JP2002079454A - Board holding device, and board polishing method and device using the same - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To make it possible to control the processing pressure concentrically and to make the film thickness distribution uniform over the entire surface of the substrate.
Furthermore, the inclination of the substrate holding surface with respect to the polishing surface of the polishing tool, the warpage of the substrate itself, undulations, etc. can be automatically equalized, enabling high-precision flattening of the substrate, and easy attachment and detachment of the substrate. Become A substrate holding apparatus C ₁ has a plurality of fluid chambers 2a to the substrate holding surface side is partitioned concentrically apertured frame body 1, 2b ... and a plurality of fluid chambers 2a, 2b ... of the respective The plurality of concentric annular pistons 3a, 3b... Arranged movably up and down and the internal pressures of the plurality of fluid chambers 2a, 2b. The pressure reduction control means 8 is provided to hold the substrate W via the backing material 11 on the surfaces of the annular pistons 3a, 3b,.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to Si, GaAs,
Substrate holding apparatus for holding a semiconductor wafer such as InP or a substrate such as a quartz or glass substrate having a plurality of island-shaped semiconductor regions formed on its surface, a substrate polishing method and a substrate polishing apparatus using the substrate holding apparatus It is about.

[0002]

2. Description of the Related Art Semiconductor devices such as Si, GaAs, InP and the like or semiconductor substrates such as quartz or glass substrates having a plurality of island-shaped semiconductor regions formed on the surface thereof are becoming increasingly finer and multi-layered. It is required to flatten the outer surface with high precision. Furthermore, the emergence of SOI wafers and 3
From the necessity of three-dimensional integration, global flattening of the outer surface of the substrate is desired.

As a planarization technique capable of performing not only global planarization of a substrate but also microscopic planarization, for example, a chemical mechanical polishing (CMP) apparatus as described below is known.

In a chemical mechanical polishing apparatus shown in FIG. 11 (see Japanese Patent Application Laid-Open No. 5-74749), a surface plate 101 having a polishing cloth 102 adhered to a processing surface and a pressure fluid 112 are sealed inside. And a top ring 110 having an elastic body 111. The semiconductor wafer 103 mounted on the polishing cloth 102 of the platen 101 is
The surface of the semiconductor wafer 103 is polished by rotating the platen 101 circularly without rotation while supplying a polishing agent (not shown) with a uniform pressing force (processing pressure) by the elastic body 111. It is configured.

Further, in a chemical mechanical polishing apparatus shown in FIG. 12 (see Japanese Patent Application Laid-Open No. Hei 8-257901),
Top ring 210 and turntable 20 each rotating
1, the turntable 201 and the top ring 21
0, the semiconductor wafer 203 is interposed, and the nozzle 22
A predetermined processing pressure is applied while the abrasive 221 is supplied from above to polish the surface of the semiconductor wafer 203, and the guide ring 213 protruding from the outer periphery of the top ring 210 is provided.
The semiconductor wafer 203 is fitted to the inner diameter of the plurality of protrusions 212a, 212b, and 212c, and the amount of downward protrusion of the plurality of protrusions 212a, 212b, and 212c is adjusted stepwise so that the protrusion 212a at the center becomes maximum. By changing, the semiconductor wafer 203 is configured to be pressed and polished in a state where the semiconductor wafer 203 is deformed into a convex shape.

[0006]

However, in the conventional chemical mechanical polishing apparatus described above, the former is configured to press the entire substrate such as a semiconductor wafer at the same pressure, and the latter is provided concentrically. A configuration in which the semiconductor wafer is pressed and polished in a deformed state by changing the amount of downward projection of the plurality of projected portions stepwise so that the projected portion at the center is maximized. None of them has an active configuration that selectively controls the pressing force of each part of the substrate to ensure uniformity of polishing, and furthermore, the substrate is moved from the top ring during polishing. There is a problem that it easily comes off.

In the former case, it is difficult to attach and detach the substrate to and from the top ring. In the latter case, the surface to be polished of the substrate does not follow the polished surface (processed surface) of a turntable which is a polishing tool. There is a problem that the thickness varies depending on the position in the IC chip.

Accordingly, the present invention has been made in view of the above-mentioned problems and unsolved problems of the prior art, and the tendency of the residual film amount distribution (polishing unevenness) after polishing is generally at the center of the substrate. Focusing on the point of symmetry, which is the point of symmetry, by controlling the processing pressure concentrically individually, the film thickness distribution over the entire surface of the substrate can be made uniform, and the substrate can be reliably secured during polishing. And a substrate holding device that can easily equalize the inclination of the substrate holding surface with respect to the polished surface of the polishing tool and the warp and undulation of the substrate itself. An object of the present invention is to provide a substrate polishing method and a substrate polishing apparatus capable of polishing a surface to be polished of a substrate with high accuracy using the substrate holding device.

[0009]

In order to achieve the above object, a substrate holding apparatus according to the present invention comprises a frame having a recess having an opening on the side of a substrate holding surface, and a concentric circle formed in the recess of the frame. A plurality of fluid chambers partitioned into a plurality of fluid chambers, and a plurality of concentric annular rings arranged inside each of the plurality of fluid chambers so as to be vertically movable and at least a surface on the substrate holding surface side is formed flat. It is characterized by comprising a piston and pressurizing / depressurizing control means for individually increasing and decreasing the internal pressure of each of the plurality of fluid chambers to individually move the annular piston.

In the substrate holding device of the present invention, the frame is
It is preferable to have an inner peripheral side surface large enough to allow the board to be detachably fitted.

In the substrate holding apparatus of the present invention, an annular guide ring having an inner peripheral side having a size capable of removably fitting the substrate is provided on the outer side of the outermost annular piston of the plurality of annular pistons. It is preferable to dispose it on the holding surface side.

In the substrate holding apparatus of the present invention, it is preferable that each of the plurality of concentric annular pistons is configured to be tiltable in each of the fluid chambers, and the frame body is opposite to the substrate holding surface side. It is preferable that the support is provided on a side surface and supported by a hemispherical bearing centered on a substantially center point of the substrate surface held on the substrate holding surface.

In the substrate holding apparatus of the present invention, it is preferable that the upper and lower positions of the plurality of annular pistons movable respectively in the vertical direction are set, and the movement ranges thereof are regulated respectively. It is preferable that at least one annular piston among the plurality of annular pistons is configured so as to be able to move largely upward in comparison to the other annular pistons, and at least one annular piston among the plurality of annular pistons is further arranged. Is configured to be able to independently move up and down within a range of -1 mm to 10 mm with reference to the height of the surface of the frame body or the guide ring on the substrate holding surface side. Respectively,
It is preferable that the frame or the guide ring is configured to be independently movable up and down within a range of ± 1 mm based on the height of the surface on the substrate holding surface side.

In the substrate holding apparatus of the present invention, a single backing material can be provided on each surface of the plurality of annular pistons on the substrate holding surface side. A separate backing material may be provided on the surface side, or a single backing material may be provided on the substrate holding surface side of a plurality of annular pistons configured to be able to move up and down within a range of ± 1 mm. A backing material different from the single backing material is provided on the surface of the at least one annular piston on the substrate holding surface side, which is configured to be able to move up and down in a range of -1 mm to 10 mm. Materials can also be provided.

In the substrate holding apparatus according to the present invention, it is preferable that the backing material is made of a material having a higher coefficient of friction than a flat surface of the annular piston on the substrate holding surface side.

In the substrate holding apparatus of the present invention, each of the plurality of concentrically arranged annular pistons is composed of a plurality of segmented pistons divided into segments, and each of the sectoral pistons is similarly divided into a plurality of segmented pistons. It is preferable that each of the fan-shaped fluid chambers is connected to pressurized / depressurized fluid control means for individually controlling the internal pressure.

According to the substrate polishing method of the present invention, the substrate held by the above-described substrate holding device is applied to the polishing surface of the polishing tool while the predetermined processing pressure is independently controlled with respect to the polishing surface of the polishing tool. The polishing is performed while supplying the polishing agent between the polishing surface of the substrate and the polishing surface of the polishing tool.

In the substrate polishing method of the present invention, when the polished substrate is separated from the substrate holding device, at least one of the plurality of annular pistons of the substrate holding device increases the internal pressure of the fluid chamber. Thus, it is preferable that the protrusion is made larger than other annular pistons.

The substrate polishing method of the present invention can be applied to a substrate during or after formation of a functional element.
A semiconductor, or an insulating substrate having a semiconductor film formed on its surface,
Alternatively, the present invention can be applied to a substrate or the like on which an insulating film and / or a metal film is formed.

In the substrate polishing apparatus of the present invention, the polished surface of the substrate held by the substrate holding device is brought into contact with the polished surface of the polishing tool, and the polished surface of the substrate is polished between the polished surface of the polishing tool. In a substrate polishing apparatus for performing polishing while supplying an abrasive to the substrate, the substrate holding apparatus is the substrate holding apparatus according to any one of claims 1 to 12.

In the substrate polishing apparatus of the present invention, the polishing tool has a polishing surface having a diameter of 1 to 2 times the diameter of the substrate,
It is preferable that an abrasive supply path for supplying an abrasive is provided at a central portion of the polishing tool, and when polishing the substrate, the abrasive is supplied from the abrasive supply path onto the surface to be polished of the substrate.

[0022]

According to the present invention, by individually controlling the pressures in a plurality of concentrically partitioned fluid chambers of the substrate holding apparatus, the projecting amounts of the plurality of concentrically arranged annular or fan-shaped pistons are controlled. Can be set to adjust the polishing pressure corresponding to the undulation or warpage of the substrate or the unevenness of polishing, eliminating concentric unevenness or local unevenness in polishing, and uniformizing the film thickness distribution over the entire surface of the substrate. The surface to be polished can be flattened with high precision.

Further, the adhesion between the surface of the frame or guide ring of the substrate holding device and the polishing surface of the polishing tool can be made uniform by the spherical seat mechanism of the substrate holding device. Adhesion can be automatically adjusted by the inclination of the annular or fan-shaped piston, precise equalization is automatically performed, and the surface to be polished can be flattened with high precision. Furthermore, since the pressure in each fluid chamber can be individually controlled, the polishing pressure of each piston can be controlled separately from the frame or the guide ring, and the average height of the surface to be polished and the frame or the guide ring is also free. Can be controlled.
This makes it possible to minimize the nonuniformity (edge exclusion) of polishing on the outer peripheral portion of the substrate, which has been considered difficult in the past.

In addition, when the substrate held by the substrate holding device is released, the pressure in at least one of the fluid chambers is increased to increase the amount of protrusion of the annular or plural fan-shaped pistons. It can be easily detached by projecting to a position away from the frame or guide ring, and can be detached without adsorbing the surface of the polished substrate, so that micro scratches and contamination on the substrate surface can be reduced, etc. Has the effect.

[0025]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a substrate holding device constituting a substrate polishing apparatus according to the present invention.
FIG. 2 is a partially cutaway perspective view of the substrate holding device shown in FIG.

The substrate holding device C shown in FIGS. 1 and 2
₁ is a frame body 1 having a recess with an opening on the substrate holding surface side and having an inner peripheral side surface 1i on the substrate holding surface side set to a size capable of detachably fitting the substrate W.
And a plurality (six in the figure) partitioned by a plurality of partition walls 1a to 1f provided concentrically in a recess of the frame body 1.
Annular fluid chambers (cylinders) 2a to 2f, each of which is vertically movably fitted into each of the fluid chambers 2a to 2f, and has at least a flat surface at least on the substrate holding surface side (six in the figure). ), The fluid supply passages 4a to 4f and the fluid discharge to the respective fluid chambers 2a to 2f so that the internal pressures of the annular pistons 3a to 3f and the respective fluid chambers 2a to 2f can be individually increased and decreased. A pressure control unit 8 is connected via the passages 5a to 5f, and a backing material 11 is provided on the flat surfaces of the annular pistons 3a to 3f exposed on the substrate holding surface side.

The pressurizing / depressurizing control means 8 includes a pressurizing control means 9 and a depressurizing control means 10, and the pressurizing control means 9 includes a control valve 6a.
Fluid supply passages 4a to 4f provided with
Is connected to each of the fluid chambers 2a to 2f through the control valve 6a to 6f, and the flow rate of the pressurized fluid introduced into each of the fluid chambers 2a to 2f is individually controlled by each of the control valves 6a to 6f. 4a to 4f are individually configured to increase the internal pressure, and the pressure reduction control means 10 includes control valves 7a to 7f.
Are connected to the respective fluid chambers 2a to 2f via fluid discharge paths 5a to 5f provided respectively, and control the flow rate of the pressurized fluid discharged from the respective fluid chambers 2a to 2f and the like to the respective control valves 7a to 7f. , The internal pressures of the fluid supply paths 4a to 4f are individually reduced.

The plurality of annular pistons 3a to 3f, which move up and down in the fluid chambers 2a to 2f by increasing and decreasing the internal pressure of the fluid chambers 2a to 2f, respectively, regulate the vertical movement range and separate the pistons. Flanges 12a to 12f are respectively provided on the outer side surfaces to prevent the outer peripheral side, and the flange 12a of the first annular piston 3a located at the center of the frame 1 is The flange 1 of the first annular piston 3a is located between the protrusion 13b provided on the inner peripheral surface of the outer second annular piston 3b and the upper end edge of the partition 1b of the frame 1.
The position where 2a abuts on the projection 13b of the second annular piston 3b is the upper limit of the movement range of the first annular piston 3a, and the position where the flange 12a abuts on the upper edge of the partition 1b is the first annular piston 3a. Is the lower limit of the movement range. As for the second annular piston 3b, its flange 12b
Is configured to be able to move between a position where it comes into contact with the convex portion 13c provided on the upper inner peripheral surface of the outer third annular piston 3c and a position where it comes into contact with the upper edge of the partition wall 1c. The same applies to the third to fifth annular pistons 3c to 3e. In the outermost sixth annular piston 3f, the flange 12f is provided on the inner peripheral side surface 1i of the frame 1. Located in the depression 1j,
The vertical movement range of the sixth annular piston 3f is a depression 1
j sets the positions of the upper and lower limits.

As described above, the plurality of annular pistons 3a to 3a
3f is movable in the vertical direction in a state where the upper and lower positions are restricted in the fluid chambers 2a to 2f, and at least one annular piston (in the present embodiment, the central first annular member). The piston 3a) is configured so as to be able to move downward by about 1 mm like the other annular pistons, and to move upward by about 10 mm, based on the height of the peripheral surface 1h of the frame body 1. That is, it is configured to be movable in a range of -1 to 10 mm based on the height of the peripheral edge surface 1h of the frame 1. The other annular pistons (in the present embodiment, the second to sixth annular pistons 3b to 3f) are individually individually about 1 mm up and down with respect to the height of the peripheral surface 1h of the frame 1. It is configured to be able to move within a range (that is, a range of ± 1 mm based on the height of the peripheral surface 1h of the frame 1). Accordingly, in this embodiment, as shown in FIG. 3 disengaged, the first annular piston 3a of the center, can be projected larger than the other annular piston, the substrate W from the substrate holding device C ₁ It is particularly effective in causing the above.

Further, in the substrate holding apparatus C _1, FIG. 4
(A), a bearing (spherical seat) formed on a surface opposite to the substrate holding surface and formed in a hemispherical shape centered on a substantially center point of the substrate surface held on the substrate holding surface. And an equalizing mechanism (hereinafter referred to as a spherical seat mechanism) 15 is provided,
The configuration is such that an error in the parallelism of the substrate holding device can be corrected. In addition, the adjacent annular piston 3a
Gaps Gp are provided between both side surfaces of the fluid chambers 2a to 3f.
f, the inner peripheral side surface 1i of the frame 1 and the annular pistons 3a to 3
A gap Gs is provided between each of the side surfaces f. These gaps Gp and Gs are 50
Preferably, the size is about 300 μm, and about 5 μm to 50 μm. By providing the gaps Gp and Gs between the adjacent annular pistons and between the annular piston and the partition of the fluid chamber in this manner, each annular piston 3
a to 3f can be respectively inclined as shown in FIG. 4B, and the planes on the substrate supporting surface side of the respective annular pistons 3a to 3f are all inclined as shown as T in FIG. 4B. And a structure that can be used.

When the pressurized fluid for controlling the vertical movement of each of the annular pistons 3a to 3f flows out of the fluid chambers 2a to 2f through the gap Gs, the through-hole for discharging the pressurized fluid to the side outside. Holes 14a to 14f and 14g are provided in each of the annular pistons 3a to 3f and the frame 1 at several positions, for example, at intervals of 60 °, 90 ° or 120 ° in the circumferential direction. Thus, the through holes 14a, 14b
...... By providing, polishing time in the through hole 14a of the substrate W held by the substrate holding device C _1, the pressurized fluid always flows out through 14b ..., polishing agent used during processing (slurry) gap This has the effect of preventing Gp and Gs from further flowing into the fluid chambers 2a to 2f.

The substrate holding device C ₁ configured as described above.
Individually controls the flow rate of the pressurized fluid introduced into each of the fluid chambers 2a to 2f by each of the control valves 6a to 6f of each of the fluid supply passages 4a to 4f to individually control the internal pressure of each of the fluid chambers 2a to 2f. By increasing the pressure, the amount of deformation of each of the annular pistons 3a to 3f protruding toward the substrate holding surface can be changed.
The flow rate of the pressurized fluid discharged from each of the fluid chambers 2a to 2f is individually controlled by each of the control valves 7a to 7f of each of the fluid discharge paths 5a to 5f to reduce the internal pressure of each of the fluid chambers 2a to 2f individually. Thereby, the amount of dent deformation on the substrate holding surface side of each of the annular pistons 3a to 3f can be changed.

[0034] Therefore, when mounting and holding the substrate W on the substrate holding device C ₁ can adjust the internal pressure of each fluid chamber 2a~2f individually, as shown in FIG. 1, each annular piston 3
The substrate W on the substrate holding side of a to 3f and the surface of the backing material 11 are positioned slightly below the peripheral surface 1h of the frame 1, and the substrate W is inserted and fitted into the inner peripheral side surface 1i of the frame 1. The upper surface (polished surface) of the substrate W is the peripheral surface 1 of the frame 1
h and is detachably held in a state of slightly protruding from h. At this time, the annular pistons 3a to 3f of the fluid chambers 2a to 2f are so arranged that the back surface of the substrate W is in close contact with the surface of the backing material 11.
The amount of projecting deformation of is controlled. In addition, as the backing material 11, a single backing material can be provided over each plane on the substrate holding side of the plurality of annular pistons 3a to 3f, or the respective planes of the plurality of annular pistons 3a to 3f can be arranged. Independent backing materials can be provided for each. Further, the backing material arranged on the plane of at least one annular piston (in this embodiment, the first annular piston 3a at the center) is separated from the backing material arranged on the plane of the other annular piston to form another backing material. You can also. Thus, the central first annular piston 3a
By placing the independent backing material 11 on the top, the first
When the annular piston 3a is largely protruded upward as shown in FIG. 3, the annular piston 3a can be smoothly moved without affecting the backing material 11 on the other annular pistons 3b to 3f. The substrate W to be placed can be moved without being displaced.
Further, when the backing material 11 is made of a material having a larger coefficient of friction than the flat surface of the annular pistons 3a to 3f on the substrate holding side, the adhesion to the substrate W can be improved.

The substrate holding device C ₁ is shown in FIG.
And (b), as shown in FIG.
a to 3f can be tilted and the spherical seat mechanism 15 is provided so that the substrate W
When polishing, the parallelism error between the substrate holding surface and the substrate polished surface with respect to the reference plane formed by the polishing surface (polishing pad) of the polishing tool can be automatically corrected. That is,
When mounting the substrate W on the substrate holding device C _1, as shown in (a) of FIG. 5, the polishing surface of the polishing tool (polishing pad)
When There there is an error in the parallelism of the parallelism and the substrate W of the substrate holding device C ₁ with respect to the reference planes constituting, the parallelism of the substrate holding device C ₁ error, the frame 1 of the substrate holding device C ₁ By pressing the peripheral surface 1h against the polishing surface of the polishing tool and pressing it, as shown in FIG.
5, the peripheral surface 1 of the frame ₁ of the substrate holding device C1.
h can polishing surface of the polishing tool to automatically correct the tilt of the substrate holding device C ₁ along the reference plane configuration. Furthermore, the error of the parallelism of the substrate W, the backing material 11
Of the parallelism or the parallelism error of the surfaces of the annular pistons 3a to 3f, as shown in FIG. 3C, the polished surface of the substrate W is polished by the annular pistons 3a to 3f. The annular pistons 3a to 3a-3 are brought into contact with each other so as to be pressed against the reference plane to be constituted by an equal force.
The correction can be made automatically by each inclination of f. In this manner, with respect to the correction of the parallelism with respect to the reference plane formed by the polishing surface of the polishing tool, the entire substrate holding device supported by the spherical seat mechanism can be automatically equalized in parallel with the polishing surface. For a warp or undulation existing in itself, precise equalization is automatically performed independently of the frame body by the inclination of the annular piston according to the warp or swell. As described above, by performing the correction using a different correction mechanism depending on the position where the tilt error occurs, the polished surface of the substrate can be flattened with high accuracy, and the uniformity of polishing can be improved.

[0036] As described above, when polishing while holding the substrate W by the substrate holding device C _1, the substrate holding device C ₁ is holding the substrate W in a state where precise equalization is automatically performed board W can be polished, and at this time, the substrate W is polished while being held with the surface to be polished slightly protruding from the peripheral surface 1h of the frame 1, so that the outer peripheral edge of the substrate W is polished. The amount can also be controlled. Furthermore, when the residual film amount distribution (polishing unevenness) occurs due to polishing, the tendency of the polishing unevenness is generally a point symmetry with respect to the center of the substrate as a point of symmetry, so that a plurality of concentrically arranged annular rings are formed. The protrusion deformation amount of each of the pistons 3a to 3f is individually controlled in accordance with the polishing unevenness, and the processing pressure is concentrically controlled, so that the film thickness distribution over the entire substrate is made uniform, and the polished surface of the substrate is formed. Flattening can be performed with high precision.

Further, when disengaging the substrate W from the substrate holding device C _1, as shown in FIG. 3, a first annular piston 3a which is arranged in the central portion of the frame 1, the first fluid By increasing the flow rate and the like of the pressurized fluid introduced into the chamber 2a and increasing its internal pressure and projecting and deforming upward in the drawing, the central portion of the backing material 11 is similarly convexly shaped upward in the drawing. The substrate W can be deformed and protrude upward from the peripheral surface 1h of the frame 1, and can be easily separated. In FIG. 3, the first annular piston 3
The backing material 11 on the other annular pistons 3b-3
f and separate from the backing material.

Further, the internal pressure of the first fluid chamber 2a is reduced to replace the first annular piston 3a with the other annular pistons 3b to 3f.
The substrate W can be sucked by making the substrate holding surface concave by deforming into a concave shape as compared with the surface of the substrate W. Further, the substrate W can be adsorbed by increasing the internal pressure of the fluid chamber of any one of the annular pistons in the intermediate portion among the annular pistons 3a to 3f so as to protrude and deform the annular piston into a donut shape.

[0039] In the substrate holding apparatus C ₁ described above, the annular piston 3 of the wheel body (3a to 3f) and the fluid chamber 2 (2a to 2f) are described for the case where a 6-fold concentrically However, the number of these annular pistons and fluid chambers is not particularly limited as long as it is two or more. In addition, the frame body 1 includes a plurality of concentric partition walls 1a to 1a.
It is also possible to form the disk-shaped member on which 1f is formed and the annular member having the inner peripheral side surface 1i to which the substrate W can be detachably fitted, and combine them to form an integrated structure.

Next, another embodiment of the substrate holding apparatus of the present invention will be described with reference to FIG. In this embodiment, the same members as those in the above-described embodiment are denoted by the same reference numerals.

The substrate holding device C ₂ of the present embodiment is provided with an annular guide ring 16 having an inner peripheral side surface 16 i of a size to which the substrate W can be removably fitted, at the peripheral edge of the frame 1. The other configuration is the same as that of the above-described embodiment. Also in this embodiment, similarly to the above-described embodiment, the polished surface of the substrate W is controlled by individually controlling the flow rate and the like of the pressurized fluid introduced into each of the fluid chambers 2a to 2f. The substrate W can be held in a state where it is slightly protruded from the surface 16h on the substrate holding surface side. Further, when the held substrate W is to be detached, when the substrate W is released as shown in FIG.
Similarly, by increasing the flow rate and the like of the pressurized fluid introduced into the first fluid chamber 2a to increase the internal pressure, the annular piston 3a is protruded and deformed upward, whereby the central portion of the backing material 11 is deformed. Similarly, the substrate W can be deformed upward and convexly, and the substrate W can be projected upward from the surface 16h of the guide ring 16, and can be easily separated.

Further, another embodiment of the substrate holding apparatus of the present invention will be described with reference to FIGS. In this embodiment, the same members as those in the above-described embodiment are denoted by the same reference numerals.

In each of the embodiments described above, the substrate holding devices C ₁ and C ₂ each having a ring-shaped annular piston have been described. However, as shown in FIGS. , A plurality of fan-shaped pistons are formed, and each fluid chamber partitioned concentrically is further subdivided into a plurality of fan-shaped fluid chambers.

In FIGS. 7 and 8, the first ring at the center is shown.
Each of the annular pistons 3b to 3f other than the annular piston 3a
Divide into four fan-shaped pistons 3b₁ ~ 3b_Four , 3c₁ ~
3c _Four ... and a fluid chamber to receive each piston
2a to 2f are also fluid chambers 2b to 2b other than the first fluid chamber 2a.
2f is divided into four and fan-shaped fluid chamber 2b₁ ~ 2b_Four 2c ₁ 
~ 2c_Four ...... With this configuration,
A plurality of fan-shaped pistons 3b on the same circumference₁ ~ 3b_Four ,
3c₁ ~ 3c_Four Each fluid chamber 2b of ...₁ ~ 2b_Four2c₁ 
~ 2c_Four If the same internal pressure is set for each,
It is possible to obtain the same effect as that of the
Independent control of the internal pressure of the fluid chamber of each fan-shaped piston
To reduce local polishing unevenness other than concentric polishing unevenness.
Can be eliminated.

Next, a substrate polishing apparatus using the substrate holding apparatus configured as described above will be described with reference to FIGS. The substrate polishing apparatus P shown in FIG.
₁ is an example in which a substrate holding device C ₁ illustrated in Figure 1 or the like, the substrate polishing apparatus P ₂ depicted in FIG. 10, use a substrate holding apparatus C ₂ having the guide ring illustrated in Figure 6 In both cases, the fluid chambers and the annular pistons are respectively concentrically arranged three times.

In the substrate polishing apparatus P ₁ shown in FIG. 9, the substrate holding apparatus C ₁ has a frame 1 on a free end side of a hollow shaft member 26 which is rotated and linearly moved by a rotation and linear drive mechanism 27. Each of the fluid chambers 2a to 2c of the frame body 1 is fixed, and fluid supply paths 4a to 4c
And the fluid discharge paths 5a to 5d connected to the pressure reduction control means 10.
5c are extended fluid supply passages 4a disposed in the shaft member 26 via joints 25a to 25c that allow the shaft member 26 to rotate.
x, 4bx, 4cx and the respective extension fluid discharge passages 5ax, 5ax,
bx, 5cx. Fluid supply path 4
Control valves 6a to 6c and 7a to 7c are arranged in the fluid discharge passages 5a to 5c.

On the other hand, the polishing tool 21 has a substrate W
Polishing pad 22 having a diameter larger than twice the diameter of
There is stuck, is arranged so as to face the substrate holding surface of the substrate holding device C _1. The polishing tool 21 is rotatably supported by a swing table (not shown), and is configured to be able to rotate around the rotation axis O and swing in the radial direction by a drive mechanism (not shown). . A nozzle 24 serving as an abrasive supply means for supplying an abrasive 23 onto the polishing pad 22 is provided with a polishing tool 2.
1.

In the substrate polishing apparatus P ₂ shown in FIG. 10, a substrate holding apparatus C ₂ having an annular guide ring 16 provided on the peripheral edge of the frame 1 is used, and the substrate holding apparatus C ₂ is immovable. And Above the substrate holding device C _2, it is placed a polishing head 30 having a polishing tool 31 having a polishing pad 32 having a diameter of 1-2 times the caliber of the substrate W, the polishing head 30, a substrate holding device A polishing pad 32 having a polishing surface is disposed on the lower surface so as to face the substrate holding surface side of C ₂ , and an abrasive supply path 33 is provided in the center. The polishing head 30 rotates on a swing table (not shown). And it is supported movably in the axial direction. By a driving mechanism (not shown), a polishing pad 32 of the polishing tool 31 moved linearly brought into contact with the substrate W held by the substrate holding device C _2, the arrow direction of the polishing tool 31 in a state that gives a predetermined processing pressure Alternatively, it is configured to be able to rotate in the direction opposite to the arrow and swing in the radial direction.

Next, the substrate polishing method of the present invention, will be described as an example the case of using the substrate polishing apparatus P ₂ depicted in FIG. 10.

As shown in FIG. 10, the substrate holding device C
₂ , the flow rate of the pressurized fluid introduced into each of the fluid chambers 2a to 2c is individually controlled to adjust the position of each of the annular pistons 3a to 3c, and the upper surface of the backing material 11 is moved from the surface 16h of the guide ring 16 to the upper surface. The substrate W is positioned slightly below.
Is fitted to the inner peripheral side surface 16i of the guide ring 16. Thus, the substrate holding device C _2, the back surface of the substrate W is held such polished surface of the substrate W is slightly higher than the surface 16h of the guide ring 16 in contact with the upper surface of the backing material 11.

The polishing tool 31 is moved downward to bring the polishing pad 32 into contact with the surface to be polished of the substrate W in a state where a predetermined processing pressure is applied. At this time, the substrate holding device C ₂ is (is not shown in FIG. 10) are equalized by tilting of and the annular piston 3a~3c spherical seat mechanism 15, the guide ring 16 and parallelism correction of the polished surface of the substrate W Is done.
Then, the polishing tool 31 is rotated at a predetermined number of revolutions while supplying the abrasive through the abrasive supply passage 33 of the polishing head 30.

After that, the rotation speed of the polishing tool 31 is increased and the polishing tool 31 is swung in the radial direction to perform chemical mechanical polishing for a predetermined time.

At the time of this chemical mechanical polishing, the polishing agent is always supplied onto the surface to be polished of the substrate W from the polishing agent supply passage 33 provided at the central portion of the polishing head 30, so that the polishing agent is supplied onto the surface to be polished. The abrasive is diffused from the supplied portion in the outer peripheral direction of the surface to be polished and distributed over the entire surface to be polished, whereby uniformity of polishing can be ensured, and unnecessary substances such as polishing debris are further reduced. The material can be discharged from the surface to be polished in the outer peripheral direction without staying on the surface to be polished, and the occurrence of scratches or the like due to unnecessary substances such as polishing chips can be prevented.

After performing the chemical mechanical polishing for a predetermined time,
The polishing head 30 is separated from the substrate W, and the surface shape of the polished surface of the substrate W is measured.

As a result of the measurement described above, when the surface to be polished of the substrate W is not polished to a predetermined surface shape, each of the fluid chambers 2 a to 2 according to the residual film amount distribution (polishing unevenness).
The internal pressure of c is controlled, the amount of protrusion deformation or the amount of depression deformation of each of the annular pistons 3a to 3f is individually controlled to control the processing pressure, and the same chemical mechanical polishing as in the above steps is performed.

The same steps as those described above are repeated until the surface to be polished of the substrate W has a predetermined surface shape. When the predetermined surface shape is obtained, the polishing tool 31 is separated from the substrate W. Finish the polishing.

After that, in the substrate holding device C ₂ ,
By increasing the inflow amount of the pressurized fluid introduced into the first fluid chamber 1a, the
By projecting deformed so as to protrude from the surface 16h of the annular piston 3a and the annular piston 3a on the backing material 11 of the guide ring 16, it is protruded to the substrate W, easily substrate W from the substrate holding device C ₂ Can be removed.

As described above, a substrate that can be polished by the present invention includes a wafer made of a semiconductor such as Si, Ge, GaAs, and InP, and an SOA having a semiconductor layer on an insulating surface.
There is an insulating substrate such as an I-wafer or ceramics, and it may be before, during, or after the production of functional elements such as a resistor, a capacitor, a diode, and a transistor. Therefore, the outer surface of the substrate that is the object to be polished, that is, the surface to be polished is a semiconductor surface, an insulating surface, a conductive surface, or a surface on which at least two of these three are mixed. obtain. Above all,
INDUSTRIAL APPLICABILITY The present invention is suitable for polishing an insulating film and / or a conductor film of a multilayer wiring that requires a film having substantially the same thickness on one substrate.

Abrasive used for polishing a substrate according to the present invention
As, a liquid containing fine particles is desirable, and specifically,
As the fine particles, silica (SiO_Two ), Alumina (Al
_Two O _Three ), Manganese dioxide (MnO)_Two ), Cerium oxide
(CeO) and the like.
(NaOH) solution, potassium hydroxide (KOH) solution
Liquid, aqueous ammonia (NH_Three ) And the like. Particulate
The particle size is preferably from 10 nm to 500 nm.
Control the degree of particle aggregation by changing the pH of H
The amount of polishing varies depending on the degree of aggregation.
Can be

In polishing the semiconductor surface, the silica-dispersed water is used as a sodium oxide solution, and in polishing the insulating film,
A potassium oxide solution is preferable as the silica dispersion water, and ammonia water is preferable as the alumina dispersion solution when polishing a metal film such as tungsten.

For example, in the case of a semiconductor surface, when a silica-dispersed NaOH aqueous solution is used as an abrasive, the silicon surface reacts with NaOH to form a Na ₂ SiO ₃ layer which is a reaction product. By removing this by mechanical polishing with silica and a polishing pad, exposing a new silicon surface,
The reaction proceeds. Such a mechanism is called a chemical mechanical polishing.

[0062]

As described above, according to the present invention,
By individually controlling each pressure in the annular fluid chamber of the substrate holding device, the amount of projection of the annular or fan-shaped piston arranged concentrically is changed, respectively, to respond to undulation or warpage of the substrate or uneven polishing. The polishing pressure can be set to a predetermined value, concentric polishing unevenness and local polishing unevenness can be eliminated, the film thickness distribution can be made uniform over the entire surface of the substrate, and the surface to be polished can be flattened with high precision.

The adhesion between the surface of the frame or guide ring of the substrate holding device and the polishing surface of the polishing tool can be made uniform by the spherical seat mechanism of the substrate holding device. Adhesion can be automatically adjusted by the inclination of the annular or fan-shaped piston, precise equalization is automatically performed, and the polished surface of the substrate can be flattened with high precision. Furthermore, since the pressure in each fluid chamber can be individually controlled, the polishing pressure of each piston can be controlled separately from the frame or the guide ring, and the average height of the surface to be polished and the frame or the guide ring is also free. Can be controlled. This makes it possible to minimize the nonuniformity (edge exclusion) of polishing on the outer peripheral portion of the substrate, which has been considered difficult in the past.

In addition, when the substrate held by the substrate holding device is released, the pressure in at least one fluid chamber is increased to increase the amount of protrusion of the annular or plural fan-shaped pistons, so that the substrate can be removed. It can be easily detached by projecting to a position away from the frame or guide ring, and can be detached without adsorbing the surface of the polished substrate, so that micro scratches and contamination on the substrate surface can be reduced, etc. Has the effect.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing an embodiment of a substrate holding device constituting a polishing apparatus of the present invention.

FIG. 2 is a perspective view showing a part of the substrate holding device shown in FIG.

FIG. 3 is a schematic configuration diagram for explaining a substrate detaching operation performed by the substrate holding device illustrated in FIG. 1;

4A and 4B are diagrams illustrating a mechanism for correcting a parallelism error in the substrate holding device illustrated in FIG. 1;
3 is a partial sectional view, and FIG. 3B is a partial sectional view showing an inclined state of an annular piston.

FIG. 5 is a schematic diagram for explaining a mode of correcting a parallelism error on the peripheral surface of the frame and a parallelism error on the substrate in the substrate holding device shown in FIG. 1;

FIG. 6 is a configuration diagram schematically showing another embodiment of the substrate holding device of the present invention.

FIG. 7 is a perspective view showing a configuration of a fan-shaped piston constituting still another embodiment of the substrate holding device of the present invention.

FIG. 8 is a perspective view showing a configuration of a frame having a fan-shaped fluid chamber which constitutes still another embodiment of the substrate holding device of the present invention.

FIG. 9 is a schematic configuration diagram showing a substrate polishing apparatus using the substrate holding device of the present invention.

FIG. 10 is a schematic configuration diagram showing another substrate polishing apparatus using the substrate holding device of the present invention.

FIG. 11 is a schematic view showing an example of a conventional chemical mechanical polishing apparatus.

FIGS. 12A and 12B are schematic views showing another example of a conventional chemical mechanical polishing apparatus, in which FIG. 12A is a view showing an entire configuration, and FIG. 12B is a partial cross-sectional view showing an operation state of a top ring.

[Explanation of symbols]

C _1, C ₂ substrate holding apparatus P _1, P ₂ substrate polishing apparatus W substrate 1 frame 1a, 1b ...... bulkhead 1h peripheral surface 1i inner circumferential side 1j recesses 2a, 2b ...... fluid chambers 3a, 3b ...... cyclic piston _{3b 1 ~3b 4, 3c 1 ~3c} 4 ... fan pistons 4a, 4b ...... fluid supply passage 5a, 5b ...... fluid discharging passage 6a, 6b ...... control valve 7a, 7b ...... control valve 8 pressurization control means Reference Signs List 9 pressure control means 10 pressure reduction control means 11 backing material 12a, 12b ... flange 13a, 13b ... convex part 14a, 14b ... through hole 15 spherical seat mechanism 16 guide ring 16h surface 16i inner peripheral side surface 21 polishing tool 22 polishing Pad 23 abrasive 24 nozzle 30 polishing head 31 polishing tool 32 polishing pad 33 abrasive supply passage

Claims (19)

[Claims] 1. A frame having a recess with an opening on the substrate holding surface side, a plurality of fluid chambers concentrically defined in the recess of the frame, and a vertical inside each of the plurality of fluid chambers. A plurality of concentric annular pistons that are arranged so as to be movable in the direction and at least the surface on the substrate holding surface side is formed flat, and the annular pistons are respectively increased and decreased by increasing and decreasing respective internal pressures of the plurality of fluid chambers. A substrate holding device, comprising: a pressurizing / depressurizing control means for individually moving. 2. The frame according to claim 1, wherein the frame has an inner peripheral side surface large enough to detachably fit the substrate.
The substrate holding device as described in the above. 3. An annular guide ring having an inner peripheral surface large enough to detachably fit a substrate is disposed on the substrate holding surface side of the frame outside the outermost annular piston of the plurality of annular pistons. The substrate holding device according to claim 1, wherein 4. The substrate holding device according to claim 1, wherein each of the plurality of concentric annular pistons is configured to be tiltable in each fluid chamber. 5. The method according to claim 1, wherein the frame is provided on a surface opposite to the substrate holding surface and supported by a hemispherical bearing centered on a substantially center point of the substrate surface held on the substrate holding surface. The substrate holding device according to any one of claims 1 to 4, wherein: 6. The plurality of annular pistons movable in the up and down direction, respectively, wherein an upper limit position and a lower limit position are respectively set, and the movement ranges thereof are respectively regulated. 2. The substrate holding device according to claim 1. 7. At least one of the plurality of annular pistons
The substrate holding device according to any one of claims 1 to 6, wherein each of the annular pistons is configured to be able to move largely upward in comparison with the other annular pistons. 8. At least one of the plurality of annular pistons
The number of the annular pistons is -1 mm to 10 mm based on the height of the surface of the frame or guide ring on the substrate holding surface side.
The other annular pistons are independently movable within a range of ± 1 mm with respect to the height of the surface of the frame or guide ring on the substrate holding surface side. The substrate holding device according to claim 1, wherein the substrate holding device is configured to be vertically movable. 9. The substrate holding apparatus according to claim 1, wherein a single backing material is provided on each surface of the plurality of annular pistons on the substrate holding surface side. 10. The substrate holding apparatus according to claim 1, wherein a separate backing material is provided on each of the plurality of annular pistons on the surface on the substrate holding surface side. . 11. A single backing material is provided on the substrate holding surface side surface of a plurality of annular pistons configured to be able to move up and down within a range of ± 1 mm, and -1 mm to 10 mm
At least one configured to be able to move up and down in the range of
9. The substrate holding apparatus according to claim 8, wherein a backing material different from the single backing material is provided on the surface of the annular pistons on the substrate holding surface side. 12. The substrate according to claim 9, wherein the backing material is made of a material having a higher coefficient of friction than a plane of the annular piston on the substrate holding surface side. Holding device. 13. Each of a plurality of concentrically arranged annular pistons is constituted by a plurality of segmented pistons, each of which is similarly divided into a plurality of segmented independent fan-shaped pistons. 13. A pressure control device for controlling the internal pressure of each of the fan-shaped fluid chambers, which is arranged inside the fluid chambers, and connected to each of the fan-shaped fluid chambers. The substrate holding device as described in the above. 14. A polishing method for polishing a substrate held by the substrate holding apparatus according to claim 1 in a state in which predetermined processing pressures are individually and independently controlled with respect to a polishing surface of a polishing tool. A substrate polishing method, comprising: abutting a polishing surface of a tool, and performing polishing while supplying an abrasive between a surface to be polished of a substrate and a polishing surface of a polishing tool. 15. When releasing a polished substrate from a substrate holding device, at least one of the plurality of annular pistons of the substrate holding device is increased in internal pressure of its fluid chamber to form another annular piston. The substrate polishing method according to claim 14, wherein the projection is made larger than that of the substrate. 16. The substrate according to claim 14, wherein the substrate is a substrate during or after formation of a functional element.
6. The substrate polishing method according to 5. 17. The substrate according to claim 14, wherein the substrate is a semiconductor, an insulating substrate having a semiconductor film formed on a surface thereof, or a substrate having an insulating film and / or a metal film formed on a surface thereof. The substrate polishing method according to any one of the above. 18. A polished surface of a substrate held by a substrate holding device is brought into contact with a polished surface of a polishing tool, and an abrasive is supplied between the polished surface of the substrate and the polished surface of the polishing tool. A substrate polishing apparatus for performing polishing while polishing, wherein the substrate holding apparatus is the substrate holding apparatus according to any one of claims 1 to 13. 19. The polishing tool has a polishing surface having a diameter of 1 to 2 times the diameter of the substrate, and a polishing agent supply path for supplying a polishing agent is provided at a central portion of the polishing tool. 19. The substrate polishing apparatus according to claim 18, wherein the polishing agent is supplied from the polishing agent supply path onto the surface to be polished of the substrate.