TWI598184B - Polishing head of CMP device including high strength alloy - Google Patents

Description

Polishing head of CMP device including high strength alloy

The present invention relates to a polishing head for a chemical mechanical polishing (CMP) device for manufacturing a semiconductor device, and more particularly to a polishing head of a CMP device including a high-strength alloy, which improves the structure of a circular porous plate forming a polishing head, By replacing the material with a high-strength special alloy, it is fundamentally prevented from cracking of the ceramic material, thereby prolonging the life of the product and maximizing the operation rate of the equipment, thereby greatly improving production efficiency.

Recently, as semiconductor devices have become highly integrated, wiring structures have been formed into a plurality of layers, and surface faults between unit cells stacked on a semiconductor substrate have increased. Therefore, it is very important to explore a technique for planarizing the surface tomography.

In the technique of planarizing the surface of the semiconductor substrate, CMP is a physical and chemical polishing of the surface of the semiconductor substrate, and after the wafer is adsorbed by the polishing head, the polishing pad and the polishing liquid attached to the upper portion of the polishing table are supplied. In the state of (slurry), the contact is rotated at a high speed.

A polishing head of a conventional CMP apparatus will be described with reference to Figs. 1 to 3 .

First, as shown in FIG. 1, the CMP apparatus includes a polishing head (10), a vacuum adsorption fixed wafer (W), and after moving to the polishing pad (21) of the polishing table (20), applying pressure contact and rotating at a predetermined speed. Turning, the flattening operation is performed; the polishing table (20) has a polishing pad (21) on the upper portion, and is rotated at a predetermined speed to directly contact the polishing surface of the wafer (W).

Further, the polishing head (10) includes: a pressure adjusting device (11) that performs a pumping operation when performing a CMP process; and an adsorption portion (12) located below the pressure adjusting device (11), utilizing The vacuum generated by the pumping of the pressure regulating device (11) directly adsorbs the wafer (W); the snap ring (13) prevents the wafer (W) from being polished during the polishing of the wafer (W) The adsorption portion (12) is detached.

Further, a polishing casing (14) is coupled to the pressure adjusting device (11), and the polishing casing (14) is coupled to a rotating shaft (15) that rotates at a high speed.

Further, a circular perforated plate (30) having a plurality of through holes formed in a surface thereof is formed at a lower portion of the pressure adjusting device (11), and pressure transmission due to the pressure adjusting device (11) is performed. The function to the adsorption unit (12).

Here, the structure of the porous plate (30) will be specifically described.

As shown in FIG. 2 and FIG. 3, the perforated plate (30) includes: a disc-shaped main body (31); an edge portion (32) surrounding the edge of the main body (31); and a positioning pin (33). a protrusion formed at an upper center of the main body (31); a plurality of holes (34) formed in the main body (31); and a porous groove (35) formed on one side of the main body (31), formed with Four holes; a central groove portion (36) forming a rear center of the main body (31); a ball (37) partially inserted and fixed in the center of the central groove portion (36); a balance pin (38) , a plurality of, inserted and fixed around the central groove portion (36).

With the circular perforated plate (30) constructed as described above, the positioning pin (33) protrudingly formed at the center of the upper portion of the main body (31) is positioned centrally, and is prevented from being prevented from being attached to the central portion of the lower portion ( 36) The effect of the crack caused by the touch or vibration of the ball (37), instead of the problem of reducing the flatness uniformity of the wafer process according to the positioning pin (33).

Further, due to the mutual sway with the ball (37), non-directional cracking occurs centering on the central portion and the center of the center groove portion (36), and a leak that should not occur occurs during the process. (Leak), the effect of ceramic powder on the surface of semiconductor wafers (W) is to seriously reduce the yield (Yield).

For this reason, the abnormality occurs when the equipment is stopped and the operation rate is low, which has a serious impact on productivity.

And, a plurality of balance pins (38) mounted on the edge portion of the central groove portion (36) are provided for balance of the entire polishing head, and the six balance pins (38) are prevented from being biased to one side in the process. , or the ability to skew the skew.

However, as shown in FIG. 3(b), the conventional balance pin (38) is attached to the central groove portion (36) by a special adhesive to fix the fixing portion (38a) at the lower end of the balance pin (38). As time passes, the adhesive solidifies and the phenomenon of powder flying occurs, which has a severely bad effect on the polishing process.

Patent Document 10-0416808, Published Patent Document 10-2000-0008534, Registered Patent Document 10-04191135, Published Patent Document 10-2010-0079165, Registered Patent Document 10-0600231, and Registered Patent Document 10-0814068.

The present invention has been developed in order to solve the above problems, and an object of the present invention is to provide a polishing head of a CMP apparatus including a high-strength alloy, which improves the structure of a circular perforated plate forming a polishing head, and replaces the material with a high-strength special alloy. The crack of the ceramic material is fundamentally prevented, thereby prolonging the life of the product and maximizing the operation rate of the equipment, thereby greatly improving the production efficiency.

In order to achieve the above object, a polishing head of a CMP apparatus of the present invention includes: a pressure adjusting device that performs a pumping action when performing a CMP process; and an adsorption portion located below the pressure regulating device, with which the pressure is adjusted The vacuum generated by the pumping of the device directly adsorbs the wafer; a circular perforated plate is located at a lower portion of the pressure regulating device, and a plurality of through holes are formed in the surface to transmit the pressure generated by the pressure adjusting device to The adsorption portion; the snap ring prevents the wafer from being detached from the adsorption portion during polishing of the wafer, the polishing head of the CMP device characterized in that the porous plate comprises: a disk-shaped body; a groove, which is a pair, is symmetrically formed on the upper center of the main body; a plurality of holes are formed in the main body; a porous groove is formed on one side of the main body, and four holes are formed; a groove portion formed at a center of a rear surface of the main body; a ball partially inserted and fixed at a center of the central groove portion; and a circular metal plate inserted and fixedly disposed at the central groove portion a central portion is formed with a bare hole so as to expose a part of the ball; a balance pin is provided in plurality, inserted and fixed around the central groove portion; and upper and lower edge portions surround the edge of the main body, Wherein, the metal plate is composed of a special alloy containing zirconium, titanium, nickel and chromium.

Further, the present invention is characterized in that the main body, the upper edge portion, and the lower edge portion are made of a special alloy material containing zirconium, titanium, nickel, and chromium.

Moreover, the invention is characterized in that the special alloy comprises 40 to 60% by weight of zirconium, 30 to 70% by weight of titanium, 5 to 15% by weight of nickel and chromium.

Further, according to the invention, the metal plate, the main body, the upper portion, and the lower edge portion are made of a metal material containing stainless steel (SUS).

Further, the present invention is characterized in that the fixing portions of the plurality of balance pins are formed in a spiral shape and are fixed to the central groove portion by screwing.

Further, the present invention is characterized in that the air supply line that is formed by the porous body formed in the main body is made of an integral metal material of the same type.

Further, the present invention is characterized in that the metal plate is made of titanium.

Further, the present invention is characterized in that the metal plate, the main body, the upper portion, and the lower edge portion are all made of titanium.

10‧‧‧ polishing head

11‧‧‧ Pressure regulating device

12‧‧‧Adsorption Department

13‧‧‧ card ring

100‧‧‧Perforated plate

110‧‧‧ Subject

111‧‧‧ positioning groove

112‧‧‧ hole

113‧‧‧Porous grooves

114‧‧‧Central Groove

115‧‧‧ ball

116‧‧‧Metal plate

116a‧‧‧ bare holes

117‧‧‧balanced pin

117a‧‧‧Fixed Department

120‧‧‧ upper edge

130‧‧‧lower edge

1 is a schematic structural view of a conventional CMP apparatus; FIG. 2 is a side structural view of a conventional circular perforated plate; FIG. 3(a)(b) is a top and bottom cross-sectional view of a conventional circular perforated plate; Figure 5 (a) (b) is a top and bottom cross-sectional view of a circular perforated plate of the present invention; Figure 6 is an exploded cross-sectional view of the circular perforated plate of the present invention.

First, the reference numerals are attached to the constituent elements of the respective drawings, and the same reference numerals are used for the same constituent elements as far as possible in different drawings. Further, in the description of the present invention, specific descriptions of well-known functions or configurations are not necessary or the description of the present invention is omitted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be more specifically described with reference to the accompanying drawings.

4 is a side structural view of a circular perforated plate of the present invention, and FIGS. 5(a) and (b) are a top and bottom cross-sectional views of the circular perforated plate of the present invention, and FIG. 6 is an exploded cross-sectional view of the circular perforated plate of the present invention.

As shown, the polishing head of the CMP apparatus of the present invention comprises: a pressure adjusting device (11) that performs a pumping action when performing a CMP process; and an adsorption portion (12) located at the pressure adjusting device (11) Below, the crystal is directly adsorbed by the vacuum generated by the pumping of the pressure adjusting device (11) a sheet (W); a circular perforated plate (100) located at a lower portion of the pressure adjusting device (11), a plurality of through holes are formed in the surface, and the pressure generated by the pressure adjusting device (11) is transmitted to The adsorption portion (12); the snap ring (13) prevents the wafer (W) from being detached from the adsorption portion (12) during polishing of the wafer (W), wherein the porous plate (100) The utility model comprises: a disc-shaped main body (110); a positioning groove (111) (111), which is a pair, bilaterally symmetrically formed at an upper center of the main body (110); and a plurality of holes (112) formed at the center a body (110); a porous groove (113) formed on one side of the body (110) and formed with four holes; a central groove portion (114) formed at a rear center of the body (110) a ball (115), a part of which is inserted and fixed in the center of the central groove portion (114); a circular metal plate (116) is inserted and fixedly disposed at a central portion of the central groove portion (114), so that a part of the ball (115) is exposed; a plurality of balance pins (117) are inserted and fixed around the central groove portion (114); upper and lower edge portions (120) (130) are fixed around the ball Subject (1 10) The edge.

The disc-shaped body (110) is formed of a ceramic material, and the upper and lower edge portions (120) (130) surrounding the edge of the main body (110) are made of a metal material.

Preferably, the upper edge portion (120) and the lower edge portion (130) are made of stainless steel (SUS) material.

And, a pair of positioning grooves (111) formed at the center of the main body (110) is a structure for positioning the polishing head, and according to the structure of the positioning groove (111), the ball (115) is prevented The one side is shaken so that the non-directional crack occurs in the central groove portion (114) at the lower portion of the main body (110) and the center, and a leak occurs during the polishing process.

Moreover, the metal plate (116) fixes the ball (115) in the center while also forming a part of the bare exposed hole (116a), and is fixedly fixed to the lower central groove portion of the main body (110) by a special adhesive. (114).

According to the invention, the metal sheet (116) is composed of a special alloy.

The special alloy consists of a metal alloy comprising zirconium, titanium, nickel and chromium.

Wherein the zirconium (Zr) of the special alloy is used for improving corrosion resistance and improving surface strength of the alloy, the titanium (Titanium, Ti) is used for lightening the alloy, and improving Use for strength.

Further, the nickel (nickel) is used for the ease of production and processing of the alloy, and the chromium (Cr) is used for the ease of production and processing of the alloy.

The special alloy may contain zirconium, titanium, nickel, and chromium in various composition ratios. In particular, in order to better exhibit corrosion resistance, high strength, and light weight characteristics, the composition may be contained in the following composition ratio.

That is, the special alloy contains 40 to 60% by weight of zirconium, 30 to 70% by weight of titanium, and 5 to 15% by weight of nickel and chromium.

When the zirconium content is less than 40% by weight, the corrosion resistance and surface strength of the alloy are lowered. When the content exceeds 60% by weight, the density of the alloy becomes high and it is difficult to be lightweight.

When the titanium content is less than 30% by weight, it is difficult to form an alloy, and when it exceeds 70% by weight, the strength of the alloy is lowered.

Further, when the nickel and chromium are contained in an amount of less than 5% by weight, it is difficult to produce an alloy, and the workability of the produced alloy is lowered. When the content exceeds 15% by weight, the content of zirconium and titanium is relatively low. The strength of the alloy is lowered to increase the weight and the corrosion resistance is low.

As described above, the metal plate (116) of the present invention is composed of the special alloy material.

With the structure of the metal plate (116) as described above, the strength can be greatly improved, thereby preventing cracking due to the use of the ceramic material, thereby greatly improving the problem of process failure.

And, the plurality of six balance pins (117) are used to prevent the polishing head from being biased to one side or skewed in the polishing process, as shown in FIG. 5(b), and the fixing portion of the lower end is processed by screws ( 117a), when fixed to the central groove portion (114), is fixed by screwing.

Therefore, the six balance pins (117) fixed as described above prevent the occurrence of a problem that occurs due to the adhesion of the adhesive, that is, the powder is scattered due to the curing of the adhesive.

Further, the air supply line that is transported by the porous recess (113) formed in the main body (110) is changed to the same material by the conventional screw coupling method, thereby causing cracks due to the corresponding portion. The equipment is stopped and the resulting costs are minimized.

Further, according to the present invention, like the metal plate (116), the disk-shaped main body (110), the upper edge portion (120), and the lower edge portion (130) are also made of the above-mentioned special alloy material.

Further, the metal plate (116), the main body (110), and the upper and lower edge portions (120) (130) are made of a metal material containing stainless steel (SUS).

Further, according to the present invention, the metal plate (116) can also be composed only of titanium.

Further, the metal plate (116), the main body (110), and the upper and lower edge portions (120) (130) may all be made of titanium.

The invention has the following advantages : as described above, the present invention has the advantages of removing the positioning pin formed on the upper portion of the existing circular perforated plate, and symmetrically generating a pair of positioning grooves required for central positioning by both sides, This greatly improves the flatness uniformity.

Moreover, the present invention has the advantages of attaching and fixing a metal plate to a central groove portion of a lower portion of the perforated plate, preventing cracks due to the current use of the ceramic material, greatly improving the defective process, and minimizing the stop of the device. To increase productivity.

Further, the present invention has the advantage that a special alloy and a metal are used instead of the ceramic, and the air supply line that is transported through the four holes of the perforated plate is changed from the conventional screw-bonding method to the one-piece metal material, thereby causing The corresponding part of the crack causes the equipment to stop and the resulting costs are minimized.

Further, the present invention has an advantage that the balance pin is fixed to the central groove portion by screwing, thereby preventing the powder from flying due to the curing of the current adhesive.

111‧‧‧ positioning groove

112‧‧‧ hole

113‧‧‧Porous grooves

115‧‧‧ ball

116‧‧‧Metal plate

116a‧‧‧ bare holes

117‧‧‧balanced pin

120‧‧‧ upper edge

130‧‧‧lower edge

Claims (8)

A polishing head of a CMP apparatus comprising a high-strength alloy, the polishing head of the CMP apparatus comprising: a pressure regulating device (11) performing a pumping action when performing a CMP process; and an adsorption portion (12) located at the pressure regulating device Below (11), the wafer (W) is directly adsorbed by a vacuum generated by pumping by the pressure adjusting device (11); a circular perforated plate (100) is located at a lower portion of the pressure adjusting device (11) a plurality of through holes are formed in the surface, and pressure generated by the pressure adjusting device (11) is transmitted to the adsorption portion (12); a snap ring (13) is prevented from being applied to the wafer (W) The wafer (W) is detached from the adsorption portion (12) during polishing, and the polishing head of the CMP device including the high-strength alloy is characterized in that the porous plate (100) comprises: a disk-shaped body (110) a pair of positioning grooves (111) (111) symmetrically formed on both sides of the upper center of the body (110); a plurality of holes (112) formed in the body (110); porous grooves ( 113), formed on one side of the main body (110), formed with four holes; a central groove portion (114) formed on the main body (110) a rear center; a ball (115), a part of which is inserted and fixed in the center of the central groove portion (114); a circular metal plate (116) inserted and fixed at a central portion of the central groove portion (114) to form There is a bare hole (116a) to expose a part of the ball (115); a plurality of balance pins (117) are inserted and fixed around the central groove portion (114); upper and lower edge portions ( 120) (130) surrounding the edge of the body (110), wherein the metal plate (116) is composed of a special alloy comprising zirconium, titanium, nickel and chromium. A polishing head for a CMP apparatus comprising a high-strength alloy according to claim 1, wherein the body (110), the upper edge portion (120) and the lower edge portion (130) are made of zirconium and titanium. It is made of special alloy material of nickel and chromium. A polishing head for a CMP apparatus comprising a high-strength alloy as described in claim 1 or 2, wherein the special alloy comprises 40 to 60% by weight of zirconium, 30 to 70% by weight of titanium, and 5 to 15% by weight of nickel and chromium. A polishing head for a CMP apparatus comprising a high-strength alloy according to claim 1, wherein the metal plate (116), the main body (110), the upper and lower edge portions (120) (130) are Made of stainless steel (SUS) made of metal. A polishing head for a CMP apparatus including a high-strength alloy according to the first aspect of the invention, characterized in that the fixing portion (117a) of the plurality of balance pins (117) is formed in a spiral shape and fixed by screwing In the central groove portion (114). A polishing head for a CMP apparatus including a high-strength alloy according to the first aspect of the invention, characterized in that the air supply line transmitted through the porous recess (113) formed in the main body (110) is integrated The same metal material is formed. A polishing head for a CMP apparatus comprising a high-strength alloy according to claim 1, wherein the metal plate (116) is formed of titanium. A polishing head for a CMP apparatus comprising a high-strength alloy according to the first aspect of the invention, characterized in that the metal plate (116), the main body (110), the upper and lower edge portions (120) (130) are all Made of titanium.