CN210650151U

CN210650151U - Polishing solution arm and chemical mechanical polishing machine

Info

Publication number: CN210650151U
Application number: CN201920954848.6U
Authority: CN
Inventors: 岳志刚; 辛君; 林宗贤
Original assignee: Huaian Imaging Device Manufacturer Corp
Current assignee: Huaian Imaging Device Manufacturer Corp
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2020-06-02
Anticipated expiration: 2029-06-24

Abstract

The utility model provides a lapping liquid arm and chemical mechanical polishing board. The grinding fluid arm includes casing, grinding pad cleaning brush and actuating mechanism, grinding pad cleaning brush set up in the casing below, actuating mechanism with grinding pad cleaning brush is connected, and is used for the drive grinding pad cleaning brush removes and rotates so that grinding pad cleaning brush contact and clean grinding pad, when the chemical mechanical polishing board is in the grinding and stops clearance or standby, actuating mechanism drive reciprocating and rotation of grinding pad cleaning brush, so that grinding pad cleaning brush contact and clean grinding pad to reduce wafer fish tail probability.

Description

Polishing solution arm and chemical mechanical polishing machine

Technical Field

The application relates to the field of semiconductors, in particular to a grinding fluid arm and a chemical mechanical grinding machine.

Background

Since the application of the CMP (Chemical Mechanical polishing) process to the integrated circuit manufacturing process, the CMP process has become a key process for promoting the continuous progress of the integrated circuit technology. The CMP device, i.e. the chemical mechanical polishing machine, mainly comprises a polishing table, a polishing pad, a polishing head, a polishing liquid arm and a polishing pad dresser. When performing chemical mechanical polishing (abbreviated as polishing), the polishing pad is placed on the polishing table, the wafer is fixed under the polishing head, then applying downward pressure on the grinding head to make the wafer tightly press on the grinding pad, finally rotating the grinding table under the drive of the motor, making the grinding head also rotate in the same direction, meanwhile, the grinding fluid is conveyed to the grinding pad through a grinding fluid supply pipe in the grinding fluid arm, the grinding fluid is uniformly distributed on the grinding pad under the action of centrifugal force, forming a liquid film of polishing slurry between the wafer and the polishing pad, wherein the chemical components in the polishing slurry react with the surface material of the wafer to convert the insoluble material into easily soluble material, or the substances with high hardness are softened, then the chemical reactants are removed from the surface of the wafer through the micro-mechanical friction action of the abrasive particles and dissolved in flowing liquid to be taken away, namely, the purpose of planarization is realized in the alternating process of chemical film removal and mechanical film removal. The polishing pad dresser is used for dressing the surface of a polishing pad, and can improve the distribution uniformity of polishing liquid on the polishing pad.

It has been found that during the polishing process, a certain amount of polishing by-products are generated, and the polishing by-products are accumulated on the surface and in the grooves of the polishing pad, and the diamonds on the surface of the pad dresser are easy to fall off during the polishing process, and the fallen diamonds are also adhered on the surface and in the grooves of the polishing pad, and the by-products and diamond particles can cause scratches to the surface of the wafer to different degrees, thus reducing the product yield.

Disclosure of Invention

An object of the utility model is to provide a lapping liquid arm, it can clean the grinding pad surface, reduces wafer fish tail probability to improve the product yield.

In order to solve the technical problem, the utility model provides a grinding fluid arm, including casing, grinding pad cleaning brush and actuating mechanism, grinding pad cleaning brush set up in the casing below, actuating mechanism with grinding pad cleaning brush connects, and is used for the drive grinding pad cleaning brush removes and rotates so that grinding pad cleaning brush contacts and clean grinding pad.

Optionally, in the polishing solution arm, the driving mechanism includes a first cylinder, a second cylinder, a motor, and a supporting member, one end of the polishing pad cleaning brush is connected to the motor, the other end of the polishing pad cleaning brush is connected to the second cylinder through the supporting member, and the motor is connected to the first cylinder.

Optionally, in the polishing solution arm, the polishing pad cleaning brush includes a roller, a sleeve and bristles, the sleeve is fixed on the roller in a penetrating manner, and the bristles are arranged on the surface of the sleeve.

Optionally, in the grinding fluid arm, one end of the roller is connected to the motor through a gear, a sprocket or a coupler, the support member is connected to the second cylinder through a first connecting rod, and the motor is connected to the first cylinder through a second connecting rod.

Optionally, in the polishing solution arm, an opening is provided on the support member, and the roller is inserted into the opening of the support member.

Optionally, in the polishing solution arm, when the first cylinder and the second cylinder are in a non-working state, the distance between the polishing pad cleaning brush and the bottom of the housing is 2cm to 3 cm; when the first cylinder and the second cylinder are in working states, the distance between the grinding pad cleaning brush and the bottom of the shell is 4-5 cm.

Optionally, in the polishing pad arm, the polishing pad arm further includes a nozzle, a water supply pipe, and a valve disposed on the water supply pipe, the nozzle is communicated with the water supply pipe, and an opening of the nozzle faces the polishing pad.

Optionally, in the slurry arm, the nozzle is fixed to a side surface of the housing.

In order to achieve the above objects and other related objects, the present invention also provides a chemical mechanical polishing apparatus, including the polishing solution arm as described above.

Optionally, in the chemical mechanical polishing apparatus, the chemical mechanical polishing apparatus further includes a control system, and the control system is configured to control the driving mechanism.

To sum up, the utility model provides a grinding fluid arm, including casing, grinding pad cleaning brush and actuating mechanism, grinding pad cleaning brush set up in the casing below, actuating mechanism with grinding pad cleaning brush connects, and is used for the drive grinding pad cleaning brush removes and rotates so that grinding pad cleaning brush contacts and clean grinding pad. When the chemical mechanical polishing machine is in a polishing stop gap or is in a standby state, the driving mechanism drives the polishing pad cleaning brush to move and rotate, and the wafer scratching probability can be reduced by cleaning the polishing pad through the polishing pad cleaning brush. Furthermore, the polishing solution arm can further comprise a nozzle, and the nozzle can spray high-pressure water to the polishing pad so as to achieve better cleaning effect.

Drawings

Fig. 1 is a schematic view of a chemical mechanical polishing apparatus according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a polishing liquid arm according to an embodiment of the present invention;

fig. 3 is a flow chart illustrating a working process of a polishing liquid arm according to an embodiment of the present invention;

in fig. 1:

10-grinding pad, 20-grinding fluid arm, 30-grinding fluid, 40-grinding by-product, 50-grinding head, 60-diamond particles and 70-grinding pad dresser;

in fig. 2:

201-housing, 202-gas supply conduit, 2021-first gas supply conduit, 2022-second gas supply conduit, 2031-first cylinder, 2032-second cylinder, 204-polishing pad cleaning brush, 205-motor, 206-control system, 207-nozzle, 208-water supply conduit, 209-base, 210-support member, 211-gas supply unit, 212-water supply unit, 2131-first connecting rod, 2132-second connecting rod.

Detailed Description

As described in the background art, in the process of polishing, the chemical mechanical polishing machine inevitably gathers polishing by-products, diamond particles, etc. on the polishing pad, thereby scratching the surface of the wafer to different degrees and reducing the yield of the wafer. Specifically, as shown in fig. 1, a polishing head 50 applies pressure to press a wafer (not shown in fig. 1) against a polishing pad 10 having a plurality of grooves for polishing, and at the same time, a polishing solution 30 is delivered to the polishing pad 10 through a polishing solution supply pipeline in a polishing solution arm 20, the polishing solution 30 is uniformly distributed on the polishing pad 10 by a centrifugal force generated by rotation of the polishing table, and a polishing pad dresser 70 is used for dressing the surface of the polishing pad 10 and improving the uniformity of distribution of the polishing solution 30 on the polishing pad 10. However, during the polishing process, the cmp apparatus generates a certain amount of polishing by-products 40, the polishing by-products 40 are collected on the surface and in the grooves of the polishing pad 10, and the diamonds on the surface of the pad dresser 70 may fall off the diamond particles 60, the diamond particles 60 are also attached to the surface and in the grooves of the polishing pad 10, and the polishing by-products 40 and the diamond particles 60 may scratch the surface of the wafer to different degrees.

Based on the above research, the present embodiment provides a novel polishing slurry arm, which can be used to clean the surface of the polishing pad. As shown in fig. 2, an arm for polishing slurry comprises a housing 201, a cleaning brush 204 for polishing pad, and a driving mechanism, wherein the cleaning brush 204 for polishing pad is disposed under the housing 201, and the driving mechanism is connected to the cleaning brush 204 for driving the cleaning brush 204 for moving and rotating to make the cleaning brush 204 contact and clean the polishing pad.

The driving mechanism may include a first cylinder 2031, a second cylinder 2032, a motor 205, and a support member 210, wherein one end of the polishing pad cleaning brush 204 is connected to the motor 205, the other end of the polishing pad cleaning brush 204 is connected to the second cylinder 2032 through the support member 210, and the motor 205 is connected to the first cylinder 2031 through a second connecting rod 2132.

The housing 201 has an accommodating space therein, and the external shape thereof may be a rectangular parallelepiped or a cube. The material of the housing 201 may be plastic, resin, metal, etc., and is not limited herein. The bottom of the housing 201 (the side near the polishing pad cleaning brush 204) is preferably closed except for the cylinder position to prevent slurry from splashing into the housing 201. Of course, in practical implementation, the bottom of the housing 201 may be provided with an opening other than the cylinder position, and the shape of the opening may be, for example, a rectangle or a U.

The arm may further include a base 209, the base 209 may also have an accommodating space therein, the external shape of the base 209 may be a rectangular parallelepiped or a cube, and the external shape of the base may be perpendicular to the housing 201, one end of the housing 201 is connected to the base 209 by riveting or welding, for example, and the accommodating space of the housing 201 is communicated with the accommodating space of the base 209. The base 209 may have supporting components, transmission components, driving components, gas and liquid pipelines and/or related circuits, etc. known to those skilled in the art, mounted therein, so as to enable the polishing liquid arm to have the functions of moving, clamping or adsorbing, etc.

The pad cleaning brush 204 includes a roller, a sleeve, and bristles (the bristles may be replaced with a coarse cloth) disposed on the surface of the sleeve. The sleeve can be internally provided with an accommodating space, the outer shape of the sleeve can be a cylindrical structure, the sleeve is fixedly arranged on the rolling shaft in a penetrating way and can rotate along with the rolling shaft, and the sleeve can be made of resin, silica gel, plastic or metal. The roller may be a hollow or solid rod-like structure, preferably of a material corresponding to the material of the sleeve. The roller and the sleeve can also be of an integrated structure, the structure is simple, and later-stage assembly is not needed. Both ends of the roller are connected to the support member 210 and the motor 205, respectively. The bristles may be wires, fibers, lint, or animal hair, among others. The polishing pad cleaning brush 204 is disposed below the housing 201, and when the first cylinder 2031 and the second cylinder 2032 are in a non-operating state, the distance between the polishing pad cleaning brush 204 and the bottom of the housing 201 is 2-3 cm, and at this time, the polishing pad cleaning brush 204 does not contact the polishing pad nor affect the ejection of the polishing liquid. When the first cylinder 2031 and the second cylinder 2032 are in an operating state, i.e., are pressed down, the distance between the polishing pad cleaning brush 204 and the bottom of the housing 201 is 4-5 cm, i.e., the polishing pad cleaning brush contacts the polishing pad.

One end of the roller of the polishing pad cleaning brush 204 may be connected to the motor 205 through a gear, a sprocket, or a coupling, and the like, and the motor 205 may also be connected to the first cylinder 2031 through a second connecting rod 2132, and the second connecting rod 2132 may be a component provided for the motor 205 itself or an additional component. After the motor 205 is started, it drives the roller of the polishing pad cleaning brush 204 to rotate, so as to drive the polishing pad cleaning brush 204 to rotate, the rotation may be clockwise rotation or counterclockwise rotation, that is, the motor 205 is used to provide the rotation power of the polishing pad cleaning brush 204.

The other end of the roller of the polishing pad cleaning brush 204 (the end away from the motor 205) is connected to the supporting member 210, and the supporting member 210 may be provided with an opening, and the roller is inserted into the opening of the supporting member 210, so that the supporting member 210 and the motor 205 together fix the polishing pad cleaning brush 204 and preferably assume a horizontal state (which is parallel to the polishing pad as much as possible). The shape of support component 210 can be square, cuboid or cylinder etc., support component 210's opening shape can be circular or square etc. and opening area is greater than or equal to the radial cross-sectional area of grinding pad cleaning brush 204 roller bearing, and preferred open-ended shape is circular, and its area slightly is greater than the cross-sectional area of the circular side of roller bearing, can satisfy the roller bearing rotates not influenced can, this kind of mode can prevent to cause the roller bearing with support component 210 breaks away from because the rocking of roller bearing in rotatory in-process, and then prevents that grinding pad cleaning brush is impaired. The support member 210 may be fixedly connected to the end surface of the roller by a connecting member such as a pin or a screw. The support member 210 is connected to the second cylinder 2032 by a first connection rod 2131, and the first connection rod 2131 may be a separately added member or may be a structure provided in the support member 210 itself.

The first cylinder 2031 and the second cylinder 2032 may be common cylinders and fixed to the side wall of the inside of the housing 201 by bolts. The second cylinder 2032 is connected to the support member 210 by a first connecting rod 2131, and the first cylinder 2031 is connected to the motor 205 by a second connecting rod 2132, preferably, the first connecting rod 2131 and the second connecting rod 2132 are connected to the centers of the second cylinder 2032, the support member 210, the first cylinder 2031 and the motor 205, respectively. In a preferred embodiment, the length of the connecting rod satisfies the following conditions: so that the center of the supporting member 210 and the center of the motor 205 are maintained on the same horizontal line, i.e., so that the polishing pad cleaning brush 204 can be maintained in a horizontal state. Preferably, the center of the second cylinder 2032 is on the same vertical line as the center of the support member 210, and the center of the first cylinder 2031 is on the same vertical line as the center of the motor 205, and in this case, when the polishing pad cleaning brush 204 can be kept horizontal, the length required for the link rod is shortest, and when the cylinders perform the same pressing operation, the distance moved by the polishing pad cleaning brush is largest. Since the first cylinder 2031 and the second cylinder 2032 need to be mechanically pressed down, openings are provided at the positions of the first cylinder 2031 and the second cylinder 2032 at the bottom of the housing 201, the openings may be rectangular, square, circular, or the like, and the size of the openings is greater than or equal to the size of the main bodies of the first cylinder 2031 and the second cylinder 2032.

The first cylinder 2031 and the second cylinder 2032 are connected to a gas supply unit 211 through a gas supply conduit 202. The gas supply pipe 202 passes through the inside of the housing 201 and the base 209 and then is connected to the gas supply unit 211. The gas supply unit 211 supplies gas, for example, air, required for the first and

second cylinders

2031 and 2032. The gas supply line 202 includes, for example, a first gas supply line 2021 and a second gas supply line 2022. The gas of the gas supply unit 211 is supplied to the first and

second cylinders

2031 and 2032 through first and second

gas supply lines

2021 and 2022, respectively. In addition, a three-way valve (not shown) may be installed on the gas supply pipe 202, and the first cylinder 2031, the second cylinder 2032 and the gas supply pipe 202 are respectively connected to three ports of the three-way valve. After entering the gas supply pipe 202, the gas from the gas supply unit 211 reaches the first cylinder 2031 and the second cylinder 2032 through a three-way valve, and the first cylinder 2031 and the second cylinder 2032 convert the gas into mechanical energy to realize the up-and-down reciprocating motion of the polishing pad cleaning brush 204.

The polishing liquid arm may further include a plurality of nozzles 207, an opening of the nozzle 207 faces the polishing pad, the nozzle 207 may be a high pressure nozzle or an air-water atomization nozzle, and the like, the high pressure nozzle refers to a nozzle which sprays liquid with a relatively high pressure (generally greater than 2MPa), and during use, the high pressure liquid and air are gathered in the nozzle and then sprayed out rapidly through the contraction of the cross section of an inner hole of the nozzle, so as to generate a high impact water flow and then clean the polishing pad, and the cleaning effect is excellent, and therefore, the high pressure nozzle is preferred. The number of the nozzles 207 may be one or two or more, and preferably, the number of the nozzles is at least two, the nozzles are arranged in parallel to the polishing pad cleaning brush, and the openings of all the nozzles are oriented in the same direction, and it can be understood that the larger the number of the nozzles 207, the larger the area of the polishing pad that can be cleaned, and the better the cleaning effect. The nozzle 207 is connected to one end of a water supply pipe 208, the other end of the water supply pipe 208 is connected to a water supply unit 212, and a valve (not shown) is disposed on the water supply pipe 208 to control whether deionized water is supplied to the nozzle 207. The water supply pipe 208 may penetrate from the inside of the housing 201 and the base 209 to be connected to the water supply unit 212, and the water supply unit 212 provides deionized water required by the nozzle.

When the bottom of the housing 201 is an open structure, the nozzle 207 is directly fixed on the inner side surface of the housing 201 or a baffle extending from the side surface. Preferably, the opening of the nozzle 207 is disposed outside the housing 201, and the rest of the opening is disposed inside the housing, so that the occupied space can be effectively saved, and the nozzle 207 can be protected. The angle range between the nozzle 207 and the rear side surface of the shell 201 is 45-75 degrees.

When the bottom of the housing 201 is closed except for the cylinder, the nozzle 207 is disposed on the outer bottom of the housing 201 or on a baffle extending from the side of the housing 201. Besides, the nozzle 207 may also pass through a nozzle opening through the bottom of the housing 201, and the rest of the nozzle opening is disposed inside the housing 201, that is, a housing bottom opening is additionally disposed at the position of the nozzle 207 at the bottom of the housing 201, the shape of the housing bottom opening may be circular or square, and the size of the housing bottom opening is greater than or equal to the size of the nozzle 207 opening. The nozzle 207 and the side surface of the shell 201 or a baffle plate on the side surface have a certain angle, and the angle range is 45-75 degrees. The nozzle 207 may perform water jet cleaning of the polishing pad, or the polishing pad cleaning brush 204.

The embodiment also provides a chemical mechanical polishing machine, which comprises the polishing solution arm. The grinding fluid arm can realize the movement and the rotation of the rolling brush to clean the surface of the grinding pad.

The chemical mechanical polishing tool further includes a control system 206. The control system 206 may be a control system of a cmp apparatus, which can be used to control the pad dresser operation and the slurry delivery, etc. to achieve the original functions of the cmp apparatus, which are well known to those skilled in the art and will not be described herein. The control system 206 may also control the drive mechanism such that the drive mechanism drives the polishing pad cleaning brush to move and rotate, which may cause the polishing pad cleaning brush to contact and clean the polishing pad.

Specifically, the control system may additionally add a motor control function to the slurry arm, that is, the control system 206 is electrically connected to the motor 205 to control the on/off of the motor 205 and thus control the rotation of the polishing pad cleaning brush 204. It is understood that the skilled person can easily know how to implement the motor control function according to the common general knowledge in the field and the disclosure of the present application, and the details are not described herein. In addition, the control system 206 can also add a cylinder control function to the slurry arm, and the control system 206 can control the opening and closing of a gas valve (not shown in the figure) to realize the cylinder control function, and those skilled in the art can easily know how to realize the cylinder control function according to the common general knowledge in the art and the disclosure of the present application. For example, in a specific implementation, the gas valve may be disposed between the gas supply pipeline 202 and the gas supply unit 211, when the chemical mechanical polishing machine is in a polishing stop gap or in a standby state, the control system 206 controls the gas provided by the gas supply unit 211 to be input into the gas supply pipeline 202 through the gas valve, and then the gas enters the first cylinder 2031 and the second cylinder 2032 through the gas supply pipeline 202, and the first cylinder 2031 and the second cylinder 2032 convert the gas into mechanical energy to realize the up-and-down movement of the cylinder piston, thereby driving the up-and-down movement of the polishing pad cleaning brush 204.

The control system 206 accomplishes cleaning of the polishing pad by means of cylinder control and motor control functions. When the chemical mechanical polishing machine is in a polishing stop gap or in a standby state, the control system 206 controls the gas valve to be in an open state, the gas provided by the gas supply unit 211 is supplied to the first cylinder 2031 and the second cylinder 2032 through the gas supply pipeline 202, the first cylinder 2031 and the second cylinder 2032 convert the gas into mechanical energy, the downward pressing action of the polishing pad cleaning brush 204 is realized, and the downward pressing is stopped when the gas valve contacts the polishing pad, that is, the control system 206 controls the gas valve to be in a closed state, and at the same time, the control system 206 controls the motor 205 to be in an open state, so as to drive the polishing pad cleaning brush 204 to rotate, clean the surface of the polishing pad, remove polishing byproducts and diamond particles, and prevent the surface of the wafer from being scratched.

The control system 206 may also add a nozzle control function to the slurry arm, i.e., the control system 206 may control the nozzle through a valve disposed on the water supply pipe 208 to control whether the deionized water is delivered to the nozzle 207. Referring to fig. 2 and 3, when the cmp apparatus is in a polishing stop gap or in a standby state, the control system 206 controls the valve to open, so as to control the deionized water provided by the water supply unit 212 to be delivered to the nozzle 207 through the water supply pipe 208, and the nozzle 207 sprays high-pressure water to the polishing pad to achieve a better cleaning effect. It is understood that the skilled person can easily know how to implement the nozzle control function according to the common general knowledge in the field and the disclosure of the present application, and the detailed description is omitted here. It should be appreciated that the slurry arm may clean the polishing pad through the nozzle 207 or through the polishing pad cleaning brush 204, but may also clean the polishing pad through both the nozzle 207 and the polishing pad cleaning brush 201.

Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. All equivalent changes and modifications made according to the content of the claims of the present invention shall fall within the technical scope of the present invention.

Claims

1. The polishing solution arm is characterized by comprising a shell, a polishing pad cleaning brush and a driving mechanism, wherein the polishing pad cleaning brush is arranged below the shell, and the driving mechanism is connected with the polishing pad cleaning brush and used for driving the polishing pad cleaning brush to move and rotate so that the polishing pad cleaning brush contacts with and cleans a polishing pad.

2. The slurry arm according to claim 1, wherein the driving mechanism comprises a first cylinder, a second cylinder, a motor, and a support member, one end of the polishing pad cleaning brush is connected to the motor, the other end of the polishing pad cleaning brush is connected to the second cylinder through the support member, and the motor is connected to the first cylinder.

3. The slurry arm as claimed in claim 2, wherein said polishing pad cleaning brush comprises a roller, a sleeve and bristles, said sleeve is fixed on said roller, and said bristles are disposed on the surface of said sleeve.

4. The slurry arm according to claim 3, wherein one end of said roller is connected to said motor through a gear, a sprocket, or a coupling, said support member is connected to said second cylinder through a first connecting rod, and said motor is connected to said first cylinder through a second connecting rod.

5. The slurry arm as claimed in claim 3, wherein said support member is provided with an opening, and said roller is inserted into said opening of said support member.

6. The slurry arm according to claim 2, wherein when the first and second air cylinders are in a non-operating state, the distance between the cleaning brush and the bottom of the housing is 2cm to 3 cm; when the first cylinder and the second cylinder are in working states, the distance between the grinding pad cleaning brush and the bottom of the shell is 4-5 cm.

7. The slurry arm according to any of claims 1 to 6, further comprising a nozzle, a water supply conduit, and a valve disposed on the water supply conduit, wherein the nozzle is in communication with the water supply conduit and opens toward the polishing pad.

8. The slurry arm according to claim 7, wherein said nozzle is fixed to a side surface of said housing.

9. A chemical mechanical polishing machine, comprising the polishing liquid arm of any one of claims 1 to 8.

10. The chemical mechanical polishing apparatus of claim 9, further comprising a control system for controlling the driving mechanism.