POLISHING HEAD AND POLISHING CARRIER APPARATUS HAVING THE SAME

Abstract

A polishing head includes a carrier body detachably fixed to a drive shaft and having a plurality of first fluid passages penetrating therethrough to extend from an upper surface to a lower surface of the carrier body, upper end portions of the first fluid passages being arranged to be spaced apart from each other in a circumferential direction about a central axis thereof, a flexible membrane clamped to a lower portion of the carrier body to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chambers is divided into a plurality of sub-chambers arranged in a circumferential direction about a central axis of the flexible membrane, the sub-chambers being in fluid communication with lower end portions of the first fluid passages respectively, and a fluid sealing part on the carrier body to support the carrier body to be rotatable and flow a fluid into each of the first fluid passages in a sealed state.

Description

CROSS-REFERENCE TO RELATED APPLICATION

Korean Patent Application No. 10-2018-0111119, filed on Sep. 17, 2018, in the Korean Intellectual Property Office (KIPO), and entitled: “Polishing Head and Polishing Carrier Apparatus having the Same,” is incorporated by reference herein in its entirety.

BACKGROUND

1. Field

Example embodiments relate to a polishing head and a polishing carrier apparatus having the same.

2. Description of the Related Art

A chemical mechanical polishing process may include polishing a wafer with rotational motion and reciprocating motion.

SUMMARY

Embodiments are directed to a polishing head, including a carrier body detachably fixed to a drive shaft and having a plurality of first fluid passages penetrating therethrough to extend from an upper surface to a lower surface of the carrier body, upper end portions of the first fluid passages being arranged to be spaced apart from each other in a circumferential direction about a central axis thereof, a flexible membrane clamped to a lower portion of the carrier body to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chambers is divided into a plurality of sub-chambers arranged in a circumferential direction about a central axis of the flexible membrane, the sub-chambers being in fluid communication with lower end portions of the first fluid passages respectively, and a fluid sealing part on the carrier body to support the carrier body to be rotatable and flow a fluid into each of the first fluid passages in a sealed state.

Embodiments are also directed to a polishing head, including a housing detachably fixed to a drive shaft, a base assembly installed beneath the housing and rotatable together with the housing, the base assembly having a plurality of first fluid passages penetrating therethrough to extend from an upper surface to a lower surface of the base assembly, a flexible membrane clamped to a lower portion of the base assembly to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chamber is divided into a plurality of sub-chambers, the sub-chambers being in fluid communication with the first fluid passages respectively, and a fluid sealing part on the base assembly around the housing to support the base assembly to be rotatable and to flow a fluid into each of the first fluid passages in a sealed state.

Embodiments are also directed to a polishing carrier apparatus, including an upper module having a rotary union, a polishing head configured to suck and pressurize a substrate to be polished, the polishing head including a carrier body detachably fixed to a drive shaft of the rotary union, a flexible membrane clamped to a lower portion of the carrier body to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chamber is divided into a plurality of sub-chambers, and a fluid sealing part on the carrier body to support the carrier body to be rotatable, a sealing housing interposed between the upper module and the polishing head, and a gas supply unit configured to supply a gas into each of the sub-chambers through the sealing housing and the fluid sealing part.

BRIEF DESCRIPTION OF THE DRAWINGS

Features will become apparent to those of skill in the art by describing in detail example embodiments with reference to the attached drawings in which:

FIG. 1 illustrates a cross-sectional view of a chemical mechanical polishing apparatus in accordance with an example embodiment.

FIG. 2 illustrates a cross-sectional view of a polishing carrier apparatus in FIG. 1.

FIG. 3 illustrates a perspective view of a polishing head in accordance with an example embodiment.

FIG. 4 illustrates an exploded perspective view of the polishing head in FIG. 3 where a stationary ring is detached from the polishing head.

FIG. 5 illustrates a cross-sectional view taken along the line I-I′ in FIG. 3.

FIG. 6 illustrates a partially exploded perspective view taken along the line I-I′ in FIG. 3.

FIG. 7 illustrates a partially exploded perspective view of the polishing head in FIG. 6 where the stationary ring is removed from the polishing head.

FIG. 8 illustrates a perspective view of a flexible membrane of the polishing head in FIG. 3.

FIG. 9 illustrates a plan view of a rotary ring and outermost sub-chambers of the flexible membrane in FIG. 3.

FIGS. 10A to 10F illustrate plan views of relative rotational movement of the stationary ring and the rotary ring of the fluid sealing part in FIG. 3.

DETAILED DESCRIPTION

Hereinafter, example embodiments will be explained in detail with reference to the accompanying drawings.

FIG. 1 is a cross-sectional view illustrating a chemical mechanical polishing apparatus in accordance with an example embodiment. FIG. 2 is a cross-sectional view illustrating a polishing carrier apparatus in FIG. 1.

Referring to FIGS. 1 and 2, a chemical mechanical polishing (CMP) apparatus 10 may include a platen 20, a polishing pad 30, a polishing carrier apparatus 200 having a polishing head 100, a slurry dispenser 40, and a pad conditioner 50.

The platen 20 may rotate the polishing pad 30 at a desired speed in order to polish a substrate such as wafer. The polishing pad 30 may be positioned on the platen 20. The platen 20 may have a disc shape. A platen driving unit 22 may include a platen driving motor that is connected to the platen 20 through a platen rotation shaft. The platen 20 may be rotated by the platen rotation shaft.

The polishing pad 30 may include abrasive particles thereon to polish the substrate. The polishing pad 30 may include an elastomeric material having a rough surface such as polyurethane. The polishing pad 30 may also be rotated by the platen 20.

The slurry dispenser 40 may dispense a slurry solution 42 onto the polishing pad 30 through a slurry dispensing nozzle. The slurry solution 42 may be used to perform a chemical mechanical polishing (CMP) process. The slurry solution 42 may be used to chemically planarize the wafer.

The polishing head 100 may hold the substrate and press a surface of the substrate to be polished against the polishing pad 30. The polishing head 100 may be connected to and combined with a drive shaft 212 of the polishing carrier apparatus 200 to move on the polishing pad 30 while rotating.

The pad conditioner 50 may be provided to adjust the abrasion of the polishing pad 30. After a period of use, protuberances on the polishing pad 30 may be worn by friction between the polishing pad 30 and the wafer. The pad conditioner 50 may regenerate the rough surface of the polishing pad 30 to maintain acceptable and consistent removal rates. Accordingly, the polishing pad 30 may be used for an extended time without being replaced.

Hereinafter, the polishing carrier apparatus 200 will be explained in detail. Other elements of the CMP apparatus 10 may be substantially the same as or similar to a general CMP apparatus.

The polishing carrier apparatus 200 may be adapted to pressurize the wafer with the polishing head 100 above the platen 20, and to revolve the polishing head 100 on a central axis of the platen 20 and rotate the polishing head 100 on a central axis of the polishing head 100. The polishing head 100 may hold the wafer, and may rotate and translate on the platen 20.

As illustrated in FIG. 2, the polishing carrier apparatus 200 may include the polishing head 100, an upper module having a rotary union 210, and a sealing housing 220. The polishing carrier apparatus 200 may include a driving unit 230 and a gas supply unit 240.

The rotary union 210 may include the drive shaft 212 in which a plurality of first gas passages 213 is formed along a longitudinal direction thereof. The rotary union 210 may support the drive shaft 212 to be rotatable on its own axis and flow a fluid into the first gas passages 213 in a sealed-up state.

The driving unit 230 may include a driving motor configured to rotate the drive shaft 212. The drive shaft 212 may be connected to the driving motor to rotate on its own axis. A driven gear may be installed in an upper end portion of the drive shaft 212. The driving motor may rotate a driving gear, which is engaged with the driven gear, to rotate the drive shaft 212. The driving motor may be installed in the upper portion of the upper end portion of the drive shaft 212. In another implementation, the driving motor may have a configuration where the driving motor is connected to the end portion of the drive shaft 212 to rotate the drive shaft 212.

The rotary union 210 may be connected to the gas supply unit 240 through first gas tubes 242. The first gas tubes 242 may be connected to the first gas passages 213 of the drive shaft 212 of the rotary union 210.

The polishing head 100 may be combined with the drive shaft 212 to rotate together with the drive shaft 212. The polishing head 100 may be fixed to a flange 214 of the drive shaft 212, e.g., by a clamp.

The sealing housing 220 may be installed in a lower portion of the upper module 202. The sealing housing 220 may have an annular shape extending around a circumference of the flange 214 of the drive shaft 212. The sealing housing 220 may be interposed between the upper module 202 and the polishing head 100. A stationary ring 160 of a fluid sealing part 150 (see FIG. 3) of the polishing head 100 may be combined fixedly with a lower surface of the sealing housing 220. The flange 214 of the drive shaft 212 may be a rotation body, and the sealing housing 220 may be a non-rotation body.

The sealing housing 220 may have a plurality of second gas passages 222 formed along a longitudinal direction thereof. The second gas passages 222 may penetrate therethrough to extend from an upper surface to a lower surface of the sealing housing 220. The second gas passages 222 may be connected to respective first through-holes 162 (see FIG. 3) of the stationary ring 160. Sealing members such as O-rings may be disposed between the lower surface of the sealing housing 220 and an upper surface of the stationary ring 160 to form fluid-tight seals between the second gas passages 222 and the first through-holes 162.

The sealing housing 220 may be connected to the gas supply unit 240 through second gas tubes 244. The second gas tubes 244 may be connected to the second gas passages 222 of the sealing housing 220.

The gas supply unit 240 may supply a gas into the polishing head 100 through the first gas passages 213 of the drive shaft 212 and the second gas passages 222 of the second gas passages 222 to provide suction and pressurization of an object subjected to polishing. The gas supply unit 240 may supply first gases into the polishing head 100 through the first gas passages 213. The gas supply unit 240 may supply second gases into the polishing head 100 through the second gas passages 222.

The gas supply unit may supply gases having different pressures independently through the first gas tubes 242 and the second gas tubes 244. For example, the gases having different pressures may be supplied independently through the first gas passages 213 and the second gas passages 222. As described below, the CMP apparatus 10 may be controlled to provide different pressures to the gases supplied through the first through-holes 162 (see FIG. 3) of the stationary ring 160 connected respectively to the second gas passages 222 in order to transfer local pressures on a flexible membrane 140 of the polishing head 100.

The polishing head 100 may be combined with the drive shaft 212 to rotate together with the drive shaft 212. A housing 110 (see FIG. 3) of the polishing head 100 may be fixed to the flange 214 of the drive shaft 212. The stationary ring 160 of the polishing head 100 may be connected fixedly to the sealing housing 220.

Hereinafter, an example embodiment of the polishing head will be explained in detail.

FIG. 3 is a perspective view illustrating a polishing head in accordance with an example embodiment. FIG. 4 is an exploded perspective view illustrating the polishing head in FIG. 3 where a stationary ring is detached from the polishing head. FIG. 5 is a cross-sectional view taken along the line I-I′ in FIG. 3. FIG. 6 is a partially exploded perspective view taken along the line I-I′ in FIG. 3. FIG. 7 is a partially exploded perspective view illustrating the polishing head in FIG. 6 where the stationary ring is removed from the polishing head. FIG. 8 is a perspective view illustrating a flexible membrane of the polishing head in FIG. 3. FIG. 9 is a plan view illustrating a rotary ring and outermost sub-chambers of the flexible membrane in FIG. 3.

The polishing head 100 may include a substrate carrier 102 fixed to the drive shaft 212 to rotate together with the drive shaft 212 and configured to suck and pressurize a substrate (e.g., wafer W as shown in FIG. 5) as an object to be polished. The polishing head 100 may include a retainer ring 130 secured under the substrate carrier 102 and surrounding a circumference of the substrate.

The substrate carrier 102 may include a carrier body 104 rotatable together with the drive shaft 212 and a flexible membrane 140 clamped to a lower portion of the carrier body 104 to form at least one a pressurizing chamber Z1, Z2, Z3, Z4, Z5, Z6. The carrier body 104 may include a housing 110 detachably fixed to the drive shaft 212 and a base assembly 120 installed beneath the housing 110 and rotatable together with the housing 110.

The housing 110 may have a cylindrical shape. An upper portion of the housing 110 may be fixed to the flange 214 of the drive shaft 212 by a clamp. Sealing members such as O-rings may be disposed between an upper surface of the housing 110 and a lower surface of the drive shaft 212 to form fluid-tight seals between first pathways and first gas passages. The first pathways 112, 114 for pneumatic control of the polishing head 100 may be connected to the first gas passages 213 formed in the drive shaft 212 respectively.

The base assembly 120 may be vertically movable under the housing 110. The base assembly 120 may include a plurality of base blocks disposed beneath the housing 110 to be rotatable together with the housing 110. For example, the base blocks may be stacked in a vertical direction and a radial direction to have a cylindrical shape under the housing 110. A rolling diaphragm 122 may be clamped to the housing 110 between a relatively inner base block and a relatively outer base block such that the carrier body 104 has a gimbal structure.

The retainer ring 130 may be fixed to a lower portion of the substrate carrier 102. The retainer ring 130 may be a generally annular ring secured at an outer edge of the base assembly 120. When the base assembly 120 moves downwardly by a pneumatic pressure of a working fluid, the retaining ring 130 may also move downwardly to apply a load to a polishing pad 30.

The flexible membrane 140 may be clamped to a lower portion of the base assembly 120 within the retainer ring 130. The flexible membrane 140 may include a disk-shaped main portion 142 having a first surface contacting a backside of the wafer W and a second surface opposite to the first surface, and a plurality of extending portions 144 protruding from the second surface of the main portion 142 to form the first to sixth pressurizing chambers Z1, Z2, Z3, Z4, Z5, Z6.

The first surface of the main portion 142 may provide a suction surface for the wafer W. End portions of the extending portions 144 may be clamped to the base assembly 120, e.g., by clamp rings respectively, such that the pressurizing chambers Z1, Z2, Z3, Z4, Z5, Z6 having an annular or circular shape may be formed between the extending portions 144 respectively. The number of the pressurizing chambers Z1, Z2, Z3, Z4, Z5, Z6 may be determined according to the number of the extending portions. In this embodiment, the flexible membrane may be a 6-zone type membrane for forming the six pressurizing chambers Z1, Z2, Z3, Z4, Z5, Z6. In other implementations, the flexible membrane may be, e.g., a 4 or 7-zone type membrane for forming four or seven pressurizing chambers.

The flexible membrane 140 may include partition portions 146 protruding from the second surface of the main portion 142 to divide the pressurizing chamber into a plurality of sub-chambers. For example, the partition portions 146 may divide the outermost pressurizing chamber Z6 into a plurality of sub-chambers Z6-1, Z6-2, Z6-3, Z6-4. The sub-chambers Z6-1, Z6-2, Z6-3, Z6-4 may be arranged in a circumferential direction about a central axis of the flexible membrane 140 to be spaced apart from each other.

Each of the sub-chambers Z6-1, Z6-2, Z6-3, Z6-4 may extend within a predetermined angle in the circumferential direction about a central axis of the flexible membrane 140. For example, each of the sub-chambers Z6-1, Z6-2, Z6-3, Z6-4 may extend within a range of about 25 degrees to about 43 degrees about the central axis of the flexible membrane 140. The number and the positions of the sub-chambers, the angle range of the sub-chamber, etc., may be varied.

In an example embodiment, a plurality of second pathways 124 may be formed to penetrate through the base assembly 120. In an example embodiment, the first pathway 114 and the corresponding second pathway 124 may be connected to each other to form a first fluid passage through which a gas G1 is supplied into each of the pressurizing chambers Z1, Z2, Z3, Z4, Z5. Each of the pressurizing chambers Z1, Z2, Z3, Z4, Z5 may be in fluid communication with the first gas passage 213 of the drive shaft 212 through the first fluid passage, that is, the first pathway 112, 114 of the housing 110 and the second pathway 124 through the base assembly 120. Accordingly, the pressurizing chambers Z1, Z2, Z3, Z4, Z5 of the six pressurizing chambers Z1, Z2, Z3, Z4, Z5, Z6 may be in fluid communication with the first gas tubes 242 of the gas supply unit 240 respectively such that the pressure of each chamber may be independently controlled.

In an example embodiment, at least one of the pressurizing chambers may be evacuated to vacuum chuck the wafer W. In an example embodiment, at least one of the pressurizing chambers may be pressurized to force the flexible membrane 140 against the wafer W.

A plurality of third pathways 126 may be formed to penetrate through the base assembly 120. The third pathway 126 may penetrate through the base assembly 120 to extend from an upper surface to a lower surface of the base assembly 120. The third pathway 126 may form a second fluid passage through which a gas G2 is supplied into each of the sub-chambers Z6-1, Z6-2, Z6-3, Z6-4.

Upper end portions of the third pathways 162 may be arranged to be spaced apart from each other in a circumferential direction about a central axis of the base assembly 120. The upper end portions of the third pathways 162 may be arranged at equal angle interval with respect to the central axis. When the number of the third pathways 162 is four, the upper end portions of the third pathways 162 may be arranged at equal angle interval of 45 degrees.

Each of the sub-chambers Z6-1, Z6-2, Z6-3, Z6-4 may be in fluid communication with the second gas passage 222 of the gas supply unit 240 respectively such that the pressure of each sub-chamber may be independently controlled. As described below, the sub-chambers may have different local pressures to effectively maintain a horizontal position of the wafer W to thereby obtain uniform polishing rate.

In example embodiments, the fluid sealing part 150 may be arranged on the carrier body 104 and supporting the carrier body 104 to be rotatable and may flow a fluid into each of the third pathways 126 in a sealed-up state. The fluid sealing part 150 may be a mechanical seal for flowing the fluid in a seal-up state in a vertical direction with respect to the rotation axis of the base assembly 120 when the base assembly 120 of the carrier body 104 rotates.

The fluid sealing part 150 may include a rotary ring 170 on the upper surface of the carrier body 104 to be rotatable together with the carrier body 104 and the stationary ring 160 supported fixedly on the rotary ring 170 and adapted so that the rotary ring 170 has a sliding movement on the stationary ring 160. The first through-holes 162 may be formed to penetrate through the stationary ring 160 and may be connected to the second gas passages 222 of the sealing housing 220 respectively. Second through-holes 172 may be formed to penetrate through the rotary ring 170 and may be connected to the third pathways 126 of the base assembly 120 respectively. For example, the number of the first through-holes 162 may be the same as the number of the second through-holes 172.

The stationary ring 160 and the rotary ring 170 may seal and adhere to each other to have a sliding movement and maintain the fluid sealing. The stationary ring 160 and the rotary ring 170 having surfaces to face each other may include a low friction material such as silicon carbide (SiC).

The rotary ring 170 may be combined fixedly with the upper surface of the base assembly 120 outside the housing 110. The rotary ring 170 may constitute at least a portion of an upper base block of the base assembly 120. The rotary ring 170 may cover the upper end portions of the third pathways 162 and may be assembled with the upper surface of the base assembly 120 such that the second through-holes 172 may be connected to the third pathways 126 of the base assembly 120 respectively.

As illustrated in FIG. 9, the second through-hole 172-1 may be in fluid communication with the first sub-chamber Z6-1 through the third pathway 126. The second through-hole 172-2 may be in fluid communication with the second sub-chamber Z6-2 through the third pathway 126. The second through-hole 172-3 nay be in fluid communication with the third sub-chamber Z6-3 through the third pathway 126. The second through-hole 172-4 may be in fluid communication with the fourth sub-chamber Z6-4.

The first through-holes 162 of the stationary ring 160 may be selectively connected to the second through-holes 172-1, 172-2, 172-3, 172-4 by a relative rotational movement of the rotary ring 170. The first through-hole may have a cylindrical shape, and the second through-holes 172-1, 172-2, 172-3, 172-4 may have a slit-type cylindrical shape extending within a predetermined angle about a central axis of the rotary ring 170. The second through-holes 172-1, 172-2, 172-3, 172-4 may extend within a predetermined angle about the central axis of the rotary ring 170 to correspond to the range of the extension angle of the sub-chamber (Z6-1, Z6-2, Z6-3, Z6-4). For example, each of the second through-holes 172-1, 172-2, 172-3, 172-4 may extend within a range of about 25 degrees to about 43 degrees about the central axis of the rotary ring 170. In another implementation, the first through-hole 162 may have a slit-type cylindrical shape extending within a predetermined angle about a central axis, and the second through-holes 172-1, 172-2, 172-3, 172-4 may have a cylindrical shape.

When the rotary ring 170 rotates, the first through-hole 162 may be connected to the corresponding second through-holes 172-1, 172-2, 172-3, 172-4 through the range of the predetermined angle. While the corresponding first and second through-holes 162, 172-1, 172-2, 172-3, 172-4 are connected to each other during the angle range, a gas G2 may be supplied into the corresponding sub-chamber (Z6-1, Z6-2, Z6-3, Z6-4) through the first and second through-holes 162, 172-1, 172-2, 172-3, 172-4 connected to each other.

Hereinafter, a method of applying a local pressure on the flexible membrane 140 of the polishing head 100 will be explained.

FIGS. 10A to 10F are plan views showing relative rotational movement of the stationary ring and the rotary ring of the fluid sealing part in FIG. 3.

Referring to FIGS. 10A to 10C, when the stationary ring 160 is fixed and the rotary ring 170 starts to rotate, a first through-hole 162-1 may be connected to a corresponding second through-hole 172-1 during a range of a predetermined angle θ. While the first through-hole 162-1 is connected to the corresponding second through-hole 172-1 during the range of the predetermined angle θ, the gas supply unit 240 may supply a gas of a first pressure to the first sub-chamber Z6-1 through the first through-hole 162-1 of the stationary ring 160 and the second through-hole 172-1 of the rotary ring 170. At this time, similarly, the gas supply unit 240 may supply a gas of a second pressure into the second sub-chamber Z6-2 through the first through-hole 162-2 and the second through-hole 172-2, the gas supply unit 240 may supply a gas of a third pressure into the third sub-chamber Z6-3 through the first through-hole-162-3 and the second through-hole 172-3, and the gas supply unit 240 may supply a gas of a fourth pressure into the fourth sub-chamber Z6-4 through the first through-hole 162-4 and the second through-hole 172-4.

Referring to FIGS. 10D to 10F, when the rotary ring 170 continues to rotate, the first through-hole 162-1 may be connected to the corresponding second through-hole 172-2 during a range of the predetermined angle θ. While the first through-hole 162-1 is connected to the corresponding second through-hole 172-2 during the range of the predetermined angle θ, the gas supply unit 240 may supply a gas of the first pressure into the second sub-chamber Z6-2 through the first through-hole 162-1 of the stationary ring 160 and the second through-hole 172-2 of the rotary ring 170. At this time, similarly, the gas supply unit 240 may supply a gas of the second pressure into the third sub-chamber Z6-3 through the first through-hole 162-2 and the second through-hole 172-3, the gas supply unit 240 may supply a gas of the third pressure into the fourth sub-chamber Z6-4 through the first through-hole 162-3 and the second through-hole 172-4, and the gas supply unit 240 may supply a gas of the fourth pressure into the first sub-chamber Z6-1 through the first through-hole 162-4 and the second through-hole 172-1.

Thus, in general, when the stationary ring 160 is stationary, the rotary ring 170 rotates, and while the first through-hole 162 is connected to the corresponding second through-hole 172 during a range of a predetermined angle θ, a gas supplied through the first through-hole 162 of the stationary ring 160 may be supplied independently a local region of the flexible membrane 140 within the range of the predetermined angle θ.

As discussed above, the polishing head 100 of the chemical mechanical polishing apparatus may include the flexible membrane 140 to rotate together with the wafer W and to apply a pressure against the wafer W, and may apply independently a local pressure on a local region of the flexible membrane 140, for example, different regions along the outermost concentric circle. Accordingly, the flexible membrane 140 may have different local pressures to effectively maintain a horizontal position of the wafer W to thereby obtain uniform polishing rate across the wafer W.

In example embodiments, the polishing head of the chemical mechanical polishing apparatus may predict a direction and a magnitude of moment generated by rotational motion and reciprocating motion during a chemical mechanical polishing process, and may transfer a local pressure directly on the wafer through the flexible membrane in order to apply a pressure matching with the moment on an opposite region. Accordingly, the horizontal position of the wafer may be maintained effectively and thus the uniform polishing rate across the wafer may be obtained.

The polishing head may be applied to a CMP process. Semiconductor devices such as DRAM, VNAND, etc., manufactured using the CMP process may be used for various systems such as a computing system. The system may be applied to computer, portable computer, laptop computer, PDA, tablet, mobile phone, digital music player, etc.

By way of summation and review, a chemical mechanical polishing process may depend on a polishing head being maintained in a horizontal position. If a polishing head has a gimbal structure for matching with rotational motion and reciprocating motion, the polishing head may be tilted due to moment generated by the rotational motion and the reciprocating motion during the chemical mechanical polishing process, so that the wafer held under the polishing head may be tilted, which may result in non-uniform polishing across the wafer.

As described above, embodiments relate to a polishing head for pressing and moving a wafer against a polishing pad and a polishing carrier apparatus having the same. Example embodiments may provide a polishing head capable of improving a polishing uniformity. Example embodiments provide a polishing carrier apparatus having the polishing head.

Embodiments may provide a polishing head of a chemical mechanical polishing apparatus that includes a flexible membrane to rotate together with a wafer and to apply a pressure against the wafer, and which may apply independently a local pressure on a local region of the flexible membrane, for example, each of different regions along an outermost concentric circle. Accordingly, the flexible membrane may have different local pressures to effectively maintain a horizontal position of the wafer to thereby obtain uniform polishing rate across the wafer.

Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

1. A polishing head, comprising:

a carrier body detachably fixed to a drive shaft and having a plurality of first fluid passages penetrating therethrough to extend from an upper surface to a lower surface of the carrier body, upper end portions of the first fluid passages being arranged to be spaced apart from each other in a circumferential direction about a central axis thereof;

a flexible membrane clamped to a lower portion of the carrier body to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chambers is divided into a plurality of sub-chambers arranged in a circumferential direction about a central axis of the flexible membrane, the sub-chambers being in fluid communication with lower end portions of the first fluid passages respectively; and

a fluid sealing part on the carrier body to support the carrier body to be rotatable and flow a fluid into each of the first fluid passages in a sealed state.

2. The polishing head as claimed in claim 1, wherein the carrier body includes:

a housing fixed to the drive shaft; and

a base assembly installed beneath the housing and rotatable together with the housing.

3. The polishing head as claimed in claim 2, wherein the first fluid passages extend from an upper surface to a lower surface of the base assembly.

4. The polishing head as claimed in claim 1, wherein the fluid sealing part includes:

a rotary ring on an upper surface of the carrier body to be rotatable together with the carrier body, wherein first through-holes penetrate through the rotary ring to be connected to the first fluid passages respectively; and

a stationary ring supported fixedly on the rotary ring such that the rotary ring has a sliding movement on the stationary ring, the stationary ring having second through-holes penetrating therethrough, wherein the first through-holes are selectively connected to the second through-holes by a relative rotational movement of the rotary ring.

5. The polishing head as claimed in claim 4, wherein the first through-holes have a slit-type cylindrical shape extending within a predetermined angle about a central axis.

6. The polishing head as claimed in claim 4, wherein a number of the first through-holes is the same as a number of the second through-holes.

7. The polishing head as claimed in claim 4, wherein a number of the first through-holes is the same as a number of the first fluid passages.

8. The polishing head as claimed in claim 4, wherein the second through-holes are arranged at equal angle intervals with respect to a central axis.

9. The polishing head as claimed in claim 1, wherein the flexible membrane includes:

a disk-shaped main portion having a first surface contacting a backside of a substrate to be polished and a second surface opposite to the first surface; and

at least one extending portion protruding from the second surface of the main portion to be clamped to the lower portion of the carrier body to form at least one of the pressurizing chambers.

10. The polishing head as claimed in claim 9, wherein the flexible membrane includes a partition portion dividing the at least one of the pressurizing chambers to form the plurality of the sub-chambers.

11. A polishing head, comprising:

a housing detachably fixed to a drive shaft;

a base assembly installed beneath the housing and rotatable together with the housing, the base assembly having a plurality of first fluid passages penetrating therethrough to extend from an upper surface to a lower surface of the base assembly;

a flexible membrane clamped to a lower portion of the base assembly to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chamber is divided into a plurality of sub-chambers, the sub-chambers being in fluid communication with the first fluid passages respectively; and

a fluid sealing part on the base assembly around the housing to support the base assembly to be rotatable and to flow a fluid into each of the first fluid passages in a sealed state.

12. The polishing head as claimed in claim 11, wherein upper end portions of the first fluid passages are arranged to be spaced apart from each other in a circumferential direction about a central axis of the base assembly.

13. The polishing head as claimed in claim 11, wherein the fluid sealing part includes:

a rotary ring on an upper surface of the base assembly, wherein first through-holes penetrate through the rotary ring to be connected to the first fluid passages respectively; and

a stationary ring supported fixedly on the rotary ring such that the rotary ring has a sliding movement on the stationary ring, the stationary ring having second through-holes penetrating therethrough, wherein the first through-holes are selectively connected to the second through-holes by a relative rotational movement of the rotary ring.

14. The polishing head as claimed in claim 13, wherein the first through-holes have a slit-type cylindrical shape extending within a predetermined angle about a central axis.

15. The polishing head as claimed in claim 13, wherein a number of the first through-holes is the same as a number of the second through-holes.

16. The polishing head as claimed in claim 13, wherein a number of the first through-holes is the same as a number of the first fluid passages.

17. The polishing head as claimed in claim 13, wherein the second through-holes are arranged at equal angle intervals with respect to a central axis.

18. The polishing head as claimed in claim 11, wherein the flexible membrane includes:

a disk-shaped main portion having a first surface contacting a backside of a substrate to be polished and a second surface opposite to the first surface; and

at least one extending portion protruding from the second surface of the main portion to be clamped to the lower portion of the base assembly to form at least one of the pressurizing chambers.

19. The polishing head as claimed in claim 18, wherein the flexible membrane includes a partition portion dividing the at least one of the pressurizing chamber into the plurality of the sub-chambers.

20. (canceled)

21. A polishing carrier apparatus, comprising:

an upper module having a rotary union;

a polishing head configured to suck and pressurize a substrate to be polished, the polishing head including a carrier body detachably fixed to a drive shaft of the rotary union, a flexible membrane clamped to a lower portion of the carrier body to form a plurality of pressurizing chambers, wherein at least one of the pressurizing chamber is divided into a plurality of sub-chambers, and a fluid sealing part on the carrier body to support the carrier body to be rotatable;

a sealing housing interposed between the upper module and the polishing head; and

a gas supply unit configured to supply a gas into each of the sub-chambers through the sealing housing and the fluid sealing part.

22-25. (canceled)