JP2003231051A - Polishing device and polishing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polishing device and a polishing method evenly polishing the whole of a surface of an object to be polished with the high polishing force. <P>SOLUTION: This polishing device has a polishing head 10 formed of a surface plate 11, a tape feeding part 14 for feeding a polishing tape 20 onto a surface of the surface plate 11 and a tape winding part 15 for winding the polishing tape 20 fed onto the surface of the surface plate 11. The polishing head 10 is rotated R by a means 50. The polishing device has a holder 18 for holding an object W to be polished and for pushing the surface of the object W to be polished to the surface of the polishing tape 20 fed onto the surface of the surface plate 11 and a nozzle 19 for supplying the polishing liquid to the surface of the polishing tape 20 on the surface of the surface plate 11. The holder 18 is rotated r by a means 60. Any one of a back surface of the polishing tape 20 and a surface of the surface plate 11 is formed flat, and the other thereof has an elastic irregular pattern. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for polishing the surface of a thin plate-shaped object to be polished made of a material such as metal, oxide crystal, glass, ceramics, plastics, etc., and more particularly to semiconductors and magnetic disks. Alternatively, the present invention relates to an apparatus and method for polishing the surface of a substrate used for a liquid crystal panel or the like.

[0002]

2. Description of the Related Art Telephones,
Electronic devices such as cameras and computers are equipped with semiconductors, magnetic disks, and so on for controlling functions and storing or displaying information.
Liquid crystal panels are used as parts.

Surfaces of semiconductor wafers, magnetic hard disk substrates, liquid crystal panel substrates, etc., which are substrates for such components, are subjected to various processes required in various component manufacturing processes such as a multilayer wiring process and a coating process after a polishing process. It is commercialized through various steps and inspection steps.

These series of steps required in the manufacturing stage of the wiring, coating, etc. applied to the surface of the substrate must be performed with an accuracy of nanometer unit in order to exhibit the performance and functions of the parts expected in the design stage. Therefore, high precision is required in each step, and it is required to highly flatten the surface of the substrate even in the polishing step.

As described above, pad polishing using a polishing pad and tape polishing using a polishing tape are widely used for polishing the surface of a substrate which requires a high degree of planarization.

In pad polishing, a polishing liquid containing polishing particles is supplied to the surface of a polishing pad while rotating a surface plate having a polishing pad attached to the surface thereof, and a substrate held by a holder is pressed onto the surface of the polishing pad. It is performed by rotating (see, for example, JP 2000-239651 A).

However, in pad polishing, woven cloth, non-woven cloth,
A polishing pad made of a porous sheet made of foam or the like is used, and the surface of the polishing pad is locally or entirely caused by clogging due to polishing debris or friction with an object to be polished over time. However, there is a problem in that the surface of the substrate cannot be uniformly flattened with good reproducibility, and that the polishing pad must be replaced regularly, which is troublesome.

On the other hand, the tape polishing is performed by pressing the polishing tape against the surface of the object to be polished while supplying the polishing liquid to the surface of the object to be polished, and moving the object to be polished and the polishing tape relative to each other.

The polishing tape has a polishing layer in which polishing particles are fixed with a resin binder and is formed on the surface of a base tape. It is very small for polishing an object to be polished which requires high smoothness and flatness. Abrasive particles (average particle size 0.001
.About.0.5 .mu.m) is used. This is because when the size of the abrasive particles used in the polishing layer is reduced, the number of particles per unit area that acts on the surface of the object to be polished increases, so that the surface of the object to be polished can be polished accurately without damaging the surface. This is because it is considered possible.

Further, according to the tape polishing, since the surface of the new polishing tape is supplied to the surface of the object to be polished during polishing, it is not necessary to re-attach the polishing pad unlike the pad polishing described above. This has the advantage that the surface of the polishing layer is extremely unlikely to be locally or totally deteriorated due to clogging caused by polishing debris, friction with the object to be polished, or the like.

However, when very small abrasive particles are used, not only the surface of the polishing layer becomes flat and the polishing power is lowered, but also the surface of the polishing liquid supplied to the surface of the object to be polished is polished on the surface of the polishing tape. There is a problem that the surface of the polishing object slides (this is called a hydroplaning phenomenon), the polishing particles of the polishing tape do not uniformly act on the entire surface of the object to be polished, and the entire surface of the object to be polished is not uniformly polished.

The present invention has been made in view of the above problems, and therefore, an object of the present invention is to provide a high polishing power.
An object of the present invention is to provide a polishing apparatus and method capable of uniformly polishing the entire surface of an object to be polished.

[0013]

A polishing apparatus according to the present invention which solves the above-mentioned problems includes a surface plate, a tape feeding portion for feeding a polishing tape onto the surface of the surface plate, and a polishing portion fed onto the surface of the surface plate. The polishing head includes a tape winding unit that winds a tape. This polishing head is rotated by means such as a motor. The polishing tape is a base tape having a polishing layer formed by fixing polishing particles with a resin binder. The polishing apparatus of the present invention holds a polishing object, and a holder for pressing the surface of the polishing object to the surface of the polishing layer of the polishing tape fed onto the surface of the surface plate, and a holder on the surface of the surface plate. And a nozzle for supplying a polishing liquid to the surface of the polishing layer of the polishing tape. This holder is rotated by means such as a motor. According to the present invention, the polishing tape can be appropriately supplied on the surface of the surface plate.

As the polishing liquid, a cooling liquid such as water or a polishing slurry in which polishing particles are dispersed is used. In order to chemically and mechanically polish the surface of the object to be polished, the cooling liquid or the polishing slurry may contain a chemical solution that chemically reacts with the surface of the object to be polished.

The surface of the object to be polished is polished by using the polishing apparatus of the present invention. Send the polishing tape onto the surface of the surface plate, rotate the polishing head, supply the polishing liquid to the surface of the polishing layer of the polishing tape on the surface of the surface plate, and polish the polishing tape sent out onto the surface of the surface plate. It is performed by pressing the surface of the polishing object held by the holder against the surface of the layer and rotating the holder.

In the first aspect of the present invention, a surface plate having a flat surface is used as the surface plate of the polishing apparatus of the present invention. At this time, as the polishing tape, a polishing tape having an uneven pattern having elasticity on its back surface is used.
When this polishing tape is delivered onto the surface of the surface plate, the uneven pattern on the back surface of the polishing tape contacts the flat surface of the surface plate. This reduces the hydroplaning phenomenon that occurs between the surface of the object to be polished and the surface of the polishing layer of the polishing tape during polishing.

The concavo-convex pattern on the back surface of the polishing tape is a plane shape consisting of a linear shape, a curved shape, or a combination of one or two kinds selected from these shapes, and a concave or convex sectional shape. is there.

In the second aspect of the present invention, a polishing tape having a flat back surface is used as the polishing tape. At this time, as the surface plate of the above-described polishing apparatus of the present invention, a surface plate having an elastic uneven pattern on the surface is used.
When the polishing tape is delivered onto the surface of the surface plate, the flat back surface of the polishing tape contacts the uneven pattern on the surface of the surface plate. This reduces the hydroplaning phenomenon that occurs between the surface of the object to be polished and the surface of the polishing layer of the polishing tape during polishing.

The concavo-convex pattern on the surface of the surface plate has a linear shape,
The pattern is a planar shape having a curved shape or a shape in which one kind or two kinds selected from these shapes are combined, and the pattern has a concave shape in cross section or a convex shape in cross section.

[0020]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the invention is a polishing apparatus and method used to polish the surface of a substrate such as a semiconductor wafer, a magnetic hard disk substrate, and the like.

<Polishing Device> The polishing device of the present invention is shown in FIG.
As shown in (a) and (b), a surface plate 11, a tape delivery unit 15 for delivering the polishing tape 20 onto the surface, and a surface plate 1
The polishing head 10 includes a tape winding unit 14 that winds the polishing tape 20 fed onto the surface of the first recording medium 1.

The surface plate 11 is provided with a support base 13 via a pillar 12.
Fixed on top. Tape sending section 14 and tape winding section 1
5 is composed of rollers 16 and 17, respectively. These rollers 16 and 17 are provided on the support table 13 below the surface plate 11.
Fixed on top. The polishing tape 20 before use is wound around the roller 16. The roller 17 is connected to a motor (not shown), and by driving this motor, the roller 17 is rotated, the polishing tape 20 is sent out from the roller 16, and the polishing tape 20 is moved on the surface of the surface plate 11 by an arrow. After moving in the T direction, the used polishing tape 20 is wound around the roller 17. Polishing tape 2
0 can be continuously or intermittently fed onto the surface of the surface plate 11 and can be wound by the roller 17. Also,
The polishing tape 20 is appropriately delivered onto the surface of the surface plate 11 according to the state of the surface of the polishing tape 20 after polishing,
It is wound around the roller 17.

The polishing head 10 is moved by means of a motor, a belt (not shown) or the like 50, and the arrow R with respect to the rotation axis A.
Is rotated in the direction of.

As shown in the figure, the polishing apparatus of the present invention further includes a holder 18 for holding the substrate W and pressing the surface of the substrate W against the surface of the polishing tape 20 fed onto the surface of the surface plate 11. Have. The holder 18 has a flat surface below which holds the substrate W. The holder 18 can hold the substrate W by sticking the substrate W on the flat surface with wax, a suction pad wet with water, or the like. Further, the holder 18 is
The lower flat surface thereof has a vent hole communicating with an external vacuum pump (not shown). By driving this vacuum pump, the substrate W is held on the lower flat surface of the holder 18.
Can be adsorbed and retained.

The holder 18 is rotated in the direction of arrow r by means 60 such as a motor and a belt (not shown).

The polishing liquid is supplied to the surface of the polishing tape 20 on the surface of the surface plate 11 through the nozzle 19.

A cooling liquid such as water or a polishing slurry in which polishing particles are dispersed is used as the polishing liquid, and the chemical liquid chemically reacts with the surface of the polishing target because it polishes the polishing target chemically and mechanically. May be included. Such a chemical solution can be appropriately selected according to the material forming the surface of the object to be polished. For example, when the material forming the surface of the object to be polished is SiO ₂ , potassium hydroxide, tetramethylammonium hydroxide, hydrofluoric acid, fluoride, etc. are used. When the surface of the object to be polished is tungsten, iron nitrate, potassium iodate, etc. are used. When the surface of the object to be polished is Cu, glycine, quinaldic acid, hydrogen peroxide, benzotriazole, etc. are used.

<Polishing Method> The surface of the substrate W is polished using the polishing apparatus of the present invention shown in FIGS. 1 (a) and 1 (b). For polishing the surface of the substrate W, the polishing tape 20 is used as the surface plate 11
Surface of the polishing tape 20 rotated on the surface of the surface plate 11 to supply the polishing liquid to the surface of the polishing tape 20 on the surface of the surface plate 11, and the surface of the polishing layer of the polishing tape 20 supplied onto the surface of the surface plate 11. Then, the surface of the substrate W held by the holder 18 is pressed, and the holder 18 holding the substrate W is rotated.

The rotation number of the polishing head 10 is 10 rpm to
It is in the range of 1000 rpm, preferably 30 rpm to 100 rpm. The rotation speed of the holder 18 is 10 rpm to 100
It is in the range of 0 rpm, preferably 30 rpm to 100 rpm. The polishing liquid supply rate is 1 ml / min to 100 ml / min,
It is preferably in the range of 5 ml / min to 50 ml / min.

<First Aspect> In the first aspect of the present invention, the surface of the polishing apparatus of the present invention (shown by reference numeral 11 in FIG. 1) has a surface as shown in FIG. 2 (a). A flat surface plate 11 is used.

In the first aspect of the present invention, the polishing tape of the polishing apparatus of the present invention described above (denoted by reference numeral 20 in FIG. 1).
As shown in FIG. 2B, the polishing tape 20 having the elastic uneven pattern on the back surface 26 is used as shown in FIG.

The polishing tape 20 shown in FIG.
As shown in (b), the base tape 21, the polishing layer 22 formed on the surface of the base tape 21, and the base tape 2
1 and the elastic layer 25 formed on the back surface.

As the base tape 21, polyester,
Known tapes with high tensile strength made of synthetic resins such as polyethylene terephthalate (PET) are used.

The polishing layer 22 is formed by fixing polishing particles 23 with a resin binder 24. As the abrasive particles 23,
One type or two or more types of particles selected from particles made of silica, alumina, cerium oxide, diamond and the like are used. The resin binder 24 is selected from polyester resins, polyurethane resins, acrylic resins and the like.

The elastic layer 25 is made of a synthetic resin such as polyester, polyurethane or polypropylene, a foamed material such as foamed polyurethane, or a material having elasticity such as rubber. The surface of the elastic layer 25 (that is, a polishing tape). The back surface 26 of 20) has an uneven pattern.

The concavo-convex pattern is a planar shape having a linear shape, a curved shape, or a shape in which one or two kinds selected from these shapes are combined, and has a concave or convex cross section. Such a concavo-convex pattern is illustrated in FIGS. The concavo-convex pattern 40a shown in FIG. 4 (a) is a planar grid pattern in which linear shapes are combined. Concavo-convex pattern 40 shown in FIG.
b is a plane circular pattern having a curved shape.
The concavo-convex pattern 40c shown in FIG. 4 (c) is a plane wave pattern having a curved shape. Each of the concave-convex patterns 40a, 40b, 40c may have a concave cross-section or a convex cross-section.

The concavo-convex pattern on the surface 26 of the elastic layer 25 is
When the elastic layer 25 is manufactured, a molding die is used, or embossing or grooving is applied to the elastic layer 25.
Can be formed on the surface of. The elastic layer 25 is fixed to the back surface of the base tape 21 using an adhesive or the like. Further, such an elastic layer 25 (or an uneven pattern having elasticity) can be directly formed on the back surface of the base tape 21. Here, when a layer made of a foam is used as the elastic layer 25, a concavo-convex pattern may be formed on the surface 26 of the layer of the foam, or the surface portion of the foam may be cut to cause the foaming. The voids of bubbles of different sizes form the surface 26 of the layer.
The voids of the bubbles may be scattered and exposed to form an uneven pattern.

In the first aspect of the present invention, the polishing tape 20 is used.
When the tape is sent onto the surface of the surface plate 11, the polishing tape 20
The concavo-convex pattern on the back surface 26 comes into contact with the flat surface of the surface plate 11. This reduces the hydroplaning phenomenon that occurs between the surface of the substrate W and the surface of the polishing layer 22 of the polishing tape 20 during polishing.

<Second Mode> In the second mode of the present invention, the polishing tape of the polishing apparatus of the present invention (reference numeral 2 in FIG. 1) is used.
As shown in FIG. 3 (b), as shown in FIG. 3 (b), a polishing layer 22 in which polishing particles 23 are fixed by a resin binder 24 is formed on the surface of the base tape 21. Here, the back surface of the polishing tape 20 (corresponding to the back surface of the base tape 21) is flat.

In the second aspect of the present invention, the surface of the polishing apparatus of the present invention (indicated by reference numeral 11 in FIG. 1) has elasticity as shown in FIG. 3 (a). The surface plate 11 including the elastic layer 35 having an uneven pattern is used.

The elastic layer 35 of the surface plate 11 is made of polyester,
It is a sheet made of a material having elasticity such as synthetic resin such as polyurethane or polypropylene, foam made of foamed polyurethane or the like, or rubber, and has unevenness on the surface of the elastic layer 35 (that is, corresponding to the surface 36 of the surface plate 11). Have a pattern.

The concavo-convex pattern is a plane shape having a linear shape, a curved shape, or a shape in which one or two kinds selected from these shapes are combined, and has a concave or convex cross section. The uneven pattern on the surface of the surface plate 11 is, as in the uneven pattern described in the first embodiment, a planar cross-sectional concave shape or cross-sectional convex shape as illustrated in FIGS. 4A to 4C, respectively. Can be a pattern.

The concavo-convex pattern on the surface 36 of the elastic layer 35 is
When the elastic layer 35 is manufactured, a molding die is used, or embossing or grooving is applied to the elastic layer 35.
Can be formed on the surface of. The elastic layer 35 is fixed on the surface plate 11 using an adhesive or the like. Here, the elastic layer 35
As an example, when a foam sheet is used, a concavo-convex pattern may be formed on the surface 36 of the foam sheet, or the surface portion of the foam sheet may be cut so that voids of bubbles having different sizes generated during foaming are formed. The foam sheet may be scattered and exposed on the surface 36, and the voids of the bubbles may be formed as an uneven pattern. Preferably, as the elastic layer 35, a foam sheet having a concavo-convex pattern having a concave cross-section in a planar lattice shape in which linear shapes as shown in FIG. 4A are combined is used on the surface. This foam sheet is made up of a surface plate 1 using an adhesive or the like.
Fixed on 1.

In the second embodiment of the present invention, the polishing tape 20
When the tape is sent onto the surface of the surface plate 11, the polishing tape 20
The flat back surface of the plate contacts the uneven pattern on the surface 36 of the surface plate 11. This reduces the hydroplaning phenomenon that occurs between the surface of the substrate W and the surface of the polishing layer 22 of the polishing tape 20 during polishing.

Example 1 The surface of a substrate having a Cu film formed on its surface was polished by using the polishing apparatus of the present invention as shown in FIG.

As the polishing tape, a polishing tape having a polishing layer in which alumina particles (# 8000) were fixed with a polyester resin binder on the surface of a PET tape was used. The back surface of this polishing tape was flat.

As the surface plate, a surface plate was cut and a foamed polyurethane sheet having a concavo-convex pattern of voids (air bubble diameter: about 50 μm) scattered on the surface was attached.

A cooling liquid (water) was used as the polishing liquid.

The polishing conditions were as shown in Table 1 below.

[Table 1]

In Example 1, the polishing power (polishing amount per unit time) was 0.32 mg / min.

<Example 2> As a surface plate, a plate having a foamed polyurethane sheet having a concavo-convex pattern having a flat cross-section (spacing 6 mm) having a combination of linear shapes on the surface and a concave cross-section (width 2 mm) is used. Polishing was performed under the same conditions as in Example 1 except for the above. In the second embodiment, the grid pattern on the surface of the surface plate is the feeding direction of the polishing tape and the direction of the vertical straight line of the vertical and horizontal straight lines forming the grid pattern. Are arranged so that they are parallel to each other. The polishing power was 0.42 mg / min.

<Example 3> As the surface plate, a plate having a planar grid-like shape (spacing 6 mm) having a combination of linear shapes on the surface and having a foamed polyurethane sheet having a concave-convex pattern having a concave cross-section (width 2 mm) is used. Polishing was performed under the same conditions as in Example 1 except for the above. In the third embodiment, the lattice pattern on the surface of the surface plate has an angle of 45 ° between the feeding direction of the polishing tape and the linear and horizontal directions forming the lattice pattern. like,
Was placed. The polishing power was 0.58 mg / min.

<Comparative Example> Polishing was performed under the same conditions as in Example 1 except that a flat surface plate having no uneven pattern was used as the platen. Polishing power is 0.12
It was mg / min.

<Polishing Results> From the polishing results of Examples 1 to 3 and Comparative Example above, it can be seen that the polishing power was remarkably improved according to the present invention.

When the surface of the substrate after polishing was visually observed, in Examples 1 to 3, the entire surface of the substrate was uniformly polished, and in Comparative Example, polishing unevenness was observed.

[0056]

Since the present invention is constructed as described above,
(1) The polishing tape can be appropriately supplied on the surface of the surface plate,
And (2) an effect that the hydroplaning phenomenon occurring between the surface of the object to be polished and the surface of the polishing layer of the polishing tape during polishing is reduced, and the entire surface of the object to be polished can be uniformly polished with a high polishing force. Play.

[Brief description of drawings]

FIG. 1 (a) is a side view of a polishing apparatus of the present invention, and FIG. 1 (b) is a plan view of the polishing apparatus of FIG. 1 (a).

FIG. 2 (a) is a side view of a surface plate, and FIG.
(B) is a cross-sectional view of the polishing tape.

FIG. 3 (a) is a side view of a surface plate, and FIG.
(B) is a cross-sectional view of the polishing tape.

4 (a), (b) and (c) are respectively,
It is a top view of the example of the uneven | corrugated pattern of the back surface of a polishing tape or the surface of a surface plate.

[Explanation of symbols]

10 ... Polishing head 11 ... surface plate 12 ... Pillar 13 ... Support stand 14 ... Tape sending unit 15 ... Tape winding section 16, 17 ... Laura 18: Holder 19 ... Nozzle 20 ... Abrasive tape 21 ... Base tape 22 ... Polishing layer 23 ... Abrasive particles 24 ... Resin binder 25 ... Elastic layer 26 ... Back side of polishing tape 35 ... Elastic layer 36 ... Surface of surface plate 40a, 40b, 40c ... uneven pattern W: substrate R ・ ・ ・ Rotation direction of polishing head r ・ ・ ・ Rotating direction of holder T ... Polishing tape sending direction

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/304 622 H01L 21/304 622F (72) Inventor Toshihiro Izumi 3-4-1, Musashino, Akishima-shi, Tokyo No. Japan Micro Coating Co., Ltd. (72) Inventor Yoichi Kawakubo 6-15-10 Minamiaoyama, Minato-ku, Tokyo F-term (reference) 3C047 FF08 GG20 3C058 AA05 AA07 AA09 CB01 DA02 DA17 3C063 AA03 AB07 BB01 BB02 BB03 BC03 BG05 BG08 BG30 BH19 DD01 EE10 FF30

Claims (7)

[Claims] 1. A surface plate, a tape delivery unit for sending out a polishing tape having an abrasive layer having abrasive particles fixed with a resin binder on the surface of a base tape to the surface of the surface plate, and a surface of the surface plate. A polishing head comprising a tape winding unit that winds the sent-out polishing tape, holding an object to be polished, and the object to be polished on the surface of the polishing layer of the polishing tape sent to the surface of the surface plate A holder for pressing the surface of the plate, a nozzle for supplying a polishing liquid to the surface of the polishing layer of the polishing tape on the surface of the surface plate, a means for rotating the polishing head, and the holder. A polishing device comprising means for rotating. 2. The surface of the surface plate is flat, and the back surface of the polishing tape has an uneven pattern having elasticity, and the surface unevenness of the polishing tape sent to the surface of the surface plate is uneven. The polishing apparatus according to claim 1, wherein a pattern contacts a surface of the surface plate. 3. The concavo-convex pattern is a planar shape having a linear shape, a curved shape, or a shape in which one or two kinds selected from these shapes are combined, and has a concave or convex cross section. The polishing apparatus according to claim 2. 4. The surface of the surface plate has an uneven pattern having elasticity, the back surface of the polishing tape is flat, and the back surface of the polishing tape fed onto the surface of the surface plate is The polishing apparatus according to claim 1, wherein the polishing apparatus is in contact with the uneven pattern on the surface of the surface plate. 5. The concavo-convex pattern is a plane shape having a linear shape, a curved shape, or a shape in which one or two kinds selected from these shapes are combined, and is a pattern having a concave cross section or a convex cross section. The polishing apparatus according to claim 4. 6. The polishing apparatus according to claim 1, wherein the polishing liquid contains a chemical liquid that chemically reacts with the surface of the object to be polished, and the surface of the object to be polished is chemically and mechanically polished. . 7. A method for polishing the surface of an object to be polished by using the polishing apparatus according to claim 1, wherein the polishing tape is fed onto the surface of the surface plate. A step of rotating the polishing head, a step of supplying a polishing liquid to the surface of the polishing layer of the polishing tape fed onto the surface of the surface plate, holding the object to be polished in the holder, A method comprising the steps of pressing the surface of the object to be polished against the surface of the polishing layer of the polishing tape fed onto the surface, and rotating the holder.