A-7-235520 (5th page, FIG. 3)
[Patent Document 2]
JP 2001-284298 A (page 4-6, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 10-83977 (page 4, FIG. 3)
[0007]
[Problems to be solved by the invention]
However, although a detailed description of the process of manufacturing a polishing pad provided with a plug (window) is made in the above-mentioned Japanese Patent Application Laid-Open No. 10-83977, the process is complicated and causes an increase in cost.
[0008]
It is also conceivable to form a hole 82 in the polishing pad 81 as shown in FIG. 10 without forming the window. In this configuration, the cost can be reduced. However, as described in JP-A-10-83977, page 4, left column, paragraph 0012, an excessive amount of slurry is accumulated in the hole, so that the end point can be detected. This is disadvantageous from the viewpoint of attenuating the laser beam.
[0009]
[Means for Solving the Problems]
The present invention is a polishing pad made to solve the above problems.
[0010]
The polishing pad of the present invention is an optical path that penetrates the polishing pad, and has an opening that penetrates in the thickness direction of the polishing pad, and leads from the opening to the periphery of the polishing pad. It has a notch part which penetrates.
[0011]
The polishing pad has an opening penetrating in the thickness direction of the polishing pad, and a notch penetrating from the opening to the periphery of the polishing pad and penetrating in the thickness direction of the polishing pad. Slurry that has fallen from the pad surface to the opening is discharged from the opening to the periphery of the polishing pad through a notch connected to the periphery of the polishing pad. At that time, since the notch is formed in a state penetrating in the thickness direction of the polishing pad in the same manner as the opening, the slurry smoothly flows from the opening to the notch. Therefore, the end point detection light is not attenuated so as to hinder the optical end point detection by the slurry in the opening. For this reason, since it is not necessary to form a window in the polishing pad, the manufacturing cost of the polishing pad can be reduced. Since the opening and the notch can be formed so as to penetrate the polishing pad, if the opening and the notch are simultaneously formed by, for example, punching, a plug (window) as in the prior art is used. The manufacturing process becomes simpler than the case of forming the cutout, and an increase in manufacturing cost due to the formation of the notch is suppressed.
[0012]
The polishing apparatus of the present invention uses the polishing pad of the present invention that can reduce the manufacturing cost of the polishing pad. Thus, since the polishing pad of the present invention is used, the operating cost of the polishing apparatus is reduced.
[0013]
The polishing method of the present invention uses the polishing pad of the present invention that can reduce the manufacturing cost of the polishing pad. Thus, since the polishing pad of this invention was used, polishing cost is reduced.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the polishing pad of the present invention will be described with reference to a plan view of FIG. 1 and a cross-sectional view taken along line AA ′.
[0015]
As shown in FIG. 1, the polishing pad 1 is formed to have a rectangular opening shape, for example, as an opening 11 through which light for end point detection passes and penetrates in the thickness direction of the polishing pad 1. ing. In the opening 11, a notch 12 that penetrates in the thickness direction of the polishing pad 1 and connects to the outer periphery of the polishing pad 1 is formed in a straight line with a width w 2 narrower than the width w 1 of the opening 11, for example. Has been.
[0016]
Specifically, as the polishing pad 1, a single layer made of polyurethane having a thickness of 1.2 mm was used as an example. The opening 11 is 2 cm × 5 cm, and the notch 12 is formed so as to extend the opening 11 outward.
[0017]
In order to attach the polishing pad 1 to a polishing surface plate (not shown), a double-sided adhesive tape is used. When the opening 11 and the notch 12 are prepared after the double-sided adhesive tape is applied to the polishing pad 1, the double-sided adhesive tape is formed with the opening 11 and the notch 12 penetrating therethrough. The On the other hand, when the double-sided pressure-sensitive adhesive tape is affixed to the polishing pad 1 after the opening 11 and the notch 12 are formed in the polishing pad 1, the opening and the notch are not formed in the double-sided pressure-sensitive adhesive tape. If the double-sided pressure-sensitive adhesive tape is substantially transparent to the wavelength of light used for end point detection, the double-sided pressure-sensitive adhesive tape is not affected even if an opening is not formed. In other words, if the double-sided pressure-sensitive adhesive tape is substantially opaque to the wavelength of light used for end point detection, it is necessary to form at least an opening in the double-sided pressure-sensitive adhesive tape.
[0018]
The polishing pad 1 has an opening 11 that penetrates in the thickness direction of the polishing pad 1 and a notch 12 that leads from the opening 11 to the periphery of the polishing pad 1. The slurry passes through the notch 12 and is discharged out of the periphery of the polishing pad 1. For this reason, it is difficult for slurry to remain in the opening 11, so that it is not necessary to form a window in the polishing pad 1. Therefore, the manufacturing cost of the polishing pad can be reduced. In addition, since the slurry hardly remains in the opening 11, the laser beam used for end point detection by the slurry in the opening 11 does not attenuate. Therefore, it is possible to accurately detect the end point.
[0019]
Next, as Comparative Example 1, a polishing pad 71 having the configuration described with reference to FIG. The polishing pad 71 is a single layer made of polyurethane having a thickness of 1.2 mm, and the opening 72 is formed in 2 cm × 5 cm. A transparent resin window 73 is embedded in the opening 72.
[0020]
Next, as Comparative Example 2, a polishing pad 81 having the configuration described with reference to FIG. The polishing pad 81 is a single layer made of polyurethane having a thickness of 1.2 mm, and the opening 82 is formed in 2 cm × 5 cm. Note that no window is formed in the opening 82. A double-sided adhesive tape is used to attach the polishing pad 81 to the polishing surface plate. Here, since the opening 82 is formed after a double-sided adhesive tape (not shown) is attached to the polishing pad 81, a similar opening is also formed through the double-sided adhesive tape.
[0021]
Polishing was performed using the polishing pad 1 of the present invention and the polishing pads 71 and 81 of the comparative example, and the relative light transmittance was measured. A general polishing apparatus was used for polishing. This apparatus includes an end point detector that uses laser light as detection light. A window is formed in the polishing surface plate, and laser light incident through the opening of the polishing pad from below the polishing surface plate is reflected on the wafer surface, and again passes through the opening of the polishing pad, and passes through the polishing surface plate. It enters the detector installed below. As a polishing sample, a wafer in which a silicon oxide film having a thickness of 100 nm, a tantalum (Ta) film having a thickness of 30 nm and a copper (Cu) film having a thickness of 1 μm are sequentially formed on a silicon wafer is used. The intensity of reflected light from the wafer after a minute was investigated.
[0022]
As a result of measuring the relative strength with the polishing pad 71 of Comparative Example 1 being 1, the polishing pad 81 of Comparative Example 2 showed a decrease in strength of 0.4, whereas the polishing pad 1 of the present invention was 1 and Similar results were obtained compared to the case with windows.
[0023]
In the present invention, if there is a concern about the contamination of the window formed on the polishing surface plate, the polishing pad is cleaned with pure water after the polishing is completed and before the next polishing is performed. It was also confirmed that the stain on the polishing platen window was removed. Further, even after about 300 wafers were polished, the reflected light intensity was not reduced due to dirt on the windows on the polishing surface plate. Furthermore, if there is a concern about the contamination of the polishing surface plate window over the long term when the polishing pad is repeatedly replaced, a transparent film should be pasted on the entire surface of the polishing surface plate or the window. It is possible to adopt a method such as exchanging it accordingly. Even if this method is used, a sufficient advantage can be obtained that the manufacturing cost of the polishing pad can be reduced.
[0024]
The polishing pad of the present invention is not limited to a single-layer polishing pad, and it is effective even if a soft polishing pad is laminated on the lower layer. In the case of using a laminated polishing pad, an opening and a cutout are provided only in the upper layer of the polishing pad as long as the lower layer of the polishing pad substantially transmits light having a wavelength necessary for end point detection. It may be.
[0025]
Next, a second embodiment according to the polishing pad of the present invention will be described with reference to a plan view of FIG. 2 and a sectional view taken along line BB ′.
[0026]
As shown in FIG. 2, the polishing pad 2 has a rectangular opening, for example, as an opening 21 that passes through the polishing pad 2 in the thickness direction, and is used to pass light for end point detection. ing. In the opening 21, a notch 22 that penetrates in the thickness direction of the polishing pad 2 and is connected to the outer periphery of the polishing pad 2 is formed linearly with a width w 1 that is the same as the width w 1 of the opening 21, for example. ing. As a result, the area of the polishing pad that contributes to polishing is slightly smaller than that of the polishing pad 1 described in the first embodiment, but the slurry can be discharged more smoothly.
[0027]
Next, a third embodiment according to the polishing pad of the present invention will be described with reference to a plan view of FIG. 3 and a sectional view taken along the line CC ′.
[0028]
As shown in FIG. 3, the polishing pad 3 has a rectangular opening, for example, as an opening 31 that passes through in the thickness direction of the polishing pad 3 and transmits light for end point detection. ing. In this opening 31, a notch 32 that penetrates in the thickness direction of the polishing pad 3 and is connected to the outer periphery of the polishing pad 3 has a width w 2 that is narrower than the width w 1 of the opening 31 and the opening 31. It is formed at an angle with respect to the longitudinal direction. Here, the notch 32 is formed in a curved shape. As a result, the area of the polishing pad that contributes to polishing is slightly smaller than that of the polishing pad 1 described in the first embodiment, but the slurry can be discharged more smoothly. The direction of rotation of the polishing pad 3 when polishing is the direction of the arrow.
[0029]
In the polishing pad 3 shown in FIG. 3, the width w1 of the opening 31 and the width w2 of the notch 32 may be formed to have the same width. Thereby, although the area of the polishing pad contributing to polishing is slightly smaller than the polishing pad 3 described in the third embodiment, the slurry can be discharged more smoothly.
[0030]
Next, a fourth embodiment according to the polishing pad of the present invention will be described with reference to the plan view of FIG. This polishing pad is used for a belt-type polishing apparatus, and is formed in a rectangular shape.
[0031]
As shown in FIG. 4, the polishing pad 4 is formed with a rectangular opening, for example, as an opening 41 that passes through the polishing pad 4 in the thickness direction and transmits light for detecting the end point. ing. In this opening 41, a notch 42 that penetrates in the thickness direction of the polishing pad 4 and connects to the outer periphery of the polishing pad 4 has a width w 2 that is narrower than the width w 1 of the opening 41, for example, and the opening 41. It is formed at an angle with respect to the longitudinal direction. Here, the notch 42 is formed in a straight line. As a result, the slurry can be discharged more smoothly. In addition, the moving direction of the polishing pad 4 when polishing is the arrow direction.
[0032]
In the polishing pad 4, the cutout portion 42 may be formed in a curved shape like the cutout portion 32 described in the third embodiment.
[0033]
Next, a fifth embodiment of the polishing pad of the present invention will be described with reference to the plan view of FIG.
[0034]
As shown in FIG. 5, for example, three circular openings are provided in the polishing pad 5 as a plurality of openings 51 through which light for end point detection passes and which penetrates in the thickness direction of the polishing pad 5. Is formed. The number of openings 11 is not limited to three and may be two or four or more.
[0035]
In each of the openings 51, a notch 52 that penetrates in the thickness direction of the polishing pad 5 and connects to the outer periphery of the polishing pad 5 has a width w narrower than the diameter d of the opening 51 and the polishing pad 5, for example. It is formed with an angle with respect to the tangential direction of the outer periphery. Here, the cutout portion 52 is formed in a straight line shape, but may be formed in a curved line shape. Further, the notch 52 may be formed with a width equivalent to the diameter of the opening 51. As a result, the slurry can be discharged more smoothly. In addition, the moving direction of the polishing pad 5 when polishing is the arrow direction.
[0036]
Next, a sixth embodiment according to the polishing pad of the present invention will be described with reference to the plan view of FIG.
[0037]
As shown in FIG. 6, for example, three rectangular openings are provided in the polishing pad 6 as a plurality of openings 61 through which light for end point detection passes in the thickness direction of the polishing pad 6. 61a, 61b and 61c are formed. The number of openings 11 is not limited to three, and may be two or four or more.
[0038]
Each opening 61 is formed with a passage 63 (63a, 63b) that communicates between adjacent openings 61 and penetrates the polishing pad 6 in the thickness direction. The passage 63 is formed with a width narrower than the width of the opening 61. Further, in the opening 61 located on the outermost periphery of the polishing pad 6, a notch 62 that penetrates in the thickness direction of the polishing pad 6 and leads to the outer periphery of the polishing pad 6 is, for example, from the width w 1 of the opening 61. It is formed with a narrow width w2. Here, the notch 62 is formed in a linear shape, but may be formed in a curved shape. Further, the notch 12 may be formed with a width equal to the width of the opening 61. As a result, the slurry can be discharged more smoothly. In addition, the moving direction of the polishing pad 1 when polishing is an arrow direction.
[0039]
The openings 11, 21, 31, 41, 61 in the above embodiments are not limited to rectangular openings, and various shapes such as a circular shape, a polygonal shape, and an elliptical shape can be adopted. . Similarly, the opening 51 can have various shapes such as a rectangular shape, a polygonal shape, and an elliptical shape.
[0040]
Next, the polishing apparatus of the present invention will be described with reference to schematic configuration perspective views shown in FIGS.
[0041]
The first polishing apparatus includes one of the polishing pads 1 to 4 for polishing the surface to be polished by bringing the polishing pad into contact with the surface to be polished and relatively moving in friction. is there.
[0042]
That is, as shown in FIG. 7, the first polishing apparatus 101 includes a polishing surface plate 111 that can freely rotate in the direction of the arrow A, for example. The polishing surface plate 111 is rotated via a rotation shaft 112 connected to a rotation drive device (not shown). Although not shown, the polishing surface plate 111 includes a light source that emits light for detecting an end point and a light receiving unit that receives reflected light. A light-transmissive window is displayed on the polishing surface plate 111, for example. It is made of transparent glass, quartz, or resin. Further, on the polishing surface plate 111, one of the polishing pads 1-3, 5, and 6 described with reference to FIGS. 1 to 3, 5, and 6 is mounted. Here, the polishing pad 1 was mounted. The polishing pad 1 is mounted on the polishing surface plate 111 such that an opening (not shown) provided in the polishing pad 1 is disposed on the window (not shown). Hereinafter, the polishing pad 1 will be described. The mounting method is based on a general polishing pad mounting method, for example, a method using an adhesive sheet (including an adhesive tape) or an adhesive. Specifically, according to the method described above.
[0043]
A polishing head 115 is provided so as to face a position facing the polishing surface plate 111 on which the polishing pad 1 is mounted, usually a position where the rotation center of the polishing surface plate 111 is removed. The polishing head 115 is configured to be movable up and down. Further, the polishing head 115 is rotated, for example, in the direction of the arrow A through a rotating shaft 116 connected to a rotation driving device (not shown). Further, an object to be polished 301 is mounted on the surface of the polishing head 115 facing the polishing surface plate 111. Various methods such as vacuum adsorption, electrostatic adsorption, adhesion using an adhesive, adhesion using a pressure-sensitive adhesive sheet, and the like can be adopted as a method for mounting the object to be polished. Further, a nozzle 121 for supplying a polishing slurry 131 (shown by an arrow for convenience) on the polishing pad 1 is provided above the polishing surface plate 111 and in the vicinity of the polishing head 115. The polishing slurry 131 is supplied so as to enter between the polishing pad 1 and the workpiece 301 as the polishing surface plate 111 rotates.
[0044]
The first polishing method of the present invention will be described below. As an example, a method for polishing using the first polishing apparatus 101 will be described. First, a desired polishing pad among the polishing pads 1 to 4 is mounted on the polishing surface plate 111. Further, an object to be polished 301 is attached to the polishing head 115. Thereafter, the polishing slurry 131 is supplied onto the polishing pad 1 from the nozzle 121 and the polishing surface plate 111 is rotated. Further, the polishing head 115 is also rotated. Then, the object to be polished 301 is brought into contact with the polishing pad 1 so as to obtain a desired processing pressure, and the surface to be polished of the object to be polished 301 is polished. As an example of the polishing conditions, for example, a case where a copper film formed on the wafer surface is polished will be described. For example, an alumina-based slurry is used as the polishing slurry 131, and the processing pressure is 300 g / cm. ² The rotational speed was set so that the peripheral speed of the polishing pad relative to the object to be polished (for example, a wafer) was 60 m / min. As the polishing slurry 131, it is preferable to use a milky white one so that the end point can be easily detected. After the polishing is completed, the workpiece 301 is separated from the polishing pad 1 to stop the supply of the polishing slurry 131 and the rotation of the polishing surface plate 111 and the polishing head 115 is stopped. Thereafter, the workpiece 301 may be detached from the polishing head 115. Note that the surface to be polished 301 may be cleaned before desorption.
[0045]
The second polishing apparatus is a belt-type polishing apparatus including the polishing pad 4 that polishes the surface to be polished by bringing the polishing pad into contact with the surface to be polished of the material to be polished and performing a relative frictional motion. The notch shape of the polishing pad 4 may be any of the notch shapes described in FIGS. 1 to 3 and FIGS.
[0046]
That is, as shown in FIG. 8, the second polishing apparatus 201 includes rotatable rollers 211 and 212 arranged in parallel, and the belt type wound around these rollers 211 and 212 in FIG. The polishing pad 4 described is provided. The polishing pad 4 is stretched by the rollers 211 and 212 so as not to bend. In addition, between the rollers 211 and 212, the polishing pad is prevented from bending inward, that is, the polishing pad is supported in the direction of the polishing head 215 from the inside. (Not shown) is preferably provided. Further, at least one of the rollers 211 and 212 is rotated, for example, in the direction of an arrow by a rotation driving device. As a result, the polishing pad 4 rotates in the direction of the arrow. Further, although not shown, an opening (not shown) provided in the rotating polishing pad 4 is provided between the rollers 211 and 212, although a light source for irradiating light for end point detection and a light receiving unit for receiving reflected light are provided. It is installed so as to pass through.
[0047]
A polishing head 215 is provided so as to face the polishing surface of the polishing pad 4. The polishing head 215 is configured to be movable up and down. Further, the polishing head 215 is rotated via a rotation shaft 216 connected to a rotation drive device (not shown). Further, an object to be polished 301 is mounted on the surface of the polishing head 215 facing the polishing pad 4. Various methods such as vacuum adsorption, electrostatic adsorption, adhesion using an adhesive, adhesion using a pressure-sensitive adhesive sheet, and the like can be adopted as a method for mounting the object to be polished 301. Further, a nozzle 221 for supplying the polishing slurry 231 onto the polishing pad 4 is provided above the polishing pad 4 and in the vicinity of the polishing head 215. The polishing slurry 231 is supplied so as to enter between the polishing pad 4 and the workpiece 301 as the polishing surface plate 111 rotates.
[0048]
The second polishing method of the present invention will be described below. As an example, a method for polishing using the second polishing apparatus 201 will be described. A polishing pad 4 is attached to the rollers 211 and 212. On the other hand, an object to be polished 301 is attached to the polishing head 115. Thereafter, the polishing slurry is supplied from the nozzle 121 onto the polishing pad 4, and the polishing pad 4 is rotated by rotating the rollers 211 and 212. Further, the polishing head 115 is also rotated. Then, the object to be polished 301 is brought into contact with the polishing pad 4 so as to achieve a desired processing pressure, and the surface to be polished of the object to be polished 301 is polished. Alumina-based slurry is used as the polishing slurry, and the processing pressure is 300 g / cm. ² The rotational speed was set so that the peripheral speed of the polishing pad relative to the object to be polished (for example, a wafer) was 60 m / min. As the polishing slurry, it is preferable to use a milky white one to facilitate end point detection. After the polishing is finished, the workpiece 301 is pulled away from the polishing pad 4, and the supply of the polishing slurry is stopped, and the rotation of the polishing pad 4 (rollers 211 and 212) and the polishing head 115 is stopped. Thereafter, the workpiece 301 may be detached from the polishing head 115. Note that the surface to be polished 301 may be cleaned before desorption.
[0049]
The polishing method described above is an example, and the polishing conditions can be changed as appropriate according to the object to be polished. Also, conventionally used polishing conditions can be used.
[0050]
【The invention's effect】
As described above, according to the polishing pad of the present invention, it is for passing the light for detecting the end point, and is connected to the opening extending through the polishing pad in the thickness direction and from the opening to the periphery of the polishing pad. Therefore, the slurry that has fallen into the opening from the surface of the polishing pad can be discharged out of the periphery of the polishing pad through the notch. Therefore, it is possible to provide a polishing pad with little light attenuation by the slurry. In addition, since it is not necessary to form a window on the polishing pad, the manufacturing cost of the polishing pad can be reduced, and the polishing pad can be provided at low cost.
[0051]
According to the polishing apparatus of the present invention, since the polishing pad of the present invention that can reduce the manufacturing cost of the polishing pad is mounted, the operating cost of the polishing apparatus can be reduced, and the polishing pad of the present invention can be reduced. An effect can be obtained.
[0052]
According to the polishing method of the present invention, since the polishing pad of the present invention that can reduce the manufacturing cost of the polishing pad is used, the polishing cost can be reduced and the function and effect of the polishing pad of the present invention can be obtained. it can.
[Brief description of the drawings]
1A and 1B are a plan view and a cross-sectional view taken along line AA ′ showing a first embodiment of a polishing pad according to the present invention.
FIGS. 2A and 2B are a plan view and a cross-sectional view taken along line BB ′ showing a second embodiment of the polishing pad of the present invention. FIGS.
FIGS. 3A and 3B are a plan view and a cross-sectional view taken along line CC ′ showing a third embodiment of the polishing pad of the present invention. FIGS.
FIG. 4 is a plan view showing a fourth embodiment according to the polishing pad of the present invention.
FIG. 5 is a plan view showing a fifth embodiment according to the polishing pad of the present invention.
FIG. 6 is a plan view showing a sixth embodiment according to the polishing pad of the present invention.
FIG. 7 is a schematic configuration perspective view showing an embodiment according to the first polishing apparatus of the present invention.
FIG. 8 is a schematic configuration perspective view showing an embodiment according to a second polishing apparatus of the present invention.
FIGS. 9A and 9B are a plan view and a cross-sectional view taken along line XX ′ showing a polishing pad according to a conventional technique. FIGS.
10A and 10B are a plan view and a cross-sectional view taken along line YY ′ showing a polishing pad according to a conventional technique.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Polishing pad, 11 ... Opening part, 12 ... Notch

Claims (9)

In a polishing pad for polishing an object to be polished,
An opening that penetrates in the thickness direction of the polishing pad as an optical path that penetrates the polishing pad;
A polishing pad having a notch that extends from the opening to the periphery of the polishing pad and penetrates in the thickness direction of the polishing pad. A plurality of the openings are provided,
The polishing pad according to claim 1, wherein the notch is formed corresponding to each of the openings. A plurality of the openings are provided,
Each opening is communicated by a passage that penetrates the polishing pad in the thickness direction;
The polishing pad according to claim 1, wherein the notch is formed continuously with the outermost opening. The polishing pad contacts the surface to be polished of the material to be polished,
In a polishing apparatus for polishing a surface to be polished by relatively frictional movement,
The polishing pad is
An opening that penetrates in the thickness direction of the polishing pad as an optical path that penetrates the polishing pad;
A polishing apparatus comprising: a notch that extends from the opening to the periphery of the polishing pad and penetrates in the thickness direction of the polishing pad. A plurality of the openings are provided,
The polishing apparatus according to claim 4, wherein the notch is formed corresponding to each of the openings. A plurality of the openings are provided,
5. The polishing apparatus according to claim 4, wherein each of the openings is communicated with a passage that penetrates the polishing pad in the thickness direction, and the notch is formed continuously to the outermost opening. . The polishing pad contacts the surface to be polished of the material to be polished,
In the polishing method for polishing the surface to be polished by the relative friction movement of the surface to be polished and the polishing pad,
The polishing pad is
An opening that penetrates in the thickness direction of the polishing pad as an optical path that penetrates the polishing pad;
A polishing method comprising: a notch that extends from the opening to the periphery of the polishing pad and penetrates in the thickness direction of the polishing pad. A plurality of the openings are provided,
The polishing method according to claim 7, wherein the notch is formed corresponding to each of the openings. A plurality of the openings are provided,
Each opening is communicated by a passage that penetrates the polishing pad in the thickness direction;
The polishing method according to claim 7, wherein the notch is formed continuously with the outermost opening.

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