Background Art [2] As semiconductor devices become more highly integrated, a multi-layered inter- connection technique has been widely employed. In this case, the multi-layered inter- connections are insulated by an interlayer insulating layer interposed therebetween.

The surface profile of the interlayer insulating layer directly affects a subsequent process such as a photolithography process. Thus, it is preferable that the interlayer insulating layer is fully planarized throughout a semiconductor substrate.

[3] Recently, a chemical-mechanical polishing (CMP) technique is widely used in the planarization process. The CMP technique is performed using a CMP apparatus having a pad conditioner.

[4] FIG. 1 is a cross-sectional view to illustrate a conventional method of fabricating a pad conditioner using an electroplating manner.

[5] Referring to FIG. 1, diamond particles 3 are uniformly distributed on a shank 1 made of stainless steel. A metal layer 5 such as a nickel layer is selectively formed on the shank 1 between the diamond particles 3 using an electroplating technique. Thus, t he diamond particles 3 are held and fixed by the metal layer 5. However, in the event that the metal layer 5 is formed using the electroplating technique, recessed regions may be formed at interface regions A between the diamond particles 3 and the metal layer 5. Thus, the diamond particles 3 may be detached from the surface of the shank 1 during a CMP process. These detached diamond particles 3 may cause a scratch at a surface of a semiconductor substrate to be polished.

[6] FIG. 2A and FIG. 2B are cross-sectional views to illustrate another conventional method of fabricating a pad conditioner using a melting technique.

[7] Referring to FIG. 2A and FIG. 2B, diamond particles 13 and metal powder 15 is uniformly distributed on a shank 11 made of stainless steel. The metal powder 15 is then melted and cooled to form a solid-state metal layer 15a that holds the diamond particles 13. In this case, a meniscus is formed at an interface region B between the diamond particles 13 and the metal layer 15a as shown in FIG. 2B. The meniscus is due to the surface tension of the melted metal. Thus, the metal layer 15a holds the diamond particles more securely as compared to the prior art described with reference to FIG. 1. However, the metal layer 15a is apt to be affected by acid slurry, which is widely used in the CMP process. Thus, the metal layer 15a in the interface region B may be easily corroded by the acid slurry. As a result, even though the metal layer 15a is formed using the melting technique, the diamond particles 13 may be easily detached from the shank 11 due to the chemical-mechanical polishing process using the acid slurry.

Disclosure of Invention Technical Problem [8] According to the conventional arts as mentioned above, diamond particles, which act as polishing particles, are held by the metal layer. Therefore, it is difficult to form a polishing pad conditioner that is suitable for the chemical-mechanical polishing process using the acid slurry.

Technical Solution [9] It is, therefore, an object of the present invention to provide methods of fabricating a high performance polishing pad conditioner using vitrified compound that has an acid-resistant property.

[10] It is another object of the present invention to provide high performance polishing pad conditioners having immunity from acid slurry.

[11] According to an aspect of the present invention, there are provided methods of fabricating polishing pad conditioners. The methods comprise a step of preparing a plate made of insulating material. A vitrified powder layer is formed on a front surface of the plate, and polishing particles are uniformly infiltrated into the vitrified powder layer. The vitrified powder layer is then melted and cooled to form a solid-state vitrified compound layer that holds the polishing particles.

[12] The plate may be formed of ceramics such as aluminum oxide (Al 2O3).

[13] The vitrified powder layer may be made of silicon oxide (SiO), aluminum oxide 2 (Al O), calcium oxide (CaO), sodium oxide (Na O), titanium oxide (TiO), zirconium 2 3 2 2 oxide (ZrO), and zinc oxide (ZnO).

2 [14] The polishing particles may be diamond particles or cubic boron nitride particles.

[15] In addition, a metal shank may be attached on a backside surface of the plate after forming the vitrified compound layer.

[16] According to another aspect of the present invention, there are provided polishing pad conditioners. The polishing pad conditioners comprise a plate made of insulating material. Polishing particles are uniformly provided on a front surface of the plate. A region between the polishing particles is filled with a vitrified compound layer. The vitrified compound layer holds the polishing particles.

[17] The plate may further include a guard ring protruded from an edge surface thereof.

In this case, the vitrified compound layer and the polishing particles are located in a recessed region surrounded by the guard ring.

[18] A surface of the vitrified compound layer preferably has the same level as the guard ring. In addition, a portion of the respective polishing particles is protruded from the surface of the vitrified compound layer.

[19] Further, a metal shank may be attached on a backside surface of the plate.

[20] According to the present invention as mentioned above, the polishing particles on the plate are held by the vitrified compound layer having an acid-resistant property.

Therefore, even though the vitrified compound layer is exposed to acid slurry, it can prevent the vitrified compound layer from being oxidized. As a result, the polishing particles may not be detached from the plate during the chemical-mechanical polishing process using the acid slurry.

Description of Drawings [21] The above and other features and advantages of the present invention will become more apparent to those of ordinary skill in the art by describing in detail preferred em- bodiments thereof with reference to the attached drawings in which: [22] FIG. 1 is a cross-sectional view to illustrate a conventional method of fabricating a pad conditioner using an electroplating technique; [23] FIG. 2A and FIG. 2B are cross-sectional views to illustrate another conventional method of fabricating a pad conditioner using a melting technique; [24] FIG. 3 is a schematic view illustrating a portion of a chemical-mechanical polishing apparatus having a pad conditioner according to the present invention; [25] FIG. 4 is a cross-sectional view illustrating the pad conditioner shown in FIG. 3; [26] FIG. 5 is a process flow chart to illustrate methods of fabricating vitrified powder used in the fabrication of pad conditioners according to the present invention; and [27] FIG. 6 to FIG. 9 are cross-sectional views to illustrate methods of fabricating pad conditioners according to the present invention.

Best Mode [28] The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these em- bodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the thickness of layers and regions are exaggerated for clarity. In addition, when a layer is described to be formed on other layer or on a substrate, which means that the layer may be formed on the other layer or on the substrate, or a third layer may be interposed between the layer and the other layer or the substrate. Like numbers refer to like elements throughout the specification.

[29] FIG. 3 is a schematic view illustrating a portion of a chemical-mechanical polishing apparatus having a pad conditioner in accordance with the present invention.

[30] Referring to FIG. 3, a polishing pad 53 is mounted on a pad plate 51. The pad plate 51 is rotated by a rotational axis 55. A wafer chuck 57 is positioned over a pre- determined region of the polishing pad 53. The wafer chuck 57 holds and fixes a wafer 59 to be loaded thereunder. The wafer chuck 57 is rotated by a rotational axis 61. In addition, the wafer chuck 57 moves upwardly and downwardly. During a chemical- mechanical polishing process for planarizing a material layer formed on the wafer 59, the wafer 59 moves down to be in contact with the polishing pad 53 and the wafer 59 and the polishing pad 53 are rotated with each other. In this case, polishing slurry is provided on the polishing pad 53. As a result, the material layer on the wafer 59 is chemically and mechanically polished to have a flat surface.

[31] In the meantime, the polishing pad 53 should have a specific surface roughness.

This is for mechanically polishing the surface of the material layer on the wafer 59.

However, when the polishing process is performed for a long time, the surface roughness of the polishing pad 53 is reduced. As a result, the efficiency of the polishing process may be degraded. In order to keep the surface roughness of the polishing pad 53 uniform and remove the remaining slurry on the polishing pad 53, a polishing pad conditioner 90 is used. The polishing pad conditioner 90 comprises a plate 71 and polishing particles 77 attached on a front surface of the plate 71.

Furthermore, the polishing pad conditioner 90 may comprise a metal shank 79 attached on a backside surface of the plate 71. The polishing pad conditioner 90 is rotated by a rotational axis 81. In addition, the polishing pad conditioner 90 may move upwardly and downwardly like the wafer chuck 57.

[32] FIG. 4 is a cross-sectional view illustrating the pad conditioner shown in FIG. 3 in detail.

[33] Referring to FIG. 4, a plurality of polishing particles 77 are uniformly distributed on the front surface of the plate 71 made of insulating material such as ceramics. The ceramics may be aluminum oxide (Al 2O3). The polishing particles 77 may be diamond particles or cubic boron nitride particles. A region between the polishing particles 77 is filled with a vitrified compound layer 75a. The vitrified compound layer 75a holds the polishing particles 77. The vitrified compound layer 75a may preferably be a non- metal layer having an acid-resistant property. For example, the vitrified compound layer 75a may be composed of silicon oxide (SiO2), aluminum oxide (Al2O3), calcium oxide (CaO), sodium oxide (Na O), titanium oxide (TiO), zirconium oxide (ZrO) and 2 2 2 zinc oxide (ZnO).

[34] Further, the plate 71 may include a guard ring 71r protruded from an edge surface thereof. As a result, the plate 71 has a recessed region 7 la surrounded by the guard ring 71r. In this case, the vitrified compound layer 75a and the polishing particles 77 are placed within the recessed region 71a. The surface of the vitrified compound layer 75a preferably has the same level as that of the guard ring 71r. A portion of the respective polishing particles 77 is protruded from the surface of the vitrified compound layer 75a to provide a specific surface roughness of the polishing pad 53 shown in FIG. 3.

[35] In addition, a metal shank 79a may be attached on the backside surface of the plate 71. The plate 71 preferably has protrusions 71b formed on the backside surface thereof. In this case, the metal shank 79 has holes 79a into which the protrusions 71b are inserted. As a result, adhesive strength between the metal shank 79 and the plate 71 may be increased. The metal shank 79 may be made of metal material such as stainless steel.

[36] Hereinafter, methods of fabricating the polishing pad conditioner 90 shown in FIG.

4 will be described with reference to FIG. 5 to FIG. 9 FIG. 5 is a process flow chart to illustrate methods of fabricating vitrified powder used in fabrication of a vitrified compound layer of a polishing pad conditioner in accordance with the present invention, and FIG. 6 to FIG. 9 are cross-sectional views to illustrate methods of fabricating the polishing pad conditioner in accordance with the present invention.

[37] Referring to FIG. 5, various vitrified elements are mixed to form a vitrified mixture (step 101). The vitrified mixture is preferably composed of 45 to 70 wt% SiO2, 5 to 30 wt% AlO, 1 to 20 wt% CaO, 5 to 30 wt% Na O, 1 to 35 wt% TiO, 0.5 to 20 wt% 2 3 2 2 ZrO, and Q 1 to 15 wt% ZnO. The vitrified mixture is then pulverized using a pul- 2 verization process to form vitrified powder. The pulverization process may comprise first and second pulverization processes (steps 103 and 105), which are sequentially performed.

[38] The first pulverization process (step 103) comprises a step of melting the vitrified mixture in a furnace, a step of rapid cooling the melted vitrified mixture to solidify, and a step of pulverizing the solidified vitrified mixture to form vitrified powder. The vitrified mixture may preferably be melted during 4 to 10 hours at a high temperature of 1400 °C to 1700 °C. The vitrified powder has a uniform mixing ratio through the first pulverization process (step 103). In addition, the vitrified powder obtained from the first pulverization process (step 103) may have a more uniform mixing ratio using the second pulverization process (step 105). The second pulverization process (step 105) may be performed using the same condition as the first pulverization process (step 103).

[39] Referring to FIG. 6, the vitrified powder obtained by the method described with reference to FIG. 5 is uniformly distributed on the front surface of the plate 71 made of insulating material such as ceramics. The ceramics may be Al2O3. A proper pressure is then applied to the vitrified powder to form a molded vitrified powder layer 75.

Preferably, the plate 71 has a guard ring 71r protruded from an edge thereof. Thus, the plate 71 has a relatively low surface at its central region as compared to the guard ring 71r. As a result, the plate 71 has a recessed region 71a surrounded by the guard ring 71r. In this case, the vitrified powder is distributed within the recessed region 71a, and the vitrified powder layer 75 is also formed to fill the recessed region 71a. The guard ring 71r prevents the vitrified powder layer 75 from being formed on the edge of the plate 71. More preferably, a protection ring 73 is additionally mounted on the edge of the plate 71, for example, on the guard ring 71r during formation of the vitrified powder layer 75. As a result, the vitrified powder layer 75 may be formed to have a surface higher than the guard ring 71r. In addition, the plate 71 may preferably include protrusions 71b formed on the backside surface of the plate 71.

[40] Referring to FIG. 7, polishing particles 77 are uniformly distributed on the vitrified powder layer 75. The polishing particles 77 may be diamond particles or cubic boron nitride particles. A predetermined pressure is applied to the polishing particles 77 so that the polishing particles 77 are infiltrated into the vitrified powder layer 75.

[41] Referring to FIG. 8, the vitrified powder layer 75 is melted at a high temperature of about 1000 °C to 1700 °C for 4 to 10 hours to form vitrified liquid. In this case, the guard ring 71r prevents the vitrified liquid from overflowing. The vitrified liquid is then cooled down to form a solid-state vitrified compound layer 75a that holds the polishing particles 77. An oxidation resistant gas may be preferably used as an ambient gas during the process for melting and cooling the vitrified powder layer 75 in order to prevent the polishing particles 77 from being oxidized. A nitrogen gas may be used as the ambient gas.

[42] The volume of the vitrified powder layer 75 may be reduced during the process of melting and cooling the vitrified powder layer 75. Thus, the surface of the vitrified compound layer 75a becomes lower than that of the vitrified powder layer 75.

Preferably, the surface of the vitrified compound layer 75a has the same level as that of the guard ring 71r. The protection ring 73 is then removed.

[43] Referring to FIG. 9, it is preferable to attach a metal shank 79 to the backside surface of the plate 71 after forming the vitrified compound layer 75a. The metal shank 79 is made of metal material such as stainless steel. The metal shank 79 functions to support the plate 71 and has holes 79a into which the protrusions 71b of the plate 71 are inserted. The metal shank 79 is connected to a rotational axis (81 of FIG. 3) of a polishing pad conditioner of the chemical-mechanical polishing apparatus.

[44] When the vitrified compound layer 75a is directly formed on the metal shank 79, adhesive strength between the vitrified compound layer 75a and the metal shank 79 may be very weak. Thus, the plate 71 is preferably interposed between the vitrified compound layer 75a and the metal shank 79 [45] In accordance with the present invention as mentioned above, polishing particles are held by a vitrified compound layer having an acid-resistant property. Therefore, even though the vitrified compound layer is exposed to acid slurry, the polishing particles may not be detached from the vitrified compound layer. As a result, a reliable polishing pad conditioner may be obtained. In addition, there is no need to rinse the polishing pad conditioner using a cleaning solution such as deionized water after the chemical-mechanical polishing process using the acid slurry. This is because the vitrified compound layer may not be corroded by the acid slurry. Therefore, the throughput of the semiconductor fabrication process using the chemical-mechanical polishing process may be improved.