TW201420270A - Damper for polishing pad conditioner - Google Patents

Abstract

A conditioner apparatus for use in substrate polishing includes a conditioner head constructed to receive an end effector for conditioning a surface of a polishing pad, an arm that supports the conditioner head, a base that supports the arm, and a damper system secured to the base. The base includes an actuator connected to the arm to move the arm and the conditioner head laterally over the polishing pad. The damper system is configured to reduce vibration of the arm.

Description

Damper for polishing pad conditioner

This disclosure relates to the adjustment of the polishing pad.

The integrated circuit is usually formed on the substrate by continuously depositing a conductor layer, a semiconductor layer or an insulating layer on the germanium wafer. The planarization of the layers on the substrate is required for a variety of manufacturing processes. For example, for certain applications (eg, grinding a metal layer to form vias, plugs, and traces in trenches of the pattern layer), the upper layer is planarized until the top surface of the patterned layer is exposed. In other applications (eg, planarizing the dielectric layer for lithography), the upper layer is ground until the desired thickness remains on the underlying layer.

Chemical mechanical polishing (CMP) is an accepted method of planarization. This planarization method typically requires the substrate to be mounted on a load bearing or grinding head. The exposed surface of the substrate typically needs to be placed in opposition to the rotating polishing pad. The carrier head provides a controllable load on the substrate to push the substrate against the polishing pad. The abrasive slurry is usually supplied to the surface of the polishing pad.

After performing a CMP process for a certain period of time, the surface of the polishing pad becomes imaged by the glass due to material and/or by-products removed from the polishing pad and/or substrate. The accumulation of the slurry. Vitrification reduces the roughness of the polishing pad and provides less localized pressure, thus reducing the polishing rate. In addition, vitrification can cause the polishing pad to lose its ability to maintain the slurry itself, further reducing the polishing rate.

Generally, the characteristics of the vitrified polishing pad can be restored by the adjustment process of the polishing pad conditioner. The pad conditioner is used to remove unwanted buildup on the pad and the pad conditioner regenerates the surface of the pad to the desired roughness. A typical polishing pad conditioner includes an abrasive head that is typically embedded with a diamond abrasive that rubs against the mat surface of the vitrified polishing pad to retexture the polishing pad.

In some adjustment systems with certain abrasive formulations, the pad conditioner (especially the pad conditioner arm) will exhibit significant vibration. Vibration is detrimental to the arm and reduces the effectiveness of the conditioning process. In addition, this vibration is usually audible and in fact loud enough to be unacceptable. However, by providing a fine-tuned damper block on the base of the regulator, vibration can be significantly reduced or eliminated.

In one aspect, a regulator apparatus for use in substrate polishing includes: a regulator head configured to receive an end effector for adjusting a polishing pad a surface; an arm supporting the adjuster head; a base supporting the arm; and a damper system to which the damper system is secured. The base includes an actuator coupled to the arm to move the arm laterally with the adjuster head over the polishing pad. The damper system is configured to reduce vibration of the arm.

Implementations may include one or more of the following features. The actuator includes a rotary actuator configured to sweep the arm over the polishing pad. The damper system can be fixed to the rotary actuator and the damper system can be rotated by the rotary actuator. The damper system can include a damper block. The damper block can be attached to the base by at least one damper. The at least one damper can be a layer of damping material. The damper block can be attached to the base by a plurality of dampers. The plurality of dampers can include a shock absorber. The plurality of dampers can be configured to define a major axis that is parallel to an axis of a primary mode of vibration of the arm. The plurality of dampers can be configured to define a major axis that is parallel to a longitudinal axis of the arm. The adjuster head can include a vertical actuator coupled to the end effector to control a vertical position of the end effector. In another aspect, a non-transitory computer program product (tangibly embodied in a machine readable storage device) includes instructions to implement the method.

Implementations may optionally include one or more of the following advantages. The vibration of the pad conditioner can be reduced, in particular the pad adjuster arm. The utility of the conditioning process can be improved. The noise generated by the pad conditioner can be reduced.

The details of one or more implementations are set forth in the drawings and the description below. Other aspects, features, and advantages will be apparent from the description and drawings.

10‧‧‧Substrate

100‧‧‧ grinding equipment

102‧‧‧Frame

110‧‧‧ polishing pad

112‧‧‧External abrasive layer

114‧‧‧Backing layer

116‧‧‧Abrased surface

120‧‧‧ Platen

122‧‧‧Motor

124‧‧‧Drive shaft

125‧‧‧Axis

130‧‧‧埠

132‧‧‧Slurry (grinding slurry)

140‧‧‧ Carrying head

142‧‧‧ positioning ring

144‧‧‧elastic film

150‧‧‧Support structure (revolving rack)

152‧‧‧ drive shaft

154‧‧‧Loading head rotating motor

155‧‧‧Axis

160‧‧‧ polishing pad adjuster (adjustment equipment)

162‧‧‧Base

164‧‧‧arms

166‧‧‧Regulator head

168‧‧‧ rinse cup

170‧‧‧End effector

172‧‧‧Adjustment disc

174‧‧‧室

174‧‧‧Drive shaft

180‧‧‧Rotary actuator

182‧‧‧Support

184‧‧‧ cover

190‧‧‧ Controller

190‧‧‧damper system

192‧‧‧damper block

194‧‧‧ damper

A‧‧‧ spindle

Figure 1 illustrates a schematic cross-sectional side view of an example of a grinding apparatus.

Figure 2 is a top view of the grinding station of the grinding apparatus.

Figure 3 is a cross-sectional view of the regulator device.

Figure 4 is a top view of the base of the adjustment device.

Similar component symbols and designations in the various figures represent similar elements.

FIG. 1 illustrates an example of a grinding apparatus 100. The grinding apparatus 100 includes a rotatable disk-shaped platen 120 having a polishing pad 110 thereon. The platen 120 is operable to rotate about the shaft 125. For example, motor 122 can rotate drive shaft 124 to rotate platen 120. The platen 120 can be rotated at approximately 30-200 rpm.

The polishing pad 110 can have an abrasive surface 116. The polishing pad 110 can be a two layer polishing pad with an outer abrasive layer 112 and a softer backing layer 114. The layer that provides the abrasive surface 116 (eg, the outer abrasive layer 112) can be a porous polyurethane, such as an IC-1000 material.

The grinding apparatus 100 can include a crucible 130 for dispensing a slurry 132 (eg, a slurry) onto the polishing pad 110. The slurry 132 may include abrasive particles of vermiculite, for example, the slurry may be SS-12.

The grinding apparatus 100 includes at least one carrier head 140. Although only one carrier head 140 is illustrated, more carrier heads can be provided to hold additional substrates so that the surface area of the polishing pad 110 can be used efficiently.

The carrier head 140 is operable to hold the substrate 10 against the polishing pad 110. The carrier head 140 can have independent control of the grinding parameters (eg, pressure) associated with each individual substrate. The carrier head 140 can include a positioning ring 142 to position the substrate 10 below the elastic film 144. One or more chambers after film 144 The pressure delivery controls the pressure supplied to the substrate 10. Although only three chambers are illustrated in Fig. 1 for ease of illustration, there may be one or two chambers, or four or more chambers, for example five chambers.

The carrier head 140 suspends the self-supporting structure 150, such as a rotating rack or track, and the carrier head 140 is coupled to the carrier head rotation motor 154 by a drive shaft 152 such that the carrier head can rotate about the shaft 155. The carrier head 140 can be rotated at approximately 30-200 rpm. Alternatively, the carrier head 140 can oscillate laterally, such as on a rotating material on a rotating rack 150 or track, or by rotational rotation of the rotating rack itself. In operation, the platen is rotated about its central axis 125 and the carrier head is rotated about its central axis 155 and traversing across the top surface of the polishing pad.

The polishing apparatus 100 can also include a polishing pad conditioner 160 to abrade the polishing pad 110 to maintain the polishing pad 110 in a consistent abrasive state. The polishing pad adjuster 160 includes a base 162; an arm portion 164 that can be swept laterally over the polishing pad 110; and an adjuster head 166 that is coupled to the base by an arm portion 164 162. The base 162 is mounted to the frame 102 of the grinding apparatus 100, which can also support other components, such as the platen 120 and the support structure 150. The adjuster head 166 includes an abrasive surface that is configured to adjust the surface 116 of the polishing pad 110. The abrasive surface is rotatable and the abrasive surface is controllable against the pressure of the polishing pad.

Referring to FIG. 2, in one mode of operation, the polishing pad 110 is adjusted by the regulator head 166 while the polishing pad 110 grinds the substrate 10, which is mounted on the carrier head 140. In some implementations, the arm 164 is pivotally connected to The base 162, and the arm portion 164 sweeps back and forth to move the adjuster head 166 across the polishing pad 110 with an oscillating sweep (illustrated by arrow S). The movement of the adjuster head 166 can be synchronized with the movement of the carrier head 140 to avoid collisions.

Alternatively, the grinding apparatus 100 can include a rinse cup 168 supported on the frame 102 and the rinse cup 168 positioned in a position that allows the arm 164 to position the adjuster head 166 in the rinse cup 168. The rinse cup 168 can contain liquid for flushing the regulator head 166, or a set of nozzles can be mounted in the rinse cup to spray the wash liquid onto the regulator head 166. The adjuster head 166 can be positioned in the rinse cup 168 to be cleaned before and after the conditioning operation.

Referring to FIG. 3, the adjuster head 166 includes a rotatable and vertically movable end effector 170 that holds the adjustment disc 172. The adjustment disk 172 has a bottom surface that is embedded with a diamond abrasive that rubs the surface of the polishing pad to retexture the polishing pad. The adjustment disk 172 can be held in the end effector by a magnet or by mechanical fasteners. The gimbal mechanism can be coupled between the end effector 170 and the regulator head 166, which allows the end effector 170 to be inclined at an angle relative to the arm portion 164.

The vertical movement of the end effector 170 and the pressure control of the adjustment disk 172 can be provided by a vertical actuator in the regulator head 166, for example, the pressurizable chamber 174 is configured to supply downward pressure to the end effect. 170. Alternatively, vertical movement and pressure control may be provided by a vertical actuator in the base 162 that lifts the entire arm 164 and the adjuster head 166 or may be between the arm 164 and the base 162 Provided by a pivotal connection that allows control of the tilt angle of the arm portion 164, and thus can control the polishing pad 110 The height of the regulator head 166 above.

Rotation of the end effector 170 can be provided by a motor in the base 162 that is coupled by a belt drive that extends through the arm 164 to engage the drive shaft 174 that is coupled to the end effector 170. A description of the head of the regulator can be found in U.S. Patent No. 6,036,583, which is incorporated herein by reference.

Controller 190 (see FIG. 1, for example, a computer) can be coupled to adjustment device 160 to control the lateral sweep of arm 164, the rate of rotation of end effector 170, and the downward force of end effector 170 on the polishing pad.

The base 162 includes a rotary actuator 180 that is retained on a mount 182 that is secured to the frame. The arm portion 164 is fixed to the rotary actuator 180, and rotation of the actuator 180 causes the arm portion 164 to traverse the lateral sweep of the polishing pad.

Damper system 190 is attached to base 162 of regulator device 160. For example, damper system 190 can be attached to rotary actuator 180. In this example, damper system 190 can be rotated by actuator 180.

The damper system 190 includes a damper block 192. The damper block 192 is a heavy body, for example, formed of metal. The mass of the damper block 192 is selected to increase the stability threshold of the arm. The cover 184 can extend over the damper block 192 to protect the damper block 192 from the slurry and other contaminants, for example, to prevent corrosion.

The damper block 192 can be secured to the base 162 by a rigid connection, such as by mechanical fasteners, or one or more dampers 194 can be disposed between the damper block 192 and the base 162.

Each damper 194 can be a shock absorber, such as a hydraulic or mechanical damper, or each damper 194 can be just a layer of viscoelastic material.

Typically, the primary mode of vibration is parallel to the longitudinal axis of the arm 164. Thus, the damper 194 can be positioned to preferentially reduce vibration in this mode. As shown in FIG. 4, the damper 194 can be positioned such that the major axis A of the shape (shown in phantom) defined by the damper 194 is parallel to the longitudinal axis of the arm 164 and is the same as the longitudinal axis of the arm 164. In the vertical plane.

In general, if the damper block 192 is not utilized or fixed with minimal damping, the natural frequency of the arm portion 164 may change such that the vibration of the adjuster arm portion 164 is significantly reduced. For example, the regulator device 160 can operate with an acceptable level of vibration above a different consumable setting and a downward force range. Generally, if the damper block 192 is coupled to the base 162 by a sufficient damper 192, the problematic vibration can be significantly reduced or effectively eliminated. Thus, the use of the damper system 190 can greatly increase the range of applications in which the arms can be used without causing any problematic vibrations.

Although the above description is focused on the regulator head, the damper system can be applied to other cantilever components in the grinding system that are susceptible to vibration. For example, the damper system can be applied to an arm that holds the grinding head.

The above described grinding apparatus and method can be applied to a variety of grinding systems. One or both of the polishing pad or carrier head can be moved to provide relative movement between the abrasive surface and the substrate. For example, the platen can be hovered rather than rotated. The polishing pad can have a shape other than a circle. Certain aspects of the endpoint detection system can be applied to linear abrasive systems, for example, where the polishing pad is a linearly moving continuous or reel-to-reel strap. The abrasive layer can be standard (eg with or without filling) Abrasive material, soft material or material with fixed abrasiveness of the filled polyurethane. The arm can move linearly, rather than sweeping at an angle.

As used in this specification, the term "substrate" may include, for example, a product substrate (eg, a product substrate including a plurality of memory and processor dies), a test substrate, a bare board, and a snuated substrate. The substrate can be at various stages of integrated circuit fabrication, for example, the substrate can be a bare wafer, or the substrate can include one or more deposited and/or patterned layers. The term "substrate" can include a disk and a rectangular plate.

All of the functional operations described in this specification and embodiments of the present invention can be implemented by digital electronic circuitry, or computer software, firmware, or hardware, including the structural means and structural equivalents thereof disclosed in this specification. , or a combination of them. Embodiments of the invention may be implemented as one or more computer program products (ie, one or more computer programs tangibly embodied in a non-transitory machine readable storage medium) for execution by a data processing device Or control operations, such as a programmable processor, a computer, or multiple processors or computers.

Specific embodiments of the invention have been described. Other embodiments are within the scope of the following patent claims.

The claimed patent scope is as follows.

160‧‧‧ polishing pad adjuster (adjustment equipment)

162‧‧‧Base

164‧‧‧arms

166‧‧‧Regulator head

170‧‧‧End effector

172‧‧‧Adjustment disc

174‧‧‧室

174‧‧‧Drive shaft

180‧‧‧Rotary actuator

182‧‧‧Support

184‧‧‧ cover

190‧‧‧ Controller

190‧‧‧damper system

192‧‧‧damper block

194‧‧‧ damper

Claims (11)

A regulator apparatus for use in substrate polishing, the regulator apparatus comprising: a regulator head configured to receive an end effector for adjusting a surface of a polishing pad An arm supporting the adjuster head; a base supporting the arm, the base including an actuator coupled to the arm to arm the arm Moving laterally with the regulator head over the polishing pad; and a damper system secured to the base, the damper system being configured to reduce vibration of the arm. The device of claim 1 wherein the actuator comprises a rotary actuator configured to sweep the arm over the polishing pad. The apparatus of claim 2, wherein the damper system is fixed to the rotary actuator, and the damper system is rotated by the rotary actuator. The apparatus of claim 1 wherein the damper system comprises a damper block. The device of claim 4, wherein the damper block is attached to the base by at least one damper. The apparatus of claim 5, wherein the at least one damper comprises a layer of damping material. The device of claim 6, wherein the damper block is attached to the base by a plurality of dampers. The apparatus of claim 7, wherein the plurality of dampers comprise a shock absorber. The apparatus of claim 7, wherein the plurality of dampers are configured to define a major axis that is parallel to an axis of a primary mode of vibration of the arm. The apparatus of claim 7, wherein the plurality of dampers are configured to define a major axis that is parallel to a longitudinal axis of the arm. The apparatus of claim 1 including a vertical actuator in the regulator head and coupled to the end effector to control a vertical position of the end effector.