KR100755011B1 - Polishing plate, and polishing apparatus, polishing method using thereof - Google Patents

Abstract

The present invention discloses a polishing plate which is composed of different materials having different thermal expansion coefficients.

As described above, according to the polishing table according to the present invention, the flatness of the surface plate can be maintained, the workpiece can be mirror-finished with high efficiency and high precision, and the temperature of the surface plate can be adjusted within a certain range by adjusting the temperature of the cooling water. Because of the control, it is possible to minimize the change of the surface shape due to thermal deformation and to flatten the entire surface of the mirror-polished workpiece.

Polishing plate, thermal expansion coefficient, different materials, double side polishing device, single side polishing device

Description

Polishing plate, polishing device and polishing method using same {POLISHING PLATE, AND POLISHING APPARATUS, POLISHING METHOD USING THEREOF}

1 is a cross-sectional view of the surface plate according to an embodiment of the present invention;

2 is a plan view of a fluid flow path in one embodiment according to the present invention;

3 is a schematic cross-sectional view of a double-side polishing apparatus according to an embodiment of the present invention,

4 is an enlarged cutaway perspective view of portion A of FIG. 3;

5 is an enlarged cross-sectional view of a portion A;

6 is a cross-sectional view of a double-side polishing apparatus according to another embodiment of the present invention,

7 is a schematic explanatory view of a sectional polishing device according to another embodiment of the present invention;

8 is a result of plotting the shape of the upper and lower plate at the deformable value for each position at 30 ° C.

9 is a result of plotting the shape of the top plate according to the temperature change with the deformation value for each position,

10 and 11 show the result of plotting the shape of the lower plate according to the temperature change with the deformation value for each position.

12 is a graph showing the SBIR (Site Back-side Ideal Range, the difference between the maximum value and the minimum value in a predetermined region with respect to the back surface of the wafer) as the temperature changes.

<Code Description of Main Parts of Drawing>

10: polishing table 11: lower portion

13: top 15: polishing pad

16, 17: temperature control means 100, 200: double-sided polishing device

110, 210: Upper plate 120, 220: Lower plate

111, 211: First polishing pad 121, 221: Second polishing pad

130, 230: carrier 133: sun gear

135: internal gear 300: single side polishing device

310: plate 320: fixed plate

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing plate for polishing a work, and more particularly, to a polishing plate for allowing a workpiece to be mirror-finished with high efficiency and high accuracy.

In general, polishing of the workpiece can be divided into single-sided polishing for processing one side of the workpiece and double-sided polishing for processing both sides.

In general, cross-sectional polishing of a workpiece is performed by adhering and fixing a workpiece to a circular fixed plate, laying a surface plate that rotates to the lower side of the fixed plate, and injecting abrasive therebetween, wherein the fixed plate and the surface plate are pressurized to the workpiece. It rotates while adding to smooth the surface of the said workpiece | work.

On the other hand, double-sided polishing is processing both sides of a workpiece, in which a workpiece is inserted into and fixed to a plurality of carriers on which a workpiece mounting hole is formed, and a polishing pad is attached to opposite surfaces of the workpiece while supplying polishing slurry in the up and down direction of the fixed workpiece. The upper and lower plates are pressed against the front and back surfaces of the work, respectively, and rotated in the relative direction, and at the same time, both surfaces of the work are simultaneously polished by rotating and revolving the carrier by the sun gear and the internal gear.

In this case, unlike the single-sided polishing, since the workpiece is not adhesively fixed and also rotates itself, the momentum difference of the workpiece does not occur, so that the processing precision may be improved.

In general, in the polishing method of the work, the case where the number of workpieces that can be polished at one time can be distinguished by a sheet type or a case where there are several cases.

In the conventional polishing process as described above, the surface plate is made of glass, metal, ceramics, etc., which is a rigid material, and adheres and fixes the workpiece with an adhesive such as wax on the surface thereof, or has a plurality of through-holes on a porous material or surface which is breathable. The workpiece was supported on the surface of the surface by vacuum adsorption or the like.

However, when polishing is performed, heat is generated in the process, and heat is gradually transferred in the order of the workpiece, the surface of the workpiece (the resin coating portion when the resin coating is applied), and the surface plate body. Heat accumulates.

For this reason, the amount of heat storage and heat dissipation varies depending on the front and back of the surface plate body. Therefore, when the number of abrasives (grinding processing number) of the polishing process increases, a temperature difference occurs between the carrier and the surface side of the surface plate body. . In order to prevent this, various research and development has been attempted such as using a low thermal expansion agent on the surface plate.

However, the conventional polishing methods and polishing apparatuses described above are based on the surface deformation caused by various mechanical defects when they rotate in addition to the heat deformation caused by the heat generated by the polishing, the movement of the surface plate and the carrier's own weight or the polishing pressure. However, since the finishing precision of the workpiece is affected by the deformation and the variation of the carrier, it is difficult to satisfy the requirements for the accuracy of the finishing surface.

In order to cope with such a problem, various creations have been made regarding the structure and material of the polishing apparatus, and the operating conditions and polishing conditions of the polishing apparatus. For example, in order to prevent thermal deformation of the structure of the apparatus, in particular, the surface plate, a plurality of recesses are formed in the lower surface plate for circulating the cooling water H, and at the same time the back surface of the surface plate is prevented to prevent deformation due to the polishing pressure. In order to form ribs and effectively prevent thermal deformation, as described in Japanese Patent Application Laid-Open No. 7-52034 or 10-296619, the structure of the surface plate and the arrangement of the cooling water flow paths, etc. Various techniques have been disclosed.

In addition, using a material having a low coefficient of thermal expansion (8 × 10 ⁻⁶ / ° C.) as the polishing plate material (WO 94/13847), a ceramic body is used to form a circulation flow path of cooling water over almost the entire area. Polishing plate of structure (Japanese Laid-Open No. 59-151655) and polishing solution (usually a weakly alkaline aqueous solution of colloidal silica is used to suppress the temperature rise of the work pad and the polishing pad due to the heat generated by the polishing operation). ), Cooling technology is supplied to the polishing pad, and the discharged abrasive solution is recycled to reduce the cost.

However, in the structure of the conventional polishing apparatus and the cooling method as described above, the temperature of the surface of the polishing pad during polishing gradually rises from the start of polishing, especially at the portion at which the surface to be polished frictionally rubs with the polished surface of the wafer. As mentioned above, the temperature of the upper surface part of the grinding | polishing surface plate just under that part also rises more than 3 degreeC.

On the other hand, the temperature of the lower surface part of the surface plate also has the effect of suppressing the temperature rise by the cooling water, and the temperature change is suppressed within 1 ° C. Therefore, a temperature difference of at least 3 ° C or more occurs between the upper and lower surfaces of the polishing table as well as between the hot and cold portions of the upper surface of the polishing table. Therefore, the surface surface shape does not have a temperature difference due to thermal deformation. On the other hand, there was a problem that a portion where deformation deformation occurred at least 100 μm in the normal direction of the surface.

Moreover, in response to the large diameter of the workpiece being polished, the diameter of the carrier is also increased. For example, in the case of 8-inch wafer polishing, the diameter is about 600 mm, and the weight of the carrier has also increased.

Therefore, not only thermal deformation of the carrier due to heat generation on the polishing surface, but also deformation during polishing due to its own weight becomes a problem. In order to suppress this, the thickness of the carrier is increased, or ceramics (silicon carbide, alumina), etc. It has been attempted to reduce the amount of deformation by using a material having a large Young's modulus.

As described above, various research and development attempts have been made to solve the problem that the entire surface of the surface plate body is deformed, and as a result, the flatness of the workpiece supported and polished is deteriorated, but at the present time an ultra high flatness workpiece is required. This alone is not enough.

Therefore, there is a need for a polishing plate that satisfies all the above requirements in consideration of thermal expansion and rigidity.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a work polishing plate made of different materials having different coefficients of thermal expansion, thereby effectively preventing thermal deformation and increasing the number of polishing operations. The present invention provides a surface plate capable of maintaining good flatness regardless, a polishing device using the surface plate, and a polishing method.

In addition, another object of the present invention is to provide a polishing method that can improve polishing accuracy and productivity by adjusting the temperature of the upper and lower plate made of different materials having different thermal expansion coefficients.

The surface plate according to the present invention for achieving the above object is characterized by consisting of different materials with different thermal expansion coefficients.

One of the dissimilar materials is characterized in that the coefficient of thermal expansion is 0.6 ~ 3.6 X10 ^-6 / ℃, the other is 8.2 ~ 12.2 X10 ^-6 / ℃.

One of the heterogeneous materials is characterized in that the Fe-Ni alloy or Fe (Ni + Co) alloy.

The surface plate is characterized in that the temperature control means is provided.

The surface plate is characterized in that the polishing pad is attached.

In addition, the double-side polishing apparatus according to the present invention for achieving the above object includes a top plate and a bottom plate, a carrier having a work mounting hole, and a slurry supply means, while supplying a slurry to the workpiece mounted on the carrier, A double-side polishing apparatus for simultaneously polishing the front and back surfaces of a workpiece by moving a carrier between the plates, wherein the upper and lower plates are made of different materials having different coefficients of thermal expansion.

The upper or lower plate is characterized in that the cooling water circulation passage is formed.

And a sun gear and an internal gear for rotating and revolving the carrier.

Further comprising a carrier holder, the carrier is characterized in that the circular motion does not accompany the rotation.

In addition, according to the present invention for achieving the above object is a polishing plate according to the present invention is a fixed plate formed with a work mounting hole, the surface plate is installed in the lower side of the fixed plate, the slurry is introduced therebetween, while the fixed plate and the surface plate apply pressure to the work A cross-section polishing apparatus for rotating and polishing a surface of the workpiece, wherein the surface plate is made of different materials having different coefficients of thermal expansion.

The surface plate is characterized in that the cooling water circulation passage is formed.

In addition, the double-side polishing method according to the present invention for achieving the above object is to move the carrier between the top plate or the bottom plate composed of different materials, the top plate and the bottom plate, and supply the slurry to the workpiece mounted on the carrier As a double-side polishing method for polishing, the temperature of the lower platen is controlled to 28 ~ 30 ℃.

It is characterized by controlling the temperature of the upper plate to 28 ~ 30 ℃.

The normal deformation in the normal direction of the upper surface of the lower surface plate is characterized in that 50 ~ 75 ㎛.

Hereinafter, with reference to the accompanying drawings will be described in detail with respect to the polishing table according to the present invention, a polishing apparatus and a polishing method using the same.

1 is a cross-sectional view of a surface plate according to an embodiment of the present invention. Referring to Figure 1, the polishing plate according to the present invention is composed of different materials having different thermal expansion coefficients, wherein the surface plate is a material having a coefficient of thermal expansion (linear expansion coefficient α) of 0.6 ~ 3.6 X 10 ^-6 / ℃ And 8.2-12.2 ^X10-6 / ° C.

At this time, the lower end portion 11 of the polishing plate 10 is composed of a material having a thermal expansion coefficient of 8.2 to 12.2 X 10 ^-6 / ℃, the upper end 13 is composed of a material having a thermal expansion coefficient of 0.6 ~ 3.6 X 10 ^-6 / ℃ By doing so, it is possible to more effectively prevent the surface plate from being deformed by heat generated by polishing.

If the surface plate 10 composed of different materials having different thermal expansion coefficients as described above, the degree of thermal expansion is the same even if there is a temperature difference between the upper and lower plate unlike the conventional.

Therefore, according to the present invention, the difference in temperature between the upper and lower surfaces of the surface plate during the polishing operation is 3 ° C or more, and more preferably 5 ° C or more, and the upper surface of the surface plate is a reference surface when there is no temperature difference between the upper and lower surfaces. Therefore, the problem that the high and low difference (deformation) of 100 micrometers or more arises depending on a position can be solved simply.

In particular, in polishing, not only thermal expansion characteristics but also resistance to withstand the polishing pressure should be considered. Considering such thermal expansion and stiffness, one of the heterogeneous materials has a low thermal expansion property of 5 × 10 ⁻⁶ / ° C. or less at room temperature to 300 ° C. It is preferable to use a Fe-Ni-based alloy or Fe (Ni + Co) alloy.

In addition, it is preferable to use ceramics such as stainless steel (SUS410, FC-300), alumina, and SiC having a thermal expansion coefficient of 8.3 to 11.3 × 10 ⁻⁶ / ° C.

As the Fe-Ni-based alloy or Fe (Ni + Co) alloy, Invar of Fe-36% Ni, Kovar of Fe-29% Ni-17% Co, or Fe-36% (Ni It is preferable to use Super Invar of + Co) and the like. The Fe and Ni are essential components for the control of thermal expansion, and can be used in various mixtures in the most suitable ratio for realizing the thermal expansion coefficient required in the temperature range used.

When Fe-Ni-based alloy or Fe (Ni + Co) -based alloy is used as one of the heterogeneous materials of the surface plate, heat generated in the work during the polishing process is transferred to and accumulated on the surface plate, and the amount of heat storage and heat dissipation according to the front and back of the surface plate. Because of this difference, it is possible to minimize the temperature difference between the carrier and the surface plate and the thermal deformation of the surface plate which are generated as the number of abrasives (abrasive processing ash) increases, thereby ultimately improving the finishing accuracy of the work.

At this time, it is preferable that the polishing pad 15 for mirror-mirroring the surface of the workpiece is attached to the upper surface of the surface plate 10. The type and material of the polishing pad are not limited, but it is preferable to use a soft foamed urethane pad, which is a general polishing pad, a soft nonwoven fabric pad impregnated with a nonwoven urethane resin, and the like. For example, Suba600, etc. of Roderus Corp. is used for the soft nonwoven fabric. Two or more layers of polishing pads in which urethane resin is foamed on the surface of other nonwoven fabrics can be used.

In addition, it is preferable to minimize the thermal deformation of the surface plate by forming the temperature control means (16, 17) on the upper and / or lower portion of the surface plate (10). At this time, the temperature control means may be installed in various forms, such as the flow of a liquid or gas of the temperature controlled in the flow path of the surface plate, if the fluid jacket or cooling water circulation flow path (flow path) is formed on the surface plate, It can be configured easily. Although the planar shape of the fluid flow path of the embodiment according to the present invention is shown in Fig. 2, the shape and position of the flow path formed on the surface plate are not limited.

By the temperature adjusting means 16, 17, the temperature difference between the surface and the back surface supporting the work of the surface plate and the temperature difference between the central portion and the outer circumference of the surface plate can be effectively eliminated. The thermal deformation of hardly occurs, so a workpiece with high flatness can be obtained.

In addition, by using the temperature adjusting means, heat generation due to polishing is eliminated, thermal expansion of the work and the surface plate is suppressed, and thus a good flat work and a good work at a horseshoe level can be produced. When the workpiece having high flatness obtained here, in particular, the workpiece is a semiconductor wafer, various film thickness defects in the high integrated device process can be reduced and the yield of the high integrated device can be improved.

Figure 3 is a schematic cross-sectional view of a double-side polishing apparatus according to an embodiment of the present invention, Figure 4 is an enlarged cutaway perspective view of the portion A of Figure 3, Figure 5 is an enlarged cross-sectional view of the portion A, as shown, It is a batch double-side polishing apparatus for simultaneously polishing the respective mirror surface and the back surface.

3 to 5, the double-sided polishing apparatus according to the present invention is placed to face each other up and down, each of which is in close contact with the workpiece (W) to rotate in opposite directions to polish the both sides of the wafer 110 And a lower plate 120, a plurality of carriers 130 installed to be coupled between the upper and lower plate 110 and 120, and a work mounting hole formed therein, and a sun gear 133 rotating and revolving the carrier. It is configured to include an internal gear 135 and the slurry supply means 140. At this time, the upper and lower platen (110, 120) is a plate composed of different materials of different thermal expansion coefficients.

The sun gear 133 has a tooth formed on the outer circumferential surface and is provided at the center of the upper surface of the lower surface plate 120, and the internal gear 135 has a tooth formed on the inner circumferential surface of the lower surface plate 120. The sun gear 133 and the internal gear 135 are placed so that the carrier 130 is coupled therebetween.

The carrier 130 serves to rotate and rotate the workpiece (W) mounted in the mounting hole 131, and has a disc shape, the outer peripheral surface of which is formed with a tooth to rotate in engagement with the sun gear and the internal gear have. The carrier rotates between the top plate and the bottom plate and rotates about the center of the bottom plate, and the workpiece rotates between the center and the periphery of the top and bottom plate, and rotates around the sun gear together with the carrier.

A first polishing pad 111 is attached to a lower surface of the upper surface plate 110 to contact the rear surface of the work W mounted on the carrier 130 to enable surface polishing. The lower surface plate 120 may include a carrier ( The second polishing pad 121 is attached to be in contact with the mirror surface of the workpiece (W) mounted on the 130 to perform mirror polishing.

As described above, the first polishing pad 111 and the second polishing pad 121 may be made of a hard foamed urethane pad, a soft nonwoven fabric pad impregnated with a urethane resin and cured, as described above.

The top plate 110 is provided with a cylinder 151 for applying rotation and polishing loads, a housing 153 for transmitting the load to the top plate, and fixing means 155 such as a bolt for fixing the housing and the top plate. In addition, the upper surface plate 110 is provided with a temperature control means (not shown) for controlling the temperature of the surface plate.

On the other hand, the lower plate 130 is also provided with a cylinder 151 for transmitting the rotation from the motor and the reducer (not shown) to the lower plate and a thrust bearing 170 for supporting the load of the plate. Also within 110 is provided a temperature control means (not shown) for controlling the temperature of the surface plate.

The slurry supply means 140 may be installed on the top plate through a rocker joint (not shown), and the supply amount of the slurry may be changed by an electron valve not shown. The slurry supply means may be formed in plurality. It is preferable that a plurality of slurry supply means is configured such that slurry is always supplied to the surface of the workpiece even if the workpiece is rocked, and is arranged in an annular region of a predetermined width in which the workpiece is always present. There is no particular limitation on the type of slurry used.

Referring to the method of simultaneously polishing the front and back surfaces of the workpiece using the double-sided polishing device.

First, after inserting and holding the workpiece | work W in the workpiece mounting hole 131 of the said several carrier 130, the upper and lower surface plates 110 and 120 of the workpiece hold | maintained by the said carrier are rotated along the axis of rotation. A lifting device (not shown) for advancing and retreating in the direction is positioned between the upper and lower plates to which the polishing pad is attached. Then, while supplying the slurry from the slurry supply means 140, the upper plate 110 is rotated in a horizontal plane from the upper rotating motor (not shown) through the cylinder 151, and the cylinder from the lower rotating motor (not shown) The lower plate 120 is rotated in the horizontal plane through the 151. At the same time, the plurality of carriers 130 may be rotated and revolved with the sun gear 133 and the internal gear 135 to simultaneously polish both front and rear surfaces of the work W.

At this time, the rotational speed of the upper and lower platen, the pressing force corresponding to each of the rotational directions, the upper and lower platen workpieces, etc. are not limited, and the pressing is preferably performed by a pressurized method using a fluid or the like. It is possible to grind to the conditions which were conventionally performed by pressing by the housing part arranged in half.

In the case where the workpiece is a silicon wafer, the pressure of the upper and lower plates is usually 100 to 300 g / cm 2, and the type of slurry used is not limited, but it is preferable to use an alkaline solution containing pH 9 to 11 containing colloidal silica. Preferably, the slurry supply amount is not limited because it depends on the size of the carrier and the like, but is preferably 2.0 to 6.0 l / min.

6 is a cross-sectional view of a double-side polishing apparatus using a surface plate composed of different materials having different thermal expansion coefficients according to another embodiment of the present invention. Referring to the operation of the double-sided polishing device in detail as follows.

First, after inserting and holding the workpiece | work W in the carrier 230 in which the workpiece mounting hole (not shown) was formed, the upper and lower surface plates 210 and 220 of the workpiece hold | maintained by the said carrier 230 rotated in the axial direction By using a lifting device (not shown) for advancing to the upper and lower positions, the upper and lower plates 210 to which the polishing pads 211 and 221 are attached are positioned between the lower and upper plates 220. Thereafter, while supplying slurry from the slurry supply means 240, the upper platen 210 is rotated in a horizontal plane through the cylinder in the upper rotating motor (not shown), and the cylinder (not shown) is lowered from the lower rotating motor (not shown). The lower plate 220 is rotated in the horizontal plane through 251. At this time, since the workpiece W is held to be rotatable in the workpiece mounting hole of the carrier 230, the rotation of the upper plate 210 and the lower plate 220 is controlled to adjust the rotational speed of the platen. It is possible to rotate (rotate) in the direction.

In addition, when the upper and lower platen (210, 220) is rotated and the carrier 230 is held by the carrier holder 290 as shown in FIG. 6, the circular motion that does not involve the rotation of the carrier, that is, the carrier It is possible to simultaneously and uniformly polish both front and back surfaces of the workpiece while performing a kind of swinging motion while turning 230 while maintaining a state of eccentric distance from the rotation axis of the upper and lower plates without rotating the 230.

7 is a schematic explanatory view of a sectional polishing apparatus using a surface plate 310 composed of different materials having different thermal expansion coefficients according to the present invention. Referring to FIG. 7, the end surface polishing apparatus 300 is supported by a fixed plate 320 having a work (W) work mounting hole (not shown), and a surface plate 310 is installed below the fixed plate 320. The slurry is injected into the plate, and the fixed plate 320 and the surface plate 310 rotate while applying pressure to the work W to polish the surface of the work.

The work W is fixed to and supported by a mounting hole of the fixing plate by adhesive wax or vacuum suction. The fixed plate 320 for supporting the work as described above is mounted to the polishing head 330 having a rotating shaft, the fixed plate 320 is rotated by the polishing head 330 and at the same time to the polishing pad 311 with a predetermined load Press the workpiece. The workpiece is polished as a slurry is supplied between the workpiece and the polishing pad.

On the upper surface of the surface plate 310, it is preferable to attach a polishing pad such as the above-described hard foamed urethane pad and a nonwoven fabric of a soft non-woven fabric pad impregnated and cured. It is more preferable to provide a temperature adjusting means so as to easily adjust the temperature of the surface plate (work).

Next, a polishing method for preventing the change of the surface shape by adjusting the temperature of the surface plate will be described. Briefly, by controlling the temperature of the cooling water to control the temperature of the surface plate within a certain range, it is possible to flatten the entire surface of the mirror-polished workpiece by minimizing the change of the surface shape due to thermal deformation without slowing down the polishing rate. It can be polished.

In the above polishing, the silicon wafer was polished by a double-side polishing apparatus using a surface plate composed of different materials having different thermal expansion coefficients according to the present invention.

The base will have a thermal expansion coefficient 1.6X10 ^-6 / ℃ of Fe-36% Ni and the thermal expansion coefficient of Invar 10.2X10 ^-6 / ℃ the thermal expansion coefficient consisting of a FC-300 with different heterogeneous material, the double-side polishing apparatus Is a double-sided polishing device in which a carrier moves as a circular motion without accompanying rotation.

First, five silicon wafers (one batch) were inserted into each wafer mounting hole of the carrier (five mounting holes were formed). Each wafer was pressed at 300 g / cm 2 by an upper and lower surface plate with a polishing pad (soft nonwoven fabric) attached thereto.

Thereafter, while the upper and lower polishing pads are pressed against both sides of the wafer, the upper and lower platen are rotated, and the timing chain is rotated to the circular motion motor while supplying slurry from the upper platen. As a result, each eccentric arm was synchronously rotated in the horizontal plane, and the carrier holder and the carrier connected to each eccentric axis were subjected to a circular motion in the horizontal plane horizontal to this surface without prior accommodating to polish both front and back sides of the wafer.

In order to examine the effect of temperature change on the top plate shape, experiments were conducted at the top plate temperature of 24 ℃ and 30 ℃ (the bottom plate temperature of 30 ℃), respectively. In order to see, the lower plate temperature was experimented by changing (the lower plate temperature 30 ℃) in 1 ℃ interval from 22 ℃ to 32 ℃.

At this time, the slurry was supplied at 0.2 L / min in which abrasive grains composed of colloidal silica having a particle size of 0.05 µm were dispersed in an alkaline solution having a pH of 10.8.

Example 1

Shape of upper and lower plate at temperature 30 ℃

" 상태에서 측정한 결과이다. Table 1 shows the deformation values of the shape of the surface plate (wafer) when the temperature adjusting means is adjusted to make the temperature of the upper plate and the lower plate 30 ° C. FIG. 8 is a graph showing the upper and lower plate shapes by plotting the positional deformation values. The result is that the upper and lower plates are placed on the horizontal plane.

"Is the result measured in the state.

Example 2

Shape change of the top plate with temperature change

By adjusting the temperature control means, the temperature of the lower plate is fixed at 30 ° C., and the deformation values of the upper plate shape for each position when the temperature of the upper plate is 24 ° C. and 30 ° C. are shown in Table 2. FIG. 9 is a graph plotting the shape of the upper plate with strain values for each position.

Example 3

Shape change of lower plate according to temperature change

The temperature of the upper plate is fixed at 30 ° C. by adjusting the temperature control means, and the deformation values of the lower plate shape for each position when the temperature of the lower plate is changed at 1 ° C. from 22 ° C. to 32 ° C. are shown in Table 3. 10 and 11 plot the shape of the lower plate with a strain value for each position and are graphically shown. In addition, as a result of evaluating the shape of the surface plate after polishing by GBIR, SBIR, SFQR, and the average value thereof are shown in Tables 4 and 5, respectively.

R_Ave .: 15 μm

R_Rate: 0.5 μm / min

GBIR: Global Back-side Ideal Range (= TTV), the difference between the maximum and minimum thicknesses over the entire area from the wafer backside

SBIR: Site Back-side Ideal Range (= LTV), the difference between the maximum and minimum values at a site with reference to the backside of the wafer

SFQR: Site Front least sQuares <site> Range, height difference of wafer surface per site

As shown in Fig. 10, Fig. 11 and Table 5, by adjusting the temperature of the lower surface plate to 28 to 30 DEG C, the normal deformation of the normal direction of the upper surface of the lower surface plate is suppressed to 50 to 75 µm or less so that the surface surface of the surface plate is generally embossed. It is desirable to prevent the deformation from being reversed.

As shown in FIG. 12 and Table 5, when the surface temperature is maintained at 30 ℃ shows a preferred result that the SBIR is the lowest value.

The surface plate composed of heterogeneous materials having different thermal expansion coefficients according to the present invention can be used in all conventional polishing apparatuses including wafers such as single wafer polishing apparatuses as well as batch polishing apparatuses.

It is apparent that the present invention is not limited to the above embodiments and can be implemented by many modifications within the technical idea of the present invention by those skilled in the art.

Thus, according to the polishing plate according to the present invention, the polishing apparatus and the polishing method using the same, there are the following effects.

The use of a surface plate made of different materials with different thermal expansion coefficients can maintain the flatness of the surface plate and allow the workpiece to be mirror-finished with high efficiency and high accuracy, thus greatly improving the yield of high-quality workpieces. .

In addition, since the temperature of the surface plate is controlled within a predetermined range by adjusting the temperature of the cooling water, the surface surface side of the surface plate can be avoided from being deformed so as to be inverted entirely. That is, the entire surface of the mirror-polished workpiece can be flattened by minimizing the change in the surface shape due to thermal deformation.

Claims (19)

Polishing plate, characterized in that the thermal expansion coefficient is composed of different materials, one of the different materials is Fe-Ni alloy or Fe (Ni + Co) alloy. It is composed of heterogeneous materials with different coefficients of thermal expansion, one of which is characterized in that the coefficient of thermal expansion is 0.6 ~ 3.6 X10 ^-6 / ℃, the other is 8.2 ~ 12.2 X10 ^-6 / ℃ Polishing plate to do. delete The method according to claim 1 or 2, The surface plate for polishing, characterized in that the temperature control means is provided. The method according to claim 1 or 2, The surface plate for polishing, characterized in that the polishing pad is attached to the surface plate. A top surface and a bottom surface, a carrier having a work mounting hole, and a slurry supply means, and both sides of which simultaneously polish both front and rear surfaces of the work by moving a carrier between the top and bottom surfaces while supplying slurry to the work mounted on the carrier. In the polishing device, The upper surface plate or the lower surface plate is composed of heterogeneous materials having different coefficients of thermal expansion, wherein one of the materials is a Fe-Ni-based alloy or a Fe (Ni + Co) -based alloy. A top surface and a bottom surface, a carrier having a work mounting hole, and a slurry supply means, and both sides of which simultaneously polish both front and rear surfaces of the work by moving a carrier between the top and bottom surfaces while supplying slurry to the work mounted on the carrier. In the polishing device, The upper plate or the lower plate is a double-side polishing device, characterized in that composed of two materials having a coefficient of thermal expansion of 0.6 ~ 3.6 X10 ^-6 / ℃ and a material of coefficient of thermal expansion of 8.2 ~ 12.2 X10 ^-6 / ℃. delete The method according to claim 6 or 7, The upper surface plate or the lower surface plate is a double-side polishing apparatus, characterized in that the coolant circulation passage is formed. The method according to claim 6 or 7, And a sun gear and an internal gear for rotating and revolving the carrier. The method according to claim 6 or 7, And a carrier holder, wherein the carrier performs a circular motion without accompanying rotation. In the fixed plate with a workpiece mounting hole, a surface plate is installed under the fixing plate, and a slurry is introduced therebetween, wherein the fixed plate and the surface plate are rotated while applying pressure to the workpiece to rotate the surface of the workpiece. The surface plate is composed of heterogeneous materials having different coefficients of thermal expansion, one of the materials is a Fe-Ni-based alloy or Fe (Ni + Co) -based polishing apparatus, characterized in that. In the fixed plate with a workpiece mounting hole, a surface plate is installed under the fixing plate, and a slurry is introduced therebetween, wherein the fixed plate and the surface plate are rotated while applying pressure to the workpiece to rotate the surface of the workpiece. The surface plate is a double-side polishing device, characterized in that the thermal expansion coefficient value of 0.6 ~ 3.6 X10 ^-6 / ℃ material and the thermal expansion coefficient value of 8.2 ~ 12.2 X10 ^-6 / ℃ two materials. delete The method according to claim 12 or 13, And the surface plate has a coolant circulation passage formed therein. In the double-side polishing method of moving a carrier between an upper plate or a lower plate composed of different materials, the upper plate and the lower plate, and supplying and polishing a slurry of the workpiece mounted on the carrier, Double-side polishing method characterized in that to control the temperature of the lower plate to 28 ~ 30 ℃. The method of claim 16, Double-side polishing method characterized in that to control the temperature of the top plate to 28 ~ 30 ℃. The method of claim 16, The normal strain in the normal direction of the upper surface of the lower surface plate is 50 to 75 ㎛ characterized in that the double-side polishing method. The method according to any one of claims 16 to 18, The upper plate or the lower plate is a double-side polishing device, characterized in that composed of two materials having a coefficient of thermal expansion of 0.6 ~ 3.6 X10 ^-6 / ℃ and a material of coefficient of thermal expansion of 8.2 ~ 12.2 X10 ^-6 / ℃.

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