KR100622267B1 - Pad Conditioner for Chemical Mechanical Planarization - Google Patents

Abstract

The present invention relates to a conditioner for use in the CMP process required for the wide-area leveling of wafers performed for high integration of a semiconductor device, and to provide a conditioner for a CMP pad capable of achieving uniform polishing of a pad. have.

The present invention is a dressing substrate comprising a metal substrate formed integrally, an abrasive fixed on the metal substrate and a metal binder layer for fixing the abrasive on the metal substrate, a holder holding the dressing substrate, and fixed to the holder. A pad conditioner for a CMP comprising a coupling member, wherein the dressing substrate is divided into a plurality of substrates;

A flexible member is inserted between the dressing substrate and the holder; And

The pad conditioner for CMP is characterized in that the inclination adjustment board is provided between each divided dressing board | substrate and a flexible member corresponding to each dressing board | substrate divided | segmented.

According to the present invention, the curved shaving of the pad can be uniformly dressed.

Pad, Conditioner, Dressing, Holder, Flexible Member, Incline Board

Description

Pad conditioner for CPM {Pad Conditioner for Chemical Mechanical Planarization}

1 is a block diagram of a conventional CMP pad conditioner, Figure 1 (a) shows a perspective view of a conventional CMP pad conditioner,

Figure 1 (b) is a detailed view of the dressing substrate of the conventional CMP pad conditioner

Figure 2 is a schematic diagram showing a state of dressing the pad using a conventional CMP pad conditioner

Fig. 3 is a block diagram of the CMP pad conditioner of the present invention, and Fig. 3 (a) shows a perspective view of the CMP pad conditioner of the present invention, and Fig. 3 (b) shows a detail of the dressing substrate of the CMP pad conditioner of the present invention.

Figure 4 is a schematic diagram showing a state of dressing the pad using the CMP pad conditioner of the present invention

5 is a detailed view of a dressing substrate with a rounded upper edge of the substrate in accordance with the present invention;

Explanation of symbols on the main parts of the drawings

10, 20. . . Conditioner 11, 21. . . Dressing substrate 12, 22. . . holder

15, 25. . . Coupling member 21a, 21b. . . Partitioned dressing substrate

23. . . Lack of flexibility 24. . . Tilt adjuster 26. . . Acid resistant waterproof cloth

111, 211. . . Metal substrates 112, 212. . . Abrasive

113,213. . . Metal binder layer. . . Edge

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conditioner for use in a chemical mechanical planarization (CMP process) required for a wide area leveling operation of a wafer performed for high integration of a semiconductor device, and more particularly, to a conditioner for a CMP pad having flexibility.

In the semiconductor industry, high-speed and high-density circuits are being developed. As the integration capacity increases, the chip size becomes larger and larger, and in order to overcome the limitations, wiring is minimized by minimizing the wiring width and the large diameter of the wafer. Making structural changes.

However, as the device density increases and the minimum line width decreases, the conventional partial planarization techniques have reached a limit that cannot be overcome. For the sake of processing efficiency or high quality, planarization across the wafer surface, that is, global planarization polishing technology (CMP) Chemical Mechanical Planarization is the only solution available. In other words, the demand for wide area leveling by CMP is inevitable in current wafer processes.

CMP is a chemical and mechanical polishing process that obtains the flatness of a semiconductor wafer by using a polishing removal process and a chemical solution dissolving action simultaneously.

The processing principle is to pressurize and relatively move the polishing pad and the wafer while supplying a slurry containing abrasive particles and chemicals on the pad. It serves to hold a constant polishing efficiency and polishing uniformity can be obtained on the entire surface of the wafer.

However, since pressure and relative speed are added during polishing, the surface of the pad will be unevenly deformed over time, and fine pores on the polishing pad will be clogged with polishing residues, causing the polishing pad to lose its role.

For this reason, it is impossible to achieve wide-area leveling on the entire surface of the wafer and polishing uniformity between wafers during the entire processing time.

In order to solve the non-uniform deformation of the pads and clogging of pores, a conditioner that fixed an abrasive such as diamond on a stainless steel or nickel plate is used to condition the micro surface of the pad by fine polishing the pad surface.

As described above, there are various methods for manufacturing the conditioner for finely polishing the pad surface, but mainly electrodeposition, fusion, or sintering methods are used.

In case of conditioner manufactured by electrodeposition, the roughness and surface of the product have the advantage of being clean, but the retention of diamond is weak compared to fusion, which may cause scratches and chip pockets that facilitate the movement of slurry. ) Is difficult to form.

On the other hand, the conditioner manufactured by fusion is superior to the conditioner manufactured by fusion in terms of the removal rate and scratch, which are important factors in the planarization of the wafer.

One example of a conventional pad conditioner is shown in FIGS. 1 and 2.

As shown in FIG. 1 and FIG. 2, the pad conditioner 10 for CMP includes a metal substrate 111 integrally formed, an abrasive 112 fixed on the metal substrate 111, and the abrasive 112. A dressing substrate 11 including a metal binder layer 113 fixed on the metal substrate 111, a holder 12 holding the dressing substrate 11, and a dressing substrate fixed to the holder 12. 11) is configured to include a coupling member 15 to be maintained in the CMP equipment.

In Fig. 1B, reference numeral 114 denotes an acid resistant coating layer.

As shown in FIG. 2, when the CMP pad 1 is polished using the CMP pad conditioner 10, the draping substrate 11 does not have flexibility, and thus the CMP pad 1 is not shown in FIG. 2. ) Is convex in the center of the pad, and in the case of concave, the pad edge is worn out, which in turn impairs the uniformity of the wafer.

That is, in the case of the conventional conditioner, it does not have flexibility (elasticity) to dress only the convex side of the pad, and the pad having a relatively low height cannot dress, resulting in non-uniform deformation of the pad, thereby causing wafers. In addition to compromising the uniformity of the conditioner, the conditioner for dressing the pad also has a problem of uneven wear and shortening of tool life.

MEANS TO SOLVE THE PROBLEM The present inventors performed research and experiment in order to solve the above-mentioned problem of the prior art, and based on the result, this invention proposes this invention. The present invention consists of a plurality of dressing substrates, and gives flexibility to the pads It is an object of the present invention to provide a pad conditioner for CMP that can achieve a polishing.

Another object of the present invention is to provide a plurality of metal substrates to provide flexibility and to remove the stress concentration generated during the dressing of the pad to achieve uniform polishing of the pad, as well as to provide the abrasives at the edge of the dressing substrate. An object of the present invention is to provide a pad conditioner for CMP that can prevent cracking, dropping, and peeling of the acid resistant coating layer.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated.

The present invention is a dressing substrate comprising a metal substrate formed integrally, an abrasive fixed on the metal substrate and a metal binder layer for fixing the abrasive on the metal substrate, a holder holding the dressing substrate, and fixed to the holder. A pad conditioner for a CMP comprising a coupling member for holding a dressing substrate in a CMP apparatus, the dressing substrate being divided into a plurality of substrates;

A flexible member is inserted between the dressing substrate and the holder; And

It relates to a pad conditioner for CMP, characterized in that between the divided dressing substrate and the flexible member is provided to correspond to the respective dressing substrate divided inclination control substrate.

Hereinafter, the present invention will be described in detail with reference to the drawings.

The present invention provides a dressing substrate comprising a metal substrate, an abrasive fixed on the metal substrate, and a metal binder layer for fixing the abrasive on the metal substrate, a holder for holding the dressing substrate, and a dressing substrate fixed to the holder for the CMP. It is applied to the conditioner for dressing the pad for CMP, including the coupling member to hold the equipment.

3 and 4 show a preferred example of the pad conditioner for CMP of the present invention.

As shown in Fig. 3A, the conditioner 20 of the present invention includes a dressing substrate 21 which is divided into a plurality of pieces, a flexible member 23 that provides flexibility to the dressing substrate 21, and The inclination adjusting substrate 24 inserted between the sex member 23 and the dressing substrate 21, the holder 22 holding the flexible member 23, and the dressing substrate 21 fixed to the holder 22. ) Is configured to include a coupling member 25 to maintain the CMP equipment.

The dressing substrate 21 is divided into a plurality of substrates 211, and as shown in FIG. 3 (b), each of the dressing substrates 21a and 21b is each a metal substrate 211a and ( An abrasive 212 fixed on 211b) and a metal binder layer 213 for fixing the abrasive 212 on the metal substrates 211a and 211b.

The divided metal substrate may be acid-resistant coated by DLC (Diamond Like Carbon), TiN, Teflon or epoxy resin, or acid-plated rhodium, chromium, gold, or platinum to have acid resistance.

The divided metal substrates of each of the dressing substrates 21a and 21b may have one shape selected from the group consisting of parallelograms, squares, trapezoids, triangles, and circles, or a combination of these shapes.

The abrasive is fixed to the metal substrate by sintering, electrodeposition, or fusion.

Stainless steel is preferable as the material of the metal substrate.

Examples of the abrasive include super abrasive grains, diamond particles, CBN particles, and the like.

After fixing the abrasive to the metal substrate by the metal binder, it is preferable to coat the acid-resistant coating to withstand the acid, this coating may be epoxy-based paint or DLC (Diamond Like Carbon).

In the present invention, the dressing substrate is divided into several parts instead of one, and thus, each metal substrate can have a different load and also have flexibility.

When the size of each divided dressing substrate is too small, that is, when the number of divided dressing substrates is too large, it is difficult to adjust the height deviation of each divided metal substrate and the number of abrasives participating in polishing is reduced. The efficiency is not good.

If the size of each of the divided dressing substrates is too large, thermal deformation of the divided metal substrates is large when the metal binder layer is formed on the metal substrates, resulting in a reduction in the number of diamonds acting on the polishing, thereby lowering the polishing efficiency. As the number of divided metal substrates that can fit into the conditioner is reduced, there is a problem such as a conditioner using a single metal substrate.

In one example of a conditioner in accordance with the present invention, the divided metal substrate has dimensions of 30 to 150 mm, 10 to 40 mm, and 1 to 10 mm in height.

The flexible member 23 provides flexibility to the dracing substrate 21, and any material having such properties may be used, and preferred materials include sponge, rubber, and micro coupling. Springs such as

The inclination adjusting substrates 24 prevent warpage of the divided dressing substrate and allow the dressing substrate to dress the curved portion of the pad evenly.

The inclination adjusting substrates 24 are provided corresponding to each of the divided dressing substrate.

That is, the inclination adjusting substrates 24 are fixed to the metal substrates 211a and 211b of the dressing substrates 21a and 21b, respectively, as shown in FIG.

The inclination adjustment substrate 24 has a uniform thickness when the pressure of the air injected into the pad is low and the height variation is small. However, when the central portion of the pad is convex due to the high air pressure, the dressing substrate may uniformly polish the pad. The thickness should be different so that they can be used.

That is, the dressing substrate may vary the thickness between the inclination adjusting substrates 24 so as to uniformly polish the pad, and / or each inclination adjusting substrate 24 may also have a different thickness for each part.

On the other hand, in the present invention, the inclination adjusting substrate 24 is made uniform and the thickness of the flexible member 23 is changed to incline the dressing substrate 21 so that the dressing substrate 21 can polish the pad evenly. You can also

In addition, all of the thicknesses of the flexible member 23 and the tilt control substrate 24 may be appropriately changed so that the dressing substrate may uniformly polish the pad.

In addition, the pads may be uniformly polished by varying the thicknesses of the dressing substrates 21a and 21b.

The dressing substrate 21 and the inclination adjusting substrate 24 may be combined using a screw or an adhesive.

The holder 22 is coupled to the flexible member 23 to hold the flexible member so as to prevent left and right distortion of the flexible member 23.

The material of the holder 22 is not particularly limited, and preferred materials include plastics.

A coupling method of the holder 22 and the flexible member 23 is not particularly limited, and a screw coupling method or a coupling method using an adhesive may be used. A preferred coupling method is a coupling method using an adhesive.

Preferably, it is preferable to surround the holder 22, the flexible member 23 and the inclination adjusting substrate 24 with the acid resistant waterproof cloth 26 so as to firmly couple them.

The acid-resistant tarpaulin 26 binds the holder 22, the flexible member 23, and the inclination adjusting substrate 24 together to secure the coupling between them, and protects them from the mountains used during the CMP process. Do it.

The fixing of the acid resistant waterproof cloth 26 is made by the coupling member 25 on the holder 22.

The coupling member 25 is fixed to the holder 22, and serves to maintain the dressing substrate 21 in the CMP equipment.

The material of the coupling member 25 is not particularly limited, and preferred materials include stainless steel.

When the pad is polished using the pad conditioner for CMP configured according to the present invention, not only a straight pad but also a curved pad as shown in FIG. 4 may be uniformly polished.

The conditioner is dressing the pad by the rotation operation and the pressing operation, the stress is concentrated in the upper edge portion 2111 of the dressing substrate 21 during the rotation operation.

When stress is concentrated on the upper edge portion 2111 of the dressing substrate 21 as described above, the abrasive near the edge of the abrasive 212 attached to the metal substrate 211 is particularly stressed due to the stress concentration. In extreme cases, the abrasive may break or fall off, causing scratches on the workpiece.

In addition, in order to use the conditioner in the metal CMP process, it is necessary to coat the acid-resistant coating to withstand acids as described above, and the adhesion between the acid-resistant coating and the metal substrate is dependent on the adhesion between the acid-resistant coating and the metal binder layer. Compared with the relatively low value, there is a fear that the acid resistant coating layer coated on the edge where stress is concentrated is peeled off.

Therefore, in order to solve the problem caused by stress concentration in the upper edge portion 2111 of the dressing substrate 21, as shown in FIG. 5, the upper edge portion 2111 of the dressing substrate 21 is chamfered or rounded surface treatment. It is desirable to.

The chamfering of the metal substrate is preferably performed at an inclined angle of 10 to 70 ° with an edge portion of 0.5 to 10 mm or a round curved surface treatment at a radius of 1 to 500 mm.

The angle of inclination more preferable at the time of chamfering is 20-40 degrees.

As described above, when the upper edge portion 2111 of the dressing substrate 21 is chamfered or rounded, the pad concentrates on the upper edge portion 2111 of the dressing substrate 21 according to the rotation and pressure of the conditioner during polishing of the pad. As the stresses are dispersed along the curved surface, it is possible to prevent cracking or dropping of the abrasive positioned on the upper edge portion 2111 of the dressing substrate 21 and peeling of the acid resistant coating layer.

In addition, the abrasive is preferably positioned at the upper edge portion 2111 of the chamfered or round curved dressing substrate 21.

As described above, the abrasive positioned at the chamfered or round curved edge portion prevents the acid resistant coating material and the abrasive binder layer from directly contacting the pad to prevent the acid resistant coating agent from peeling off or the abrasive binder layer is worn out.

Hereinafter, the present invention will be described in more detail with reference to Examples.

(Example)

The conditioner (invention material 1) of the present invention consisting of a conventional conditioner (conventional material) in which a dressing substrate is integrally formed, a divided dressing substrate having an edge at right angles, and a dressing substrate having a rounded curved edge and a divided portion The conditioner (invention material 2) of this invention was prepared.

The conventional conditioner prepared as described above and the conditioner of the present invention were evaluated under the conditions of the edge wear, micro-scratch occurrence and conditioner life in the actual CMP process under the following conditions, and the results are shown in Table 1 below.

The evaluation conditions were measured by polishing the 8-inch wafer about 3000 mm 3 using an IPEC CMP machine.

division Evaluation results Edge wear Micro scratch occurrence degree Conditioner life Comprehensive Evaluation Conventional Corner and edge wear Average 100ea / wafer 40 hours Bad Invention 1 Low wear Average 40ea / wafer 80 hours Good Invention Material 2 Low wear Average 30ea / wafer 100 hours Great

As shown in Table 1, it can be seen that the conventional material caused a lot of scratches due to the stress concentration of the edge portion with the peeling of the acid-resistant coating layer at the edge portion caused a lot of scratches and short life.

In addition, it can be seen that the inventive material (1) exhibits better characteristics than the conventional material by preventing uneven wear in the conditioner by allowing different load values to be transmitted to each divided metal substrate.

In addition, the invention material (2) with the effect of the invention material (1) by dispersing the stress concentrated on the edge through the round curved surface peeling problem of the acid-resistant coating layer occurring at the edge portion and the diamond near the edge of the polishing surface is broken It can be seen that the particles exhibit the best performance by preventing the risk of particles falling off during conditioning and causing micro scratches.

As described above, according to the present invention, it is possible to uniformly dress the curved surface of the pad, and to minimize the risk of diamond cracking or falling off occurring near the edge of the dressing substrate, and also to peel off the acid resistant coating layer. Can be suppressed, thereby not only greatly improving the life of the tool but also performing uniform pad dressing.

Claims (18)

A dressing substrate comprising an integrally formed metal substrate, an abrasive fixed on the metal substrate, and a metal binder layer for fixing the abrasive on the metal substrate, a holder holding the dressing substrate, and a dressing substrate fixed to the holder. In the pad conditioner for CMP comprising a coupling member held in the CMP equipment, The dressing substrate is divided into a plurality of substrates; A flexible member is inserted between the dressing substrate and the holder; And Pad conditioner for CMP, characterized in that between the divided dressing substrate and the flexible member is provided to correspond to each dressing substrate divided inclined control substrate The pad conditioner for a CMP according to claim 1, wherein the flexible member, the holder, and the coupling member are surrounded by an acid resistant waterproof cloth. The pad conditioner for CMP according to claim 1 or 2, wherein the upper edge portion of the dressing substrate is chamfered or rounded. 4. The pad conditioner for CMP according to claim 3, wherein the abrasive is fixed to the chamfered or rounded surface. The metal substrate of the divided dressing substrate has one shape selected from the group consisting of parallelograms, squares, trapezoids, triangles and circles, or a complex shape in which two or more thereof are combined. Pad conditioner for CMP 4. The CMP according to claim 3, wherein the metal substrate of the divided dressing substrate has one shape selected from the group consisting of parallelograms, squares, trapezoids, triangles, and circles, or a complex shape in which two or more are combined. Pad conditioner 5. The CMP according to claim 4, wherein the metal substrate of the divided dressing substrate has one shape selected from the group consisting of parallelograms, squares, trapezoids, triangles, and circles or a complex shape in which two or more are combined. Pad conditioner The metal substrate of the divided dressing substrate is acid-resistant coated by DLC (Diamond Like Carbon), TiN, Teflon or epoxy resin, or rhodium, chromium, gold or platinum is acid-resistant. Pad conditioner for CMP, characterized by being plated 4. The method of claim 3, wherein the metal substrate of the divided dressing substrate is acid-resistant coated by DLC (Diamond Like Carbon), TiN, Teflon or epoxy resin, or rhodium, chromium, gold, or platinum is acid-resistant plated. Featuring a Pad Conditioner for CMP 5. The method of claim 4, wherein the metal substrate of the divided dressing substrate is acid-resistant coated by DLC (Diamond Like Carbon), TiN, Teflon or epoxy resin, or rhodium, chromium, gold, or platinum is acid-resistant plated. Featuring a Pad Conditioner for CMP 6. The method of claim 5, wherein the metal substrate of the divided dressing substrate is acid-resistant coated by DLC (Diamond Like Carbon), TiN, Teflon or epoxy resin, or rhodium, chromium, gold, or platinum is acid-resistant plated. Featuring a Pad Conditioner for CMP The pad conditioner for CMP according to claim 1 or 2, wherein the abrasive is fixed to the metal substrate by sintering, fusion, or electrodeposition. 4. The pad conditioner for CMP according to claim 3, wherein the abrasive is fixed to the metal substrate by sintering, fusion, or electrodeposition. The pad conditioner for CMP according to claim 4, wherein the abrasive is fixed to the metal substrate by sintering, fusion, or electrodeposition. The pad conditioner for CMP according to claim 5, wherein the abrasive is fixed to the metal substrate by sintering, fusion, or electrodeposition. The pad conditioner for CMP according to claim 1 or 2, wherein the abrasive is one selected from the group consisting of super abrasive grains, diamond grains, and CBN. The pad conditioner for CMP according to claim 3, wherein the abrasive is at least one selected from the group consisting of ultra abrasive grains, diamond grains, and CBN. The pad conditioner for CMP according to claim 4, wherein the abrasive is at least one selected from the group consisting of ultra abrasive grains, diamond particles, and CBN particles.

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