Polishing end point detection system and method, controller and chemical mechanical polishing equipment

Abstract

The invention relates to the technical field of polishing end point detection, and discloses a polishing end point detection system and method, a controller and chemical mechanical polishing equipment, and the polishing end point detection system comprises an ion generator, a spectrograph and the controller; the ion generator is arranged in the polishing disc and used for emitting an ion beam, the surface, emitting the ion beam, of the ion generator faces the surface, where the polishing stop layer is located, of the wafer, and the ion beam is used for inducing electrons in the polishing stop layer to enter an excited state; the spectrograph is arranged in the polishing disc, located on the side edge of the ion generator and used for detecting a target spectrum formed by light emitted when the electrons return to the ground state from the excited state and sending the target spectrum to the controller; and the controller is used for controlling the ion generator to emit the ion beam, receiving the target spectrum and determining whether a polishing end point is reached or not according to the target spectrum and a preset spectrum. Influences of polishing environment factors can be ignored as much as possible, and the accuracy of polishing end point detection is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of polishing endpoint detection, and in particular to a polishing endpoint detection system, method, controller and chemical mechanical polishing equipment. Background Art

[0002] Chemical Mechanical Planarization (CMP) is a technology used in semiconductor device manufacturing that uses chemical corrosion and mechanical force to flatten wafers or other substrate materials during processing. The chemical mechanical polishing equipment required for integrated circuit manufacturing usually needs to be equipped with an end point detection system (EPD). The end point detection system is used to determine whether the polishing has reached the end point to avoid over-polishing or under-polishing of the wafer, which affects the processing quality of the wafer.

[0003] There are many forms of endpoint detection systems, one of which is based on optical detection of the polishing endpoint. Specifically, during the polishing process, a light beam of a certain wavelength is irradiated on the surface of the wafer. Since the reflection intensity of different media on the wafer is different, the polishing endpoint can be determined based on the intensity change of the received light beam. Since the medium in the wafer reacts with the polishing liquid, chemical reaction products are selectively produced (for example, when a polishing liquid containing KOH polishes a wafer containing nitride, ammonia is produced), the polishing endpoint can also be detected by the chemical reaction products produced during the polishing process.

[0004] However, based on the optical detection of the polishing endpoint, due to the influence of polishing environmental factors such as the grinding fluid, the relative rotation of the grinding head and the polishing pad, and the swing of the grinding head, the received light beam will introduce a large number of invalid signals or noise signals, resulting in poor accuracy in determining the polishing endpoint. Based on the detection of the polishing endpoint by chemical reaction products, the detection result has a certain lag, which may cause over-polishing. Summary of the invention

[0005] In view of this, the present invention provides a polishing endpoint detection system, method, controller and chemical mechanical polishing equipment to improve the problem of inaccurate polishing endpoint detection.

[0006] In a first aspect, the present invention provides a polishing endpoint detection system, which includes an ion generator, a spectrometer and a controller; the ion generator is arranged in a polishing disk and is used to emit an ion beam, the surface of the ion generator emitting the ion beam is toward the surface of the polishing stop layer in the wafer, and the ion beam is used to induce electrons in the polishing stop layer to enter an excited state; the spectrometer is arranged in the polishing disk and is located on the side of the ion generator, and is used to detect a target spectrum formed by light emitted when the electrons return from the excited state to the ground state, and send the target spectrum to the controller; the controller is used to control the ion generator to emit the ion beam, to receive the target spectrum, and to determine whether the polishing endpoint is reached based on the target spectrum and a preset spectrum.

[0007] The polishing endpoint detection system provided by the present invention has the advantages of simple structure and easy operation. By setting an ion generator and a spectrometer, during the polishing process, the polishing endpoint can be detected by a target spectrum formed by atomically excited light of a specific frequency. The system has strong real-time performance, and the excited light has strong penetrability and is not easily affected by polishing environmental factors such as the grinding fluid, the relative rotation of the grinding head and the polishing pad, and the swing of the grinding head. No complex algorithms are required for filtering and calculation, thereby improving the accuracy of polishing endpoint detection.

[0008] In an optional embodiment, the surface of the ion generator from which the ion beam is emitted extends in the radial direction of the polishing disk, and the length of the surface of the ion generator from which the ion beam is emitted in the radial direction is greater than the diameter of the wafer.

[0009] The configuration of this embodiment can scan the entire wafer, thereby avoiding the problem of residual medium (such as metal) and further improving the accuracy of the polishing endpoint detection result.

[0010] In an optional embodiment, there are multiple spectrometers, which are spaced apart along the radial direction of the polishing disk; the controller is used to receive multiple target spectra, and to determine whether the polishing endpoint is reached based on the multiple target spectra and preset spectra.

[0011] In this embodiment, multiple spectrometers are provided, which can not only avoid the situation where the spectrometer cannot collect the target spectrum, but also detect multiple positions of the polishing medium layer, avoid residual medium material as much as possible, and improve the accuracy of endpoint detection.

[0012] In an optional embodiment, the controller is also used to determine the target energy of the ion beam based on the material of the polishing stop layer, and to control the output voltage of the ion generator so that the energy of the ion beam is greater than or equal to the target energy, wherein the target energy is the energy required for the ion beam to induce electrons to enter an excited state.

[0013] In a second aspect, the present invention provides a polishing endpoint detection method, which is applied to a controller of a polishing endpoint detection system provided in the first aspect or any corresponding embodiment thereof, the method comprising: controlling an ion generator to emit an ion beam, wherein the ion beam is used to induce electrons in a polishing stop layer to enter an excited state; obtaining a target spectrum formed by light emitted when electrons return from an excited state to a ground state detected by a spectrometer; and determining whether the polishing endpoint has been reached based on the target spectrum and a preset spectrum.

[0014] In an optional implementation, determining whether the polishing endpoint is reached according to the target spectrum and the preset spectrum includes: when the target spectrum and the preset spectrum are the same, determining that the polishing of the wafer has reached the polishing endpoint.

[0015] In an optional embodiment, there are multiple spectrometers, and determining whether the polishing endpoint is reached based on the target spectrum and the preset spectrum includes: determining whether the polishing endpoint is reached based on multiple target spectra and the preset spectra.

[0016] In an optional embodiment, before controlling the ion generator to emit the ion beam, the method also includes: determining a target energy of the ion beam based on the material of the polishing stop layer, wherein the target energy is the energy required for the ion beam to induce electrons to enter an excited state; and controlling the output voltage of the ion generator so that the energy of the ion beam is greater than or equal to the target energy.

[0017] In a third aspect, the present invention provides a controller for a polishing endpoint detection system, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the method of the second aspect or any corresponding embodiment thereof by executing the computer instructions.

[0018] In a fourth aspect, the present invention provides a chemical mechanical polishing device, comprising the polishing endpoint detection system of the above-mentioned first aspect or any corresponding embodiment thereof, or comprising a controller of the polishing endpoint detection system of the above-mentioned first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the related technologies, the drawings required for use in the specific embodiments or the related technical descriptions will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 is a structural schematic diagram of a polishing endpoint detection system according to an embodiment of the present invention;

[0021] Figure 2 is a top view schematic diagram of another polishing endpoint detection system according to an embodiment of the present invention;

[0022] Figure 3 is a side view schematic diagram of another polishing endpoint detection system according to an embodiment of the present invention;

[0023] Figure 4 is a schematic structural diagram of an ion generator and a spectrometer according to an embodiment of the present invention;

[0024] Figure 5 is a schematic diagram of a target spectrum according to an embodiment of the present invention;

[0025] Figure 6 is a schematic diagram of a scanning path of an ion generator according to an embodiment of the present invention;

[0026] Figure 7 is a schematic flow chart of a polishing endpoint detection method according to an embodiment of the present invention;

[0027] Figure 8 4 is a flow chart of another polishing endpoint detection method according to an embodiment of the present invention.

[0028] Reference numerals: 110, grinding pad; 111, transparent window; 120, polishing disk; 200, wafer; 310, ion generator; 311, ion beam; 312, first surface; 320, spectrometer. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0030] Chemical mechanical polishing (CMP) is actually a technique for polishing each layer of a wafer by evenly and continuously removing the protruding parts of each layer in small amounts, thereby making each layer of the wafer flat. It plays an important role in the multi-layer interconnection process of large-scale integrated circuits. During the polishing process, if the thickness of the film removed during the CMP process cannot be effectively controlled, the wafer may be over-polished or under-polished. Therefore, CMP endpoint detection is a very critical step for the yield of integrated circuits. The chemical mechanical polishing equipment is equipped with an endpoint detection system (EPD) to control the process more effectively.

[0031] For example, the traditional chemical mechanical polishing process control of metal layers mainly includes three steps: the first step is to remove a large amount of metal layer on the wafer surface, leaving a small amount of metal layer; the second step is to completely remove the metal layer on the wafer surface to expose the barrier layer; the third step is to completely remove the barrier layer to expose the dielectric layer. The endpoint detection system is aimed at the second step, that is, to detect whether the metal layer on the wafer surface is completely polished.

[0032] For another example, the control of the traditional chemical mechanical polishing process of the dielectric layer mainly includes three steps: the first step is to remove a large amount of dielectric layer on the wafer surface; the second step is to completely remove the dielectric layer on the wafer surface; the third step is to wet remove the nitride barrier layer after cleaning. The endpoint detection system is aimed at the second step, that is, to detect whether the dielectric layer on the wafer surface is completely polished, such as the shallow trench isolation (STI) process in semiconductor manufacturing.

[0033] There are many forms of endpoint detection, such as based on optics, eddy current, drive motor current, temperature or product, etc. These technologies have their own characteristics, but also have certain limitations. Among them, the most commonly used and effective method is optical detection, which tracks the process progress by detecting the changes in reflected light on the wafer surface to determine whether the polishing endpoint has been reached.

[0034] Specifically, Figure 1 As shown, a transparent window 111 is provided on the grinding pad 110 and the polishing disk 120, and a light source emitting device and a light source receiving device are placed in the transparent window of the polishing disk 120. When polishing the wafer 200, the grinding pad 110 is placed on the polishing disk 120, and the grinding pad 110 contains grinding liquid. The polishing disk 120 drives the grinding pad 110, the light source emitting device and the light source receiving device to rotate counterclockwise (or clockwise), and the grinding head (not shown in the figure) absorbs the wafer 200, places the wafer 200 on the rotating grinding pad 110, and drives the wafer 200 to rotate, wherein the stop medium layer (also called polishing stop layer) and the target layer in the wafer 200 are in contact with the grinding liquid to polish the stop medium layer and the target layer.

[0035] During the polishing process, the light source emitting device emits light of a certain wavelength, and the emitted light can be irradiated to the stopping medium layer and the target layer of the wafer through the transparent window 111 on the grinding pad 110. The stopping medium layer and the target layer reflect the light, and the light source receiving device receives the light reflected from the stopping medium layer and the target layer through the transparent window 111. Since the reflection intensity of different media is different, it can be determined whether the polishing of the wafer has reached the polishing end point by the change in the reflection intensity.

[0036] However, in the above process, the reflected light will be affected by polishing environmental factors such as the grinding liquid, the relative rotation of the grinding head and the polishing pad, and the swing of the grinding head before entering the light source receiving device, introducing a large number of invalid signals and noise signals. As a result, the light source receiving device needs to perform a large amount of filtering and calculations when receiving the reflected light. This may lead to the problem of being unable to detect the polishing end point, resulting in over-polishing, which in turn leads to serious product quality problems.

[0037] In addition, studies have shown that during the CMP process, when the polishing liquid reacts with the polishing stop layer or the target layer, it will selectively produce chemical reaction products (for example, when polishing a wafer with a nitride film in a polishing liquid containing KOH, ammonia will be produced). Therefore, the endpoint detection system can also detect the polishing endpoint through different chemical products. However, in fact, since the above method detects the product removed after polishing, the detection result has a certain hysteresis, which affects the accuracy of polishing endpoint detection.

[0038] In view of this, the present invention provides a polishing endpoint detection system and method. During the polishing process, the polishing endpoint is detected by the spectrum formed by atomic excitation of light of a specific frequency. This system has strong real-time performance, and the excited light has strong penetrability and is not easily affected by polishing environmental factors, thereby improving the accuracy of polishing endpoint detection.

[0039] First, the polishing endpoint detection system provided by the present invention is described in detail below with reference to the accompanying drawings.

[0040] like Figure 2 , Figure 3 and Figure 4 As shown, the polishing endpoint detection system includes an ion generator 310, a spectrometer 320 and a controller (not shown in the figure).

[0041] Among them, the ion generator 310 is arranged in the polishing disk 120, and is used to emit an ion beam 311. The surface of the ion generator 310 that emits the ion beam 311 (called the first surface 312) is toward the surface where the polishing stop layer in the wafer is located, that is, the first surface 312 and the polishing stop layer in the wafer 200 placed on the grinding pad 110 are arranged relative to each other, and the ion beam is used to induce electrons in the polishing stop layer to enter an excited state.

[0042] Exemplarily, the polishing plate 120 is provided with a groove opening upward, and the ion generator 310 may be disposed in the groove.

[0043] It should be understood that an ion generator is a device that can generate high-energy ions, which can form positively or negatively charged ions by causing atoms or molecules to lose or gain electrons through specific physical or chemical methods. The ions generated by an ion generator usually have high energy and can be accelerated under the action of an electric field, a magnetic field or other forces. The ion generator in the present invention can be a conventional ion generator in the art and will not be described in detail here.

[0044] The spectrometer 320 is also disposed in the polishing plate 120 and is located on the side of the ion generator 310, and is used to detect the target spectrum formed by the light emitted when the electron returns from the excited state to the ground state, and send the target spectrum to the controller. The target spectrum can be a curve representing the distribution of the intensity or wavelength of the light collected at different times. For example, the target spectrum can be as follows: Figure 5 shown.

[0045] Exemplarily, the spectrometer 320 may also be disposed in the groove and distributed on at least one side of the ion generator 310, for example, Figure 2 As shown, spectrometers 320 are provided on both the left and right sides of the ion generator 310. The spectrometer 320 may be a conventional spectrometer in the art, and will not be described in detail herein.

[0046] It should be understood that electrons are usually in a lower energy ground state. When electrons are acted upon by external energy (in this application, the collision kinetic energy generated by high-energy ion collisions), they can absorb energy and transition to a higher energy state (i.e., an excited state). However, the excited state is unstable. After a certain period of time, the electrons will release energy in the form of light and return to the ground state from the excited state.

[0047] The controller is used for controlling the ion generator to emit an ion beam, for receiving a target spectrum, and for determining whether a polishing end point is reached according to the target spectrum and a preset spectrum.

[0048] Specifically, the controller can control the spectrometer and the ion generator to turn on and off. After the controller turns on the ion generator and the spectrometer, the ion generator and the spectrometer can remain in the on state until the polishing is completed. After receiving the target spectrum, if the target spectrum is the same as the preset spectrum, the controller determines that the polishing of the wafer has reached the polishing end point and ends the polishing; if the target spectrum is not the same as the preset spectrum, the controller determines that the polishing of the wafer has not reached the polishing end point and continues polishing.

[0049] The preset spectrum is a target spectrum acquired by the spectrometer when the polishing medium layer is at a preset position, and the preset spectrum is pre-stored in the controller. If the overlap between the target spectrum and the preset spectrum reaches more than 80%, the target spectrum is considered to be the same as the preset spectrum.

[0050] Exemplarily, the controller may be a microcontroller unit (MCU).

[0051] Specifically, the polishing endpoint detection system provided by the present invention, after the polishing disc 120 drives the ion generator 310 to rotate, the controller turns on the ion generator 310 and the spectrometer 320, the ion generator 310 emits an ion beam 311, when the ion generator 310 rotates to the bottom of the wafer 200, the ions in the ion beam 311 collide with the polishing stop layer in the wafer 200, and the collision kinetic energy generated induces the electrons in the polishing stop layer to enter the laser state. After the electron enters the laser state, the electron will emit light of a specific frequency when it returns from the excited state to the ground state. At this time, the spectrometer 320 collects the target spectrum formed by the light emitted when the electron returns from the excited state to the ground state, and sends the target spectrum to the controller. The controller receives the target spectrum, if the target spectrum is the same as the pre-stored preset spectrum, it is determined that the polishing of the wafer has reached the polishing endpoint, and the polishing is stopped; if the target spectrum is the same as the pre-stored preset spectrum, it is determined that the polishing of the wafer has not reached the polishing endpoint, and the polishing is continued until the polishing endpoint is reached.

[0052] The polishing endpoint detection system provided by the present invention has the advantages of simple structure and easy operation. By setting an ion generator and a spectrometer, during the polishing process, the polishing endpoint can be detected by a target spectrum formed by atomically excited light of a specific frequency. The system has strong real-time performance, and the excited light has strong penetrability and is not easily affected by polishing environmental factors such as the grinding fluid, the relative rotation of the grinding head and the polishing pad, and the swing of the grinding head. No complex algorithms are required for filtering and calculation, thereby improving the accuracy of polishing endpoint detection.

[0053] For example, Figure 2 and Figure 3 As shown, the surface of the ion generator that emits the ion beam (ie, the first surface 312 ) extends along the radial direction of the polishing pad 120 , and the length of the first surface 312 in the radial direction is greater than the diameter of the wafer.

[0054] Specifically, when the length of the first surface 312 in the radial direction is greater than the diameter of the wafer, the scanning path L1 of the ion generator 310 can be as follows: Figure 6 As shown, the scanning path L1 can cover the entire wafer, that is, the stop dielectric layer on the entire wafer surface can be detected.

[0055] Compared to Figure 1 The scanning path L2 of the light source emitting device shown in the figure can scan the entire wafer in the configuration of this embodiment, thus avoiding the problem of residual medium (such as metal) and further improving the accuracy of the polishing endpoint detection result.

[0056] in, Figure 6The scanning path L1 of the ion generator and Figure 1 The scanning path L2 of the light source emitting device is a schematic diagram only when the polishing plate 120 rotates.

[0057] In some embodiments, Figure 3 and Figure 4 As shown, there are multiple spectrometers 320, which are spaced apart along the radial direction of the polishing plate 120. The controller is used to receive multiple target spectra, and to determine whether the polishing endpoint is reached according to the multiple target spectra and the preset spectrum.

[0058] Specifically, each spectrometer 320 is capable of collecting a target spectrum formed by light emitted when an electron returns from an excited state to a ground state, and sending the collected target spectrum to the controller. After receiving multiple target spectra, if most of the target spectra in the multiple target spectra (for example, more than 90% of the target spectra) are the same as the preset spectrum, it is determined that the polishing of the wafer has reached the polishing endpoint; if most of the target spectra in the multiple target spectra are different from the preset spectrum, it is determined that the polishing of the wafer has not reached the polishing endpoint.

[0059] In this embodiment, multiple spectrometers are provided, which can not only avoid the situation where the spectrometer cannot collect the target spectrum, but also detect multiple positions of the polishing medium layer, avoid residual medium material as much as possible, and improve the accuracy of endpoint detection.

[0060] Exemplarily, the controller is also used to determine the target energy of the ion beam based on the material of the polishing stop layer, and to control the output voltage of the ion generator so that the energy of the ion beam is greater than or equal to the target energy, wherein the target energy is the energy required for the ion beam to induce electrons to enter an excited state.

[0061] Specifically, before turning on the ion generator 310, the controller determines the target energy according to the theoretical model and controls the output voltage so that the energy of the ion beam is greater than or equal to the target energy, thereby avoiding the situation where the electrons in the polishing medium layer cannot be excited into an excited state.

[0062] This embodiment also provides a polishing endpoint detection method, which can be used in the controller of the above-mentioned polishing endpoint detection system. Figure 7 is a flow chart of a polishing endpoint detection method according to an embodiment of the present invention. Figure 7 As shown, the method comprises the following steps:

[0063] Step S701, controlling the ion generator to emit an ion beam.

[0064] Therein, an ion beam is used to induce electrons in the polish stop layer into an excited state.

[0065] Step S702, obtaining a target spectrum formed by light emitted when an electron returns from an excited state to a ground state detected by a spectrometer.

[0066] Specifically, electrons are usually in a ground state with lower energy. When affected by external energy, they can absorb energy and transition to a state with higher energy (i.e., an excited state). However, the excited state is unstable. After a certain period of time, the electrons will release energy in the form of light and return to the ground state from the excited state.

[0067] The target spectrum may be a curve representing the distribution of the intensity or wavelength of light collected at different times. The controller may detect the target spectrum formed by electronic luminescence through a spectrometer and obtain the target spectrum from the spectrometer.

[0068] Step S703: determining whether the polishing end point has been reached according to the target spectrum and the preset spectrum.

[0069] Specifically, when the target spectrum is the same as the preset spectrum, it is determined that the polishing of the wafer has reached the polishing endpoint; when the target spectrum is different from the preset spectrum, it is determined that the polishing of the wafer has not reached the polishing endpoint.

[0070] The polishing endpoint detection method provided in this embodiment detects the polishing endpoint through the spectrum formed by atomic excitation of light of a specific frequency during the polishing process. It can ignore the influence of polishing environment factors on the polishing endpoint detection as much as possible, and does not require complex algorithms for filtering and calculation, which can improve the real-time and accuracy of polishing endpoint detection.

[0071] This embodiment also provides a polishing endpoint detection method, which can be used in the controller of the above-mentioned polishing endpoint detection system. Figure 8 FIG. 1 is a flow chart of another polishing endpoint detection method according to an embodiment of the present invention. Figure 8 As shown, the method comprises the following steps:

[0072] Step S801, determining the target energy of the ion beam according to the material of the polishing stop layer.

[0073] The target energy is the energy required for the ion beam to induce electrons to enter an excited state.

[0074] Step S802, controlling the output voltage of the ion generator so that the energy of the ion beam is greater than or equal to the target energy.

[0075] Step S803, controlling the ion generator to emit an ion beam.

[0076] For details, please see Figure 7 Step S701 of the illustrated embodiment will not be described in detail here.

[0077] Step S804, obtaining a target spectrum formed by light emitted when electrons return from an excited state to a ground state detected by multiple spectrometers.

[0078] Specifically, there are multiple spectrometers, each spectrometer detects a target spectrum formed by light emitted when an electron returns from an excited state to a ground state, and sends the target spectrum to the controller, and the controller receives multiple target spectra.

[0079] Step S805 , determining whether the polishing endpoint is reached according to the multiple target spectra and the preset spectra.

[0080] Specifically, if most of the target spectra among the multiple target spectra (for example, more than 90% of the target spectra) are the same as the preset spectra, it is determined that the polishing of the wafer has reached the polishing endpoint; if most of the target spectra among the multiple target spectra are not the same as the preset spectra, it is determined that the polishing of the wafer has not reached the polishing endpoint.

[0081] In this embodiment, whether the polishing endpoint is reached is determined based on multiple target spectra and preset spectra, and multiple positions of the polishing medium layer can be detected to avoid residual medium material as much as possible, thereby improving the accuracy of endpoint detection.

[0082] The present invention also provides a controller for a polishing endpoint detection system, including one or more processors, a memory, and interfaces for connecting various components, including a high-speed interface and a low-speed interface. The various components communicate with each other using different buses and can be installed on a common mainboard or in other ways as needed.

[0083] The processor may be a central processing unit, a network processor or a combination thereof. The processor may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0084] The memory stores instructions executable by at least one processor, so that the at least one processor executes the method shown in the above embodiment.

[0085] The memory may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required by at least one function; the data storage area may store data created according to the use of the controller, etc. In addition, the memory may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices.

[0086] The memory may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid state drive; the memory may also include a combination of the above types of memory.

[0087] The present invention also provides a chemical mechanical polishing device, including the polishing endpoint detection system provided by any of the above embodiments, or including a controller of the polishing endpoint detection system provided by any of the above embodiments.

[0088] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0089] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0090] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, a plurality of steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0091] In the description of this specification, the description with reference to the terms "this embodiment", "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described 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 the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0092] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0093] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the present invention.

Claims

1. A polishing endpoint detection system, characterized in that: The polishing endpoint detection system includes an ion generator, a spectrometer and a controller; The ion generator is arranged in the polishing plate and is used to emit an ion beam. The surface of the ion generator emitting the ion beam is directed toward the surface of the polishing stop layer in the wafer. The ion beam is used to induce electrons in the polishing stop layer to enter an excited state. The spectrometer is arranged in the polishing plate and located on the side of the ion generator, and is used to detect the target spectrum formed by the light emitted when the electron returns from the excited state to the ground state, and send the target spectrum to the controller; The controller is used to control the ion generator to emit the ion beam, to receive the target spectrum, and to determine whether the polishing endpoint is reached according to the target spectrum and a preset spectrum.

2. The polishing endpoint detection system according to claim 1, characterized in that: The surface of the ion generator from which the ion beam is emitted extends in a radial direction of the polishing disk, and the length of the surface of the ion generator from which the ion beam is emitted in the radial direction is greater than the diameter of the wafer.

3. The polishing endpoint detection system according to claim 1, characterized in that: There are multiple spectrometers, and the multiple spectrometers are arranged at intervals along the radial direction of the polishing plate; The controller is used to receive the plurality of target spectra, and to determine whether the polishing endpoint is reached according to the plurality of target spectra and the preset spectrum.

4. The polishing endpoint detection system according to any one of claims 1 to 3, characterized in that: The controller is also used to determine the target energy of the ion beam based on the material of the polishing stop layer, and to control the output voltage of the ion generator so that the energy of the ion beam is greater than or equal to the target energy, wherein the target energy is the energy required for the ion beam to induce the electrons to enter an excited state.

5. A polishing endpoint detection method, characterized in that: A controller for a polishing endpoint detection system according to any one of claims 1 to 4, wherein the method comprises: controlling the ion generator to emit an ion beam, wherein the ion beam is used to induce electrons in the polishing stop layer to enter an excited state; Acquire a target spectrum formed by light emitted when the electron returns from the excited state to the ground state detected by a spectrometer; Whether the polishing endpoint is reached is determined according to the target spectrum and the preset spectrum.

6. The method according to claim 5, characterized in that The step of determining whether the polishing endpoint is reached according to the target spectrum and the preset spectrum includes: When the target spectrum is identical to the preset spectrum, it is determined that the polishing of the wafer reaches a polishing endpoint.

7. The method according to claim 5, characterized in that The number of the spectrometers is multiple, and determining whether the polishing endpoint is reached according to the target spectrum and the preset spectrum includes: Whether the polishing endpoint is reached is determined according to the plurality of target spectra and the preset spectra.

8. The method according to claim 5, characterized in that Before controlling the ion generator to emit the ion beam, the method further comprises: Determining the target energy of the ion beam according to the material of the polishing stop layer, wherein the target energy is the energy required by the ion beam to induce the electrons to enter an excited state; The output voltage of the ion generator is controlled so that the energy of the ion beam is greater than or equal to the target energy.

9. A controller for a polishing endpoint detection system, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the method according to any one of claims 5 to 8 by executing the computer instructions.

10. A chemical mechanical polishing device, characterized in that: A polishing endpoint detection system comprising any one of claims 1 to 4, or a controller comprising the polishing endpoint detection system according to claim 9.

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