JP4159558B2 - Polishing equipment - Google Patents

Description

  The present invention relates to a polishing apparatus that polishes a polishing object such as a semiconductor wafer in a flat and mirror-like shape, and more particularly to a polishing apparatus that includes a mechanism for controlling the polishing amount of a peripheral portion of the polishing object.

  In recent years, as semiconductor devices are highly integrated, circuit wiring is becoming finer and the distance between wirings is becoming narrower. In particular, in the case of photolithography having a line width of 0.5 μm or less, the allowable depth of focus becomes shallow, so that the flatness of the imaging surface of the stepper is required. Therefore, it is necessary to flatten the surface of the semiconductor wafer, but polishing is performed by a polishing apparatus as one means of this flattening method.

  Conventionally, this type of polishing apparatus has a turntable and a top ring, the top ring applies a constant pressure to the turntable, and an object to be polished is interposed between the turntable and the top ring, so that an abrasive liquid is obtained. The surface of the polishing object is polished to a flat and mirror surface.

  In the polishing apparatus described above, an attempt has been made to make the pressing force applied from the top ring to the polishing object uniform by attaching an elastic mat such as polyurethane to the semiconductor wafer holding surface of the top ring. This is intended to alleviate the local polishing of the semiconductor wafer by making the pressing force uniform, and to improve the flatness of the polishing object.

  FIG. 9 is a diagram showing a main part of a conventional polishing apparatus. The polishing apparatus supplies a polishing liquid 42 to the turntable 41 that rotates with a polishing cloth 42 on the upper surface, a top ring 45 that holds a semiconductor wafer 43 that is a polishing target so that it can be rotated and pressed, and the polishing cloth 42. A polishing liquid supply nozzle 48 is provided. The top ring 45 is connected to a top ring shaft 49, and the top ring 45 includes an elastic mat 47 such as polyurethane on the lower surface thereof, and holds the semiconductor wafer 43 in contact with the elastic mat. Further, the top ring 45 is provided with a cylindrical guide ring 46 at the outer peripheral edge so that the semiconductor wafer 43 does not come off from the lower surface of the top ring 45 during polishing. Here, the guide ring 46 is fixed to the top ring 45, and the lower end surface thereof is formed so as to protrude from the holding surface of the top ring 45, and the semiconductor wafer 43, which is a polishing object, is held in the holding surface. In addition, it is prevented from jumping out of the top ring by frictional force with the polishing pad 42 during polishing.

  The semiconductor wafer 43 is held below the elastic mat 47 on the lower surface of the top ring 45, the semiconductor wafer 43 is pressed against the polishing cloth 42 on the turn table 41 by the top ring 45, and the turn table 41 and the top ring 45 are rotated. Then, the polishing cloth 42 and the semiconductor wafer 43 are moved relative to each other for polishing. At this time, the abrasive liquid Q is supplied from the abrasive liquid supply nozzle 48 onto the polishing cloth 42. As the abrasive liquid, for example, an abrasive solution in which abrasive grains made of fine particles are suspended is used, and a semiconductor wafer is polished by a combined action of a chemical polishing action by alkali and a mechanical polishing action by abrasive grains.

  FIG. 10 is an enlarged cross-sectional view showing the state of the semiconductor wafer, polishing cloth and elastic mat during polishing. As shown in FIG. 10, the periphery of the semiconductor wafer 43, which is an object to be polished, is a boundary between contact / non-contact with the polishing pad 42 and at the same time, contact / non-contact with the elastic mat 47. Yes. For this reason, the polishing pressure applied to the polishing object becomes non-uniform at the periphery of the polishing object, which is the boundary between them, and only the periphery of the polishing object is polished much, which causes a so-called “dragging”. There was a point.

FIG. 11 shows the relationship between the radial position obtained by the finite element method and the polishing pressure and the radial position for a 6-inch semiconductor wafer in which a film such as an oxide film (SiO ₂ ) is formed on the semiconductor wafer. It is a graph which shows the relationship with a film thickness. In the figure, white circles indicate calculated values of polishing pressure (gf / cm ² ) determined by the finite element method, and black circles indicate measured values of film thickness (angstrom) after polishing. The polishing pressure obtained by the calculation is non-uniform at the peripheral edge (70 to 74 mm) of the semiconductor wafer, and the film thickness is accordingly non-uniform at the peripheral edge (70 to 73.5 mm) of the semiconductor wafer. . As can be seen from the actually measured value of the film thickness, it can be seen that the peripheral edge of the semiconductor wafer is overpolished and edge fringing occurs.

  Conventionally, in order to prevent the edge of the semiconductor wafer described above, the guide ring is configured by a ring-shaped weight, the guide ring can be moved up and down with respect to the top ring, and the polishing cloth is pressed by the weight of the guide ring. Some have been adopted (for example, JP-A-55-157473). Also, there is a structure in which a spring is interposed between the top ring and the guide ring and the guide ring is pressed against the polishing cloth by the spring force (for example, Japanese Patent Publication No. 58-10193).

  In the conventional structure that presses the polishing cloth by the weight of the guide ring, the pressing force by which the top ring presses the semiconductor wafer, which is the polishing object, against the polishing cloth is changed according to the polishing object and polishing conditions. Even so, the pressing force with which the guide ring presses the polishing cloth is always constant and cannot be changed, so the pressing force of the guide ring against the polishing cloth is too low or too high compared to the pressing force of the top ring. In some cases, only the peripheral edge of the semiconductor wafer is often polished, and conversely, the amount of polishing is small.

  Further, in the structure in which the guide ring is pressed against the polishing cloth by the spring force described above, the pressing force is determined by the spring to be used, and similarly to the above, depending on the polishing object and polishing conditions, the top ring Even if the pressing force that presses the semiconductor wafer against the polishing cloth is changed, the pressing force that the guide ring presses the polishing cloth cannot be changed. In some cases, the pressing force against the polishing cloth is too low or too high, so that only the peripheral edge of the semiconductor wafer is polished or the polishing amount is small.

  The present invention has been made in view of the above circumstances, and the polishing amount in the peripheral portion of the polishing object is excessive by allowing the guide ring to apply an optimum pressing force to the polishing cloth in accordance with the polishing object and polishing conditions. An object of the present invention is to provide a polishing apparatus capable of preventing deficiency and performing polishing with higher flatness.

  Further, according to the present invention, depending on the polishing object such as a semiconductor wafer, there is a request to increase the polishing amount from the inner side at the peripheral portion of the polishing object or on the contrary, the polishing is performed so that this request can be answered. It is an object of the present invention to provide a polishing apparatus that can intentionally increase or decrease the polishing amount of the peripheral edge of an object.

In order to achieve the above-described object, the first aspect of the polishing apparatus of the present invention includes a table having an upper surface with an abrasive cloth, a top ring for holding a polishing object, and the polishing object via the top ring. A first pressing mechanism to which a first air pressure for applying a pressing force is supplied; a guide ring for pressing the polishing cloth disposed to move up and down around the top ring; and the top ring A second pressing mechanism that is fixed and is supplied with a second air pressure for applying a pressing force to the guide ring; and a guide ring and the second pressing mechanism for applying a pressing force to the guide ring. A guide ring presser interposed therebetween, wherein the first pressing mechanism and the second pressing mechanism are air cylinders .

According to a second aspect of the polishing apparatus of the present invention, a table having a polishing cloth pasted on an upper surface, a top ring for holding a polishing object, and a first air pressure for applying a pressing force to the polishing object are supplied. A first pressing mechanism, a guide ring for pressing the polishing cloth disposed around the top ring so as to be movable up and down, and fixed to the top ring for applying a pressing force to the guide ring A second pressing mechanism to which a second air pressure is supplied, and a guide ring presser interposed between the guide ring and the second pressing mechanism for applying a pressing force to the guide ring. It is what.

According to a third aspect of the polishing apparatus of the present invention, a table with a polishing cloth affixed to the upper surface, a top ring for holding the polishing object, and a first air pressure for applying a pressing force to the polishing object are supplied. A first pressing mechanism, a guide ring for pressing the polishing cloth disposed around the top ring so as to be movable up and down, and a first ring for fixing the top ring and applying a pressing force to the guide ring. And a compressed air source connected to the first pressing mechanism and the second pressing mechanism .

  FIG. 1 is a diagram showing the basic concept of the present invention. In FIG. 1, reference numeral 1 denotes a top ring, and an elastic mat 2 is attached to the lower surface of the top ring 1. A guide ring 3 is disposed on the outer periphery of the top ring 1. The guide ring 3 is movable up and down with respect to the top ring 1.

In the above configuration, the pressing force F ₁ (pressure per unit area, gf / cm ² ) for pressing the semiconductor wafer 4 whose top ring 1 is the polishing object against the polishing pad 6 on the turntable 5 is variable, The pressing force F ₂ (pressure per unit area, gf / cm ² ) at which the guide ring 3 presses the polishing pad 6 is variable. The pressing force F ₁ and the pressing force F ₂ can be changed independently. Therefore, the pressing force F _{2 at} which the guide ring 3 presses the polishing pad 6 can be changed according to the pressing force F ₁ at which the top ring 1 presses the semiconductor wafer 4 against the polishing pad 6.

In this case, theoretically, if equal to the pressing force F ₂ which pressing force F ₁ and the guide ring 3 top ring 1 to press the semiconductor wafer 4 to the polishing pad 6 to press the polishing cloth 6, polishing object The distribution of the polishing pressure from the central part of the semiconductor wafer 4 to the peripheral part and further to the outer peripheral part of the guide ring 3 outside the semiconductor wafer 4 becomes continuous and uniform. Therefore, it is possible to prevent the polishing amount from being excessive or insufficient at the peripheral portion of the semiconductor wafer 4 that is the polishing object.

Figure 2 is a schematic diagram of a case of changing the relationship between the pressing force F ₂ which pressing force F ₁ and the guide ring 3 top ring 1 to press the semiconductor wafer 4 to the polishing pad 6 to press the polishing cloth 6, FIG. 2A shows the case of F ₁ > F ₂ , FIG. 2B shows the case of F ₁ ≈F ₂ , and FIG. 2C shows the case of F ₁ <F ₂ .
As shown in FIGS. 2A, 2 </ b> B, and 2 </ b> C, when the pressing force F ₂ is applied to the guide ring 3, the polishing cloth 6 is compressed, and the polishing cloth 6 is pressed against the peripheral edge of the semiconductor wafer 4. The contact state changes. Therefore, by changing the relationship between F ₁ and F ₂ , the distribution of the polishing pressure of the semiconductor wafer 4 can be changed variously between the inner side and the peripheral portion.

As apparent from FIG. 2, when F ₁ > F ₂ , the polishing pressure at the peripheral edge of the semiconductor wafer 4 is higher than the inside, and the polishing amount at the peripheral edge of the semiconductor wafer 4 is made larger than the internal polishing amount. Can do.
In the case of F ₁ ≈F ₂ , the distribution of the polishing pressure from the central part to the peripheral part of the semiconductor wafer 4 and further to the outer peripheral part of the guide ring becomes continuous and uniform, and the semiconductor wafer 4 is uniform from the central part to the peripheral part. A sufficient amount of polishing can be obtained.
In the case of F ₁ <F ₂ , the polishing pressure at the peripheral portion of the semiconductor wafer 4 becomes lower than the inside, and the polishing amount at the peripheral portion of the semiconductor wafer 4 can be made smaller than the internal polishing amount.

FIG. 3 is a graph showing experimental results when a semiconductor wafer is polished based on the basic concept of the present invention. A semiconductor wafer of 8 inches is used, the pressing force (polishing pressure) applied to the semiconductor wafer by the top ring is constant at 400 gf / cm ² , and the pressing force of the guide ring is changed from 600 to 200 gf / cm ^2. It is. 3 (a) is guiding the pressing force of the ring 600 gf / cm ^2, FIG. 3 (b) 500 gf / cm ² of the same pressing force, FIG. 3 (c) 400 gf / cm ² of the same pressing force, FIG. 3 ( FIG. 3D shows the same pressing force of 300 gf / cm ² , and FIG. 3E shows the same pressing force of 200 gf / cm ² . In each figure, the horizontal axis represents the distance (mm) from the center of the semiconductor wafer, and the vertical axis represents the polishing amount (angstrom).

As can be seen from FIG. 3, the polishing amount at the radial position of the semiconductor wafer is affected by changing the pressing force of the guide ring. That is, when the pressing force of the guide ring is 200 to 300 gf / cm ² (FIGS. 3D and 3E), the edge of the semiconductor wafer is edged, and the pressing force is 400 for ~500gf / cm ² (FIG. 3 (b), the FIG. 3 (c)) case anyone less edge of the peripheral portion of the semiconductor wafer, further the pressing force of 600 gf / cm ² (FIGS. 3 (a) ) Is insufficiently polished at the periphery of the semiconductor wafer.

  As described above, it was confirmed from the experimental results that the polishing amount at the peripheral edge of the polishing object can be adjusted by changing the pressing force of the guide ring independently of the pressing force of the top ring. Theoretically, when the pressure of the guide ring is equal to the pressure of the top ring, the polishing result of the peripheral part of the polishing object should be better, but it cannot be said unconditionally depending on the polishing object and polishing conditions. In the present invention, the pressing force of the guide ring is selected to an optimum value based on the pressing force of the top ring depending on the polishing object and polishing conditions.

  In addition, depending on the polishing object such as a semiconductor wafer, there is a request to intentionally increase the amount of polishing on the periphery of the polishing object from the inside or vice versa. By selecting the optimum value based on the pressing force of the top ring, the polishing amount of the peripheral portion of the polishing object can be intentionally increased or decreased.

  According to the polishing apparatus of the present invention, it is possible to prevent the pressing pressure distribution at the peripheral portion of the polishing object from becoming non-uniform during polishing and to make the polishing pressure uniform over the entire surface of the polishing object, It is possible to prevent the polishing amount of the portion from becoming excessive or insufficient. Therefore, the entire surface of the polishing object can be polished to a flat and mirror surface. Further, it is possible to perform polishing with higher quality by using it in a semiconductor manufacturing process and the like, and it is possible to use the product up to the peripheral edge of the semiconductor wafer, which contributes to the improvement of the yield of the semiconductor wafer.

  In addition, according to the present invention, depending on the polishing object such as a semiconductor wafer, there is a request to intentionally increase or decrease the polishing amount from the inner side at the periphery of the polishing object. The amount of polishing of the peripheral edge of the polishing object can be intentionally increased or decreased so that

Hereinafter, an embodiment of a polishing apparatus according to the present invention will be described with reference to FIGS. FIG. 4 is a cross-sectional view showing the overall configuration of the polishing apparatus, and FIG. 5 is a cross-sectional view showing the main configuration of the polishing apparatus.
4 and 5, reference numeral 1 denotes a top ring, and an elastic mat 2 is attached to the lower surface of the top ring 1. A guide ring 3 is disposed on the outer periphery of the top ring 1. Further, below the top ring 1, a turntable 5 having an abrasive cloth 6 pasted on the upper surface is installed.

  The top ring 1 is connected to a top ring shaft 8 via a ball 7, and the top ring shaft 8 is connected to a top ring air cylinder 10 fixed to a top ring head 9. The top ring shaft 8 moves up and down by the air cylinder 10, and the semiconductor wafer 4 held on the lower end surface of the top ring 1 is pressed against the turntable 5.

  The top ring shaft 8 is connected to a rotary cylinder 11 via a key (not shown), and the rotary cylinder 11 has a timing pulley 12 on the outer periphery thereof. The timing pulley 12 is connected via a timing belt 13 to a timing pulley 15 provided in a top ring motor 14 fixed to the top ring head 9. Therefore, when the top ring motor 14 is rotationally driven, the rotary cylinder 11 and the top ring shaft 8 are integrally rotated via the timing pulley 15, the timing belt 13 and the timing pulley 12, and the top ring 1 is rotated. The top ring head 9 is supported by a top ring head shaft 16 fixedly supported by a frame (not shown).

  On the other hand, the guide ring 3 is connected to the top ring 1 via a key 18, and the guide ring 3 can move up and down with respect to the top ring 1 and can rotate together with the top ring 1. The guide ring 3 is connected to a guide ring air cylinder 22 via a bearing retainer 20 holding a bearing 19 and a shaft 21. The guide ring air cylinder 22 is fixed to the top ring head 9. A plurality (three in this embodiment) of guide ring air cylinders 22 are arranged on the circumference.

  The top ring air cylinder 10 and the guide ring air cylinder 22 are connected to a compressed air source 24 via regulators R1 and R2, respectively. Then, by adjusting the air pressure supplied to the top ring air cylinder 10 by the regulator R1, the pressing force by which the top ring 1 presses the semiconductor wafer 4 against the polishing pad 6 can be adjusted, and the guide ring air is adjusted by the regulator R2. By adjusting the air pressure supplied to the cylinder 22, the pressing force with which the guide ring 3 presses the polishing pad 6 can be adjusted.

  A polishing liquid supply nozzle 25 is installed above the turntable 5, and the polishing liquid Q is supplied onto the polishing cloth 6 on the turntable 5 by the polishing liquid supply nozzle 25.

  In the polishing apparatus configured as described above, the semiconductor wafer 4 is held on the lower surface of the top ring 1, the top ring air cylinder 10 is operated to press the top ring 1 toward the turn table 5, and the turn table 5 rotating. The semiconductor wafer 4 is pressed against the polishing cloth 6 on the upper surface. On the other hand, by flowing the polishing abrasive liquid Q from the abrasive liquid supply nozzle 25, the polishing abrasive liquid Q is held on the polishing cloth 6, and polishing is performed between the surface (lower surface) of the semiconductor wafer 4 to be polished and the polishing cloth 6. Polishing is performed in the state where the abrasive liquid Q is present.

The semiconductor wafer 4 is polished by appropriately adjusting the pressing force of the guide ring air cylinder 22 against the polishing pad 6 according to the pressing force of the top ring 1 by the top ring air cylinder 10. The top ring 1 by the regulator R1 during polishing can change the pressing force F ₁ for pressing the semiconductor wafer 4 to the polishing cloth 6 on the turntable 5, the pressing force F ₂ which is a guide ring 3 presses the polishing cloth 6 by the regulator R2 Can be changed (see FIG. 1). Therefore, during the polishing, the pressing force F ₂ at which the guide ring 3 presses the polishing cloth 6 can be changed according to the pressing force F ₁ at which the top ring 1 presses the semiconductor wafer 4 against the polishing cloth 6. By appropriately adjusting the pressing force F ₂ with respect to the pressing force F ₁ , the distribution of the polishing pressure from the central portion of the semiconductor wafer 4 to the peripheral portion and further to the outer peripheral portion of the guide ring 3 outside the semiconductor wafer 4 is continuous. And become uniform. Therefore, excessive or insufficient polishing amount at the peripheral edge of the semiconductor wafer 4 can be prevented.

Also, when it is desired to intentionally increase the polishing amount from the inner side at the peripheral edge of the semiconductor wafer 4 or to decrease it, the guide ring ring pressing force F ₂ is an optimum value based on the top ring pressing force F _1. By selecting this, the polishing amount of the peripheral edge of the semiconductor wafer 4 can be intentionally increased or decreased.

FIG. 6 is a view showing a second embodiment of the polishing apparatus of the present invention.
In this embodiment, the guide ring 3 on the outer periphery of the top ring 1 is held by a guide ring presser 26, and the guide ring presser 26 is pressed by a plurality of rollers 27. The roller 27 is connected via a shaft 28 to a guide ring air cylinder 22 fixed to the top ring head 9. The guide ring 3 is movable up and down with respect to the top ring 1 and can rotate with the top ring 1 as in the embodiment shown in FIGS.

In this embodiment, while the top ring 1 is rotating, the roller 27 is in sliding contact with the guide ring presser 26 and rotates around its own axis, and the guide ring 3 is pressed downward by the roller 27 via the guide ring presser 26. Is done. As a result, the guide ring 3 presses the polishing pad 6 with a predetermined pressing force. Other configurations are the same as those of the embodiment shown in FIGS. The operational effects are also the same as those of the embodiment shown in FIGS.
As described above, in the first and second embodiments, the guide ring is provided via the members 21 and 28 that are separately provided around the top ring shaft 8 and do not rotate together with the top ring shaft 8. Since the pressing force is transmitted, the guide ring pressing force can be changed even during polishing, that is, when the top ring is rotating.

FIG. 7 is a view showing a third embodiment of the polishing apparatus of the present invention.
In the present embodiment, the guide ring 3 on the outer periphery of the top ring 1 is connected to a guide ring air cylinder 31 fixed to the top ring 1. The guide ring air cylinder 31 is connected to the compressed air source 24 via the communication path 8a in the top ring shaft 8, the rotary joint 32, and the regulator R2.

  The top ring air cylinder 10 is connected to the compressed air source 24 via the regulator R1 as in the embodiment of FIG. The regulators R1 and R2 are connected to the calculator 33.

  Also in this embodiment, the semiconductor wafer 4 is pressed against the polishing cloth 6 by the pressing force of the top ring 1 by the top ring air cylinder 10 and polished. The guide ring 3 is pressed against the polishing pad 6 by the guide ring air cylinder 31. When the guide ring 3 is pressed against the polishing cloth 6, the guide ring 3 receives a reaction force and affects the pressing force of the top ring 1. Therefore, in this embodiment, set values of the pressing force of the top ring 1 and the pressing force of the guide ring 3 are input to the calculator 33, and the calculator 33 inputs the set values to the top ring air cylinder 10 and the guide ring air cylinder 31. The supplied air pressure is calculated, regulators R1 and R2 are adjusted, and air of a predetermined air pressure is supplied to the top ring air cylinder 10 and the guide ring air cylinder 31, respectively. As a result, desired values can be obtained as the pressing force of the top ring 1 and the pressing force of the guide ring 3, respectively. That is, the pressing force of the top ring 1 and the pressing force of the guide ring 3 can be changed independently without being affected during polishing. Other configurations are the same as those of the embodiment shown in FIGS. The operational effects are also the same as those of the embodiment shown in FIGS. Also in the third embodiment, since the compressed air is supplied via the rotary joint, the guide ring pressing force can be changed even during polishing, that is, when the top ring is rotating.

FIG. 8 is an explanatory view showing an example in which the polishing amount of the peripheral portion of the polishing object is intentionally reduced from the inner side.
In the example shown in FIG. 8, the semiconductor device includes a base material 40 made of silicon, an oxide film 41 on the base material 40, a metal film 42 on the oxide film 41, and an oxide film 43 on the metal film 42. Has been. FIG. 8A shows a state before polishing, and FIG. 8B shows a state after polishing. After polishing, the metal film 42 is exposed at the peripheral edge of the semiconductor device. When the chemical solution is cleaned after polishing, the metal film 42 is attacked by the chemical solution as shown in FIG. In order to prevent the metal film 42 from being attacked by the chemical solution, it is preferable to leave the peripheral portion of the oxide film 43 thick by reducing the polishing amount of the peripheral portion from the inner side as shown in FIG. The present invention is suitable for such a demand.

  In the above embodiment, a semiconductor wafer is used as an object to be polished. However, the object to be polished can be applied to a glass product, a liquid crystal plate, a ceramic product, or the like. Further, although the air cylinder has been described as the pressing means for the top ring 1 and the guide ring 3, a liquid pressure cylinder may of course be used. Furthermore, although the mechanical means has been described as the pressing means for the guide ring, an electric means using a piezo element or electromagnetic force may be used.

It is explanatory drawing explaining the basic concept of this invention. It is explanatory drawing explaining the behavior at the time of changing the relationship between the pressing force of a top ring and the pressing force of a guide ring. It is a graph which shows the experimental result at the time of grind | polishing a semiconductor wafer based on the basic concept of this invention. It is sectional drawing which shows the whole structure of 1st Example of the polishing apparatus based on this invention. It is sectional drawing which shows the principal part structure of 1st Example of the polishing apparatus which concerns on this invention. It is sectional drawing which shows the principal part structure of 2nd Example of the polishing apparatus which concerns on this invention. It is sectional drawing which shows the principal part structure of 3rd Example of the polishing apparatus which concerns on this invention. It is explanatory drawing which shows the example in the case of reducing the grinding | polishing amount intentionally from the inner side about the peripheral part of a polishing target object. It is sectional drawing which shows schematic structure of the conventional polishing apparatus. It is an expanded sectional view which shows the state of the semiconductor wafer, polishing cloth, and elastic mat in the conventional polishing apparatus. It is a graph which shows the relationship between the radial direction position and polishing pressure of a semiconductor wafer, and the relationship between a radial direction position and a film thickness.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Top ring 2 Elastic mat 3 Guide ring 4 Semiconductor wafer 5 Turntable 6 Polishing cloth 7 Ball 8 Top ring shaft 9 Top ring head 10 Top ring air cylinder 18 Key 19 Bearing 20 Bearing presser 22 Guide ring air cylinder 24 Compressed air Source 25 Abrasive liquid supply nozzle 26 Guide ring presser 27 Roller 31 Air cylinder for guide ring 32 Rotary joint 33 Calculator R1, R2 Regulator

Claims (3)

A table with a polishing cloth on the top surface;
A top ring to hold the polishing object;
A first pressing mechanism that is supplied with a first air pressure for applying a pressing force to the polishing object via the top ring;
A guide ring for pressing the polishing cloth, which is arranged to move up and down around the top ring;
A second pressing mechanism fixed to the top ring and supplied with a second air pressure for applying a pressing force to the guide ring;
Possess a guide ring holding member which is interposed between the guide ring and the second pressing mechanism to give a pressing force to the guide ring,
The polishing apparatus according to claim 1, wherein the first pressing mechanism and the second pressing mechanism are air cylinders . A table with a polishing cloth on the top surface;
A top ring to hold the polishing object;
A first pressing mechanism to which a first air pressure for applying a pressing force to the polishing object is supplied;
A guide ring for pressing the polishing cloth, which is arranged to move up and down around the top ring;
A second pressing mechanism fixed to the top ring and supplied with a second air pressure for applying a pressing force to the guide ring;
A polishing apparatus comprising: a guide ring presser interposed between the guide ring and the second pressing mechanism for applying a pressing force to the guide ring. A table with a polishing cloth on the top surface;
A top ring to hold the polishing object;
A first pressing mechanism to which a first air pressure for applying a pressing force to the polishing object is supplied;
A guide ring for pressing the polishing cloth, which is arranged to move up and down around the top ring;
A second pressing mechanism fixed to the top ring and supplied with a second air pressure for applying a pressing force to the guide ring;
A polishing apparatus comprising: a compressed air source connected to the first pressing mechanism and the second pressing mechanism.

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