CN116214358A

CN116214358A - Chemical mechanical polishing system

Info

Publication number: CN116214358A
Application number: CN202211722045.0A
Authority: CN
Inventors: 王剑; 路新春
Original assignee: Huahaiqingke Co Ltd
Current assignee: Huahaiqingke Co Ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-06-06

Abstract

The invention discloses a chemical mechanical polishing system, which comprises: a front unit; a polishing unit; the cleaning unit is arranged between the front unit and the polishing unit; the cleaning unit comprises a first cleaning unit and a second cleaning unit, and the first cleaning unit and the second cleaning unit are symmetrically arranged relative to the transverse center line of the cleaning unit; the first cleaning unit and the second cleaning unit comprise post-treatment modules which are transversely and longitudinally staggered, the post-treatment modules close to the transverse central line are multi-layered and vertically stacked, and the post-treatment modules close to the side parts of the cleaning units are single-layered; the device also comprises a transmission manipulator which is arranged close to the post-processing module and symmetrically arranged on two sides of the transverse center line.

Description

Chemical mechanical polishing system

Technical Field

The invention belongs to the technical field of chemical mechanical polishing, and particularly relates to a chemical mechanical polishing system.

Background

The integrated circuit industry is the core of the information technology industry and plays a key role in the process of converting and upgrading the boosting manufacturing industry into digital and intelligent conversion. The chip is a carrier of an integrated circuit, and the chip manufacturing involves the process flows of integrated circuit design, wafer manufacturing, wafer processing, electrical measurement, dicing packaging, testing, and the like. Among them, chemical mechanical polishing belongs to one of five main core processes in the wafer manufacturing process.

Chemical mechanical polishing (Chemical Mechanical Polishing, CMP) is a globally planarized ultra-precise surface finish technique. CMP systems typically include a pre-unit, a polishing unit, and a cleaning unit, which enable a wafer to be obtained that meets process requirements by chemical mechanical polishing.

Because the functions of the front unit and the polishing unit are relatively fixed, the process of the cleaning unit is complex, and the cleaning unit involves the procedures of pre-cleaning, brushing, drying and the like; the arrangement of each module in the cleaning unit is compact, and accessories such as an electric part, a liquid path and the like are particularly required to be configured, so that the maintenance space of the cleaning unit is seriously reduced, and the normal maintenance operation of operators is not facilitated.

Disclosure of Invention

The embodiment of the invention provides a chemical mechanical polishing system, which aims at solving at least one of the technical problems existing in the prior art.

A first aspect of an embodiment of the present invention provides a chemical mechanical polishing system, comprising:

a front unit;

a polishing unit;

the cleaning unit is arranged between the front unit and the polishing unit;

the cleaning unit comprises a first cleaning unit and a second cleaning unit, and the first cleaning unit and the second cleaning unit are symmetrically arranged relative to the transverse center line of the cleaning unit; the first cleaning unit and the second cleaning unit comprise post-treatment modules which are transversely and longitudinally staggered, the post-treatment modules close to the transverse central line are multi-layered and vertically stacked, and the post-treatment modules close to the side parts of the cleaning units are single-layered; the device also comprises a transmission manipulator which is arranged close to the post-processing module and symmetrically arranged on two sides of the transverse center line.

In some embodiments, the vertical height of the aftertreatment module proximate the side of the wash unit is the same as the corresponding vertical height of the aftertreatment module proximate the upper layer of the lateral centerline.

In some embodiments, the chemical mechanical polishing system further comprises a buffer mechanism located between the vertically stacked post-processing modules.

In some embodiments, the buffer mechanism is also disposed below the aftertreatment module proximate to the side of the wash unit.

In some embodiments, the caching mechanism is disposed below the aftertreatment module adjacent to the lead unit.

In some embodiments, the first cleaning unit is configured with a pair of transfer robots, one of which is disposed adjacent to the front unit and the other of which is disposed adjacent to the polishing unit.

In some embodiments, the transfer robot is configured with a vertical slide rail that is movable in a vertical direction to transfer wafers between adjacent post-processing modules.

In some embodiments, the post-processing module includes a brush module, a pre-rinse module, and a dry module that process the wafer surface in a horizontal manner.

In some embodiments, the drying module is disposed adjacent to the head unit.

In some embodiments, a side of the aftertreatment module is configured with a switch door disposed toward the transfer robot.

The beneficial effects of the invention include:

a. the post-processing modules run independently and are not interfered with each other, so that the fault tolerance of the cleaning unit is improved;

b. the post-processing modules are arranged in a staggered manner along the transverse direction and the longitudinal direction of the cleaning unit, so that the maintenance space of the cleaning unit is increased, and the convenience of using and maintaining the CMP system is improved;

c. the lateral part of the cleaning unit is provided with a single-layer post-processing module, and accessories such as corresponding electric liquid are arranged below or above the single-layer post-processing module, so that the internal space of the cleaning unit is fully utilized, and the maintainability of equipment is improved.

Drawings

The advantages of the present invention will become more apparent and more readily appreciated from the detailed description given in conjunction with the following drawings, which are meant to be illustrative only and not limiting of the scope of the invention, wherein:

FIG. 1 is a schematic diagram of a chemical mechanical polishing system according to one embodiment of the present invention;

FIG. 2 is a front view of the chemical mechanical polishing system of FIG. 1;

FIG. 3 is a schematic diagram of a buffering mechanism according to an embodiment of the present invention;

FIG. 4 is a side view of the chemical mechanical polishing system corresponding to FIG. 1;

FIG. 5 is a schematic view of a corresponding cleaning unit of FIG. 1;

FIG. 6 is a schematic diagram of a cleaning unit according to an embodiment of the present invention;

FIG. 7 is a schematic view of a brush module according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a pre-cleaning module according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of a drying module according to an embodiment of the present invention;

fig. 10 is a roadmap for wafer transport in a chemical mechanical polishing system.

Detailed Description

The following describes the technical scheme of the present invention in detail with reference to specific embodiments and drawings thereof. The examples described herein are specific embodiments of the present invention for illustrating the concept of the present invention; the description is intended to be illustrative and exemplary in nature and should not be construed as limiting the scope of the invention in its aspects. In addition to the embodiments described herein, those skilled in the art can adopt other obvious solutions based on the disclosure of the claims of the present application and the specification thereof, including those adopting any obvious substitutions and modifications to the embodiments described herein.

The drawings in the present specification are schematic views, which assist in explaining the concept of the present invention, and schematically show the shapes of the respective parts and their interrelationships. It should be understood that for the purpose of clearly showing the structure of various parts of embodiments of the present invention, the drawings are not drawn to the same scale and like reference numerals are used to designate like parts in the drawings.

In the present invention, "chemical mechanical polishing (Chemical Mechanical Polishing, CMP)" is also referred to as "chemical mechanical planarization (Chemical Mechanical Planarization, CMP)", and Wafer (W) is also referred to as Substrate (Substrate), the meaning and actual function are equivalent.

Embodiments of the present disclosure relate generally to Chemical Mechanical Polishing (CMP) units used in the semiconductor device manufacturing industry, in which a polishing liquid composed of submicron or nano abrasive particles and a chemical solution flows between a wafer and a polishing pad, the polishing liquid is uniformly distributed under the action of a transmission and rotation centrifugal force of the polishing pad to form a liquid film between the wafer and the polishing pad, chemical components in the liquid chemically react with the wafer to convert insoluble substances into soluble substances, and then the chemical reactants are removed from the wafer surface by micro-mechanical friction of the abrasive particles and taken away in the flowing liquid, i.e., surface materials are removed during an alternating process of chemical film formation and mechanical film removal to achieve surface planarization, thereby achieving global planarization.

FIG. 1 is a schematic diagram of a chemical mechanical polishing system according to an embodiment of the present invention, comprising:

a front unit 1, which may be abbreviated as EFEM (Equipment Front End Module), for storing wafers to be polished and polished;

a polishing unit 3 for performing chemical mechanical polishing to accomplish material removal of the wafer surface;

the cleaning unit 2 is arranged between the front unit 1 and the polishing unit 3 to remove particles remained on the surface of the wafer in the polishing process, so as to ensure that the cleanliness of the surface of the wafer meets the process requirements.

Further, the front unit 1 includes 4 front opening unified pods 1a and a front robot 1b, wherein the front opening unified pods 1a (Front Opening Unified Pod, FOUP) are used for storing wafers. The front robot 1b is disposed at one side of the front opening unified pod 1a, and the front robot 1b is used for transferring wafers between the front unit 1 and the cleaning unit 2. The front-end robot 1b is generally configured with an upper clamping jaw and a lower clamping jaw to respectively grasp a polished wafer and a wafer to be polished, so as to avoid cross contamination during wafer clamping.

In fig. 1, the cleaning unit 2 includes a first cleaning unit 2A and a second cleaning unit 2B, wherein the first cleaning unit 2A and the second cleaning unit 2B are symmetrically disposed with respect to a lateral center line CL of the cleaning unit 2. The transverse center line CL is disposed along the length direction of the cleaning unit 2, that is, a line connecting the midpoints of the width of the cleaning unit 2. In the present invention, the lateral direction of the cleaning unit 2 refers to the longitudinal direction of the cleaning unit 2; the longitudinal direction of the cleaning unit 2 refers to the width direction of the cleaning unit 2.

Since the structures and the layout of the first cleaning unit 2A and the second cleaning unit 2B are substantially identical, the composition and the connection relationship of the first cleaning unit 2A will be described in detail below. For convenience of description, the component names in the first cleaning unit 2A start with "first", and the component numbers end with "a"; accordingly, the part names in the second cleaning unit 2B start with "second", and the part numbers end with "B".

The first cleaning unit 2A includes a plurality of post-treatment modules 20, and the post-treatment modules 20 are staggered in the lateral and longitudinal directions. The first cleaning unit 2A further includes a transfer robot 30, the transfer robot 30 being disposed proximate to the post-processing modules 20 to facilitate transfer of wafers between the post-processing modules 20.

Specifically, the first cleaning unit 2A includes four post-treatment modules 20; wherein, the post-processing modules 20 close to the transverse center line CL are two layers, and the post-processing modules 20 are stacked along the vertical direction; the aftertreatment module 20 adjacent to the side of the wash unit 2 is a single layer. That is, the single-layer post-processing module 20 and the double-layer stacked post-processing module 20 form a 'delta' structure, and the staggered post-processing modules 20 can provide space for daily maintenance or fault maintenance of operators, thereby being beneficial to improving the convenience of using the CMP system.

Further, the transfer robot 30 includes a front transfer robot 31 and a rear transfer robot 32, wherein the front transfer robot 31 is disposed adjacent to the front unit 1 and the rear transfer robot 32 is disposed adjacent to the polishing unit 2.

In fig. 1, the first cleaning unit 2A includes a first front transfer robot 31A and a first rear transfer robot 32A, the post-processing modules 20 stacked on each other are substantially aligned with the first front transfer robot 31A and the first rear transfer robot 32A, and a line connecting the positions of the first front transfer robot 31A and the first rear transfer robot 32A is parallel to the transverse center line CL.

Fig. 2 is a front view of the chemical mechanical polishing system of fig. 1, and the vertical height of the post-processing module 20 near the side of the cleaning unit 2 is the same as the corresponding vertical height of the post-processing module 20 near the upper layer of the lateral center line CL shown in fig. 1. So configured, the wafer transfer robot 30 may be disposed in a relatively fixed vertical position to facilitate transfer of wafers between adjacent post-processing modules 20, improving transfer efficiency of the wafers in the cleaning unit 2.

As an embodiment of the present invention, the cmp system further includes a buffer mechanism 40, as shown in fig. 2, where the buffer mechanism 40 is located between the post-processing modules 20 arranged vertically in a stack, so as to buffer the wafers inside the cleaning unit 2, balance the difference in processing time between the processes, and reduce the process waiting time.

Fig. 3 is a schematic view of a buffer mechanism 40 according to an embodiment of the present invention, where the buffer mechanism 40 includes a buffer main body 41 and a claw portion 42, the claw portion 42 is disposed above the buffer main body 41, and the number of claw portions 42 is plural to clamp a wafer W placed in the buffer mechanism 40.

In the embodiment shown in fig. 2, the buffer mechanism 40 is also disposed below the post-processing module 20 near the side of the cleaning unit 2 to provide a wafer buffer station during wafer transport.

Further, the buffer mechanism 40 is disposed under the post-processing module 20 adjacent to the pre-unit 1. The front robot 1b in the front unit 2 may place the wafer to be polished adjacent to the buffer mechanism 40 of the front unit 1 so that the transfer robot 30 transfers the buffered wafer toward the polishing unit 3.

The invention eliminates the scheme of a transverse beam in the prior art, and the buffer mechanism 40 is arranged between the post-processing modules 20 or below the post-processing modules 20, which is beneficial to simplifying the transmission route of the wafer, reducing the size of the cleaning unit 2, reducing the occupation of the cleaning unit to the space and further reducing the occupation area of the CMP system.

Further, the post-processing modules 20 operate independently of each other, without interfering with each other, which is advantageous for improving the fault tolerance of the cleaning unit 2. Specifically, if one of the post-processing modules 20 fails to stop, the other post-processing modules 20 will not be interfered by the failed post-processing module 20 and will normally operate, so as to ensure the operation stability of the cleaning unit 2.

Fig. 4 is a side view of the chemical mechanical polishing system corresponding to fig. 1, and fig. 5 is a schematic diagram of the corresponding cleaning unit 2 in fig. 1.

In the present invention, the transfer robot 30 is further provided with a vertical slide rail 33, as shown in fig. 4 and 5, and the transfer robot 30 can move in a vertical direction to transfer the wafer between the adjacent post-processing modules 20.

In the embodiment shown in fig. 1, the CMP system further includes a multi-layer buffer device 50 disposed between the cleaning unit 2 and the polishing unit 3 to buffer the wafer to be polished or cleaned, so as to solve the problem of uneven processing time between the respective processes, and ensure the operation beat of the CMP system.

In fig. 1, a multi-layered buffer device 50 is provided in the polishing unit 3. It will be appreciated that the multi-layered buffer device 50 may also be provided in the cleaning unit 2; alternatively, the multi-layered buffer device 50 is provided between the cleaning unit 2 and the polishing unit 3.

Fig. 6 is a schematic diagram of a cleaning unit 2 according to an embodiment of the present invention, where the first cleaning unit 2A and the second cleaning unit 2B operate independently of each other without interfering with each other, which is advantageous for ensuring a stable operation of wafer cleaning. The aftertreatment modules 20 are arranged staggered in the transverse direction of the washing unit 2, the aftertreatment modules 20 being arranged in the vertical direction instead of being laid out side by side in the transverse and/or longitudinal direction of the washing unit 2. This is advantageous in that the maintenance space of the cleaning unit 2 is increased, and the convenience of the operation of the CMP system is improved.

In the embodiment shown in fig. 1, the post-processing module 20 includes a brushing module 20A shown in fig. 7, a pre-cleaning module 20B shown in fig. 8, and a drying module 20C shown in fig. 9, to remove particles and chemicals remaining on the surface of the wafer, thereby obtaining a clean surface wafer.

Fig. 7 is a schematic diagram of a brush module 20A according to an embodiment of the present invention, in which a wafer is horizontally supported by a roller, and is rotated by friction force between the roller and the edge of the wafer, a brush and a liquid supply portion are disposed on the front and the back of the wafer, the brush rotates around its axis, and at the same time, the liquid supply portion supplies cleaning liquid toward the brush and/or the surface of the wafer, so as to remove larger particles on the surface of the wafer, and achieve rough cleaning of the wafer. It should be noted that the pre-cleaning module 20A further includes a housing to ensure that the wafer is brushed against the wafer surface in a relatively airtight housing.

Fig. 8 is a schematic view of the pre-cleaning module 20B, in which a wafer W is horizontally held by a plurality of claws and rotated by a not-shown rotation driving device. Further, the pre-cleaning module 20B includes a dual-fluid tube and a brush head, the dual-fluid tube sprays cleaning liquid, N2 and/or deionized water towards the wafer W to remove smaller particles on the wafer surface, so as to realize fine cleaning of the wafer; the brush head is arranged above the wafer through a swing arm, and the swing arm can swing around a fixed point so as to drive the brush head to move on the surface of the wafer to clean tiny particles on the surface of the wafer. It should be noted that the pre-cleaning module 20B further includes a housing, not shown, to ensure that the wafer is pre-cleaned in a relatively airtight housing.

Fig. 9 is a schematic diagram of a drying module 20C according to an embodiment of the present invention, in which a wafer is horizontally clamped by a clamping jaw and is driven to rotate at a high speed, and a drying mechanism, not shown, such as a marangoni drying mechanism, is disposed above the wafer to integrally strip a water film on the surface of the wafer, so as to dry the wafer.

In the embodiment shown in fig. 1, the drying modules 20C configured by the first cleaning unit 2A and the second cleaning unit 2B need to be horizontally adjacent to the pre-unit 1, so that the pre-robot 1B in the pre-unit 1 can directly place the dried wafers in the front opening wafer transfer box 1a, thereby reducing the turnover number of the wafers and avoiding pollution in the process of transferring.

In fig. 9, since the drying module 20C needs to be provided with a Fan Filter unit 20C-1 (FFU) that circularly supplies the drying gas, the Fan Filter unit 20C-1 is disposed above the housing. If the fan filter unit 20C-1 and the buffer mechanism 40 are simultaneously installed between the vertically stacked post-processing modules 20, the height of the cleaning unit 2 corresponding to the rack body is increased, and the space occupation of the CMP system in the vertical direction is increased.

In the present invention, the side of the post-processing module 20 is configured with a switch door, which is disposed toward the transfer robot 30, so as to facilitate the transfer of the wafer.

Further, the drying module 20C is configured with a switch door towards the side of the front unit 1, and the front manipulator 1b in the front unit 1 can directly grasp the wafer through the switch door and transfer the dried wafer to the front open wafer transfer box 1a of the front unit 1, so as to reduce the process turnover times, avoid pollution caused by the wafer transfer process, and ensure the processing quality of the wafer.

Fig. 10 is a route diagram of the wafer transfer in the chemical mechanical polishing system, and the general transfer process of the wafer between the front end unit 1, the cleaning unit 2, and the polishing unit 3 will be briefly described with reference to fig. 10.

In fig. 10, a process in which a wafer is transferred from the head unit 1 to the polishing unit 3 via the cleaning unit 2 is illustrated using the first cleaning unit 2A, and the corresponding transfer route is indicated by a chain line.

Firstly, the front manipulator 1b of the front unit 1 places the wafer to be polished on the buffer mechanism 40 (shown in fig. 2) under the post-processing module 20 of the front unit 1, namely, the transmission of the step (1) is completed; next, the first front transfer robot 31A transfers the wafer from the buffer mechanism 40 under the post-processing module 20 near the pre-unit 1 to the buffer mechanism 40 near the lateral center line CL, thereby completing the transfer of step (2); next, the first rear transfer robot 32A transfers the wafer placed in the buffer mechanism 40 adjacent to the lateral center line CL to the multi-layered buffer device 50, i.e., the transfer of step (3) is completed; next, the robot in the polishing unit 3 may grasp the wafer to be polished from the multi-layered buffer apparatus 50. It will be appreciated that the wafer may also be transported towards the polishing unit 3 via the second cleaning unit 2B, independently of each other, without affecting each other.

In fig. 10, a process in which a wafer is transferred from the polishing unit 3 to the head unit 1 via the cleaning unit is illustrated using the second cleaning unit 2B, and the corresponding transfer route is indicated by a dotted line.

First, the polished wafer is transferred from the multi-layered buffer device 50 to the post-processing module 20 adjacent to the polishing unit 3 by the second rear transfer robot 32B, that is, the transfer of step (4) is completed; it should be noted that the wafer may be transferred between the post-processing modules 20; next, the second rear transfer robot 32B transfers the wafer from the post-processing module 20 adjacent to the polishing unit 2 to the post-processing module 20 adjacent to the lateral center line CL, that is, the transfer of step (5) is completed; next, the second front transfer robot 31B transfers the wafer from the post-processing module 20 adjacent to the lateral center line CL to the post-processing module 20 adjacent to the pre-unit 1, i.e., the transfer of step (6) is completed; finally, the front robot 1b transfers the post-processed wafer to the front opening unified pod 1a of the front unit 1, and the (7) th transfer is completed.

In the description of the present specification, reference to the terms "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A chemical mechanical polishing system, comprising

A front unit;

a polishing unit;

the cleaning unit is arranged between the front unit and the polishing unit;

2. A chemical mechanical polishing system according to claim 1, wherein the vertical height of the post-treatment module near the side of the cleaning unit is the same as the corresponding vertical height of the post-treatment module near the upper layer of the lateral centerline.

3. The chemical mechanical polishing system of claim 1, further comprising a buffer mechanism positioned between the vertically stacked post-processing modules.

4. A chemical mechanical polishing system according to claim 3, wherein the buffer mechanism is further disposed below the post-processing module adjacent to the side of the cleaning unit.

5. A chemical mechanical polishing system as recited in claim 4, wherein the buffer mechanism is disposed below the post-processing module adjacent the pre-unit.

6. The chemical mechanical polishing system of claim 1, wherein the first cleaning unit is configured with a pair of transfer robots, one of which is disposed adjacent to the head unit and the other of which is disposed adjacent to the polishing unit.

7. The chemical mechanical polishing system of claim 1 wherein the transfer robot is configured with vertical slide rails that are movable in a vertical direction to transfer wafers between adjacent post-processing modules.

8. The chemical mechanical polishing system of claim 1, wherein the post-processing module comprises a brush module, a pre-rinse module, and a dry module that process the wafer surface in a horizontal manner.

9. The chemical mechanical polishing system of claim 8, wherein the drying module is disposed adjacent to the head unit.

10. The chemical mechanical polishing system of claim 1, wherein a side of the post-processing module is configured with an opening and closing door disposed toward the transfer robot.