CN217045949U - Wafer loading device and chemical mechanical polishing system - Google Patents

Abstract

The utility model discloses a wafer loading attachment and chemical mechanical polishing system, wafer loading attachment includes: a base; a carriage located above the base and vertically movable to load and/or unload the wafer; and the detection unit is arranged on the outer peripheral side of the bracket and comprises a swinging assembly and a detection piece, the swinging assembly extends from the edge of the bracket to the center of the bracket, the swinging assembly is at different positions along with whether the wafer is loaded on the swinging assembly, and the detection piece is used for detecting the position of the swinging assembly.

Description

Wafer loading device and chemical mechanical polishing system

Technical Field

The utility model belongs to the technical field of chemical mechanical polishing, particularly, relate to a wafer loading attachment and chemical mechanical polishing system.

Background

Chemical Mechanical Polishing (CMP) is a globally planarized ultra-precise surface processing technique. In chemical mechanical polishing, a wafer is usually attracted to the bottom surface of a carrier head, one surface of the wafer with a deposition layer is pressed against the upper surface of a polishing pad, and the carrier head rotates in the same direction as the polishing pad under the actuation of a driving assembly and gives a downward load to the wafer; meanwhile, the polishing solution is supplied to the upper surface of the polishing pad and distributed between the wafer and the polishing pad, so that the chemical mechanical polishing of the wafer is completed under the combined action of chemistry and machinery.

The chemical mechanical polishing system is further configured with a wafer loader (load cup) to achieve wafer interaction, such as a robot placing a wafer on the wafer loader, and the carrier head attracting the wafer on the wafer loader and transferring the wafer to the polishing pad. In order to realize quick and accurate interaction of the wafers, whether the wafers are placed in the wafer loading device needs to be detected and judged so as to ensure the accuracy of the wafer transfer operation.

The current wafer detection methods include: the method has the problems of certain light pollution and low stability when the photoelectric sensor is used for detection; the detection is performed by using a water pressure sensor, which is difficult to adapt to in-situ detection of a wafer with a special process, such as a trimming wafer (trimming wafer), the edge part of which is provided with a circumferential cutting area, and the wafer cannot be detected by using the water pressure sensor.

With the increasing demand of good wafer yield, how to fully utilize the edge area of the wafer to form qualified devices to the maximum becomes the development direction of wafer manufacturing.

SUMMERY OF THE UTILITY MODEL

An embodiment of the utility model provides a wafer loading attachment and chemical mechanical polishing system aims at solving one of the technical problem that exists among the prior art to a certain extent at least.

The utility model discloses a first aspect of the embodiment provides a wafer loading attachment, and it includes:

a base;

a carrier positioned above the base and vertically movable to load and/or unload wafers;

the detection unit is arranged on the outer peripheral side of the bracket and comprises a swinging assembly and a detection piece, wherein the swinging assembly extends from the edge of the bracket to the center of the bracket, the swinging assembly is at different positions along with whether wafers are loaded on the swinging assembly, and the detection piece is used for detecting the position of the swinging assembly.

In some embodiments, the swing assembly includes a swing member hinged above the bracket and a sensing member swingable about a hinge fulcrum following the swing member.

In some embodiments, the detecting element is disposed under the sensing element for detecting the position of the sensing element.

In some embodiments, the pendulum is disposed to extend obliquely downward toward the center of the bracket.

In some embodiments, the oscillating member is provided with a sensing member at one end and an inclined surface at least on a part of the surface of the other end.

In some embodiments, the inclined surface is inclined downward toward the center of the bracket.

In some embodiments, the inclined surface is inclined at an angle of 3-5 °.

In some embodiments, the pendulum is arranged in line contact with the edge of the wafer.

In some embodiments, the upper surface of the pendulum is provided with a flexible structure for contacting the wafer.

In some embodiments, the upper surface of the pendulum is streamlined to avoid accumulation of contaminants.

In some embodiments, the wafer loading apparatus includes at least two of the detecting units, and the detecting units are spaced along an outer circumferential side of the tray.

A second aspect of the embodiments of the present invention provides a chemical mechanical polishing system, which comprises a polishing platen, a carrier head, a trimming device and a liquid supply device, and further comprises a wafer loading device as described above, wherein the wafer loading device is horizontally adjacent to one side of the polishing platen.

The beneficial effects of the utility model include: a detection unit is arranged on the outer periphery of the bracket, and a swinging piece in the detection unit is arranged towards the center of the bracket; at least one part of the swinging piece is obliquely arranged, so that the edge of the wafer is in line contact with the swinging piece, and the swinging piece is prevented from being in direct contact with a device circuit on the surface of the wafer to influence the yield of the wafer.

Drawings

The advantages of the present invention will become more apparent and more readily appreciated from the detailed description given herein below, taken in conjunction with the accompanying drawings, which are given by way of illustration only, and which do not limit the scope of the invention, and in which:

FIG. 1 is a schematic view of a chemical mechanical polishing system provided by an embodiment of the present invention;

fig. 2 is a schematic view illustrating a wafer loading apparatus according to an embodiment of the present invention;

fig. 3 is a schematic view illustrating a connection between a detecting unit and a bracket according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 3 within the dashed box;

fig. 5 is a schematic diagram of a detection unit according to an embodiment of the present invention;

FIG. 6 is an exploded view of the detection unit of FIG. 5;

fig. 7 to 9 are schematic views of an embodiment of a swing assembly provided by the present invention;

fig. 10 is an exploded view of the swing assembly of fig. 9.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the following embodiments and accompanying drawings. The embodiments described herein are specific embodiments of the present invention and are provided to illustrate the concepts of the present invention; the description is intended to be illustrative and exemplary and should not be taken to limit the scope of the invention. In addition to the embodiments described herein, those skilled in the art will be able to employ other embodiments that are obvious based on the disclosure of the claims and their description, including those that employ any obvious substitutions and modifications to the embodiments described herein.

The drawings in the present specification are schematic views to assist in explaining the concept of the present invention, and schematically show the shapes of the respective portions and the mutual relationships thereof. It should be understood that the drawings are not necessarily to scale, the same reference numerals being used to identify the same elements in the drawings in order to clearly illustrate the structure of the various elements of the embodiments of the invention.

In the present invention, "Chemical Mechanical Polishing (CMP)" is also referred to as "Chemical Mechanical Planarization (CMP)", and wafers (Wafer, W) are also referred to as substrates (Substrate), and their meanings and practical effects are equivalent.

As shown in fig. 1, an embodiment of the present invention provides a chemical mechanical polishing system, which includes a wafer loading device 100, a polishing platen 200, a polishing pad, a carrier head 300, a liquid supply device 400, and a dressing device 500. Wherein, the polishing pad is disposed on the upper surface of the polishing disc 200, and the polishing pad and the polishing disc 200 rotate together; the carrier head 300 capable of moving horizontally is arranged above the polishing pad, and the wafer to be polished is sucked at the bottom of the carrier head 300; the liquid supply device 400 is disposed above the polishing pad to distribute the polishing liquid on the surface of the polishing pad; the dressing apparatus 500 swings about a fixed point, and the dressing head provided thereon rotates itself and applies a downward load to dress the polishing pad surface. While the wafer loader 100 is horizontally adjacent to one side of the polishing platen 200, the carrier head 300 may transfer the wafer in the wafer loader 100 above the polishing pad, or the carrier head 300 may place the polished wafer in the wafer loader 100 to wait for a wafer transferring device such as a robot or other transferring tool to transfer the polished wafer to the next process.

During chemical mechanical polishing, polishing solution composed of submicron or nanometer abrasive particles and chemical solution flows between a wafer and a polishing pad, the polishing solution is uniformly distributed under the action of transmission and rotating centrifugal force of the polishing pad to form a layer of liquid film between the wafer and the polishing pad, chemical components in the liquid and the wafer generate chemical reaction to convert insoluble substances into soluble substances, then the chemical reactants are removed from the surface of the wafer through micro-mechanical friction of the abrasive particles and dissolved in the flowing liquid to be taken away, namely surface materials are removed in an alternating process of chemical film forming and mechanical film removing to realize surface planarization treatment, so that the aim of global planarization is fulfilled.

Fig. 2 is a schematic structural diagram of the wafer loading apparatus 100 according to the present invention, wherein the wafer loading apparatus 100 includes:

a base 10 which is an annular structure with a through hole arranged in the middle, a vertical driving mechanism 30 is arranged below the base 10, and the operation end of the vertical driving mechanism 30 penetrates through the through hole of the base 10;

and the bracket 20 is arranged above the base 10, and the working end of the vertical driving mechanism 30 is connected with the bracket 20 so as to drive the bracket 20 to move along the vertical direction, adjust the vertical position of the bracket 20 and complete the loading and/or unloading actions of the wafer in a matching way.

In the polishing system, before the carrier head 300 and the wafer transferring apparatus perform various operations, it is required to detect whether the carrier 20 of the wafer loading apparatus 100 is loaded with wafers or not, so as to prevent the wafers from being broken due to repeated loading of the wafers, or the carrier head 300 performs the loading operation on the carrier 20 without wafers and reports errors.

In order to solve the above technical problem, as shown in fig. 2, the wafer loading apparatus 100 further includes a detection unit 40, wherein the detection unit 40 is disposed at an outer circumferential side of the tray 20 to detect whether a wafer is placed on the tray 20.

Fig. 3 is a schematic view of the connection of the detecting units 40 to the bracket 20, and the number of the detecting units 40 is two, and the detecting units 40 are arranged at intervals along the outer peripheral side of the bracket 20. In fig. 3, the interval angle between the adjacent detecting units 40 is 120 °. It is understood that the inspection units 40 may be provided in other numbers, such as three, four, etc., and that the inspection units 40 are spaced apart substantially to prevent the loaded wafers from being offset from the center of the carrier 20 and causing missed or misleading inspections.

Fig. 4 is a partially enlarged view of a dotted frame portion of fig. 3, and the detecting unit 40 includes a swing member 41 and a detecting member 42, the swing member 41 extending from an edge of the tray 20 toward a center of the tray 20, the swing member 41 being in different positions depending on whether or not wafers are loaded thereon, and the detecting member 42 for detecting a position of the swing member 41.

In fig. 4, the detector 42 is provided on the outer peripheral side of the bracket 20 via a fixing base 43. Specifically, the fixing base 43 is configured with a fixing hole, and the detection head of the detection member 42 is inserted into the fixing hole. That is, the detecting member 42 is disposed away from the center of the bracket 20, so that the operation stability of the detecting member 42 can be ensured. This is because the intermediate position of the bracket 20 is usually provided with a component such as a nozzle for moisturizing the wafer, and if the detection piece 42 is in or close to a watery environment for a long time, if the detection piece 42 adopts a proper waterproof measure, the operation stability of the detection piece 42 is affected, and the accuracy of wafer detection is affected.

Fig. 5 is a schematic structural diagram of the detecting unit 40 of the present invention, and fig. 6 is an exploded view of the detecting unit 40 corresponding to fig. 5. The swing assembly 41 includes a swing member 41a and a sensing member 41b, as shown in fig. 6. One end of the swinging piece 41a is a columnar structure, a mounting hole is formed in the columnar structure, and the sensing piece 41b is fixed in the mounting hole. Further, the detecting member 42 is a proximity switch that determines the distance between the sensing member 41b and the detecting member 42 by detecting the magnetic field generated by the sensing member 41 b. In one aspect of the present embodiment, the sensing member 41b is made of metal, the sensing member 41b forms a magnetic field, and the detecting member 42 detects a position change of the sensing member 41b to determine whether the wafer is pressed against the upper surface of the swinging member 41 a.

In order to ensure the detection accuracy of the detecting member 42, the detecting member 42 is disposed under the sensing member 41 b. Specifically, the detecting element 42 is disposed at a position right below the sensing element 41b, and during the swinging of the swinging assembly 41 around the rotating shaft 45, the vertical projection of the sensing element 41b and the top surface of the detecting head of the detecting element 42 are overlapped to the maximum extent.

Further, the swinging member 41a is hinged to the support base 44 through a rotating shaft 45 shown in fig. 6, and the support base 44 is fixed above the bracket 20. The sensing member 41b disposed at the end of the swinging member 41a can swing around the hinge pivot along with the swinging member 41a to change the distance between the sensing member 41b and the detecting member 42, thereby determining whether the wafer is placed above the carrier 20.

In fig. 3, no wafer is placed on the upper side of the carrier 20, and the sensing member 41b of the swing member 41 is at the detection limit position of the detection member 42, for example, 2-3 mm. If the end of the swing assembly 41 near the center of the bracket 20 is pressed, the sensing member 41b is out of the detection range of the detection member 42, and the detection member 42 has no detection signal. That is, the detecting member 42 detects the presence or absence of the signal to determine whether or not the wafer is placed above the carrier 20.

Further, without a wafer being placed above the carrier 20, the swing member 41 may be disposed to extend obliquely downward toward the center of the carrier 20, as shown in fig. 3. That is, the swinging member 41a shown in fig. 6 extends toward the center position of the bracket 20 such that the upper surface of the swinging member 41a forms a contact surface toward the inside of the bracket 20. With such an arrangement, a line contact is formed between the upper surface of the swing element 41 and the edge of the wafer to be loaded, so as to prevent the device circuit on the surface of the wafer from being in hard contact with the swing element 41, thereby reducing the yield of device processing.

When the wafer is not pressed against the swinging member 41a, the swinging member 41 fixed at the hinge point is inclined toward the center of the bracket 20, which is achieved by means of a counterweight, so that the swinging member 41 fixed to the rotating shaft 45 is relatively balanced. If the end of the swing component 41 is pressed, the swing component 41 will lose balance instantly and change the tilt angle, so that the detecting component 42 can detect the position change of the sensing component 41b accurately.

In fig. 7, a sensor 41b (shown in fig. 6) is provided in a columnar structure at one end of the oscillating piece 41a, and an inclined surface 41c that abuts against the edge of the wafer is provided at the other end of the oscillating piece 41 a. The inclined surface 41c is provided to ensure line contact between the swing member 41 and the edge of the wafer.

Further, the inclined surface 41c is inclined at an angle of 3 to 5 °. The inclination angle of the inclined surface 41c is an angle between a plane perpendicular to the central axis of the columnar structure at the end of the oscillating member 41a and the reference plane, and the inclined surface 41c is inclined with respect to the reference plane. In the embodiment shown in fig. 7, the inclined surface 41c is inclined at an angle of 3.5 °, and the inclined surface 41c is formed at a part of the upper surface of the swinging member 41 a.

As a variation of the embodiment of fig. 7, the upper surface of the swinging member 41a may be integrally formed with an inclined surface 41c toward the center of the bracket 20.

In the embodiment shown in fig. 7, the inclined surface 41c of the oscillating member 41a is disposed in the same direction as the inclined surface 41c of the oscillating member 41c, so as to ensure that the edge of the wafer to be loaded is in linear contact with the inclined surface 41c, and to avoid the direct hard contact between the end of the oscillating member 41a near the center of the carrier 20 and the device circuit on the surface of the wafer.

Fig. 8 is a schematic view of another embodiment of the swing assembly 41, the swing assembly 41 can be horizontally hinged to the supporting base 44 through a rotating shaft 45, and the end of the swing member 41a near the center of the bracket 20 is provided with an inclined surface 41c abutting against the edge of the wafer.

In the chemical mechanical polishing, in order to avoid corrosion of the components by chemical liquid and pollution of metal ions, special engineering plastics are required to be selected for manufacturing the components. In the embodiment shown in fig. 7 and 8, the oscillating member 41a is made of polyoxymethylene, polytetrafluoroethylene, polyphenylene sulfide, or the like. To prevent the sensing member 41b made of metal from directly contacting the wafer, the sensing member 41b is wrapped around the end of the oscillating member 41 a.

In order to prevent the fluid mixed with particles formed in the chemical mechanical polishing from splashing on the upper surface of the oscillating member 41 to form crystals, the upper surface of the oscillating member 41a has a streamline structure, so that the pollutants can flow down along the upper surface of the oscillating member 41a, and the pollutants can be prevented from accumulating and crystallizing.

Fig. 9 and 10 are schematic views illustrating another embodiment of the wafer loading apparatus 100 according to the present invention, wherein the swing assembly 41 further includes a flexible structure 41d, and a position of the flexible structure 41d matches with an edge position of a wafer to be loaded. In fig. 9, the flexible structure 41d is detachably provided to the inclined surface 41 c. Specifically, the inclined surface 41c of the swinging member 41a is provided with a catching groove, and the flexible structure 41d is inserted into the catching groove. The flexible structure 41d is made of a material with good elasticity, such as rubber, polyurethane, etc., so as to further protect the device circuit on the wafer surface and avoid the swing assembly 41 from scratching the device circuit.

A second aspect of the embodiments of the present invention provides a chemical mechanical polishing system, which comprises a polishing platen 200, a carrier head 300, a liquid supply device 400 and a dressing device 500, as shown in fig. 1, wherein the chemical mechanical polishing system further comprises a wafer loading device 100 as described above, and the wafer loading device 100 is horizontally adjacent to one side of the polishing platen 200. When a wafer to be polished is placed on the carrier 20 of the wafer loading apparatus 100 by a wafer transferring apparatus such as a robot, the edge of the wafer presses the swing member 41, the swing member 41 swings toward the center of the carrier 20, so that the sensing member 41b at the end of the swing member 41a moves upward, and the detecting member 42 detects the position change of the sensing member 41b, that is, determines that the wafer is placed above the carrier 20.

It is understood that the carrier 20 is further configured with a component, such as a pin, for ensuring the concentric arrangement of the wafers, so as to ensure that the loaded wafers are concentrically arranged above the carrier 20 to be picked up by the carrier head 300.

After the wafer on-site inspection of the wafer loading apparatus 100 is completed, the carrier head 300 is moved to above the carrier 20, and the elastic membrane assembly at the lower portion of the carrier head 300 sucks and moves the wafer to above the polishing pad 200, so as to perform chemical mechanical polishing according to the polishing process.

The utility model provides a wafer loading attachment 100 adopts the mechanical type to detect the wafer on the throne, has effectively avoided the photoinduced corrosion problem that photoelectric sensing brought, has compensatied the not enough of the unable wafer (trimming wafer) that detects the marginal attenuate processing of traditional pressure detection, and full play mechanical type detects the advantage of stability, can be applied to the detection on the throne of various wafers.

In addition, the length of the swinging piece 41a in the swinging assembly 41 is changed, so that the in-situ detection device can be quickly adapted to in-situ detection of wafers with various specifications and sizes such as 12 inches, 8 inches, 6 inches and the like, has the advantage of strong flexibility, and is suitable for large-scale popularization and application.

In the description of the present specification, reference to the description of "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like 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 present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. 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: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims (12)

1. A wafer loading apparatus, comprising:

a base;

a carrier positioned above the base and vertically movable to load and/or unload wafers;

and the detection unit is arranged on the outer peripheral side of the bracket and comprises a swinging assembly and a detection piece, the swinging assembly extends from the edge of the bracket to the center of the bracket, the swinging assembly is at different positions along with whether the wafer is loaded on the swinging assembly, and the detection piece is used for detecting the position of the swinging assembly.

2. The wafer loading apparatus as claimed in claim 1, wherein the swing assembly includes a swing member hinged above the carrier and a sensing member swingable about a hinge fulcrum following the swing member.

3. The wafer loading apparatus as claimed in claim 2, wherein the detecting member is disposed below the sensing member for detecting the position of the sensing member.

4. The wafer loading apparatus as claimed in claim 2, wherein the swinging member is provided to extend obliquely downward toward the center of the carrier.

5. The wafer loading apparatus as claimed in claim 4, wherein the oscillating member has one end provided with a sensing member and the other end having at least a part of its surface formed as an inclined surface.

6. The wafer loading apparatus as recited in claim 5, wherein the inclined surface is inclined downward toward a center of the tray.

7. The wafer loading apparatus as claimed in claim 6, wherein the inclined surface is inclined at an angle of 3-5 °.

8. The wafer loading apparatus of claim 2, wherein the oscillating member is disposed in line contact with an edge of the wafer.

9. The wafer loading apparatus as claimed in claim 2, wherein the upper surface of the swinging member is provided with a flexible structure for contacting the wafer.

10. The wafer loading apparatus of claim 2 wherein the upper surface of the oscillating member is streamlined to avoid accumulation of contaminants.

11. The wafer loading apparatus as claimed in claim 1, wherein at least two of the inspection units are provided at intervals along an outer circumferential side of the tray.

12. A chemical mechanical polishing system comprising a polishing platen, a carrier head, a conditioning apparatus and a liquid supply apparatus, and further comprising a wafer loading apparatus according to any of claims 1 to 11, the wafer loading apparatus being horizontally adjacent to a side of the polishing platen.

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