TW201434583A - Sapphire polishing pad trimmer and manufacturing method thereof - Google Patents

Abstract

The invention relates to a sapphire polishing pad trimmer and its manufacturing method, which utilize photolithography process to process a sapphire layer to form a plurality of sapphire abrasive particles on the surface of the sapphire layer, and the shaped sapphire layer and the sapphire abrasive particles are applied in the grinding surface of the polishing pad trimmer. The profile of the sapphire abrasive particles can be shaped and controlled by etching. There is no need to combine by utilizing electroplating or sintering. Therefore, the sapphire abrasive particles have excellent uniformity and are the same material as the bottom sapphire layer, so that there is no problem of thermal expansion and contraction at the interface. It is capable of preventing particles from falling off during polishing process, reducing the problem of scratching the wafer by the particles, thereby improving the service life and processing yield of the trimmer.

Description

Sapphire polishing pad dresser and manufacturing method thereof

The present invention relates to a polishing pad conditioner and a method of manufacturing the same, and more particularly to a sapphire polishing pad conditioner using a sapphire material as a polishing surface of a dresser and a method of manufacturing the same.

Press, Chemical Mechanical Polishing (CMP) is a technology in the manufacturing process of semiconductor devices. It uses chemical etching and mechanical force to planarize germanium wafers or other substrate materials during processing. Called chemical mechanical planarization. Before the introduction of chemical mechanical polishing technology, there were planarization techniques such as reverse etching, glass reflow, and spin coating. However, the effect was not satisfactory. Until the late 1980s, IBM developed chemical mechanical polishing technology to flatten the surface. More elaborate processing lays a key position in the manufacture of large-scale integrated circuits.

The chemical mechanical polishing system combines the processing methods of chemical etching and mechanical grinding, and is mainly divided into polishing and trimming. The polishing system consists of a polishing plate for wafer grinding, a wafer holder for fixing the wafer, and a device for supplying a slurry. First, the carrier uses vacuum. The wafer is sucked and applied to a polishing platform covered with a polishing pad, and the relative movement generated by the rotation of both the wafer carrier and the polishing platform is polished, and the wafer is polished while being wafer-polished. A polishing liquid is added between the surface and the polishing pad, and the polishing liquid has the function of lubrication and erosion to remove the convex portion of the surface of the wafer to achieve the goal of comprehensive planarization. Trimming refers to the use of a diamond dresser with thousands of diamond abrasive particles to rotate or oscillate the surface of the polishing pad to remove the grinding debris and engrave the groove on the surface of the polishing pad to enhance the polishing pad to the wafer. The frictional resistance, in turn, maintains the polishing rate and keeps the wafer clean; wherein the trimming process is divided into two types: in-situ trimming and off-situ trimming. The so-called in-line trimming refers to polishing while also performing The trimming action, while the offline trimming is done after the polishing is completed.

In order to achieve stable chemical mechanical polishing performance over the life of the polishing pad, a diamond dresser is used to maintain the texture normality of the polishing pad surface and remove polishing by-products such as wear debris. Please refer to FIG. 1A and FIG. 2A, which are schematic structural diagrams of a conventional polishing pad conditioner which is made by sintering or adhering diamond abrasive grains B to the surface of the metal substrate A. Due to the height, appearance and size of the diamond abrasive grain B exposed on the surface of the metal substrate A, the utilization rate of the diamond abrasive grain B is unstable, and tens of thousands of diamond abrasive grains B are plated or brazed. The method of sintering is combined with the metal substrate A, and the bonding force is positively correlated with the size and state of the contact area. There is a thermal expansion between the diamond abrasive grain B and the metal substrate A, which causes the diamond particle B to fall off, and another diamond abrasive grain. In the mode of B shedding, the surface of the metal substrate A is coated with the adhesive layer C, and the diamond abrasive particles B are adhered to the surface of the adhesive layer C. If the layer C is subsequently corroded by the polishing liquid, the subsequent effect is lost, and the diamond abrasive grains are lost. B falls off. As a result of the falling off of the diamond abrasive grains, it may cause scratches and fragmentation loss of a part or a large area of the workpiece.

For example, Taiwan Patent Publication No. I264345 "Chemical Mechanical Abrasive Dresser" has improved superabrasive adhesion in a resin layer. The CMP polishing pad includes a resin layer, superabrasive grains fixed in the resin layer so that an exposed portion of each superabrasive grain protrudes from the resin layer, and a superabrasive grain and the resin layer are disposed An intermetallic coating wherein the exposed portion is substantially outside the metal coating. The metal plating serves to enhance the superabrasive adhesion in the resin layer as compared to the superabrasive without the metal plating. However, although the former case uses a metal plating layer to enhance the adhesion of the superabrasive particles to the resin layer, it still cannot solve the disadvantage that the polishing liquid corrodes the resin layer and makes the superabrasive particles easily fall off by the corrector.

For example, the Taiwan Patent Publication No. I289093 "Diamond Disc Process" includes the steps of: providing a receiving unit and forming an adhesive layer in the accommodating unit, and covering a hollow piece having a plurality of meshes on the adhesive layer In the above, a plurality of diamond particles are implanted on the hollow member and embedded in the mesh of the hollow member, and the diamond particles are adhered to the adhesive layer, and then a resin material is poured into the receiving unit to fix the diamond particles. The resin material finally detaches the resin material together with the diamond particles from the accommodating unit, thereby obtaining a diamond dish base in which the diamond particles are evenly distributed and aligned. However, the method attaches the diamond particles to the adhesion layer and injects the resin material to fix the diamond particles. When the resin material contacts the polishing liquid, it will be corroded after reacting with it, and the diamond particles will fall off, causing the processed object (such as Wafer) scratched or fragmented.

Therefore, how to make uniformity, avoid the difference in thermal expansion coefficient between the diamond abrasive grains and the metal substrate, and the corrosion of the polishing layer by the polishing layer, resulting in the loss of the diamond during processing, loss of the processed object, and long-term polishing with the polishing pad. The polishing pad dresser, which can accurately control the state of the abrasive grains and improve the yield and reliability of the chemical mechanical polishing process, is an important issue.

Since the prior art is still unable to perfect such problems, it is necessary to break through and solve them. Therefore, how to improve convenience, practicability and economic benefits is a key project that the industry should strive to solve and overcome.

Therefore, the inventors of the present invention have started to develop a solution in view of the fact that the conventional diamond polishing pad conditioner and its manufacturing method are not ideal, and hope to develop a more convenient and practical The highly economical sapphire polishing pad conditioner and its manufacturing method have the advantages of the present invention in order to promote the development of society.

The object of the present invention is to provide a sapphire polishing pad conditioner which is formed on the surface of a sapphire layer to form a plurality of sapphire abrasive grains, which can be combined by means of electroplating or sintering, thereby avoiding the occurrence of crystal falling off during the polishing process and lowering the crystal. The problem that the circle is scratched by the grain improves the yield of chemical mechanical polishing (CMP), and the size of the sapphire abrasive grains increases the number of Working Crytals, and the rate of grain smoothing. Slow, therefore, the rate at which the wafer removal rate decreases will also slow down, improving the life of the dresser and the processing yield.

The object of the present invention is to provide a method for manufacturing a sapphire polishing pad conditioner, which is processed by lithography on the surface of a sapphire layer to integrally form a plurality of sapphire abrasive grains on the surface of the sapphire layer, and the formed sapphire abrasive grain shape can be etched by etching. Control to improve the uniformity of grain size, avoid wafer peeling and scratch the wafer, and improve the yield and reliability of the chemical mechanical polishing process.

To achieve the above object, the present invention provides a sapphire polishing pad conditioner comprising a carrier disk; a sapphire layer disposed on the carrier plate; and a plurality of sapphire abrasive particles integrally formed on the sapphire layer surface.

In order to achieve the above object, the present invention provides a method for manufacturing a sapphire polishing pad conditioner, the method comprising: providing a sapphire layer; performing a lithography process on the sapphire layer; forming a plurality of sapphire abrasive grains on the surface of the sapphire layer; And setting the sapphire layer on a carrier.

10. . . Carrier disk

20. . . Sapphire layer

30. . . Sapphire abrasive

A. . . Metal substrate

B. . . Diamond abrasive

C. . . Next layer

Figure A is a schematic view of the structure of a conventional diamond polishing pad conditioner (1);
The first B picture is a schematic diagram of the structure of a conventional diamond polishing pad conditioner (2);
2A is a schematic structural view (1) of a preferred embodiment of the present invention;
2B is a schematic structural view of a preferred embodiment of the present invention (2);
Figure 3A is a plan view (1) of the structure of the preferred embodiment of the present invention;
3B is a top plan view of a preferred embodiment of the present invention; and FIG. 4 is a flow chart showing the steps of a preferred embodiment of the present invention.

For a better understanding and understanding of the structural features and the achievable effects of the present invention, the preferred embodiments and the detailed description are as follows:

Since the conventional diamond polishing pad conditioner fixes the diamond abrasive grains to a metal substrate by means of inlaying, electroplating, sintering or adhesion, the connection interface is easily separated by the thermal expansion coefficient, or the adhesive layer is in contact with the polishing liquid. After causing corrosion of the adhesive layer and loss of adhesion, the diamond abrasive grains are peeled off from the surface of the metal substrate, resulting in a decrease in the wafer removal rate and the abrasion rate, and scratching of the wafer or the fragment. The present invention is directed to techniques for improving conventional disadvantages.

First, please refer to FIG. 2A and FIG. 2B, which are a schematic structural diagram (1) and a structural schematic diagram (2) of a preferred embodiment of the present invention; as shown in the figure, the embodiment includes a carrier 10 and a carrier The sapphire layer 20 and the plurality of sapphire abrasive grains 30 are disposed on the carrier disk 10, and the sapphire abrasive grains 30 are integrally formed on the surface of the sapphire layer 20.

The sapphire abrasive grains 30 have a height of 50 to 200 μm. The sapphire abrasive grains 30 are shaped as a pointed cone, a flat cone, a three-sided cone, a flat three-sided cone, or a combination thereof, and the sapphire abrasive grains shown in the second A and second B 30 is a pointed cone column and a flat cone column, which can change the shape of the sapphire abrasive grain 30 according to the needs of use, to polish and grind the polishing pad. The sapphire layer 20 and the plurality of sapphire abrasive particles 30 are of a single crystal structure, a polycrystalline structure, or a combination thereof.

Please refer to FIG. 3A and FIG. 3B together, which are top view (1) and top view (2) of the structure of the preferred embodiment of the present invention; as shown in FIG. 3A, the sapphire abrasive grains 30 are The arrangement of the surfaces of the sapphire layer 20 may be arranged in a specific order, or may be arbitrarily ordered, and the arrangement thereof is not limited. The sapphire abrasive particles 30 can be combined in different outer shapes and in different orders, as shown in FIG.

Therefore, the structure in which the sapphire layer 20 is integrally formed with the sapphire abrasive grains 30 and the variable shape and arrangement order of the sapphire abrasive grains 30 make the sapphire abrasive grains 30 less likely to fall off from the sapphire layer 20, thereby enhancing the grinding of the wafer. Rate of removal, rate of removal, and yield.

Please refer to the fourth figure, which is a flow chart of the steps of the preferred embodiment of the present invention; as shown in the figure, the method for forming the anti-adhesive transparent film of the present embodiment has the following steps:

Step S50: providing a sapphire layer;

Step S60: performing a lithography process on the sapphire layer;

Step S70: forming a plurality of sapphire abrasive grains on the surface of the sapphire layer; and

Step S80: setting the sapphire layer on a carrier tray.

The step of performing a photolithography process on the sapphire layer comprises:

Step S62: coating a photoresist layer on the surface of the sapphire layer;

Step S64: setting a photomask over the photoresist layer and performing exposure;

Step S66: immersing the exposed photoresist layer in a developer; and

Step S68: etching the developed sapphire layer.

The photoresist layer is selected from a positive photoresist layer or a negative photoresist layer, and has a photoresist thickness of 20 to 200 μm. The sapphire abrasive grains have a height of 50 to 200 μm. The sapphire abrasive grains are shaped as a pointed cone, a flat cone, a three-sided cone, a flat three-sided cone, or a combination thereof. The light source of the exposure is selected from the group consisting of ultraviolet light, far ultraviolet light, X-ray, electron beam or ion beam. The sapphire layer and the plurality of sapphire abrasive grains are selected from a single crystal structure, a polycrystalline structure or a combination thereof.

In addition, the etching process may be selected from the group consisting of dry etching, wet etching, or a combination thereof. The etching process may be performed by dry etching, followed by wet etching, or vice versa. The gas for dry etching may be BCl ₃ /Cl ₂ /Ar or BCl ₃ /HBr/Ar, and the solution selected for wet etching may be H ₂ SO ₄ /H ₃ PO ₄ , Br ₂ /MeOH or NH ₄ OH/H. ₂ O ₂ /H ₂ O.

In summary, the present invention applies a sapphire material to the polishing surface of a polishing pad conditioner, and processes the sapphire material by a photolithography process, and after forming, developing, and etching, integrally forms a plurality of sapphire on the surface of a sapphire layer. The abrasive grains, the sapphire abrasive grains formed by the lithography have good uniformity, and the shape can also be easily changed by changing the mask pattern. Since the sapphire abrasive grains are integrally formed on the surface of the sapphire layer, there is no connection interface. And the two materials are the same material, so the connection interface is not separated due to the difference in thermal expansion coefficient, so that the service life, the grinding rate and the grinding efficiency of the polishing pad dresser can be improved, and the workpiece can be avoided. Scratched or fragmented.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

10. . . Carrier disk

20. . . Sapphire layer

30. . . Sapphire abrasive

Claims (10)

A sapphire polishing pad conditioner for trimming a polishing pad comprising:
a carrier disk;
a sapphire layer disposed on the carrier plate; and a plurality of sapphire abrasive grains integrally formed on the surface of the sapphire layer. The sapphire polishing pad conditioner according to claim 1, wherein the sapphire abrasive grains have a height of 50 to 200 μm. The sapphire polishing pad conditioner according to claim 1, wherein the sapphire abrasive grains are formed by a pointed cone, a flat cone, a three-sided cone, a flat three-sided cone, or a combination thereof. The sapphire polishing pad conditioner of claim 1, wherein the sapphire layer and the plurality of sapphire abrasive grains are a single crystal structure, a polycrystalline structure or a combination thereof. A method for manufacturing a sapphire polishing pad conditioner, the steps of which include:
Provide a sapphire layer;
Performing a photolithography process on the sapphire layer;
Forming a plurality of sapphire abrasive grains on the surface of the sapphire layer; and disposing the sapphire layer on a carrier. The method for manufacturing a sapphire polishing pad conditioner according to claim 5, wherein the step of performing a photolithography process on the sapphire layer comprises:
Coating a photoresist layer on the surface of the sapphire layer;
Forming a photomask over the photoresist layer and performing exposure;
The photoresist layer after immersion exposure is applied to a developer; and the sapphire layer after etching is developed. The method for manufacturing a sapphire polishing pad conditioner according to claim 6, wherein the photoresist layer is selected from a positive photoresist layer or a negative photoresist layer. The method of manufacturing a sapphire polishing pad conditioner according to claim 6, wherein the source of the exposure is selected from the group consisting of ultraviolet light, far ultraviolet light, X-ray, electron beam or ion beam. The method of manufacturing a sapphire polishing pad conditioner according to claim 6, wherein the etching process is selected from the group consisting of dry etching, wet etching, or a combination thereof. The sapphire polishing pad conditioner of claim 5, wherein the sapphire layer and the plurality of sapphire abrasive grains are single crystal structures, polycrystalline structures or a combination thereof.