JPH10552A - Chemical machine polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly polish a plural number of workpieces by simultaneously applying uniform pressure on all of the workpieces by using a plural number of holding bodies of the workpieces. SOLUTION: Each of a plural number of holding bodies 6 of workpieces has an elastic thin film 13 forming a pressure fluid chamber 14 respectively by receiving pressure fluid of water, air, etc., and a workpiece W is held on the side of a lower surface of the elastic thin film 13. Each of the pressure fluid chambers 14 is communicated to each other through a solid chamber 16 having larger capacity than the pressure fluid chamber. It is possible to flatten each of the workpieces W as equalization of surfaces to be polished of the workpieces W is automatically carried out, equally distributed pressure is applied, the same pressure is simultaneously applied on all of the workpieces W and the surfaces to be polished of a plural number of the workpieces W are polished with uniform working pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical mechanical polishing apparatus for polishing a plurality of substrates such as wafers with high precision.

[0002]

2. Description of the Related Art In recent years, semiconductor devices have become ultra-miniaturized and highly stepped, and with this, quartz, in which a plurality of island-shaped semiconductor regions are formed on a semiconductor wafer such as Si, GaAs, InP, or the like, or the like, has It is required to flatten the surface of a substrate such as a glass substrate with high precision. As processing means for flattening the surface of a substrate such as a wafer with high precision,
A chemical mechanical polishing (CMP) apparatus as described below is known.

As shown in FIG. 3, this conventional chemical mechanical polishing apparatus includes a polishing pad rotating table 101 on which a polishing pad 102 having a relatively large diameter is integrally mounted, and a substrate such as a wafer as a workpiece. A workpiece holder 103 for detachably holding the substrate 104 on the lower surface, and a polishing slurry supply nozzle 106 for supplying a polishing slurry (abrasive) 107 onto the polishing pad 102 are provided. The polishing pad rotating table 101 is rotated while being pressed against the polishing pad 102 so as to apply a predetermined processing pressure to the workpiece holding member 10.
3 is also configured to rotate or linearly move and simultaneously perform chemical mechanical polishing while supplying a polishing slurry between the polishing pad 102 and the substrate 104.

[0004] Further, with respect to the workpiece holder, an Air / Water bac capable of equalizing the processing pressure over the entire polished surface of the substrate and uniformly polishing the polished surface of the substrate.
A k-system is known. That is, A shown in FIG.
The workpiece holder of the ir / Water back system is
Elastic body 11 in which a pressure fluid such as air or water is sealed.
2 and a weight 110 for pressing the elastic body downward. When the elastic body 112 is brought into contact with the substrate 104 which is in contact with the upper surface of the polishing pad 102 mounted on the polishing pad rotating table 101, the upper surface of the elastic body 112 Side weight 1
The surface to be polished of the substrate 104 is the polishing pad 1
In this state, the workpiece holder 103 is rotated and revolved and the rotary table 101 is rotated and linearly moved to perform chemical mechanical polishing. Since the substrate 104 is pressed against the polishing pad 102 through the elastic body 112 in which the pressure fluid is sealed,
The entire surface to be polished of the substrate was uniformly pressed, and even if the degree of parallelism and flatness of the surface to be polished of the substrate were insufficient, uniform polishing was possible and planarization was possible. .

[0005]

However, the above conventional technique has the following problems.

A polishing pad having a larger diameter than a substrate as a workpiece is provided with one workpiece holder for polishing, which is not preferable in terms of productivity and efficiency. Even if a plurality of workpiece holders are arranged for one polishing pad in order to utilize the characteristics of the workpiece holder of the / Waterback system, the conventional Air /
In the work holder of the Water back system, the pressure fluid is filled and sealed inside the elastic body, and the processing pressure is formed by the elastic bodies which are independent of each other.
Although the workpiece holder presses evenly the entire surface to be polished of each substrate, it is difficult to maintain the same processing pressure on the surfaces to be polished of all the substrates in a plurality of substrates. Was.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and the equalization of a polished surface of a workpiece is automatically performed individually, and a plurality of workpieces are polished. An object of the present invention is to provide a chemical mechanical polishing apparatus capable of simultaneously applying the same processing pressure to workpieces and uniformly polishing the entire polished surfaces of a plurality of workpieces.

[0008]

In order to achieve the above-mentioned object, a chemical mechanical polishing apparatus according to the present invention provides a polishing pad having a surface to be polished of a workpiece held by a workpiece holder and a predetermined processing pressure. In a chemical mechanical polishing apparatus that performs polishing while supplying an abrasive between the surface to be polished and the polishing pad, a pressure fluid is supplied to form a pressure fluid chamber. A plurality of workpiece holders having an elastic thin film and holding the workpiece on the lower surface side of the elastic thin film, wherein the plurality of pressure fluid chambers are connected via a solid chamber having a larger capacity than the pressure fluid chamber. And are in communication with each other.

Further, the chemical mechanical polishing apparatus according to the present invention comprises a rotary table which removably holds and rotates a polishing pad, and a plurality of rotary tables which are disposed opposite to the rotary table and which removably hold a workpiece. A workpiece holder, a revolving table that supports the plurality of workpiece holders rotatably and axially movably, and revolves the workpiece holder, and a plurality of workpiece holders. A means for rotating the workpiece and a means for moving a plurality of workpiece holders in the axial direction are provided, and a surface to be polished of the workpiece held by the workpiece holder is fixed to the polishing pad by a predetermined amount. In a chemical-mechanical polishing apparatus that performs abrasion while supplying a polishing agent between the surface to be polished and the polishing pad while being brought into contact with each other while applying a processing pressure, the workpiece holders each have a pressure fluid. Pressure fluid channel An elastic thin film forming an elastic film, and a workpiece is held on a lower surface side of the elastic thin film. The pressure fluid chamber communicates with each other through a solid chamber having a larger capacity than the pressure fluid chamber. It is characterized by doing.

[0010] The pressure fluid supplied to the pressure fluid chamber formed by the elastic thin film of the present invention is preferably a gas or a liquid.

Further, in the chemical mechanical polishing apparatus of the present invention, individually adjustable fluid resistors are provided in respective pipes connecting the pressure fluid chamber and the solid chamber of the plurality of workpiece holders. Is preferred.

[0012]

Each of the plurality of workpiece holders has an elastic thin film that forms a pressure fluid chamber by receiving a supply of liquid or gas pressure fluid, and holds the workpiece on the lower surface side of the elastic thin film. The pressure fluid chambers are configured to communicate with each other through a large-capacity solid chamber so that the workpieces are pressed at equal distribution pressures in the workpiece holders, and the workpieces are polished. Surface equalization is done automatically. Further, the same pressure can be applied to all the workpieces in the plurality of workpiece holders,
The surfaces to be polished of a plurality of workpieces can be polished with a uniform processing pressure and can be flattened.

[0013] Further, by providing individually adjustable fluid resistors in each branch pipe connecting each pressure fluid chamber and the solid chamber, fluctuation and pressure of the pressure fluid in each pressure fluid chamber can be temporarily reduced. The working pressure can be adjusted according to the state of the workpiece, and the polishing can be finally flattened with a uniform working pressure.

[0014]

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

In the chemical mechanical polishing apparatus of the present invention, as shown in FIG. 1, a rotary table 1 on which a polishing pad 5 is detachably mounted has a bearing 3 mounted on a slide 3 which is movable in a radial direction with respect to a base (not shown). Through a rotary shaft 2 rotatably supported via a rotary drive mechanism (not shown),
The polishing pad 5 mounted on the turntable 1 is configured to be able to move in the radial direction with rotation.

A support arm 4 provided integrally with a base (not shown) projects above the rotary table 1, and a revolving table 8 rotatably supported on the support arm 4 via a bearing is provided. I have. The revolution table 8 is driven by a revolution table rotation drive mechanism (not shown) fixed to the support arm 4.

The revolving table 8 supports, via a bearing, a shaft 7 that supports the plurality of workpiece holders 6 and 6 so as to be rotatable and vertically movable in the axial direction. The shaft portion 7 of the workpiece holder 6 is rotated by a rotation drive mechanism 9 to form a gear transmission system 10.
, And a vertical drive mechanism 11 is attached to the upper end thereof.

As described above, the substrate W which is the workpiece
Is vertically moved by the vertical movement drive mechanism 11 to bring the substrate W into close contact with the polishing pad 5 on the rotary table 1 or to polish the substrate W. Separate from pad 5. The plurality of workpiece holders 6 respectively rotate at high speed by driving of the rotation drive mechanism 9, and further revolve according to the rotation of the revolving table 8.

The plurality of workpiece holders 6 and 6 have the same structure, and as shown in FIGS. 1 and 2, a cylindrical frame 12 attached to the shaft 7 has a pressure inside. The elastic thin film 13 forming the fluid chamber 14 is disposed, and a suppression member 15 for suppressing the elastic thin film 13 and suppressing upward movement is disposed on the upper surface side. The restraining member 15 may be a fixed restraining member integrally fixed to the cylindrical frame 12, or a weight that presses the elastic thin film 13 supplied with the pressure fluid into the pressure fluid chamber 14 downward. It can also be configured as a body. The lower surface of the elastic thin film 13 is configured to hold the substrate W via a holding member such as an adsorption.

A pressure fluid chamber 14 formed by the elastic thin film 13 of each workpiece holder 6 is provided with a branch pipe 17 for supplying a gas or liquid pressure fluid such as air or water. Via the pressure fluid chamber 14
It communicates with a solid chamber 16 formed to a larger volume. The solid chamber 16 is mounted on a base (not shown) or the revolving table 8, and is connected to a pressure fluid supply source via a main pipe 18.

Thus, a plurality of pressure fluid chambers 14,
14 communicates with a large-capacity solid chamber 16 through respective branch pipes 17, and the plurality of pressure fluid chambers 14, 14 communicate with each other via the solid chamber 16. The pressure fluid chamber 14 formed by the elastic thin film 13 of the workpiece holder 6 is a solid chamber 16
When the substrate W held on the lower surface side of the elastic thin film 13 is brought into contact with the polishing pad 5, each elastic thin film 13 forming the pressure fluid chamber 14 is supplied.
At the same time, the substrate W is pressed at an equal distribution pressure in each of the workpiece holders 6, and the polished surface of the substrate W is automatically equalized. Since the same pressure is applied between the holders 6, the polished surfaces of all the substrates are pressed with a uniform pressure. Further, even if a sudden external force acts on the pressure fluid chamber 14 of any one of the workpiece holders 6 during polishing, a large-capacity solid chamber 16 is interposed between the pressure fluid chambers 14. In addition, the polishing process can be performed without immediately affecting the other pressure fluid chambers 14.

Further, individually adjustable fluid resistors can be provided in the respective branch pipes 17 between the solid chamber 16 and the pressure fluid chamber 14 of each workpiece holder 6, and these fluid resistors can be provided. By arranging the resistors and adjusting the fluid resistors individually, it is possible to adjust the fluctuation and pressure of the pressure fluid in the individual pressure fluid chambers, for example, in the initial stage of the polishing process, In a plurality of substrates, when the height of the polished surface of the substrate is different, it is possible to temporarily apply a processing pressure higher than the other to the high polished surface. ,
Polishing is performed in this state, and finally, the polished surfaces of all the substrates can be uniformly polished by the same processing pressure.

Next, the operation of this embodiment will be described.

Rotary table 1 with polishing pad 5 attached
Is moved below the plurality of workpiece holders 6 by moving the slider 3 in the radial direction, and is positioned.
Thereafter, the substrate W held by the workpiece holder 6 is moved downward so as to contact the polishing pad 5 on the turntable 1. In the present invention, the vertical drive mechanism 1
A desired processing pressure can be easily set by lowering the plurality of workpiece holders 6 by means of 1 and 11 and adjusting the pressure by supplying a pressure fluid to the pressure fluid chambers 14 and 14.

When a plurality of substrates W are brought into contact with the polishing pad 5 at a desired processing pressure, the workpiece (polishing slurry) is supplied from a polishing agent (polishing slurry) supply means (not shown) while the workpiece is processed. The holder 6 is revolved and rotated at a high speed, and at the same time, the rotary table 1 is rotated and moved with a short stroke in the radial direction to perform chemical mechanical polishing.

As described above, while each substrate W is held by the elastic thin film 13 forming the pressure fluid chamber 14,
Since it is pressed against the polishing pad 5, the surface to be polished of each substrate W is automatically equalized, uniform polishing is performed, and the plurality of substrates W are connected to the pressure fluid chambers 14, Since the same pressure is applied at the same time, the entire surface to be polished of the plurality of substrates W can be polished with a uniform pressure.

Further, by providing individually adjustable fluid controllers in the branch pipe 12 between the solid chamber 16 and each pressure fluid chamber 14, fluctuations and pressures of the pressure fluid in each pressure fluid chamber 14 can be obtained. Can be temporarily adjusted, and the processing pressure can be temporarily changed according to the state of the substrate W to be processed, so that optimal polishing can be obtained.

The workpieces suitable for polishing by the polishing apparatus of the present invention include Si, Ge, GaAs, and In.
A semiconductor wafer such as P, or a quartz or glass substrate having a plurality of island-shaped semiconductor regions formed on the surface thereof may be used. In any case, a flat surface is required to form a wiring or an insulating region patterned by photolithography, and the surface to be polished is an insulating film or a metal film, or a mixed surface thereof. .

As the polishing pad of the present invention, it is desirable to use the surface of a pad such as a nonwoven fabric or polyurethane foam.

As the abrasive, a liquid containing fine particles is desirable. Specifically, as the fine particles, silica (S
iO ₂ ), alumina (Al ₂ O ₃ ), manganese oxide (M
nO ₂ ), cerium oxide (CeO) and the like, and examples of the liquid include NaOH, KOH, H ₂ O _{2 and the} like.
The particle size of the fine particles is preferably 8 nm to 50 nm.
The degree of aggregation of the particles can be controlled by changing the pH of OH.

When polishing a semiconductor surface, a silica-dispersed sodium hydroxide solution is preferable, when polishing an insulating film, a silica-dispersed potassium hydroxide solution is preferable, and when polishing a metal film such as tungsten, Aqueous hydrogen peroxide dispersed with alumina or manganese oxide is preferred.

[0032]

According to the present invention, as described above, the surface to be polished of each workpiece can be uniformly pressed with an evenly distributed pressure, and the surface to be polished of each workpiece can be pressed. Is automatically performed, and the same pressure can be applied to a plurality of workpieces simultaneously, so that even if the height of the polished surface of the substrate is different, all of the plurality of workpieces are Can be polished at a uniform processing pressure, and a plurality of workpieces can be uniformly polished and flattened.

[0033] Further, by providing individually adjustable fluid resistors in each of the branch pipes communicating the pressure fluid chamber formed by the plurality of elastic thin films and the solid chamber, each pressure fluid chamber in each pressure fluid chamber is provided. Fluctuations and pressures of the pressure fluid can be temporarily adjusted, the processing pressure can be optimized according to the state of the substrate, and finally flattening can be performed with a uniform processing pressure.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a chemical mechanical polishing apparatus of the present invention.

FIG. 2 is a schematic partial sectional view showing a workpiece holder of the present invention.

FIG. 3 is a schematic perspective view showing a conventional chemical mechanical polishing apparatus.

FIG. 4 is a partial cross-sectional view of a conventional Air / Water back work holder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary table 5 Polishing pad 6,6 Workpiece holder 8 Revolution table 13,13 Elastic thin film 14,14 Pressure fluid chamber 15,15 Suppression member 16 Solid chamber 17,17 Branch pipe

Claims (4)

[Claims] 1. A polishing surface of a workpiece held by a workpiece holder is brought into contact with a polishing pad while applying a predetermined processing pressure, and a polishing pad is provided between the polishing surface and the polishing pad. A chemical mechanical polishing apparatus for performing polishing while supplying an abrasive, comprising: an elastic thin film that receives a supply of a pressure fluid to form a pressure fluid chamber, and holds a workpiece on a lower surface side of the elastic thin film. A chemical mechanical polishing apparatus comprising a plurality of object holders, wherein the plurality of pressure fluid chambers communicate with each other via a solid chamber having a larger capacity than the pressure fluid chamber. 2. A rotating table for detachably holding and rotating a polishing pad, a plurality of workpiece holders disposed opposite to the rotating table and holding a workpiece detachably, and A revolving table for rotatably supporting the plurality of workpiece holders and movably in the axial direction and revolving the workpiece holder, means for rotating the plurality of workpiece holders, and a plurality of workpieces. Means for moving the workpiece holder in the axial direction, wherein the polished surface of the workpiece held by the workpiece holder is brought into contact with the polishing pad while applying a predetermined processing pressure to the polishing pad. In the chemical mechanical polishing apparatus for performing polishing while supplying an abrasive between the surface to be polished and the polishing pad, the workpiece holders each receive a supply of a pressure fluid to form a pressure fluid chamber. The elastic thin film A chemical mechanical polishing apparatus comprising a workpiece held on a lower surface side of a thin film, wherein the pressure fluid chamber communicates with each other via a solid chamber having a larger capacity than the pressure fluid chamber. . 3. The chemical mechanical polishing apparatus according to claim 1, wherein the pressure fluid supplied to the pressure fluid chamber formed by the elastic thin film is a gas or a liquid. 4. A fluid resistor which can be individually adjusted in each of the pipes connecting the pressure fluid chamber and the solid chamber of the plurality of workpiece holders. 4. The chemical mechanical polishing apparatus according to any one of 3.