Polishing head and polishing device

Abstract

Provided is a polishing head and a polishing processing device that can prevent the occurrence of uneven polishing such as partial under-polishing or over-polishing of the polished surface of a substrate, further improve the ESFQR of the substrate surface, and perform high-quality and stable multiple polishing processes. The polishing head includes: a head housing, having a first flange extending from the upper position of the circumference of a cylindrical body to the outside and a second flange extending from the lower position of the circumference to the outside; a membrane support ring, which has a size surrounding the outer periphery of the second flange, and a third flange located between the first and second flanges is formed at its upper end; a membrane, which covers the lower end opening of the membrane support ring and holds the wafer through a back membrane attached to its surface side; a retaining ring, which surrounds the outer periphery of the substrate; and a driving mechanism, which rotates the head housing, the membrane support ring, and the retaining ring horizontally as a whole.

Description

Technical Field

[0001] The invention relates to a polishing head and a polishing device for polishing a substrate, such as a semiconductor wafer or a glass substrate. Background Art

[0002] In recent years, in the manufacturing process of semiconductor devices, with the high integration of substrates such as semiconductor wafers and glass substrates (hereinafter referred to as wafers), the flattening technology of the substrate surface has become increasingly important. Among these flattening technologies, the most important technology is chemical mechanical polishing (CMP (Chemical Mechanical Polishing)). This chemical mechanical polishing uses a polishing device (also called a polishing device) to provide a polishing liquid containing abrasive particles such as silicon dioxide (SiO2) on the polishing surface of a polishing pad, etc., while allowing the substrate to slide and connect on the polishing surface for polishing.

[0003] In addition, in order to prevent the wafer from flying outward due to the sliding friction force caused by the rotation during the polishing process, a retaining ring is provided on the polishing head that holds the wafer, and the retaining ring blocks the wafer being polished on its inner circumference to control the wafer from flying out.

[0004] In addition, in order to facilitate the disassembly and assembly of the polishing head, a series of components including a retaining ring can also be used as a template.

[0005] For example, the CMP apparatus disclosed in Patent Document 1 can suppress excessive pressure of the back film pressing the wafer edge even when the template is worn and the thickness of the template gradually decreases. Thus, even if the thickness of the template changes over time, it is possible to suppress significant fluctuations in the polishing rate of the wafer edge compared to the polishing rate of other areas of the wafer.

[0006] Furthermore, the polishing machine disclosed in Patent Document 2 effectively suppresses polishing defects at the corners of a square material to be polished by applying uniform pressure to the corners of the material to be polished when polishing the square material to be polished.

[0007] In addition, the polishing head disclosed in Patent Document 3 applies the pressure of the pressure fluid amount enclosed in a plurality of pressure chambers from each pressure chamber to the back side of the substrate, and applies the required pressure to the entire processed surface of the substrate without discontinuous parts, and further, makes the outer diameter of the back film smaller than the outer diameter of the wafer to prevent stress concentration at the end of the wafer. Thus, by uneven pressure, it is possible to prevent uneven polishing, insufficient polishing, and excessive polishing, significantly improve the deterioration of ESFQR (Edge Site Flont least sQuare Range), and realize high-quality production technology.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Publication No. 2019-121650

[0011] Patent Document 2: Japanese Patent Publication No. 2004-034217

[0012] Patent Document 3: Japanese Patent Publication No. 2014-018933 Summary of the invention

[0013] Problems to be solved by the invention

[0014] In such a polishing apparatus, if the relative speed and pressure between the surface to be polished (hereinafter referred to as the polished surface) and the polishing head are not uniform over the entire polishing surface, uneven polishing such as insufficient polishing or excessive polishing may occur. In the following, insufficient or excessive situations may also be referred to as excessive / small amount.

[0015] For example, as an evaluation index (flatness evaluation index) for evaluating the flatness near the wafer end (edge), ROA (Roll Off Amount: roll-off amount, also called edge roll-off amount) and indicators such as ESFQR are used. In addition, ROA and ESFQR are parameters that represent the accuracy of the wafer outer peripheral surface.

[0016] Furthermore, in recent years, even the periphery of the wafer is required to be flat, and these flatness evaluation indicators require a polishing device capable of performing advanced polishing with a flatness of 10 (nm) or less.

[0017] In addition, the template retaining ring wears and becomes thinner as the number of produced sheets increases, wherein the gradual thinning of the template thickness is explained, and specifically the impact on the polishing accuracy caused by the wear of the retaining ring is explained.

[0018] Fig.14 The following is a model diagram of the polishing amount RR (Removal Rate) of the conventional template under specific processing pressure conditions. The horizontal axis is the wafer radius r, and the vertical axis is the polishing amount RR. (a) is the wafer thickness Wt = 770μm, the retaining ring thickness RRt = 820μm, (b) is Wt = 770μm, RRt = 770μm, and (c) is Wt = 770μm, RRt = 720μm.

[0019] Fig.14 (a) is the ideal form, and the following appears Fig.16 behavioral effect (pressure area diameter < wafer diameter). Fig.14 (b) is consistent with FEM analysis theory. However, Fig.14 In (c), the wafer end is stressed by the perpendicular force of the film tension, and the ESFQR is much worse than the theoretical trend.

[0020] Fig.15 This is an explanatory diagram of the polishing amount RR model based on the "pressing area diameter < wafer diameter" template of Patent Document 1 and Patent Document 3.

[0021] Fig.15 In (a), ESFQR ratio Fig.14 (b) The wafer full pressure state is significantly improved, but Fig.15 (b) With the low friction of the retaining ring, the vertical component of the tension of the film on the wafer edge is pressed, and the ESFQR ratio Fig.15 (a) A little worse.

[0022] like Fig.15 As shown, in the conventional template, it can be seen that the polishing amount RRS changes significantly with the wear of the retaining ring. Therefore, there is a problem that it is difficult to correspond to the accuracy specification in the current polishing process.

[0023] In addition, even if according to Fig.15 The template of Patent Document 1 shown in FIG. 1 is required to further stabilize the polishing amount RR in the current precision standard of polishing processing from the perspective of mass production technology.

[0024] In addition, in the polishing head disclosed in Patent Document 3, a phenomenon of variation in wafer flatness (ESFQR) is observed as processing time increases during polishing.

[0025] The main subject of the present invention is to provide a polishing head and a polishing processing device, which can prevent the occurrence of uneven polishing such as partial under-polishing or over-polishing of the polished surface of the substrate, achieve further improvement of the ESFQR of the substrate surface, and perform high-quality and stable multiple polishing processes.

[0026] Means of solving problems

[0027] The present invention is a polishing processing device, which includes a polishing table and a polishing head, wherein the polishing table includes a polishing pad, and the polishing head holds the polishing processing object-substrate so that its polished surface slides and contacts the polishing pad, and is characterized in that the polishing head includes: a head shell, which includes a first flange portion and a second flange portion, the first flange portion extending outward from a position above the circumference of a cylindrical body, and the second flange portion extending outward from a position below the circumference; an annular body, which is an outer dimension surrounding the second flange portion, and a third flange portion is formed on its upper end portion and is located between the first flange portion and the second flange portion; an elastic body, which covers the lower end side opening of the annular body and holds the substrate by a back film attached to its surface side; a retaining ring, which is a shape surrounding the periphery of the substrate; a driving device, which rotates the head shell, the annular body and the retaining ring horizontally as a whole; the back side of the elastic body is provided with an annular an elastic body, wherein a correction pressure ring for applying pressure to the upper surface of the annular elastic body is arranged inside the annular body; a first pressure regulating device for regulating the pressure of the space surrounded by the head shell, the annular body and the elastic body and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device for regulating the pressure applied to the polishing pad by the retaining ring based on the first flange; a third pressure regulating device for regulating the processing pressure applied to the back side edge of the polished surface by raising or lowering the annular body based on the second flange; a fourth pressure regulating device for regulating the compensation pressure applied to the periphery of the back side of the polished surface through the annular elastic body of the correction pressure ring based on the second flange; a control device for controlling the driving device and the actions of the first, second, third and fourth pressure regulating devices.

[0028] In addition, the polishing head of the present invention is a polishing head provided on a polishing processing device with a horizontally rotating polishing pad, characterized in that it includes: a head shell, which includes a first flange portion and a second flange portion, the first flange portion extending outward from a position above the circumference of the cylindrical body, and the second flange portion extending outward from a position below the circumference; an annular body, which is an outer dimension surrounding the second flange portion, and a third flange portion located between the first flange portion and the second flange portion is formed at its upper end portion; an elastic body covering the lower end side opening of the annular body and holding the substrate by a back film attached to its surface side; a retaining ring, which is a shape surrounding the periphery of the substrate; a driving device, which rotates the head shell, the annular body and the retaining ring horizontally as a whole; an annular elastomer is provided on the back side of the elastomer, and a ring is provided inside the annular body on the upper surface of the annular elastomer A correction pressure ring for applying pressure, a first pressure regulating device, regulating the pressure of the space surrounded by the head shell, the annular body and the elastic body and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, taking the first rim as a reference, regulating the pressure applied by the retaining ring to the polishing pad; a third pressure regulating device, taking the second rim as a reference, raising or lowering the annular body through the third rim, and regulating the pressure applied to the back side edge of the polished surface; a fourth pressure regulating device, taking the second rim as a reference, regulating the compensation pressure applied to the back side periphery of the polished surface through the annular elastic body of the correction pressure ring; a control device, controlling the drive device, the actions of the first, second, third and fourth pressure regulating devices.

[0029] In addition, the polishing method performed by the polishing head of the polishing device provided with a horizontally rotating polishing pad is characterized in that it includes: a first step of applying processing pressure to the back side of the polished surface through the first pressure regulating device, applying pressure to the polishing pad through the second pressure regulating device, raising the annular body through the third pressure regulating device, and relatively reducing the processing pressure of the back side edge of the polished surface compared with the processing pressure of the first pressure regulating device; a second step of stopping the application of the processing pressure of the first pressure regulating device, applying pressure to the polishing pad through the second pressure regulating device, lowering the annular body through the third pressure regulating device, canceling the reduction of the processing pressure of the back side edge of the polished surface, and applying compensation pressure near the periphery of the back side of the polished surface of the fourth pressure regulating device.

[0030] Effects of the Invention

[0031] According to the present invention, a polishing head and a polishing device can be provided which can prevent the occurrence of uneven polishing such as partial under-polishing or over-polishing of the polished surface of the substrate, further improve the ESFQR of the substrate surface, and perform high-quality and stable multiple polishing processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a diagram for explaining an example of a buffing head included in a buffing processing apparatus and its surrounding configuration.

[0033] Figure 2 It is a schematic longitudinal section view for explaining an example of a buffing head included in a buffing processing apparatus and its surrounding configuration.

[0034] Figure 3 (a) Figure 3 (b) Figure 3 (c) is a schematic longitudinal cross-sectional view showing an example of the cross-sectional shape of the annular elastic body (colloid ring).

[0035] Figure 4 (a) Figure 4 (b) is a schematic longitudinal section view showing an example of the cross-sectional shape of the correction pressure ring.

[0036] Figure 5 This is a diagram for explaining "pad pressing" in which the retaining ring presses the polishing pad surface.

[0037] Figure 6 It is a schematic longitudinal section diagram for explaining the rising or falling action of the membrane support ring.

[0038] Figure 7 It is a schematic longitudinal section diagram for explaining the action of the correction pressure ring.

[0039] Figure 8 is a graph showing RR after polishing (dimensionless display).

[0040] Fig. 9 (a) is a graph for explaining a method of making the surface pressures at the extreme end and the center of a wafer consistent, and (b) is a graph showing an example of the relationship between the pressurized area and the stress attenuation at the end.

[0041] Fig.10 (a) Fig.10 (b) is a diagram illustrating an example of a compensating pressure pattern designed based on the spherical earth pressure principle.

[0042] Fig.11 1 is a diagram showing an example of a distribution curve (compensation pressure pattern) of the compensation pressure applied to the vicinity of the periphery on the back side of the polished surface of the wafer W.

[0043] Fig.12This is a flowchart illustrating an example of main control procedures of the control unit when performing the polishing process.

[0044] Fig.13 (a)~ Fig.13 (d) is a description Fig.12 Schematic diagram of the first process and the second process in the process of step S108.

[0045] Fig.14 (a) Fig.14 (b) Fig.14 (c) is an illustration of the polishing amount RR model of the conventional template.

[0046] Fig.15 (a) Fig.15 (b) is an explanatory diagram of the “pressing area diameter < wafer diameter” template polishing amount RR model according to Patent Document 1.

[0047] Fig.16 This is a diagram for explaining the basic concept that concentrated stress at the wafer end can be alleviated.

[0048] Fig.17 It is a schematic longitudinal sectional view for explaining an example of a buffing head and its surrounding configuration included in a buffing processing apparatus according to a modified example.

[0049] Fig.18 (a) Fig.18 (b) is a schematic longitudinal sectional view showing an example of the cross-sectional shape of the first and second annular elastic bodies.

[0050] Fig.19 It is a schematic longitudinal section diagram for explaining the operation of the first and second correction pressure rings. DETAILED DESCRIPTION

[0051] Next, use Fig.16 The basic concept of the present invention is explained.

[0052] The existing polishing head mechanism uniformly applies a stepped processing pressure along the radial direction to the entire area of ​​the wafer (from the center to the outer peripheral end). In particular, the pressurized state of the outer peripheral end has a great impact on ESFQR. For example, the soft pad in the FEM analysis applies a comprehensive and uniform pressure to the wafer. When the Gap value (the distance from the inner periphery of the retaining ring 105 to the end of the wafer W) is a few millimeters, the maximum compressive stress at the end becomes weaker and is 1.5 to 2 times the pressure in the center. In addition, the stress influence range is, taking a 300mm wafer as an example, at a position 15 (mm) away from the end. From the analysis results, it can be seen that if a processing decompression pressure is applied to the outer peripheral end, the stress at the end will be equivalent to that in the center.

[0053] Fig.16This is the result of the analysis of the 300mm wafer with a portion 5mm away from the end as a non-pressurized state (pressurized portion diameter is 290mm). The figure shows that there is displacement, and the settlement displacement of the pad toward the end is about 1 / 2 of the central portion, indicating that the processing pressure has become a decompression pressure. The decompression phenomenon starts to occur near 30mm from the end, and it is judged to be about 6 times the non-pressurized width of 5mm. Based on this principle, the conditions for ESFQR≒0 can be explored by adjusting the diameter of the pressurized portion area, maintaining the ring pressure, and the Gap value.

[0054] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In addition, the polishing device of this embodiment uses a substrate such as a semiconductor wafer or a glass substrate (hereinafter also referred to as a wafer) as a polishing object. In this specification, one surface of the substrate is referred to as a circular or substantially circular polished surface. In addition, the surface of the polishing pad that contacts the polished surface of the wafer is referred to as a polishing surface.

[0055] The polishing processing device has a polishing table to which a polishing member (a polishing pad) is bonded, and is used to horizontally rotate the polishing pad; and a polishing head that faces the polished surface of the substrate to the polishing pad so that the polished surface is in sliding contact with the polishing pad.

[0056] The substrate is pressed against the polishing pad by the polishing head. Then, the polishing table and the polishing head are rotated while supplying a polishing liquid (slurry) to the polishing pad, thereby performing a polishing process on the surface to be polished.

[0057] (Implementation Method)

[0058] Figure 1 Schematic diagram of the structure of the polishing device S of this embodiment.

[0059] Figure 1 The polishing processing apparatus S shown includes a polishing table 51 , to the surface of which a polishing pad 50 is bonded.

[0060] The polishing processing device S also includes: a polishing head 100 that holds the substrate (wafer) W and presses its polished surface onto the polishing pad 50; a nozzle N that supplies polishing liquid to the polishing pad 50; a motor (not shown) that rotates the polishing table 51 and the polishing head 100 horizontally, respectively; a polishing liquid supply mechanism (not shown) connected to the nozzle N; and a control unit 20 that includes an electronic computer for controlling each drive unit including the motor.

[0061] The polishing pad 50 is in the shape of a disk, and its radius is larger than the maximum diameter (diameter) of the polished surface of the wafer W. This mechanism is a mechanism that can change the number of rotations and the direction of rotation of the polishing pad 50 and the polishing head 100 to adjust the relative polishing speed within the surface of the wafer W. In addition, the polishing pad 50 itself has elasticity, and can be made of a material available on the market, such as a non-woven fabric or an object made of polyurethane foam.

[0062] The polishing head 100 includes a holding mechanism and a pressing mechanism, wherein the holding mechanism holds the wafer W in a state where the polished surface thereof is in sliding contact with the polishing pad 50, and the pressing mechanism applies pressure to the held wafer W from the back side (back side) of the polished surface thereof toward the polishing pad 50. The details of these mechanisms will be described later.

[0063] The control unit 20 mainly positions the nozzle N, controls the start or stop of the supply of the polishing liquid from the nozzle N, controls the average supply amount per unit time of the polishing liquid sprayed from the nozzle N, and controls the start and stop of the motor. The rotational force of the motor controlled by the control unit 20 is transmitted to the polishing table 51 through a driving unit not shown in the figure. As a result, the polishing table 51 rotates horizontally or stops rotating.

[0064] The rotational force (torque) of the motor is also transmitted to the polishing head 100 through a driving unit (eg, a universal joint) not shown in the figure. As a result, the polishing head 100 is horizontally rotated or stops rotating.

[0065] Generally, the rotation direction of the polishing table 51 is the same as the rotation direction of the polishing head 100. This is because if the directions are opposite, the relative polishing speed within the wafer surface will become uneven, and it may not be possible to polish uniformly. By making the rotation direction of the polishing table 51 the same as the rotation direction of the polishing head 100 and adjusting the rotation speeds of the two, the polishing accuracy can be improved.

[0066] In addition, the rotational force of a single motor can be transmitted to the polishing table 51 and the polishing head 100 respectively through gears with different gear ratios, or the rotational force can be transmitted respectively through respective motors. Both can be designed arbitrarily. The control steps of the control unit 20 are described later.

[0067] Under the control of the control unit 20 , when the rotation speed of the polishing table 51 reaches a preset value, the polishing liquid is supplied from the nozzle N to the polishing pad 50 for a preset time.

[0068] Next, the buffing head 100 and its surrounding configuration included in the buffing processing apparatus S will be described in detail.

[0069] (Polishing head and its related structural components)

[0070] Figure 2FIG. 1 is a schematic longitudinal section diagram illustrating an example of a polishing head 100 and its related structural components of a polishing processing device S. Figure 2 An example of the structural composition of the polishing head 100 will be described.

[0071] In addition, in the following description, in order to further improve the GBIR (Global backside ideal range) of the wafer surface, the pressure controlled by the polishing processing device S is used to maintain the wafer W in a state where its polished surface is in sliding contact with the polishing pad 50, and pressure is applied to the maintained wafer W from the back side (back side) of its polished surface toward the polishing pad 50.

[0072] (Structural composition of polishing head)

[0073] Figure 2 The polishing head 100 shown is roughly divided into a holding mechanism for applying polishing pressure (processing pressure) to the wafer W to be polished, so that the wafer W is in sliding contact with the polishing pad 50. The polishing head 100 also includes a pressing mechanism for applying polishing pressure (processing pressure) and pressing the holding ring 6 toward the polishing pad 50 side.

[0074] In addition, the holding ring 6 in this embodiment controls the wafer W, which is biased by the rotational force of the polishing head 100 and the polishing table 51, from flying outward. In addition, the contact pressure between the wafer end and the polishing pad 50 is also controlled.

[0075] The polishing head 100 includes a head housing 2 , a membrane support ring 3 , a membrane 4 , a back membrane 5 , a retaining ring 6 , and a flexible plate 7 .

[0076] The polishing head 100 is configured so that a driving force (e.g., a rotational force (torque) of a motor, which is a starter) is transmitted through a flexible plate 7 connected to the head housing 2. Specifically, the flexible plate 7 is connected to the head housing 2, the membrane support ring 3 is connected to the flexible plate 7 (the connection portion is not shown), and the retaining ring 6 is connected to the membrane support ring 3 through a transmission pin 8.

[0077] Thus, the various structural components of the polishing head 100 can be rotated horizontally as a whole, or stop rotating. In this way, the flexible plate 7 functions as a driving device for making the membrane support ring 3 and the retaining ring 6 rotate horizontally as a whole.

[0078] In addition, the control unit 20 controls the start and stop of the rotation, the rotation amount per unit time, and the like based on preset contents.

[0079] The head housing 2 includes a first flange portion 21 extending from an upper position of the circumference of the cylindrical body to the outside and a second flange portion 22 extending from a lower position of the circumference to the outside. Figure 2In FIG. 1 , an example in which the head case 2 , the first flange portion 21 , and the second flange portion 22 are combined and constituted is shown, but the present invention is not limited thereto and they may be integrally formed.

[0080] The membrane support ring 3 is an annular body having a size surrounding the outer periphery of the second flange 22 of the head housing 2, and a third flange 31 is formed at its upper end and located between the first flange 21 and the second flange 22. The membrane support ring 3 is formed of a material such as SUS. Figure 2 An example in which the membrane support ring 3 and the third flange portion 31 are combined is shown, but the invention is not limited thereto and the membrane support ring 3 and the third flange portion 31 may be formed integrally.

[0081] The membrane 4 covers the lower end opening of the membrane support ring 3 and holds the wafer W through the backing film 5 attached to the surface side thereof. The membrane 4 is a cylindrical elastic body having a substantially cylindrical (pot-shaped) structure with an inner diameter that can be embedded in the outer peripheral surface of the membrane support ring 3. The membrane 4 is formed of a rubber material having excellent strength and durability, such as EPDM and silicone rubber.

[0082] The back film 5 is a film-like thin film stretched on the outer bottom surface (outer surface) of the film 4. For example, a porous material such as a non-woven fabric can be used as its material. The back film 5 keeps the polished surface of the wafer W in a face-to-face (contact) and sliding contact state with the polishing pad 50. In this way, the film 4 and the back film 5 serve as a holding mechanism for holding the wafer W.

[0083] The retaining ring 6 is shaped to surround the periphery of the wafer W. The retaining ring 6 controls the wafer W from flying outward toward the periphery due to the rotational force of the polishing head 100 and the polishing table 51 , and also controls the contact pressure between the wafer end and the polishing pad 50 .

[0084] During the polishing process, in the polishing head 100, there is a gap between the end of the wafer W and the inner wall of the inner circumference of the retaining ring 6. In addition, the retaining ring 6 can press the surface of the polishing pad 50 with high accuracy. In this way, the retaining ring 6 functions as a part of the pressing mechanism of the polishing head 100.

[0085] A colloid ring 10 (hereinafter referred to as an annular elastic body 10) is provided on the back side of the film 4 of the polishing head 100, and a correction pressure ring 11 for applying pressure to the upper surface of the annular elastic body 10 is provided inside the film support ring 3 (annular body 3). The structural components of the annular elastic body 10 and the correction pressure ring 11 are described in detail below.

[0086] Figure 3 1 is a schematic longitudinal sectional view showing an example of the cross-sectional shape of the annular elastic body 10 .

[0087] The annular elastic body 10 is an elastic body in the shape of a ring having a relatively small size compared to the size of the wafer W. For example, it may be Figure 3The cross section shown in (a) is a rectangular shape (corresponding to Figure 2 ),like Figure 3 The cross section shown in (b) is relatively wide compared to the width of the upper bottom surface and is roughly trapezoidal in shape. Figure 3 The cross section shown in (c) is generally semicircular in shape or the like.

[0088] The annular elastic body 10 can be formed of, for example, H0-100·C (soft), H5-100·C7 (normal), H15-100·C15 (hard), etc. manufactured by EXSEAL.

[0089] In addition, the hardness of the glue used, the width and height of the glue ring, the shape of the pressure head of the correction pressure ring 11, etc. are selected based on the spherical earth pressure principle described later, and the "compensation pressure mode" of the compensation pressure applied to the periphery (periphery vicinity area) of the back side of the polished surface of the wafer W is determined, and then these shapes are set. In addition, the pressure head shape is the pressing surface shape of the correction pressure ring 11 that presses the upper surface of the annular elastic body 10.

[0090] Figure 4 1 is a schematic longitudinal sectional view showing an example of the cross-sectional shape of the correction pressure ring 11 .

[0091] The correction pressure ring 11 includes a ring-shaped upper surface portion 11b and a lower surface portion 11c, and a plurality of cylindrical connecting portions 11d. The upper surface portion 11b and the lower surface portion 11c are connected by the connecting portions 11d. In addition, the correction pressure ring 11 is held by the flexible plate 7 connected to the membrane support ring 3. Specifically, the connecting portion 11d is movably inserted into the hole portion (not shown) of the flexible plate 7, and the correction pressure ring 11 is held.

[0092] The pressing surface shape of the correction pressure ring 11 can be as follows Figure 4 (a) shows a flat pressing surface shape (corresponding to Figure 2 ),like Figure 4 The cross section shown in (b) is a pressing surface shape that is approximately semicircular.

[0093] In addition, the pressing surface shape of the correction pressure ring 11 is a combination of the hardness of the glue used and the width and height of the glue ring. It is designed based on the spherical earth pressure principle described later. After determining the "compensation pressure mode" of the compensation pressure applied to the back side of the polished surface of the wafer W near the periphery (the area near the periphery), its shape is specified.

[0094] (Pressing mechanism)

[0095] like Figure 2As shown, in the polishing head 100, the space formed by the second flange 22 of the head housing 2, the membrane support ring 3 (annular body 3) and the membrane 4 is a pressure chamber (a sealed air chamber), and the pressure chamber applies pressure to the wafer W from the back side (back side) of the polished surface thereof toward the polishing pad 50. The pressure chamber formed in the polishing head 100 is a space corresponding to the area on the membrane 4 projected by the back membrane 5, and the back membrane 5 is mounted on the membrane 4.

[0096] The second flange portion 22 of the head case 2 and the membrane support ring 3 (annular body 3) are connected via the sealing partition 12. The sealing partition 12 is formed of an elastic body such as rubber.

[0097] In the polishing head 100 of the polishing processing device S, a pressure fluid (such as compressed air) can be supplied to the pressure chamber or the supplied pressure fluid can be recovered through an air pipe connected to a fluid supply mechanism (not shown). Figure 2 The amount of processing pressure P1 applied to the wafer W can be generated.

[0098] These structures, through the control unit 20, function as a first pressure regulating device for regulating the pressure of the space (pressure chamber) surrounded by the head shell 2 (second flange portion 22), the membrane support ring 3 and the membrane 4, and regulating the processing pressure P1 applied to the back side of the polished surface of the wafer W.

[0099] Figure 5 This is a diagram for explaining “pad pressing” in which the surface of the polishing pad 50 is pressed by the retaining ring 6 .

[0100] like Figure 2 As shown, in the polishing head 100 of the polishing processing device S, an air bag P2 is provided between the first flange portion 21 of the head housing 2 and the retaining ring 6 .

[0101] In addition, if Figure 2 As shown, in the polishing head 100 of the polishing processing device S, a pressure fluid (such as compressed air) can be supplied to the air bag P2 or the supplied pressure fluid can be recovered through an air pipe connected to a fluid supply mechanism (not shown). Figure 2 The amount of pressure P2 (shown by the dotted line P2) can generate a pressure P2 pressing the surface of the polishing pad 50 through the retaining ring 6.

[0102] The air bag P2 is formed into a ring shape, and the pressure fluid is sealed in the air bag P2 to expand. Figure 5 As shown, the retaining ring 6 can press the polishing pad 50 by the pressure P2 corresponding to the amount of the sealed pressure fluid.

[0103] These structural components function as a second pressure regulating device for regulating the amount of pressure fluid supplied to the air bag P2 by the control unit 20, and regulating the pressure P2 applied by the retaining ring 6 to the polishing pad 50 based on the first flange portion 21. In other words, the second pressure regulating device can also be called a structure for optimizing the stress at the end of the wafer.

[0104] Figure 6 It is a schematic longitudinal sectional view for explaining the rising or falling action of the membrane support ring 3.

[0105] like Figure 2 As shown, in the polishing head 100 of the polishing processing device S, an air bag P3 is provided between the second flange portion 22 of the head housing 2 and the third flange portion 31 of the membrane support ring 3 .

[0106] In addition, if Figure 2 As shown, in the polishing head 100 of the polishing processing device S, a pressure fluid (such as compressed air) can be supplied to the air bag P3 or the supplied pressure fluid can be recovered through an air pipe connected to a fluid supply mechanism (not shown). Figure 2 The amount of the dotted line P3) shown allows the membrane support ring 3 to be raised or lowered.

[0107] The air bag P3 is formed into a ring shape, and the pressure fluid is sealed in the air bag P3 to expand. Figure 6 As shown, according to the amount of sealed pressure fluid, the membrane support ring 3 rises ( Figure 2 ),decline( Figure 6 ). That is, as the membrane support ring 3 rises or falls, the membrane 4 and the back membrane 5 also rise or fall accordingly.

[0108] As the film 4 and the back film 5 are raised or lowered in association with the raising or lowering of the film support ring 3, the area in the edge region of the wafer W where the back film 5 contacts changes. According to this change, the processing surface pressure applied to the back side edge of the polished surface of the wafer W also changes accordingly (see Figure 2 , Figure 6 , Fig.16 ).

[0109] In addition, the outer periphery of the film 4 is lifted by the air bag P3, so that an area where the processing surface pressure is applied (referred to as a pressure circumferential area) and an area where the processing surface pressure is not applied (referred to as a non-pressure circumferential area) are formed on the outer periphery of the wafer W. The annular elastic body 10 is provided at the boundary between the pressure circumferential area and the non-pressure circumferential area in the film 4 and the wafer W (refer to Fig.11 The center of the bottom surface of the annular elastic body 10 matches the interface. Thus, by configuring the annular elastic body 10, the principle mechanism of ESFQR≒0, which is impossible with the existing polishing head, can be studied clearly, and the GBIR can also be greatly improved.

[0110] These components function as a third pressure regulating device. These components regulate the processing pressure applied to the back side of the polished surface of the wafer W by the control unit 20, and by regulating the amount of pressure fluid supplied to the air bag P3, thereby regulating the pressurized area P1' applied to the back side edge of the polished surface by the third flange 31 with the second flange 22 as the reference.

[0111] In addition, the polishing head 100 of the polishing processing device S includes a stopper 13 that controls the film support ring 3 to be raised to a preset range. The stopper 13 is composed of, for example, a screw.

[0112] Figure 7 It is a schematic longitudinal sectional view for explaining the operation of the correction press ring 11.

[0113] As mentioned above, the back side of the film 4 of the polishing head 100 is provided with an annular elastic body 10, and a correction pressure ring 11 for applying pressure is provided on the upper surface of the annular elastic body 10. Figure 7 As shown, an air bag P4 is provided between the second flange portion 22 of the head shell 2 and the correction pressure ring 11 .

[0114] In addition, if Figure 2 As shown, in the polishing head 100 of the polishing treatment device S, a pressure fluid (such as compressed air) can be supplied to the air bag P4 or the supplied pressure fluid can be recovered through an air pipe connected to a fluid supply mechanism (not shown). Figure 2 The amount of the dotted line P4) shown makes it possible to correct the rising or falling action of the pressure ring 11.

[0115] In addition, in this embodiment, the lifting action of the correction pressure ring 11 is lifted by the elastic deformation force of the spring 11a.

[0116] The air bag P4 is formed into a ring shape, and the pressure fluid is sealed in the air bag P4 to expand. Figure 7 As shown, according to the amount of sealed pressure fluid, the correction pressure ring 11 rises ( Figure 2 ),decline( Figure 6 ). That is, according to the rising or falling action of the membrane support ring 3, the pressure applied to the upper surface of the annular elastic body 10 also changes accordingly.

[0117] The pressure applied to the upper surface of the annular elastic body 10 changes with the rising or falling action of the correction pressure ring 11. According to this change, the compensation pressure pattern of the compensation pressure P4 applied to the periphery (periphery vicinity area) of the back side of the polished surface of the wafer W also changes accordingly (refer to Figure 2 , Figure 7 ).

[0118] These structural components function as a fourth pressure regulating device. The fourth pressure regulating device adjusts the amount of pressure fluid supplied to the air bag P4 in the processing pressure applied to the back side of the polished surface of the wafer W through the control unit 20, and adjusts the compensation pressure P4 applied to the periphery (peripheral vicinity area) of the back side of the polished surface with the second flange 22 as a reference.

[0119] (Polishing)

[0120] Next, the polishing process performed by the polishing process apparatus S according to the present embodiment will be described.

[0121] According to the polishing process performed by the polishing processing apparatus S of this embodiment, the operating conditions (processing conditions) are first determined according to the characteristics of a certain batch of wafers and the state of the polishing processing apparatus, and then the wafer polishing process (mass production) is continuously performed according to the operating conditions.

[0122] Next, the procedure for determining the operating conditions (processing conditions) will be described.

[0123] (Determination of pressure P2)

[0124] Figure 8 RR curves of the wafer end before and after polishing are shown. The vertical axis represents the polishing amount RR (Removal Rate) (μm / min) dimensionlessly, and the horizontal axis represents the diameter of the wafer (mm). In this embodiment, ΔRR=0.2 was observed.

[0125] As a first step, the air bag P3 is set to a pressure-free state where no pressure fluid is supplied. At this time, the membrane support ring 3 is in a lowered state (refer to Figure 6 ). In addition, the air bag P4 is set to a pressure-free state in which no pressure fluid is supplied. At this time, the correction ring 11 is in a state in which no pressing force is applied to the upper surface of the annular elastic body 10.

[0126] Then, while applying the process pressure P1 to the wafer W, the pressure P2 at which the holding ring 6 presses the surface of the polishing pad 50 is adjusted so as to satisfy RR=1.2 (Pr=1.75*P1). In this embodiment, ΔRR=0.2 is observed.

[0127] in addition, Figure 8 The ΔRR shown fluctuates greatly due to the Gap. In addition, the Gap fluctuates between 0 and 1 (mm) per rotation in the rotation axis of the wafer. Therefore, it is more accurate to obtain the average behavior of ΔRR from actual operation data rather than measuring it on a static surface pressure plate.

[0128] (Compensation curve)

[0129] Fig. 9 (a) is a graph for explaining a method of making the surface pressures at the end and center of a wafer equal. The vertical axis represents the polishing amount RR (Removal Rate) (μm / min) in a dimensionless manner, and the horizontal axis represents the diameter of the wafer (mm).

[0130] from Fig. 9 As can be seen from the graph in (a), the compensation curve of the solid black line is obtained from the overall average behavior of the dashed black line (polishing RR) and the dotted black line (pressure decay).

[0131] in addition, Fig. 9 (b) is a diagram showing an example of the relationship between the pressurized area and the end stress attenuation, and is a graph showing the curve of the back contact area of ​​the film and the wafer, that is, the radius of the load surface pressure diameter (PAR) and the end stress attenuation. The vertical axis represents the polishing amount RR (Removal Rate) (μm / min) dimensionlessly, and the horizontal axis represents the diameter of the wafer (mm).

[0132] (Position adjustment of the lifting action of the membrane support ring 3 (H))

[0133] As a second step, pressure fluid is supplied to the air bag P3. At this time, the membrane support ring 3 is raised (refer to Figure 2 ). The membrane support ring 3 is controlled to rise to the stopper 13 within the preset range (position adjustment: height H), and the adjustment is performed to satisfy RR=1.0 at the edge point. In addition, the air bag P4 is still in a pressure-free state where no pressure fluid is supplied.

[0134] This adjustment can be performed by measuring H vs RR (DL) using a surface pressure plate. H can be measured using, for example, LS-100CN manufactured by Optex.

[0135] Fig.10 This is a diagram for explaining an example of a compensating pressure pattern designed based on the spherical earth pressure principle. Fig.10 (a) shows an example of the range in which the load (surface pressure width; B·pressure per unit area: q) and stress act according to the spherical earth pressure principle. Fig.10 (b) shows an example of a compensated pressure mode based on the spherical earth pressure principle.

[0136] like Fig.10 As shown, the compensation pressure P4 generated by the correction pressure ring 11 and applied to the periphery (peripheral vicinity area) of the back side of the polished surface of the wafer W through the annular elastic body 10 propagates in the spherical earth pressure behavior to form a compensation pressure mode.

[0137] In addition, the compensation pressure mode can be measured using, for example, I-SCAN·20-F02 (resolution pitch: 0.2 (mm)) manufactured by Tekscan.

[0138] Fig.11 FIG. 1 is a diagram showing an example of a distribution curve (compensation pressure pattern) of the compensation pressure applied to the vicinity of the periphery (periphery vicinity region) of the back side of the polished surface of the wafer W (compensation pressure Fig. 9 (a) shows the concave portion of the black solid line.) The vertical axis shows the polishing amount RR (Removal Rate) (μm / min) in a dimensionless manner, and the horizontal axis shows the diameter of the wafer (mm).

[0139] like Fig.11 As shown, through the first step and the second step, the compensation pressure mode of the compensation pressure P4 is determined. The compensation pressure mode of the compensation pressure P4 is generated according to the correction pressure ring 11, and the compensation pressure P4 is applied to the periphery of the back side of the polished surface of the wafer W (the periphery vicinity area) through the annular elastic body 10.

[0140] (Polishing process control steps)

[0141] Next, a processing procedure of the polishing apparatus S according to the present embodiment will be described. Fig.12 1 is a flowchart for explaining an example of the main control steps of the control unit 20 when performing the polishing process. The process steps explained below are steps for continuously performing the polishing process (mass production) of wafers based on the above-mentioned operating conditions.

[0142] The control unit 20 starts control (S100) upon receiving a start instruction input by an operator of the polishing device S. In addition, as an operating condition, a compensation pressure pattern for obtaining the compensation pressure P4 has been completed. The compensation pressure pattern is a compensation pressure P4 applied to the vicinity of the periphery (peripheral vicinity region) of the back side of the polished surface of the wafer W by the correction pressure ring 11 of the annular elastic body 10.

[0143] After the preset initial processing, the control unit 20 starts holding the wafer W by the holding mechanism of the polishing head 100 ( S101 ).

[0144] The control unit 20 holds the wafer W from a wafer transfer stage (not shown) and moves the polish head 100 to a start position of the polishing process ( S102 ).

[0145] The control unit 20 supplies a preset amount of pressure fluid to the pressure chamber, the air bag P2, and the air bag P3, respectively, to prepare the processing pressure P1, the pressurized area P1', and the pressure P2 (S103).

[0146] When the control unit 20 confirms that each pressure according to the supply amount of the pressure fluid is appropriate (S104: Yes), it issues an instruction to the motor (not shown) (S105) to start the rotation of the polishing table 51 and the polishing head 100. Thus, the polishing table 51 and the polishing head 100 start to rotate horizontally.

[0147] After instructing the polishing table 51 and the polishing head 100 to start rotating, the control unit 20 instructs the nozzle N to position and issues an instruction to the polishing liquid supply mechanism to start supplying the polishing liquid (S106). As a result, the polishing liquid is supplied from the nozzle N to the surface of the polishing pad 50. In this way, the control unit 20 starts polishing (S107).

[0148] The control unit 20 starts pressure adjustment of the machining pressure based on the operating conditions (S108). The pressure adjustment in the process of step S108 will be described below. The pressure adjustment in the process of step S108 is roughly divided into a first process and a second process.

[0149] In the first step, the control unit 20 applies a processing pressure P1 to the back side of the polished surface of the wafer W through the aforementioned first pressure regulating device, applies a pressure P2 to the polishing pad 50 through the aforementioned second pressure regulating device, and raises the membrane support ring 3 through the aforementioned third pressure regulating device to adjust the pressure area P1', respectively, so that the processing pressure at the back side edge of the polished surface is relatively reduced compared to the processing pressure P1 according to the first pressure regulating device. At this time, the control unit 20 controls the air bag P4 to be in a non-pressure state where no pressure fluid is supplied.

[0150] In the second process, the control unit 20 stops applying the processing pressure P1 through the aforementioned first pressure regulating device, applies pressure P2 to the polishing pad 50 through the aforementioned second pressure regulating device, lowers the membrane support ring 3 through the aforementioned third pressure regulating device to release the reduced state of the processing pressure at the back side edge of the polished surface (the state of the pressurized area P1′), and applies a compensation pressure P4 near the periphery of the back side of the polished surface of the wafer W (the area near the periphery) through the aforementioned fourth pressure regulating device.

[0151] In addition, the first step and the second step are switched by an internal sequence while the polishing table 51 and the polishing head 100 are kept rotating.

[0152] Then, the control unit 20 determines whether polishing is completed (S109). This determination is based on, for example, the detection result of the sensor. When it is determined that the wafer W is polished to a desired thickness, polishing is completed. Otherwise, when the determination is negative (S109: No), the process returns to step S108.

[0153] When the control unit 20 determines that the polishing is completed (S109: Yes), it instructs the polishing liquid supply mechanism to stop supplying the polishing liquid (S110).

[0154] Afterwards, the control unit 20 issues a stop instruction to the motor to stop the rotation of the polishing table 51 and the polishing head 100 (S111). Afterwards, the polishing head 100 is moved to the table surface carrying the polished wafer W (S112). Thus, a series of polishing processes are completed.

[0155] In addition, the judgment of whether to release the hold can also be sensed by various sensors, such as those not shown. In addition, after the rotation of the polishing table 51 and the polishing head 100 is stopped, the supplied pressure fluid can also be recovered. Through such control, the polished wafer W can be prevented from accidentally falling off during transportation.

[0156] Fig.13 It is used to illustrate Fig.12 Schematic diagram of the first process and the second process in the process of step S108.

[0157] Fig.13 (a) and (b) show the first step. Fig.13 (c) and (d) show the second step. As shown by the arrows in the figure, the first step and the second step are carried out in a series of steps from (a) to (b), (b) to (c), and (c) to (d).

[0158] In the first step, a processing pressure P1 is applied to the back side of the polished surface of the wafer W, a pressure P2 is applied to the polishing pad 50, and the film support ring 3 is raised to adjust the pressure area P1' to a state where the processing pressure at the back side edge of the polished surface is relatively lower than the processing pressure P1. In addition, the air bag P4 is in a non-pressure state where no pressure fluid is supplied.

[0159] like Fig.13 As shown in (a), in the first step, as the pressure area is reduced, Fig.13 (b) The end convexity phenomenon shown.

[0160] In the second step, the application of the processing pressure P1 is stopped, pressure P2 is applied to the polishing pad 50, the membrane support ring 3 is lowered, the reduced state of the processing pressure at the back side edge of the polished surface is released (the state of the pressurized area P1′), and a compensation pressure P4 based on a compensation pressure mode of operating conditions is applied near the periphery of the back side of the polished surface of the wafer W (the area near the periphery).

[0161] like Fig.13 As shown in (c), in the second step, a partial correction pressure is applied by using a compensation pressure P4 of a compensation pressure pattern based on the operating conditions. Then, the pressure P2 ( Fig.13 (d)), the processing of the second step is completed.

[0162] According to the polishing head 100 of the present embodiment and the polishing processing device S having the same, high-quality and stable polishing processing can be performed by adjusting and controlling the processing pressure P1, the pressurized area P1', the pressure P2, and the compensation pressure P4. In addition, the occurrence of uneven polishing such as partial under-polishing or over-polishing of the polished surface of the substrate can be prevented, thereby further improving the ESFQR of the substrate surface.

[0163] In addition, the present embodiment provides a polishing head 100 and a polishing processing device S having the same, wherein a non-pressurized area is set at the end of the wafer to reduce the increase in the end surface pressure when the entire area is pressurized, and a compensating pressure is applied to the surface pressure uneven portion to balance the surface pressure at the end of the wafer.

[0164] (Variation Example)

[0165] In the polishing head 100 and the polishing apparatus S having the same described in the embodiment, the same reference numerals are used for the same components as those described above, and the description thereof will be omitted.

[0166] Fig.17 1 is a schematic longitudinal section view of an example of a polishing head 200 and its related structural components of a polishing processing device S according to a modified example. Fig.17 An example of the structural composition of the polishing head 200 will be described.

[0167] In addition, in the following description, in order to further improve the GBIR (Global backside ideal range) of the wafer surface, the wafer W is held in a state where its polished surface is in sliding contact with the polishing pad 50 under the pressure controlled by the polishing processing device S, and pressure is applied to the held wafer W from the back side (back side) of its polished surface toward the polishing pad 50.

[0168] (Polishing head processing components)

[0169] Fig.17 The polishing head 200 shown is roughly divided into a holding mechanism for applying polishing pressure (processing pressure) to the wafer W to be polished, so that the wafer W is in sliding contact with the polishing pad 50. The polishing head 200 also includes a pressing mechanism for applying polishing pressure (processing pressure) and pressing the holding ring 6 toward the polishing pad 50 side.

[0170] The polishing head 200 includes a head housing 40 , a membrane support ring 3 , a membrane 4 , a back membrane 5 , a retaining ring 6 , and a flexible plate 7 .

[0171] The polishing head 200 is configured so that a driving force (e.g., a rotational force (torque) of a motor, which is a starter) is transmitted through the flexible plate 7 connected to the head housing 40. Specifically, the flexible plate 7 is connected to the head housing 40, the membrane support ring 3 is connected to the flexible plate 7 (the connection portion is not shown), and the retaining ring 6 is connected to the membrane support ring 3 through the transmission pin 8.

[0172] Thus, the various structural components of the polishing head 200 can be rotated horizontally as a whole, or stop rotating. In this way, the flexible plate 7 functions as a driving device for making the membrane support ring 3 and the retaining ring 6 rotate horizontally as a whole.

[0173] In addition, the control unit 20 controls the start and stop of the rotation, the rotation amount per unit time, and the like based on preset contents.

[0174] The film support ring 3 is an annular body having an inner diameter of a size surrounding the outer periphery of the substrate (wafer W) to be polished. The film support ring 3 is connected to the head housing 40. The film support ring 3 is formed of a material such as SUS.

[0175] The film 4 covers the lower end opening of the film support ring 3 , and holds the wafer W via a backing film 5 attached to the surface side thereof.

[0176] The membrane 4 is a cylindrical elastic body having a substantially cylindrical (pot-shaped) structure with an inner diameter capable of being fitted into the outer peripheral surface of the membrane support ring 3. The membrane 4 is formed of a rubber material having excellent strength and durability, such as EPDM and silicone rubber.

[0177] The back film 5 is a film-like thin film stretched on the outer bottom surface (outer surface) of the film 4. For example, a porous material such as a non-woven fabric can be used as its material. The back film 5 keeps the wafer W in a state where the polished surface and the polishing pad 50 face each other (contact) and are in sliding contact. In this way, the film 4 and the back film 5 serve as a holding mechanism for holding the wafer W.

[0178] The retaining ring 6 is shaped to surround the periphery of the wafer W. The retaining ring 6 controls the wafer W from flying outward toward the periphery due to the rotational force of the polishing head 200 and the polishing table 51 , and also controls the contact pressure between the wafer end and the polishing pad 50 .

[0179] A gel ring 30 a (first annular elastic body 30 a ) and a gel ring 30 b (second annular elastic body 30 b ) are provided on the back side of the film 4 of the polishing head 200 .

[0180] Furthermore, a first correction pressure ring 31 a for applying pressure to the first annular elastic body 30 a and a second correction pressure ring 31 b for applying pressure to the upper surface of the second annular elastic body 30 b are provided inside the membrane support ring 3 (annular body 3 ).

[0181] like Fig.17 As shown, in the polishing head 200, a pressure fluid (such as compressed air) can be supplied to the air bag P4 or the supplied pressure fluid can be recovered through an air pipe connected to a fluid supply mechanism (not shown). Fig.17 The amount of the dotted line P4) shown makes it possible to raise or lower the first and second correction pressure rings.

[0182] In addition, if Fig.17 In the polishing head 200 shown, as an example, the first and second correction pressure rings are raised or lowered by the spring 31c. The composition of the correction pressure ring is described in detail below.

[0183] Fig.18 The figure is a schematic longitudinal section diagram showing an example of the cross-sectional shape of the first and second annular elastic bodies.

[0184] Fig.19 It is a schematic longitudinal section diagram for explaining the actions of the first and second correction pressure rings.

[0185] As mentioned above, the annular elastic body of the polishing head 200, such as Fig.17 As shown, it is divided into a first annular elastic body 30a on the inner peripheral side and a second annular elastic body 30b on the outer peripheral side.

[0186] In addition, the correction pressure ring of the polishing head 200 includes a first correction pressure ring 31a that applies pressure to the first annular elastic body 30a, and a second correction pressure ring 31b that applies pressure to the second annular elastic body 30b.

[0187] Therefore, if Fig.19 As shown, in the compensation pressure applied to the vicinity of the periphery (area near the periphery) of the back side of the polished surface, the compensation pressure is applied to the inner peripheral side by the first annular elastic body 30a, and the compensation pressure is applied to the outer peripheral side by the second annular elastic body 30b.

[0188] In addition, a deformation prevention ring 33 is provided between the first annular elastic body 30a and the second annular elastic body 30b to reduce the influence of the deformation of the first annular elastic body 30a and the deformation of the second annular elastic body 30b on each other when the compensation pressure is applied.

[0189] In addition, in the previously described embodiment (polishing head 100), the annular elastic body 10 and its bottom center are combined and arranged at the boundary between the pressure circumferential area and the non-pressure circumferential area in the film 4 and the wafer W (refer to Fig.11 In the polishing head 200 of this modified example, the deformation prevention ring 33 is set at the intersection position. Therefore, the principle mechanism of ESFQR≒0 that is impossible for the existing polishing head can be studied and explored, and the GBIR can also be greatly improved.

[0190] like Fig.18 As shown in (a), the first annular elastic body 30a is in a trapezoidal shape with an inclined side surface on the inner peripheral side.

[0191] The second annular elastic body 31 b has a trapezoidal shape with an inclined side surface on the outer side. In addition, the second annular elastic body 31 b has a relatively small size compared to the size of the wafer W.

[0192] In addition, if Fig.18 As shown in (a), the first correction pressure ring 31a covers all or part of the inclined surface (the side surface on the inner circumference side) of the first annular elastic body 30a.

[0193] The second correction pressure ring 31b covers all or part of the inclined surface (side surface on the outer peripheral side) of the second annular elastic body 30b. Fig.18 (b)). Thus, the omission of the compensation pressure due to the deformation of the first annular elastic body 30a and the deformation of the second annular elastic body 30b when the compensation pressure is applied can be reduced. That is, while the compensation pressure applied according to the pressure of the fourth pressure regulating device is conveniently adjusted, the pressure can be more appropriately applied to the periphery of the back side of the polished surface of the wafer W (the periphery vicinity area).

[0194] In addition, if Fig.18 As shown in (a), the first correction pressure ring 31a covers the upper surface of the first annular elastic body 30a, and while applying pressure from the fourth pressure adjustment device, the pressure of the space surrounded by the head housing 40, the first correction pressure ring 31a and the elastic body (film 4) is adjusted, and the processing pressure P1 applied to the back side of the polished surface is also applied to the upper surface of the first annular elastic body 30a. In this way, the first correction pressure ring 31a can apply the processing pressure P1 to the back side of the polished surface of the wafer W through the bottom surface of the first annular elastic body 30a by covering the upper surface of the first annular elastic body 30a.

[0195] In the pressure adjustment process (step: S108) of applying the compensation pressure P4 of the compensation pressure pattern based on the operating conditions to the vicinity of the periphery (periphery vicinity) of the back side of the polished surface of the wafer W, the compensation pressure in the vicinity of the deformation prevention ring 33 can be easily adjusted by the first annular elastic body 30a and the second annular elastic body 30b (refer to Fig.19 ).

[0196] The embodiments described above are for more specific description of the present invention, and the scope of the present invention is not limited to these examples.

[0197] Description of Reference Numerals

[0198] 2. 40 head shell

[0199] 3 membrane support ring

[0200] 4. Film

[0201] 5 back film

[0202] 6Retaining ring

[0203] 7 Flexible board

[0204] 20. Control Unit

[0205] 50 polishing pads

[0206] 51 Polishing Table

[0207] 100, 200 polishing head

[0208] S Polishing Device

[0209] N Nozzle

[0210] W Wafer

Claims

1. A polishing device, comprising: A polishing table including a polishing pad; a polishing head holding a substrate to be polished and bringing the polished surface of the substrate into sliding contact with the polishing pad; Characterized in that the polishing head comprises: The head housing includes a first flange portion extending from an upper position of the circumference of the cylindrical body to the outside and a second flange portion extending from a lower position of the circumference to the outside; an annular body having a size surrounding the periphery of the second flange portion, wherein an upper end portion of the annular body is formed with a third flange portion located between the first flange portion and the second flange portion; An elastic body covering the lower end opening of the annular body and holding the substrate via a backing film attached to the surface side of the elastic body; a retaining ring having a shape surrounding a periphery of the substrate; A driving device for horizontally rotating the head housing, the annular body and the retaining ring as a whole; An annular elastic body is disposed on the back side of the elastic body, and a correction pressure ring is disposed inside the annular body to apply pressure to the upper surface of the annular elastic body. a first pressure regulating device for regulating the pressure of a space enclosed by the head housing, the annular body and the elastic body, and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, based on the first flange portion, regulating the pressure applied by the retaining ring to the polishing pad; a third pressure regulating device, based on the second flange, raising or lowering the annular body through the third flange to regulate the processing pressure applied to the back side edge of the polished surface; a fourth pressure regulating device, based on the second flange portion, regulating the compensation pressure applied to the vicinity of the periphery of the back side of the polished surface through the annular elastic body of the correction pressure ring; A control device, controlling the actions of the driving device, the first pressure regulating device, the second pressure regulating device, the third pressure regulating device, and the fourth pressure regulating device; The control device, In the first step, the first pressure regulating device is controlled to apply a processing pressure to the back side of the polishing surface, the second pressure regulating device is controlled to apply pressure to the polishing pad, and the third pressure regulating device is controlled to raise the annular body, so that the processing pressure at the back side edge of the polished surface is relatively reduced compared with the processing pressure of the first pressure regulating device. In the second process, the first pressure regulating device is controlled to stop applying processing pressure, the second pressure regulating device is controlled to apply pressure to the polishing pad, the third pressure regulating device is controlled to lower the annular body to release the reduction in processing pressure at the edge near the periphery of the back side of the polished surface, and the fourth pressure regulating device is controlled to apply compensation pressure near the periphery of the back side of the polished surface.

2. The polishing device according to claim 1, characterized in that: The second pressure regulating device regulates the pressure fluid flowing into the air bag disposed between the first flange portion and the retaining ring through the control device, thereby regulating the pressure applied by the retaining ring to the polishing pad.

3. The polishing device according to claim 1 or 2, characterized in that: The third pressure regulating device adjusts the pressure fluid flowing into the air bag arranged between the second flange portion and the third flange portion through the control device, raises or lowers the annular body, and adjusts the pressurized area applied to the back side edge of the polished surface.

4. The polishing device according to claim 1 or 2, characterized in that: The fourth pressure regulating device regulates the pressure fluid flowing into the air bag arranged between the third flange and the correction pressure ring through the control device, and regulates the compensation pressure applied from the annular elastic body to the vicinity of the outer periphery of the back side of the polished surface.

5. The polishing device according to claim 1 or 2, characterized in that: The invention comprises a control device for controlling the raising of the annular body to a predetermined range according to the third pressure regulating device.

6. The polishing device according to claim 1 or 2, characterized in that: The size of the annular elastic body is relatively small compared with the size of the base plate.

7. The polishing device according to claim 1 or 2, characterized in that: The annular body is connected to a flexible plate, the flexible plate is connected to the head shell, and the retaining ring is connected to the annular body via a transmission pin shaft.

8. A polishing head, provided on a polishing processing device having a horizontally rotating polishing pad, and holding a substrate as a polishing processing object, and slidingly contacting the polished surface of the substrate onto the polishing pad, characterized in that: include: The head housing includes a first flange portion extending from an upper position of the circumference of the cylindrical body to the outside and a second flange portion extending from a lower position of the circumference to the outside; an annular body having a size surrounding the periphery of the second flange portion, wherein an upper end portion of the annular body is formed with a third flange portion located between the first flange portion and the second flange portion; An elastic body covering the lower end opening of the annular body and holding the substrate via a backing film attached to the surface of the elastic body; a retaining ring having a shape surrounding a periphery of the substrate; A driving device for horizontally rotating the head housing, the annular body and the retaining ring as a whole; An annular elastic body is disposed on the back side of the elastic body, and a correction pressure ring is disposed inside the annular body to apply pressure to the upper surface of the annular elastic body. a first pressure regulating device for regulating the pressure of a space enclosed by the head housing, the annular body and the elastic body, and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, using the first flange as a reference, to regulate the pressure applied by the retaining ring to the polishing pad; a third pressure regulating device, taking the second flange as a reference, raising or lowering the annular body through the third flange to adjust the pressure area applied to the back side edge of the polished surface; a fourth pressure regulating device, which uses the second flange as a reference and adjusts the compensation pressure applied to the vicinity of the periphery of the back side of the polished surface through the annular elastic body of the correction pressure ring; A control device, controlling the actions of the driving device, the first pressure regulating device, the second pressure regulating device, the third pressure regulating device, and the fourth pressure regulating device; The control device, In the first step, the first pressure regulating device is controlled to apply a processing pressure to the back side of the polishing surface, the second pressure regulating device is controlled to apply pressure to the polishing pad, and the third pressure regulating device is controlled to raise the annular body, so that the processing pressure at the back side edge of the polished surface is relatively reduced compared with the processing pressure of the first pressure regulating device. In the second process, the first pressure regulating device is controlled to stop applying processing pressure, the second pressure regulating device is controlled to apply pressure to the polishing pad, the third pressure regulating device is controlled to lower the annular body to release the reduction in processing pressure at the edge near the periphery of the back side of the polished surface, and the fourth pressure regulating device is controlled to apply compensation pressure near the periphery of the back side of the polished surface.

9. A polishing method, The polishing head is provided on a polishing processing device having a horizontally rotating polishing pad, and holds a substrate to be polished, and slides the polished surface of the substrate onto the polishing pad. It is characterized in that The polishing head comprises: The head housing includes a first flange portion extending from an upper position of the circumference of the cylindrical body to the outside and a second flange portion extending from a lower position of the circumference to the outside; an annular body having a size surrounding the periphery of the second flange portion, wherein an upper end portion of the annular body is formed with a third flange portion located between the first flange portion and the second flange portion; An elastic body covering the lower end opening of the annular body and holding the substrate via a backing film attached to the surface of the elastic body; a retaining ring having a shape surrounding a periphery of the substrate; A driving device for horizontally rotating the head housing, the annular body and the retaining ring as a whole; An annular elastic body is disposed on the back side of the elastic body, and a correction pressure ring is disposed inside the annular body to apply pressure to the upper surface of the annular elastic body. a first pressure regulating device for regulating the pressure of a space enclosed by the head housing, the annular body and the elastic body, and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, based on the first flange portion, regulating the pressure applied by the retaining ring to the polishing pad; a third pressure regulating device, based on the second flange, raising or lowering the annular body through the third flange to regulate the processing pressure applied to the back side edge of the polished surface; a fourth pressure regulating device, based on the second flange portion, regulating the compensation pressure applied to the vicinity of the periphery of the back side of the polished surface through the annular elastic body of the correction pressure ring; A control device, controlling the actions of the driving device, the first pressure regulating device, the second pressure regulating device, the third pressure regulating device, and the fourth pressure regulating device; The polishing method comprises: In a first step, the control device controls the first pressure regulating device to apply a processing pressure to the back side of the polished surface, controls the second pressure regulating device to apply pressure to the polishing pad, and controls the third pressure regulating device to raise the annular body, so as to relatively reduce the processing pressure at the back side edge of the polished surface compared with the processing pressure according to the first pressure regulating device; In the second step, the control device controls the first pressure regulating device to stop applying the processing pressure, controls the second pressure regulating device to apply pressure to the polishing pad, controls the third pressure regulating device to lower the annular body to release the reduction of the processing pressure on the back side edge of the polished surface, and controls the fourth pressure regulating device to apply compensation pressure near the periphery of the back side of the polished surface.

10. A polishing device, comprising: A polishing table, the polishing table comprising a polishing pad; a polishing head, holding a substrate as a polishing object, and bringing the polished surface of the substrate into sliding contact with the polishing pad; Characterized in that the polishing head comprises: Head housing; an annular body having an inner circumference of a size surrounding the periphery of the substrate to be polished, and connected to the head housing; An elastic body covering the lower end opening of the annular body and holding the substrate via a backing film attached to the surface of the elastic body; a retaining ring having a shape surrounding a periphery of the substrate; A driving device for horizontally rotating the head housing, the annular body and the retaining ring as a whole; an annular elastic body, arranged on the back side of the elastic body, applying a compensating pressure to the vicinity of the periphery of the back side of the polished surface; a first pressure regulating device for regulating the pressure of a space enclosed by the head housing, the annular body and the elastic body, and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, based on the annular body, regulating the pressure applied by the retaining ring to the polishing pad; a fourth pressure regulating device for regulating the compensating pressure applied by the annular elastic body to the vicinity of the periphery of the back side; A control device, controlling the actions of the driving device, the first pressure regulating device, the second pressure regulating device, and the fourth pressure regulating device; The control device, In the first step, the first pressure regulating device is controlled to apply a processing pressure to the back side of the polishing surface, and the second pressure regulating device is controlled to apply a pressure to the polishing pad. In the second process, The first pressure regulating device is controlled to stop applying the processing pressure, the second pressure regulating device is controlled to apply pressure to the polishing pad, and the fourth pressure regulating device is controlled to apply a compensation pressure near the periphery of the back side of the polished surface.

11. The polishing device according to claim 10, characterized in that: The fourth pressure regulating device is configured to apply pressure to the annular elastic body through a correction pressure ring disposed inside the annular body.

12. The polishing device according to claim 11, characterized in that: The annular elastic body is configured to be divided into a first annular elastic body on the inner circumference side and a second annular elastic body on the outer circumference side, The corrective pressure ring includes a first corrective pressure ring for applying pressure to the first annular elastomer and a second corrective pressure ring for applying pressure to the second annular elastomer. Among the compensating pressures applied near the periphery of the back side of the polished surface, the inner side is applied by the first annular elastomer, and the outer side is applied by the second annular elastomer.

13. The polishing device according to claim 12, characterized in that: A deformation preventing ring is provided between the first annular elastic body and the second annular elastic body.

14. The polishing device according to claim 12, characterized in that: The first annular elastic body is in a trapezoidal shape with an inner circumference of the first annular elastic body being an inclined surface. The second annular elastic body is in a trapezoidal shape with an inclined outer side. The first correction pressure ring covers at least a portion of the inclined surface on the inner circumference side of the first annular elastic body. The second correcting pressure ring covers at least a portion of the inclined surface on the outer peripheral side of the second annular elastic body.

15. The polishing device according to claim 14, characterized in that: The first correcting pressure ring covers the upper surface of the first annular elastomer, and while pressure is applied from the fourth pressure regulating device, the upper surface of the first annular elastomer is covered through the first pressure regulating device so that the processing pressure applied to the back side of the polished surface is also applied to the upper surface of the first annular elastomer.

16. A polishing head, provided on a processing device having a horizontally rotating polishing pad, and holding a substrate to be polished, and slidingly contacting the polished surface of the substrate onto the polishing pad, characterized in that: include: Head housing; an annular body having an inner circumference of a size surrounding the periphery of the substrate to be polished and connected to the head housing; An elastic body covering the lower end opening of the annular body and holding the substrate via a backing film attached to the surface side of the elastic body; a retaining ring having a shape surrounding a periphery of the substrate; A driving device for horizontally rotating the head housing, the annular body and the retaining ring as a whole; an annular elastic body, arranged on the back side of the elastic body, applying a compensating pressure to the vicinity of the periphery of the back side of the polished surface; a first pressure regulating device for regulating the pressure of a space enclosed by the head housing, the annular body and the elastic body, and regulating the processing pressure applied to the back side of the polished surface; a second pressure regulating device, based on the annular body, regulating the pressure applied by the retaining ring to the polishing pad; a fourth pressure regulating device for regulating the compensating pressure applied by the annular elastic body to the vicinity of the periphery of the back side; A control device, controlling the actions of the driving device, the first pressure regulating device, the second pressure regulating device, and the fourth pressure regulating device; The control device, In the first step, the first pressure regulating device is controlled to apply a processing pressure to the back side of the polishing surface, and the second pressure regulating device is controlled to apply a pressure to the polishing pad. In the second process, The first pressure regulating device is controlled to stop applying the processing pressure, the second pressure regulating device is controlled to apply pressure to the polishing pad, and the fourth pressure regulating device is controlled to apply a compensation pressure near the periphery of the back side of the polished surface.

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