TW201641214A - Dry polishing apparatus - Google Patents

Abstract

To prevent foreign matters such as polishing debris or dusts from adhering to a measuring device that measure states of a wafer. A dry polishing apparatus includes a holding table, a polishing mechanism, and a polishing process feeding mechanism. The holding table holds the wafer. The polishing mechanism has a spindle unit. The spindle unit is installed in such a way that a center of a polishing pad that polishes is in line with a center of an axis of rotation. The polishing process feeding mechanism performs polishing feeding such that the polishing mechanism and the holding table in relatively close and distant directions, and forms the following structure: a through hole formed at the spindle unit communicating a hollow hole formed at a center of the polishing pad, and a sealed space that communicates the through hole is formed by blocking a cover mechanism at a top of the through hole, and the states of the wafer is measured through the through hole by a measuring device disposed in the sealed space.

Description

Dry grinding device Field of invention

This invention relates to a dry milling apparatus for grinding wafers in a processing chamber in a dry environment.

Background of the invention

In the grinding process, the grinding strain remaining on the surface to be ground by grinding the ground wafer is increased to increase the bending strength. Conventionally, a dry polishing apparatus that polishes a wafer without using a polishing liquid as a polishing apparatus is known (for example, see Patent Document 1). In the dry type polishing apparatus described in Patent Document 1, fine particles such as dust generated by polishing or abrasion due to abrasion of the polishing pad are discharged from the processing chamber by exhaust gas (intake). The foreign matter discharged from the processing chamber is wetted and treated as a waste liquid. Since the foreign matter is made into a waste liquid in a state where the processing chamber is formed in a dry environment, foreign matter does not scatter in the processing chamber, and the clean room in which the polishing device is installed is not contaminated.

Further, a device for polishing a wafer using a polishing pad having a larger diameter than the outer diameter of the wafer as a dry polishing apparatus is also known (for example, see Patent Document 2). In the dry polishing apparatus described in Patent Document 2, the polishing pad is brought into contact with the wafer while the center of the polishing pad is shifted from the center of the wafer. It becomes possible to grind the wafer with a polishing pad more efficiently. In the dry polishing apparatus described in Patent Documents 1 and 2, in order to prevent surface scorching caused by frictional heat during wafer polishing, the surface temperature of the wafer during polishing is measured, or for higher precision. Measurement of the thickness of the wafer during the grinding process for grinding is considered to be necessary.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent No. 4464113

Patent Document 2: Japanese Patent No. 4754870

Summary of invention

However, in the dry polishing apparatus of Patent Document 2, since the entire semiconductor wafer is covered by the polishing pad, there is no place where the measuring instrument for temperature measurement of the wafer and the measuring device for wafer thickness measurement are disposed. . In this case, the configuration is such that a hole is formed in the center of the polishing pad, and a through hole connected to the hole is formed in the spindle unit, and the state of the wafer is measured through the through hole from above the spindle unit. However, when fine foreign matter enters into the pores of the polishing pad, foreign matter may adhere to the measuring device through the through hole of the spindle unit to contaminate the measuring device.

The present invention has been made in view of the above problems, and an object of the invention is to provide a dry polishing apparatus capable of preventing foreign matter such as polishing dust or dust from adhering to a measuring instrument in a state of measuring a wafer.

A dry polishing apparatus according to the present invention includes: a holding stage that holds a wafer; and a polishing unit that has a spindle unit that is used to polish the center of the polishing pad held by the wafer of the holding stage, and is aligned with the center of the rotating shaft And a grinding processing feeding mechanism that performs grinding and feeding in a direction in which the polishing mechanism and the holding table are relatively close to and away from each other, wherein the polishing mechanism has a cylindrical hole, a through hole and a cover a member, the cylindrical hole is centered on a center of the polishing pad; the through hole is penetrated in the extending direction of the rotating shaft of the spindle unit and one end thereof communicates with the hole; the cover member A closing space that communicates with the other end of the through hole is formed, and a measuring device that measures the state of the wafer being polished is disposed in the closed space.

According to this configuration, since the other end of the through hole of the polishing mechanism is blocked by the closing space of the cover member, the air in and out of the hole and the through hole is suppressed. Therefore, since the air flow in the through hole does not exist, even if fine foreign matter such as polishing dust or dust adhering to the polishing pad or the wafer is wound up, it is difficult for the fine foreign matter to enter the void and the through hole. Since the fine foreign matter does not easily enter the occlusion space connected to the other end of the through hole, it is possible to prevent foreign matter from adhering to the measuring device that has been disposed in the occlusion space. Thereby, it is possible to polish while the state of the wafer is properly measured by a dry polishing apparatus.

Further, the dry polishing apparatus includes an air supply mechanism that communicates the air supply source for the closed space and the supply air, and at least when the polishing surface of the polishing pad approaches the upper surface of the wafer, The air supply mechanism supplies air to make the closed space a positive pressure.

According to the invention, the other end of the through hole of the polishing mechanism is blocked by the closed space of the cover member, and the entry and exit of the air with respect to the hole and the through hole is suppressed, so that the adhesion of the fine foreign matter to the measuring wafer can be prevented. State of the measurer.

1‧‧‧dry grinding device

11‧‧‧Abutment

12‧‧‧Working table cover

13‧‧‧Dust cover

14‧‧‧ pillar

21‧‧‧ Keeping the table

22‧‧‧Rotating mechanism

23‧‧‧ Keep face

24‧‧‧Mobile agencies

31‧‧‧Machining feed mechanism

33‧‧‧Z-axis abutment

34, 53‧‧‧ Ball screw

35, 54‧‧‧ drive motor

40‧‧‧Rotary axis

41‧‧‧ grinding mechanism

42‧‧‧Shaft housing

43‧‧‧ spindle unit

44‧‧‧ Mounting

45‧‧‧Flange

46‧‧‧ polishing pad

47‧‧‧ holes

48‧‧‧through holes

49‧‧‧Grinding surface

51‧‧‧rails

52‧‧‧X-axis abutment

60, 61‧‧‧ measurer

62‧‧‧ Cover member

63‧‧‧Closed space

64‧‧‧Air supply agency

65‧‧‧Air supply source

70‧‧‧ Foreign objects

81‧‧‧ upper surface

W‧‧‧ wafer

X, Y, Z‧‧ Direction

Fig. 1 is a perspective view of a dry polishing apparatus according to a first embodiment.

2A-2B of Fig. 2 is an explanatory diagram showing a situation in which the measuring device is contaminated by foreign matter.

3A-3C of Fig. 3 are views showing an example of a polishing operation of the polishing mechanism of the first embodiment.

4A-4C of Fig. 4 are views showing an example of a polishing operation of the polishing mechanism of the second embodiment.

Form for implementing the invention

A dry polishing apparatus according to this embodiment will be described with reference to the drawings. Fig. 1 is a perspective view of a dry polishing apparatus according to a first embodiment. Fig. 2 is an explanatory view showing a state in which a measuring device is contaminated by foreign matter. Further, the dry polishing apparatus of the present embodiment is not limited to the one dedicated to polishing as shown in FIG. 1, and may be attached to, for example, a series of processes such as grinding, polishing, and washing, which are performed in a fully automatic manner. In the Full Auto Type processing unit.

As shown in FIG. 1, the dry polishing apparatus 1 is configured to polish the ground wafer W by using the polishing mechanism 41 to remain on the wafer W. The grinding strain of the ground surface (upper surface 81) is removed. The dry polishing apparatus 1 is a device for polishing a wafer W in a processing chamber (not shown) in a dry environment without using a polishing liquid, and dust or the like caused by grinding debris or abrasion of the polishing pad from the processing chamber. The fine foreign matter is sucked and exhausted. Further, the wafer W may be a semiconductor substrate such as tantalum or gallium arsenide, or may be a hard inorganic material substrate such as sapphire or tantalum carbide. Further, the wafer W may be a semiconductor substrate or an inorganic material substrate after the device is formed.

A rectangular opening extending in the X-axis direction is formed on the upper surface of the base 11 of the dry grinding apparatus 1, and the opening is moved by the table cover 12 and the bellows-like dust cover 13 which are movable together with the holding table 21. cover. Below the dust cover 13, a moving mechanism 24 for moving the holding table 21 in the X-axis direction and a rotating mechanism 22 for continuously rotating the holding table 21 are provided. On the surface of the holding table 21, a holding surface 23 for adsorbing the wafer W with a porous porous material is formed. The holding surface 23 is connected to a suction source (not shown) through a flow path in the holding stage 21, and the wafer W is sucked and held by the negative pressure generated on the holding surface 23.

The moving mechanism 24 has a pair of guide rails 51 disposed on the base 11 in parallel with the X-axis direction, and an X-axis base 52 that is driven by a motor that is slidable on the pair of guide rails 51. A nut portion (not shown) is formed on the back side of the X-axis base 52, and a ball screw 53 is screwed into the nut portion. Then, the drive motor 54 coupled to one end portion of the ball screw 53 is rotationally driven to move the holding table 21 in the X-axis direction along the pair of guide rails 51. The rotating mechanism 22 is disposed on the X-axis base 52 and supports the holding table 21 so as to be rotatable about the Z-axis.

The strut 14 on the base 11 is provided with a lapping feed mechanism 31 for grinding and feeding the polishing mechanism 41 and the holding table 21 in the Z-axis direction which is relatively close to and away from the holding table 21. The lapping feed mechanism 31 has a pair of guide rails 32 that are disposed on the strut 14 in parallel with the Z-axis direction, and a Z-axis base 33 that is driven by a motor that is slidable on the pair of guide rails 32. A nut portion (not shown) is formed on the back side of the Z-axis base 33, and a ball screw 34 is screwed into the nut portion. The ball screw 34 is rotationally driven by a drive motor 35 coupled to one end of the ball screw 34 to grind the grinding mechanism 41 along the guide rail 32.

The polishing mechanism 41 is attached to the front surface of the Z-axis base 33 through the casing 42 and is provided with a polishing pad 46 at the lower portion of the spindle unit 43. The spindle unit 43 is provided with a flange 45, and the polishing mechanism 41 is supported by the housing 42 through the flange 45. The lower portion of the spindle unit 43 is a mount 44, and the lower surface of the mount 44 is provided with a polishing pad 46 for polishing the wafer W held on the holding table 21. The polishing pad 46 is formed of a foamed material, a fibrous material, or the like, and is attached to the spindle unit 43 of the polishing mechanism 41 such that the center of the polishing pad 46 coincides with the center of the rotating shaft.

The dry grinding apparatus 1 is provided with a control unit (not shown) that integrates the respective parts of the control unit. The control unit is constituted by a processor, a memory, or the like that performs various processes. The memory is composed of one or a plurality of storage media such as a ROM (Read Only Memory) or a RAM (Random Access Memory) depending on the application. In the dry polishing apparatus 1 configured as described above, the polishing pad 46 is moved toward the holding table 21 while rotating around the Z axis by the spindle unit 43. Further, the wafer W is rotationally contacted by the polishing pad 46 so that the ground surface of the wafer W is polished.

Further, in the polishing of the dry polishing apparatus 1, temperature measurement is performed to prevent surface scorching caused by frictional heat, and thickness measurement of the wafer W is performed to perform high-precision polishing processing. However, the dry polishing apparatus 1 of the present embodiment is not used for temperature measurement in a state where the wafer W is covered with the polishing pad 46 by using the polishing pad 46 having an outer diameter larger than the outer diameter of the wafer W. And the setting space of the measuring device for thickness measurement. Therefore, the configuration considered is that, as shown in the comparative example of FIG. 2A, a hole 47 is formed in the center of the polishing pad 46, and a through hole 48 connected to the hole 47 is formed in the spindle unit 43 to measure the measuring device. 60, 61 are arranged such that the upper portion of the autonomous shaft unit 43 passes through the through hole 48 for measurement.

However, as shown in Fig. 2B, since the measuring devices 60, 61 are present directly above the through hole 48 of the spindle unit 43, the following problems occur: the grinding debris generated by the grinding process and the wear due to the polishing pad 46 are formed. The fine foreign matter 70 such as dust adheres to the measuring devices 60, 61, so that the measurement accuracy is deteriorated. Here, the inventors of the present invention have observed in detail that the measuring devices 60 and 61 are contaminated by the foreign matter 70, and have confirmed the following situation: in the polishing of the wafer W, at the beginning of the polishing operation, The foreign matter 70 is wound up by the force path when the polishing mechanism 41 approaches the wafer W, and is attached to the measuring devices 60 and 61 through the through holes 48.

It is considered that this is because when the polishing pad 46 is close to the wafer W, the air in the gap between the polishing surface 49 of the polishing pad 46 and the upper surface 81 of the wafer W is compressed and flows into the through hole 48 through the hole 47, and The flow of air ejected from the upper end (the other end) of the through hole 48 is formed. Therefore, in the present embodiment, the upper end of the through hole 48 is blocked by the cover member 62 (see Fig. 3) to block The flow of this air. Further, a clogging space 63 connected to the upper end of the through hole 48 is provided in the cover member 62, and the measuring devices 60, 61 are disposed in the occluding space 63, thereby eliminating the flow of air in the through hole 48, and The adhesion of the foreign matter 70 to the measuring devices 60, 61 is suppressed.

Hereinafter, the configuration of the polishing mechanism and the polishing operation will be described in detail with reference to FIG. 3. Fig. 3 is a view showing an example of a polishing operation of the polishing mechanism of the first embodiment. In the following description, the headstock of the spindle unit is omitted for convenience of explanation, and the state in which the rotating shaft is exposed is exemplified.

As shown in FIG. 3A, a mounting seat 44 is provided at a lower portion of the rotating shaft 40 in the spindle unit 43, and the mounting seat 44 is provided with a polishing pad 46 having an outer diameter larger than the outer diameter of the wafer W on the holding table 21. A hole 47 is formed in the center opening of the polishing pad 46, and a through hole 48 is formed in the extending direction (up-and-down direction) at the center of the rotating shaft 40 of the spindle unit 43. One end (lower end) of the through hole 48 communicates with the hole 47 of the polishing pad 46. In other words, the polishing mechanism 41 includes a cylindrical hole 47 having a center of the polishing pad 46 as a center, and a through hole 48 penetrating in the extending direction of the rotating shaft 40.

Moreover, the polishing mechanism 41 is provided with a cover member 62 that blocks the flow of the air in the through hole 48 by blocking the other end (upper end) of the through hole 48. A closing space 63 that communicates with the other end of the through hole 48 is formed in the cover member 62, and measuring devices 60 and 61 that measure the state of the wafer W during polishing are disposed in the closing space 63. The measuring devices 60 and 61 are disposed directly above the through hole 48 and pass through the through hole 48 and the hole 47 to measure the wafer W from directly above. At this time, since the other end of the through hole 48 is blocked by the cover member 62, the passage is made The flow of air passing through the through holes 48 toward the measuring devices 60, 61 in the occlusion space 63 is suppressed.

Here, the state of the wafer W during polishing is as described above, and the surface temperature of the wafer W, the thickness of the wafer W, and the like are exemplified. The measuring device 60 is a so-called radiation thermometer and measures the surface temperature of the wafer W in a non-contact manner. The measuring device 61 is a photo sensor of an interference spectrometer or the like, and measures the thickness of the wafer W in a non-contact manner. From the measurement results of the measuring devices 60 and 61, the surface temperature and the amount of polishing of the wafer W during polishing are measured, and surface burnt due to frictional heat can be prevented, and the wafer W can be polished with high precision. The measurement results of the measuring devices 60 and 61 are output to the control unit (not shown) during polishing, and the control unit controls the operation of the polishing mechanism 41 based on the measurement result.

In the polishing mechanism 41, when the wafer W is placed on the holding table 21, the wafer W is held by the holding surface 23 of the holding table 21. The holding stage 21 is moved below the polishing mechanism 41 to position the wafer W directly under the polishing pad 46. At this time, since the polishing mechanism 41 is stopped at the standby position where the polishing pad 46 is sufficiently away from the wafer W, there is no space between the upper surface 81 of the wafer W and the polishing surface 49 of the polishing pad 46 and the through hole 48. Produces the flow of air. Then, the polishing mechanism 41 is moved from the standby position toward the upper surface 81 of the wafer W while rotating the polishing pad 46.

As shown in FIG. 3B, when the polishing surface 49 of the polishing pad 46 is close to the upper surface 81 of the wafer W, the air in the gap between the polishing surface 49 of the polishing pad 46 and the upper surface 81 of the wafer W is compressed. Although the air in the gap is formed to escape along the upper surface 81 of the wafer W, since the other end (ie, the upper end) of the through hole 48 is blocked by the cover member 62, there is no escape path of air inside the radial direction of the wafer W. . Therefore, the air in the gap flows to the radially outer side of the wafer W, and the air is prevented from flowing in the holes 47 and the through holes 48. The escape passage of the air that escapes upward through the through hole 48 is blocked by the cover member 62, and the flow of the air is controlled.

At this time, since the air flows toward the radially outer side of the wafer W, it is possible to prevent the fine foreign matter 70 adhering to the polishing pad 46 and the wafer W from being rolled up. Even when it is rolled up, since there is no flow of air in the through hole 48, the foreign matter 70 becomes difficult to enter the through hole 48. Thereby, it is difficult for the foreign matter 70 to enter the closing space 63 through the through hole 48, and the adhesion of the foreign matter 70 to the measuring instruments 60 and 61 disposed in the closing space 63 can be prevented. In this way, the flow of the air is induced to the outside in the radial direction of the wafer W by the cover member 62, whereby the adhesion of the foreign matter 70 to the measuring devices 60, 61 is prevented with a simple configuration.

As shown in FIG. 3C, when the polishing surface 49 of the polishing pad 46 contacts the upper surface 81 of the wafer W, the upper surface 81 of the wafer W is ground by the polishing pad 46. At this time, the surface temperature and thickness of the wafer W are instantaneously measured by the measuring devices 60, 61 in the occluding space 63, and the grinding mechanism 41 is controlled based on the measurement results of the measuring devices 60, 61. The temperature measured by the measuring device 60 continues the polishing of the wafer W during a temperature lower than the temperature at which the surface is burnt, and when the temperature at which the surface is burnt is formed, the polishing of the wafer W is suspended. Then, the polishing mechanism 41 is ground and fed to the thickness of the wafer W measured by the measuring device 61 to the thickness of the target for removing the polishing strain.

As described above, in the dry polishing apparatus 1 of the first embodiment, the upper end of the through hole 48 of the polishing mechanism 41 is blocked by the closed space 63 of the cover member 62, so that the air is allowed to enter and exit with respect to the hole 47 and the through hole 48. Suppressed. Therefore, since the flow of the air in the through-holes 48 is not provided, even if the fine foreign matter 70 such as the polishing dust adhering to the polishing pad 46 and the wafer W and the dust is rolled up, the fine foreign matter 70 hardly enters the holes 47 and the through holes. Within 48. Since the fine foreign matter 70 hardly enters the closing space 63 connected to the upper end of the through hole 48, it is possible to prevent the foreign matter 70 from adhering to the measuring devices 60 and 61 that have been disposed in the occluding space 63. Thereby, the dry grinding apparatus 1 can perform the grinding while properly measuring the state of the wafer W.

Next, a polishing mechanism of the dry polishing apparatus according to the second embodiment will be described with reference to Fig. 4 . 4 is a view showing an example of a polishing operation of the polishing mechanism of the second embodiment. Further, in the second embodiment, the polishing pad is brought close to the wafer while forming a positive pressure in the through hole, which is different from the first embodiment. Therefore, the main points are explained in detail. In the following description, the headstock of the spindle unit is omitted for convenience of explanation, and the state in which the rotating shaft is exposed is exemplified.

As shown in FIG. 4A, the polishing mechanism 41 of the second embodiment has the same configuration as the polishing mechanism 41 of the first embodiment except that the air supply mechanism 64 that connects the closing space 63 and the air supply source 65 for supplying air is provided. . The air supply mechanism 64 is configured to supply air to the closing space 63 and form a positive pressure in the closing space 63 at least when the polishing surface 49 of the polishing pad 46 is brought close to the upper surface 81 of the wafer W. In addition, the air supply source 65 may be configured such that the air can be supplied to the closing space 63 through the air supply mechanism 64. For example, the air supply source 65 may be provided in the factory in which the dry polishing apparatus 1 is installed, or may be provided in the apparatus itself.

In this polishing mechanism 41, when the wafer W is placed on the holding stage 21 In the upper case, the wafer W is held by the holding surface 23 of the holding table 21. The holding stage 21 is moved below the polishing mechanism 41 to position the wafer W directly under the polishing pad 46. At this time, since the polishing mechanism 41 is stopped at the standby position where the polishing pad 46 is sufficiently away from the wafer W, there is no space between the upper surface 81 of the wafer W and the polishing surface 49 of the polishing pad 46 and the through hole 48. Produces the flow of air. Further, the polishing mechanism 41 is moved from the standby position toward the upper surface 81 of the wafer W while rotating the polishing pad 46.

As shown in FIG. 4B, when the polishing pad 46 is lowered from the standby position toward the wafer W, air is supplied from the air supply source 65 to the occlusion space 63 by the air supply mechanism 64. At this time, the supply of air to the closed space 63 is controlled by an on-off valve (not shown) provided in the line of the air supply mechanism 64. When the air is supplied to the closing space 63, the closing space 63 is formed with a positive pressure, and the through hole 48 and the hole 47 communicating with the closing space 63 are also positive pressure. Thereby, even if the air in the gap between the polishing surface 49 of the polishing pad 46 and the upper surface 81 of the wafer W is compressed, the air in the gap flows to the radially outer side of the wafer W.

At this time, since the air flows toward the radially outer side of the wafer W, it is possible to prevent the fine foreign matter 70 adhering to the polishing pad 46 and the wafer W from being wound up. Even when it is rolled up, since there is no flow of air in the through hole 48, the foreign matter 70 becomes difficult to enter the through hole 48. Thereby, the foreign matter 70 becomes difficult to pass through the through hole 48 and enters the closing space 63 without the foreign matter 70 adhering to the measuring devices 60 and 61 disposed in the closing space 63. In this manner, by the air supply mechanism 64, the flow of the air toward the radially outer side of the wafer W is created, and the foreign matter 70 is surely prevented from being applied to the measuring devices 60, 61. Attached.

As shown in FIG. 4C, when the polishing surface 49 of the polishing pad 46 is in contact with the upper surface 81 of the wafer W, the supply of air from the air supply source 65 is stopped, and the upper surface of the wafer W is polished by the polishing pad 46. 81. At this time, the surface temperature and thickness of the wafer W are instantaneously measured by the measuring devices 60, 61 in the occluding space 63, and the grinding mechanism 41 is controlled based on the measurement results of the measuring devices 60, 61. The temperature measured by the measuring device 60 continues the polishing of the wafer W during a temperature lower than the temperature at which the surface is burnt, and when the temperature at which the surface is burnt is formed, the polishing of the wafer W is suspended. Then, the polishing mechanism 41 is polished and fed to the thickness of the wafer W measured by the measuring device 61 to the target thickness.

As described above, in the dry polishing apparatus 1 of the second embodiment, the positive pressure is formed by the closing space 63 in which the measuring devices 60 and 61 are disposed, and the air is ejected from the holes 47 toward the wafer W through the through holes 48. Thereby, when the polishing operation of the polishing mechanism 41 is performed, air does not enter the holes 47 and the through holes 48, and foreign matter 70 does not adhere to the measuring devices 60, 61 disposed in the closing space 63. The situation. Thereby, the dry grinding apparatus 1 can perform the grinding while properly measuring the state of the wafer W.

Furthermore, the present invention is not limited to the embodiments described above, and can be implemented in various modifications. In the above-described embodiments, the size, shape, and the like shown in the drawings are not limited thereto, and may be appropriately changed within the scope of the effects of the present invention. Further, the invention can be carried out with appropriate modifications without departing from the scope of the invention.

For example, in the first and second embodiments, a polishing pad is used. 46 has a configuration that can cover the entire size of the wafer W, but is not limited to this configuration. The polishing pad 46 can also be formed to be smaller than the wafer W.

Further, in the first and second embodiments, the polishing feed mechanism 31 is configured to polish the feed polishing pad 46 with respect to the holding table 21, but the configuration is not limited thereto. The polishing processing feed mechanism 31 may be configured to polish and feed the polishing mechanism 41 and the holding table 21 in a direction in which they are relatively close to and away from each other, and the polishing processing unit 31 is configured to polish the feed holding table 21 with respect to the polishing pad 46. Also.

Further, in the first and second embodiments, the cylindrical holes 47 are formed in the polishing pad 46, but the configuration is not limited thereto. The shape of the hole 47 of the polishing pad 46 is not particularly limited as long as it is formed so as not to hinder the measurement of the measuring instruments 60, 61.

In the first and second embodiments, the cover member 62 is configured to block the upper end of the through hole 48, but the configuration is not limited thereto. The cover member 62 is not limited to the configuration in which the upper end of the through hole 48 is completely blocked, and the escape passage of the air may be formed so as not to allow the foreign matter 70 to enter the closing space 63. That is, the occlusion space 63 is not limited to the state in which the escape route is completely free of air.

Further, in the first and second embodiments, the configuration in which the surface temperature and the thickness of the wafer W are simultaneously measured by the measuring devices 60 and 61 in the dry polishing apparatus 1 has been described, but the configuration is not limited thereto. The dry grinding apparatus 1 can also measure any one of the surface temperature and the thickness of the wafer W by the measuring device 60 or the measuring device 61. Further, the dry polishing apparatus 1 may be provided with a measurement for measuring the state of the wafer W during polishing other than the surface temperature and thickness of the wafer W. Device.

Further, in the second embodiment, the air supply mechanism 64 supplies air to the closing space 63 until the polishing surface 49 of the polishing pad 46 comes into contact with the upper surface 81 of the wafer W, but is not affected. Limited to this configuration. The air supply mechanism 64 may be configured to supply air to the closing space 63 at least when the polishing surface 49 of the polishing pad 46 approaches the polishing feed operation of the upper surface 81 of the wafer W. For example, the air supply mechanism 64 may continue to supply air continuously to the occlusion space 63 during polishing, and may supply air only to an instant before the polishing surface 49 of the polishing pad 46 comes into contact with the upper surface 81 of the wafer W. The occlusion space 63 is also possible.

Industrial availability

As described above, the present invention has an effect of preventing the adhesion of foreign matter such as grinding dust or dust to the measuring device for measuring the state of the wafer, and is particularly useful for a dry grinding device for polishing a wafer in a processing chamber in a dry environment.

21‧‧‧ Keeping the table

22‧‧‧Rotating mechanism

23‧‧‧ Keep face

40‧‧‧Rotary axis

41‧‧‧ grinding mechanism

43‧‧‧ spindle unit

44‧‧‧ Mounting

46‧‧‧ polishing pad

47‧‧‧ holes

48‧‧‧through holes

49‧‧‧Grinding surface

60, 61‧‧‧ measurer

62‧‧‧ Cover member

63‧‧‧Closed space

70‧‧‧ Foreign objects

81‧‧‧ upper surface

W‧‧‧ wafer

Claims (2)

A dry polishing apparatus comprising: a holding stage for holding a wafer; and a polishing mechanism having a spindle unit that is used to polish a center of the polishing pad held by the wafer of the holding stage, and is aligned with a center of the rotating shaft And a grinding processing feeding mechanism that performs grinding and feeding in a direction in which the polishing mechanism and the holding table are relatively close to and away from each other, wherein the polishing mechanism has a cylindrical hole, a through hole and a cover a member, the cylindrical hole is centered on a center of the polishing pad; the through hole is penetrated in the extending direction of the rotating shaft of the spindle unit and one end thereof communicates with the hole; the cover member A closing space that communicates with the other end of the through hole is formed, and a measuring device that measures the state of the wafer being polished is disposed in the closed space. A dry polishing apparatus according to claim 1, comprising: an air supply mechanism that communicates the occlusion space and an air supply source for supplying air, and at least when the polishing surface of the polishing pad approaches a polishing feed operation of the upper surface of the wafer, The air supply means supplies air to make the occlusion space a positive pressure.