Polishing pad trimmer and chemical mechanical polishing equipment

Abstract

The utility model provides a polishing pad trimmer and chemical mechanical polishing equipment. The polishing pad trimmer comprises a trimming head and a driving unit for driving the trimming head to move, the finishing head is configured to finish the working surface of the grinding pad when acting on the working surface of the grinding pad; the driving unit comprises a base unit, a driving arm and a driven arm; the first end of the driving arm is rotationally connected with the base unit; the first end of the driven arm is rotationally connected with the second end of the driving arm; the finishing head is connected with the second end of the driven arm, and the working surface of the finishing head faces the grinding pad. The grinding pad trimmer is provided with a double-rod swing structure, further, the pressure of the terminal trimming head is monitored in real time through the torque sensor, and therefore the trimming effect and quality are guaranteed.

Description

Technical Field

[0001] The utility model relates to the field of semiconductor processing equipment, in particular to a grinding pad dresser and chemical mechanical grinding equipment. Background Art

[0002] In the manufacturing process of semiconductor integrated circuits, various functional layer structures such as semiconductor layers, conductive layers, and oxide layers are usually deposited on the wafer in sequence. After the deposition of the above functional layers, an etching process is performed to form the desired pattern to form circuit elements. The etching process will cause the surface of the deposited layer structure to be uneven or uneven, thereby causing defects during subsequent process steps. Therefore, it is necessary to flatten the surface of the device. Chemical Mechanical Polishing (CMP) is currently the most effective wafer flattening method. Chemical Mechanical Polishing technology combines mechanical polishing and chemical etching to grind semiconductor wafers by utilizing chemical and mechanical effects.

[0003] Typical chemical mechanical polishing equipment includes a polishing head, a rotating table, a polishing pad and a polishing pad dresser, wherein the polishing pad is adhered to the surface of the rotating table and has multiple small holes thereon to help retain and transfer abrasives and improve polishing uniformity; the polishing head is used to load and fix the wafer to be polished, and to make the surface to be polished of the wafer to be polished face the polishing pad; when polishing, the polishing head applies downward pressure to press the wafer to be polished against the polishing pad, so that the polishing surface of the wafer to be polished reacts chemically with the chemical polishing liquid to form a surface layer that is relatively easy to remove, and then the surface layer is mechanically ground away by the relative motion between the polishing pad and the action of the polishing particles, thereby achieving the purpose of flattening the wafer to be polished.

[0004] The polishing pad dresser includes a dressing head placed on the polishing pad and a motion device that drives the dressing head to move. The dressing head is used to dress the polishing pad to remove the polishing residues on the surface grooves of the polishing pad or repair the shape of the surface grooves of the polishing pad. The current motion device in the industry is a swing arm type. The dressing head is a pneumatic structure. The downward pressure and lifting of the dressing head are achieved through air pressure. The air pressure can be controlled to achieve different downward pressures of the dressing head to complete the dressing of the polishing pad. The pressure of the dressing head is adjusted by air pressure linear pressure. When the machine stops, it can be detected whether the pressure of the dressing head meets the requirements and is stable. However, when the machine is running, it is impossible to detect the pressure change in real time at the terminal. It can only detect whether the air pressure is stable. If the pressure is unstable or offset due to terminal reasons such as the dressing head, it cannot be detected, which greatly affects the dressing quality and effect of the dresser on the polishing pad. Therefore, it is necessary to develop a chemical mechanical polishing device that can detect the pressure change of the dressing head in real time.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to those skilled in the art. Utility Model Content

[0006] In view of the problems in the prior art, the purpose of the utility model is to provide a grinding pad dresser and chemical mechanical grinding equipment. The grinding pad dresser with a double-rod swing structure can monitor the pressure of the terminal dressing head in real time through a torque sensor, thereby ensuring the dressing effect and quality.

[0007] The dressing head is configured to dress the working surface of the polishing pad when acting on the working surface of the polishing pad;

[0008] The driving unit comprises a base unit, an active arm and a driven arm;

[0009] The first end of the active arm is rotatably connected to the base unit;

[0010] The first end of the driven arm is rotatably connected to the second end of the active arm;

[0011] The dressing head is connected to the second end of the driven arm and the working surface of the dressing head faces the grinding pad.

[0012] According to a first aspect of the utility model, the base unit comprises a support platform, two bearing seats arranged on the support platform, and a bearing;

[0013] The bearing is rotatably arranged on the two bearing seats, the bearing is penetrated through the first end of the active arm, and the rotation of the bearing drives the second end of the active arm to rotate around the first end of the active arm.

[0014] According to a first aspect of the utility model, the base unit further comprises a first motor;

[0015] The rotation of the output shaft of the first motor drives the rotation of the bearing.

[0016] According to the first aspect of the utility model, the grinding pad dresser further comprises a second motor, a power pulley, a transmission pulley and a belt;

[0017] The power pulley and the transmission pulley are respectively arranged at the first end and the second end of the active arm, and the belt wraps around the power pulley and the transmission pulley;

[0018] The output shaft of the second motor is connected to the power pulley, and the rotation of the output shaft of the second motor drives the rotation of the power pulley;

[0019] The rotation of the power pulley drives the rotation of the transmission pulley through the belt.

[0020] According to the first aspect of the utility model, a first gear is provided at one end of the transmission pulley;

[0021] A second gear is disposed at the first end of the driven arm, and the second gear is meshed with the first gear.

[0022] According to a first aspect of the utility model, the polishing pad dresser further comprises a recess and a spherical joint;

[0023] The recess is connected to the second end of the driven arm;

[0024] The spherical joint is connected to an end of the trimming head facing away from the working surface;

[0025] The ball joint is received in the recess and connected to form a male-female connection by at least one bolt.

[0026] According to the first aspect of the utility model, the grinding pad dresser further comprises a third motor, the output shaft of the third motor is connected to the dresser head and drives the dresser head to rotate.

[0027] According to the first aspect of the utility model, the grinding pad dresser further comprises a control unit;

[0028] The control unit is configured to receive torque information monitored by the torque sensor, and is configured to control rotation of the first motor and the second motor according to the torque information monitored by the torque sensor.

[0029] According to some examples of the present invention, the polishing pad dresser further includes a torque sensor configured to measure the torque of an output shaft of the third motor.

[0030] The second aspect of the utility model provides a chemical mechanical polishing device, comprising the polishing pad dresser.

[0031] The grinding pad dresser of the utility model has a double-rod swing structure. Furthermore, the pressure of the terminal dressing head is monitored in real time through a torque sensor, thereby ensuring the dressing effect and quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings herein are incorporated into the specification and constitute a part of the specification, showing embodiments consistent with the present application, and together with the specification, are used to explain the principles of the present application. By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, purposes and advantages of the utility model will become more obvious. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In addition, the drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same figure numbers in the figures represent the same or similar parts, and their repeated descriptions will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0033] Figure 1 A schematic structural diagram of a grinding pad dresser according to an embodiment of the utility model;

[0034] Figure 2 and Figure 3 They are respectively a schematic diagram of the connection structure and a schematic diagram of the connection principle of a base unit and an active arm of a grinding pad dresser according to an embodiment of the utility model;

[0035] Figure 4 and Figure 5 This is a schematic diagram of the connection between the active arm and the driven arm of an embodiment of the utility model;

[0036] Figure 6 This is a rendering of a polishing pad dresser according to an embodiment of the present invention, in which a dressing head is supported on a wafer; and

[0037] Figure 7 The utility model is a schematic diagram of the connection structure between the driven arm and the dressing head of the grinding pad dresser according to one embodiment of the present invention. DETAILED DESCRIPTION

[0038] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the disclosure will be more comprehensive and complete and to fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0039] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" and the like mean that the specific features, structures, materials or characteristics represented in conjunction with the embodiment or example are included in at least one embodiment or example of this specification. Moreover, the specific features, structures, materials or characteristics represented may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples represented in this specification without contradiction.

[0040] Throughout the specification, when it is said that a device is "connected" to another device, this includes not only the case of "direct connection" but also the case of "indirect connection" by placing other elements therebetween. Terms indicating relative spaces such as "front", "rear", "upper", and "lower" may be used to more easily explain the relationship of a device illustrated in the accompanying drawings relative to another device. Such terms refer not only to the meanings indicated in the accompanying drawings, but also to other meanings or operations of the device in use. For example, if the device in the accompanying drawings is turned over, a device that was described as being "under" other devices is described as being "over" other devices. Therefore, the exemplary term "under" includes both upper and lower sides. The device can be rotated 90° or other angles, and the terms representing relative spaces are interpreted accordingly.

[0041] Although the terms first, second, etc. are used to represent various elements in some examples, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, the first interface and the second interface, etc. are represented. Moreover, as used in this article, the singular forms "one", "one" and "the" are intended to also include plural forms, unless there is an opposite indication in the context. It should be further understood that the terms "comprising" and "including" indicate that there are the described features, steps, operations, elements, components, projects, kinds, and / or groups, but do not exclude the existence, occurrence or addition of one or more other features, steps, operations, elements, components, projects, kinds, and / or groups. The terms "or" and "and / or" used herein are interpreted as inclusive, or mean any one or any combination. Therefore, "A, B or C" or "A, B and / or C" means "any of the following: A; B; C; A and B; A and C; B and C; A, B and C". Only when the combination of elements, functions, steps or operations is inherently mutually exclusive in some way, will there be an exception to this definition.

[0042] Although not fully defined, all terms, including technical and scientific terms, used herein have the same meaning as those generally understood by those skilled in the art to which this specification belongs. Terms defined in commonly used dictionaries are additionally interpreted as having meanings consistent with the relevant technical literature and the current disclosure, and unless defined, shall not be overly interpreted as having an ideal or very formal meaning.

[0043] In integrated circuit manufacturing, with the reduction of feature size and the increase of metal interconnection layers, the requirements for wafer surface flatness are becoming more and more stringent. The chemical mechanical polishing process has become the most effective global flattening technology. It clamps the wafer on a rotating polishing head and presses it on a rotating polishing pad (CMP Pad) with a certain pressure. The polishing liquid, composed of abrasive particles and chemical solution, flows between the wafer and the polishing pad, using chemical and mechanical interactions to achieve surface flattening. However, in the above-mentioned CMP process, as the polishing process proceeds, the surface of the polishing pad will gradually wear and become uneven. At present, the polishing pad conditioner usually repairs the surface of the polishing pad through a diamond grinding disc. However, since the diamond grinding disc is prone to produce diamond debris during the repair process, the diamond debris falls on the surface of the polishing pad, causing the polishing pad to cause serious scratches on the wafer during the subsequent polishing process, resulting in the scrapping of the wafer and affecting the production yield.

[0044] In view of the problems in the prior art, the utility model provides a grinding pad dresser and chemical mechanical grinding equipment, wherein the grinding pad dresser includes a dressing head and a driving unit for driving the dressing head to move; the dressing head is configured to dress the working surface of the grinding pad when acting on the working surface of the grinding pad; the driving unit includes a base unit, an active arm and a driven arm; the first end of the active arm is rotationally connected to the base unit; the first end of the driven arm is rotationally connected to the second end of the active arm; the dressing head is connected to the second end of the driven arm and the working surface of the dressing head faces the grinding pad. The grinding pad dresser of the utility model has a double-rod swing structure, and further, the pressure of the terminal dressing head is monitored in real time by a torque sensor, so as to ensure the dressing effect and quality.

[0045] The structures of the polishing pad dresser and chemical mechanical polishing equipment of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments. It can be understood that the various specific embodiments are not intended to limit the protection scope of the present invention.

[0046] Figure 1The schematic diagram of the structure of the grinding pad dresser of one embodiment of the utility model; specifically, the grinding pad dresser includes a dresser head 4 and a driving unit for driving the dresser head to move; the dresser head 4 is configured to dress the working surface of the grinding pad when acting on the working surface of the grinding pad, that is, when the grinding pad dresser is in operation, the correction working surface A of the dresser head 4 contacts the working surface of the grinding pad. The driving unit of the utility model is a double-rod swing structure, specifically including a base unit, an active arm 2 and a driven arm 3; the first end of the active arm 2 is rotationally connected to the base unit; the first end of the driven arm 3 is rotationally connected to the second end of the active arm 2; the dresser head 4 is connected to the second end of the driven arm 3 and the working surface of the dresser head 4 faces the grinding pad.

[0047] Figure 2 and Figure 3 The following are respectively a schematic diagram of the connection structure and a connection principle diagram of the base unit and the active arm of the grinding pad dresser of one embodiment of the utility model. It can be seen that the base unit includes a support table 10, two bearing seats 11 and a bearing 12 arranged on the support table 10; the bearing 12 is rotatably arranged on the two bearing seats 11, and the bearing 12 is passed through the first end of the active arm 2, and the rotation of the bearing 12 drives the second end of the active arm 2 to rotate around the first end of the active arm 2. In some embodiments, the base unit may also include a first motor 91, and the rotation of the output shaft of the first motor 91 drives the rotation of the bearing. Figure 3 In the embodiment, the output shaft 911 of the first motor 91 can be connected to the two rollers 101, and the two rollers 101 are linked with the bearing 12, such as the rollers 101 and the bearing 12 can be gear transmission. The first motor 91 and the two rollers 101 can be arranged in the support platform 10. Since the second end of the active arm 2 needs to reciprocate within a certain angle, the output shaft of the first motor needs to be able to reciprocate within a certain angle, and therefore, the first motor can be a reciprocating motor.

[0048] Figure 4 and Figure 5The present invention is a schematic diagram of the connection between the active arm and the driven arm of an embodiment of the present invention, wherein the grinding pad dresser further comprises a second motor 92, a power pulley 21, a transmission pulley 22 and a belt 23; the power pulley 21 and the transmission pulley 22 are respectively arranged at the first end and the second end of the active arm 2, and the belt 23 surrounds the power pulley 21 and the transmission pulley 22; the output shaft of the second motor 92 is connected to the power pulley 21 and the rotation of the output shaft of the second motor 92 drives the rotation of the power pulley 21; and the rotation of the power pulley 21 drives the rotation of the transmission pulley 22 through the belt 23. A first gear 221 is arranged at one end of the transmission pulley 22; a second gear 311 is arranged at the first end of the driven arm 3, and the second gear 311 is meshed with the first gear 221. In the above structure, the second motor 92 drives the power pulley 21 to rotate, and drives the transmission pulley 22 to rotate through the belt 23, and the first end of the transmission driven arm 3 is gear-driven through the transmission pulley 22, so that the second end of the transmission driven arm 3 rotates around the first end of the transmission driven arm 3.

[0049] Figure 6 This is a rendering of the dressing head of the grinding pad dresser of one embodiment of the utility model being supported on a wafer. Through the coordination of the rotation of the first motor 91 and the second motor 92, such as the rotation of the first motor 91 controlling the β angle of rotation of the active arm, and the rotation of the second motor 92 controlling the angle θ between the active arm 2 and the driven arm 3, the second end of the transmission driven arm 3 is in a different position, such as moving from position X on the grinding pad 8 to position X'.

[0050] Theoretically, the movement range of the dressing head at the second end of the driven arm 3 needs to be from the edge of the grinding pad 8 to the center of the crystal grinding pad 8. At this time, when the grinding pad 8 rotates, the dressing head of the grinding pad dresser can dress the entire grinding pad 8. At the same time, in order to ensure that the correction working surface A of the dressing head 4 is in contact with the working surface of the grinding pad at each position, or in other words, to ensure that the correction working surface A of the dressing head 4 faces the working surface of the grinding pad 8, the grinding pad dresser also includes a recess 32 and a spherical joint 41; the recess 32 is connected to the second end of the driven arm 3; the spherical joint 41 is connected to the end of the dressing head 4 away from the working surface; the spherical joint 41 is accommodated in the recess 32 and is connected to a concave-convex connection member through at least one bolt, see Figure 7 The concave-convex connection piece ensures that the correction working surface A of the trimming head connected at the lower end is always facing downward.

[0051] The dressing head 4 may further include a connecting portion 42, connecting the spherical joint 41 and the dressing head 4, and the grinding pad dresser may further include a third motor (not shown). Figure 7As shown in FIG. 4 , the third motor may be accommodated in the connecting portion 42 , and its output shaft 931 extends out of the connecting portion 42 and is connected to the trimming head 4 , and the rotation of the output shaft 931 of the third motor drives the trimming head 4 to rotate.

[0052] Further, in some embodiments, the grinding pad dresser also includes a torque sensor (not shown in the figure), and the torque sensor is configured to measure the torque of the output shaft 931 of the third motor. When the dressing head 4 is in different positions, or when the positions of the active arm 2 and the driven arm 3 are different, the pressure between the dressing head 4 and the working surface of the grinding pad 8 is different, and accordingly, the torque driving the dressing head 4 to rotate will also be different. It can be experimentally determined, such as by setting the dressing head 4 on a simulated working surface provided with a pressure sensor, and by monitoring the torque of the output shaft 931 of the third motor and the pressure value between the dressing head 4 and the simulated working surface to obtain the pressure relationship between the two, so that when the dressing head 4 dresses the working surface of the grinding pad 8, the pressure between the dressing head 4 and the working surface of the grinding pad 8 can be calculated by reading the torque of the output shaft 931 of the third motor, so as to achieve real-time monitoring of the terminal pressure during the process of the grinding pad dresser dressing the grinding pad, so as to adjust the terminal pressure of the dressing as needed, and improve the dressing effect and quality.

[0053] At the same time, the grinding pad dresser may also include a control unit; the control unit is configured to receive the torque information monitored by the torque sensor, and is configured to control the rotation of the first motor and the second motor according to the torque information monitored by the torque sensor, that is, to control the position of the dressing head 4. The above-mentioned control of the rotation of the first motor and the second motor may be an empirical value, or it may be regulated on the basis of establishing the relationship between the rotation of the first motor and the second motor and the position of the dressing head 4.

[0054] The utility model also provides a chemical mechanical polishing device, including the polishing pad dresser. The chemical mechanical polishing device also includes a polishing head, a rotating table, a polishing pad placed on the rotating table, etc., but when polishing is required, the position of the dressing head of the polishing pad dresser is adjusted to make it contact with the polishing pad, thereby dressing the polishing pad, and foreign matter on the polishing pad can be removed according to the different functions of the dressing head, so as to avoid damage to the wafer due to foreign matter remaining on the polishing pad during the subsequent wafer polishing process, ensure the stability and quality of the polishing process, improve the production yield, and help meet the high requirements of modern semiconductor manufacturing processes for flatness and surface quality.

[0055] It should be pointed out that in the technical solutions of the polishing pad dresser and chemical mechanical polishing equipment of the utility model, the various functional modules and module units included therein can correspond to specific hardware circuits in the integrated circuit structure, and therefore only involve improvements in specific hardware circuits. The hardware part is not merely a carrier for executing control software or computer programs, and therefore solving corresponding technical problems and obtaining corresponding technical effects do not involve the application of any control software or computer programs. In other words, the utility model can solve the technical problems to be solved and obtain corresponding technical effects by only utilizing improvements in the hardware circuit structure involved in these modules and units, and does not require the assistance of specific control software or computer programs to achieve the corresponding functions.

[0056] The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the utility model is limited to these descriptions. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic features of the present application. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present application is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present application. Any figure mark in the claims should not be regarded as limiting the claims involved.

Claims

1. A grinding pad dresser, characterized in that: It includes a trimming head and a driving unit for driving the trimming head to move; The dressing head is configured to dress the working surface of the polishing pad when acting on the working surface of the polishing pad; The driving unit comprises a base unit, an active arm and a driven arm; The first end of the active arm is rotatably connected to the base unit; The first end of the driven arm is rotatably connected to the second end of the active arm; The dressing head is connected to the second end of the driven arm and the working surface of the dressing head faces the grinding pad.

2. The polishing pad dresser according to claim 1, characterized in that: The base unit includes a support platform, two bearing seats arranged on the support platform, and a bearing; The bearing is rotatably arranged on the two bearing seats, the bearing is penetrated through the first end of the active arm, and the rotation of the bearing drives the second end of the active arm to rotate around the first end of the active arm.

3. The polishing pad dresser according to claim 2, characterized in that: The base unit also includes a first motor; The rotation of the output shaft of the first motor drives the rotation of the bearing.

4. The polishing pad dresser according to claim 1, characterized in that: The grinding pad dresser also includes a second motor, a power pulley, a transmission pulley and a belt; The power pulley and the transmission pulley are respectively arranged at the first end and the second end of the active arm, and the belt wraps around the power pulley and the transmission pulley; The output shaft of the second motor is connected to the power pulley, and the rotation of the output shaft of the second motor drives the rotation of the power pulley; The rotation of the power pulley drives the rotation of the transmission pulley through the belt.

5. The polishing pad dresser according to claim 4, characterized in that: A first gear is provided at one end of the transmission pulley; A second gear is disposed at the first end of the driven arm, and the second gear is meshed with the first gear.

6. The polishing pad dresser according to claim 1, characterized in that: The polishing pad dresser also includes a recessed portion and a spherical joint; The recess is connected to the second end of the driven arm; The spherical joint is connected to an end of the trimming head facing away from the working surface; The ball joint is received in the recess and connected to form a male-female connection by at least one bolt.

7. The polishing pad dresser according to claim 1, characterized in that: The grinding pad dresser further comprises a third motor, an output shaft of which is connected to the dresser head and drives the dresser head to rotate.

8. The polishing pad dresser according to claim 7, characterized in that: The abrasive pad dresser further includes a torque sensor configured to measure a torque of an output shaft of the third motor.

9. The polishing pad dresser according to claim 8, characterized in that: The polishing pad dresser also includes a control unit; The control unit is configured to receive torque information monitored by the torque sensor, and is configured to control rotation of the first motor and the second motor according to the torque information monitored by the torque sensor.

10. A chemical mechanical polishing device, characterized in that: The invention comprises the polishing pad dresser as claimed in any one of claims 1 to 9.

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