TW536454B - Apparatus and method for detecting polishing endpoint of chemical-mechanical planarization/polishing of wafer - Google Patents

Abstract

The present invention provides apparatus for detecting polishing endpoint of chemical-mechanical planarization/polishing of a wafer comprising the following steps: (1) using an acoustic/audio sensor for receiving vibration frequency and amplitiude of a chemical-mechanical polishing device that is polishing a semiconductor wafer film, wherein the film is adjacent to a structural layer located therebeneath, (2) transmitting the vibration frequency and amplitude of the chemical-mechanical device received by the acoustic/audio sensor to a computer processing system, wherein the computer processing system stores characteristic data associated with endpoint of film polishing, the characteristic data including vibration characteristic data associated with the situation where the film is partially polished out and a portion of the structural layer is exposed and where the film is completely polished out and the structural layer is exposed; and (3) a computer processing system for processing and comparing the characteristic data associated with the endpoint of film polishing with vibration frequency and amplitude of the chemical-mechanical polishing device received by the acoustic/audio sensor to determine the endpoint of polishing operation of the film.

Description

536454 V. Description of the invention (1) Field of the invention: The present invention relates to a kind, especially a kind of method and method. BACKGROUND OF THE INVENTION Recently, as the accumulation rate has increased, not only has the file size become smaller. Therefore, in integrated electrical technology, chemical mechanical Polishing (CMP) can be used in chemical-mechanical research (end-point dete < foot or grinding excessive. The eye method is to use horse monitoring) method, in the optical method, the beam is irradiated on the Apparatus and method for polishing chemical mechanical planarization process There is a method for studying the polishing end point detection device of the mechanical zhengtan process. The packing circuit has a faster and smaller size, and the distance between the components has been achieved. Each film layer of the mesh path where the integration degree of the integrated circuit is increased is flattened. In the flattening grinding method (Chemical Mechanical can make the film layer achieve better overall flattening. During the grinding process, it is necessary to use the grinding end point detection method: 11 ο η) to control the grinding end point to prevent most of the grinding The grinding end point detection method does not use the light-torque monitor and the motor-torque to detect the end point of the grinding order. The end of the grinding time. 4 The principle of the reading method is to measure the intensity of the reflected light on a layer of laser light. From 536454 5. Description of the invention (2) ^^. The reflected light will vary with the thickness of the film There are different interference effects, resulting in different light intensities. Therefore, the normalized light intensity is used as the vertical axis, time is used as the y-axis, and the slope of the light intensity as a function of time can be used to separate the thickness of the film layer. Detection of the end point of mechanical grinding. For traditional chemical mechanical grinding methods, please refer to U.S. Patent Nos. 6 1 1 16 34, 6 1 0 8 0 9 1 and 6 0 7 j} 7 7 respectively, or See "SiHc〇n Pr〇c" by Wolf and RN · Tauber essing f〇r VLSI Era ”Vol · 1 '2nd ed, 2000. Here is a brief description of the traditional chemical mechanical polishing method using optical methods to detect the end point of polishing: Refer to Figure 1. When performing chemical mechanical polishing, A polishing head 30 is used to hold the back surface of the wafer 28 and press the polishing head 30 to press the front surface of the wafer 28 against the slurry layer 26 (the slurry layer 26 is used The slurry is continuously sprayed on a polishing pad to form), and the wafer layer 28 is polished by the slurry layer 26 to flatten the film layer to be polished on the wafer 28. The slurry layer 2 6 It is driven by a belt 22, and there is a polishing platen 18 under the belt 22. There is a transparent window 20 and a second transparent window 24 on the polishing platform 18 and the leather f 2 2, respectively. The design of the grinding platform 18 is fixed and mobile. If the design of the grinding platform 18 is fixed, there is an air bearing (not shown) between the grinding platform 1 § and the belt 22, To support the wafer 2 8 above the belt 2 2. When the belt 2 2 runs along two rollers (not 536454 3. Description of the invention (3): When the rotation is repeated, the second transparent window 24 will be rotated, and it is located at ΐ1. The bright window 24 is rotated to be directly opposite to the first transparent window 20, and S is transparent. The emitted light 14 from the light source 10 directly below the window 20 is transparent t2 °, the second transparent lens 24, and the research lens, and the second-transparent lens 20: Yes: the sample is' only when the second transparent lens 24 is turned to and !! 4- ^, 夺, the reflected light reflected back through the surface of the wafer 28, ^ the transparent window 20, the second transparent window 24, and the slurry layer 26: the light sensor directly below the first transparent window 20 丨2 received.

The design of the right grinding platform 18 is mobile, and the belt 2 2 is adhered to 1 flat. 18, where the polishing platform is used to support the wafer 28 above the belt 22, and when the polishing platform 18 rotates, the belt 22 will rotate synchronously with it. At this time, the second transparent window 24, the first transparent window 20, and The light source 10 and the light sensor 12 under the first transparent window 20f will also rotate synchronously. When the first transparent window 24 and the first transparent window 20 are rotated directly below the wafer 28 (measurement point position), the emitted light 14 emitted by the light source located directly below the first transparent window 20 The surface of the wafer 28 can be reached through the first transparent window 20, the second transparent window ", and the ground layer 26 '. Similarly, only when the second transparent window

2 4. When the first transparent window 20 is rotated directly below the wafer 28, the reflected light 16 reflected from the surface of the wafer 28 can pass through the first transparent window 20, the second transparent window ^, and the slurry layer. 26, and is received by the light sensor 12 directly below the first transparent window 20. Because the above hardware mechanism is out of the specification (for example: light 1 1 Η 1 I a page 7 536454 V. Description of the invention (4) When the source 10 emits light 14, the second transparent window 20 is directly opposite Position), the window 24 has not been rotated to the first meeting and will be dried. Therefore, the grinding process will be blocked or the optical signal will take a long time each time: the end point detection fails. In addition, the smooth passing of the first-transparent f 20 and second-second can make the emitted light 14 and reflected light 16 to detect the grinding end point, so it is limited to the bright window 24 and the research layer 26, and the & A system made the end point detection system. Sampling rate). The signature im right spear 1 uses a motor-torque method to perform grinding and may detect end points. “Because of the stable in the CMP tool, the grinding platform has an inherently high inertia.” Motor-torque usually has a low signal / miscellaneous Signal ratio cannot 'reliably capture the end point during the grinding process. Therefore, how to develop a method for detecting the end point of polishing to avoid the above problems has become an important issue in the integrated circuit industry. OBJECTS AND SUMMARY OF THE INVENTION: The purpose of the present invention is to provide a polishing endpoint detection device and method for a chemical mechanical planarization process, so that the probability of insufficient or excessive polishing due to failure of the polishing endpoint in the CMP process of the wafer is reduced to lowest. According to an embodiment of the present invention, a method for detecting a polishing end point of a chemical mechanical planarization process includes the following steps: (1) using an acoustic (tic) / audio (aud i 0) sensor to receive 536454 under development V. Description of the invention (5) A chemical machine for grinding a semiconductor wafer film layer, which is under the film layer to be polished) The vibration frequency of acoustic / audio chemical mechanical polishing device _ Tongzhong 'which The computer processing system records the sign data, and this characteristic data includes the vibration% generated by the part of the structural layer being ground and the structural layer being ground by the system, which is accompanied by the end of the film grinding (acoustic) / audio ( audio) The vibration frequency and amplitude of the grinding device are used to determine whether the grinding end point has been reached. According to another embodiment of the present invention, the grinding end point detection method is a sonic detection method for performing chemical mechanical measurement. The vibration frequency and vibration structure layer of the mechanical grinding device are adjacent to it. (2 (audio) The special film layer received by the sensor and the amplitude transmitted to a computer processing system is accompanied by the end point of the film layer being worn out, resulting in the exposed film layer being worn out, resulting in the exposure of characteristic information (3) The computer-processed feature data and the chemical-mechanical research process and comparison from the acoustic sensor are used to confirm the film-layer research. The proposed chemical-mechanical planarization uses the light wave detection method and the planarization process simultaneously. The grinding end point is a sound wave detection method including the following steps: (υ uses an acoustic / audio sensor to receive the vibration frequency of the chemical mechanical polishing device of a semiconductor wafer film layer and 4, where there is a structural layer below the ground film layer adjacent to it ^ The vibration frequency and amplitude of the chemical mechanical polishing device received by the acoustic / audio sensor are transmitted to a computer for processing, 536454 V. Description of the invention (6) In the system, the computer processing system records the data associated with the end point of the rubbing layer grinding, and this characteristic data includes part of the film layer being worn out. Part of the structural layer from the rain is ground, and the film layer is worn out, which results in the vibration characteristics of the structural layer being ground. (3) The electrical + brain processing system will accompany the end point of the film layer. The characteristic data and the vibration frequency and amplitude of the chemical mechanical polishing device transmitted from the acoustic tic / audio sensor are processed and compared to confirm whether the film polishing end point has been reached. China Grinding 丨 Research Ⅰ—I Set C: Grinding the stepping machine to learn the encapsulation method, when the Founder detects the detection line wave light and light, and the source uses the light to guide the light. The upper layer of the back film shoots the round inverted crystal layer and analyzes the circular split crystal. The system guidance system is half-closed, and the electrical sense is used to measure the light. It is true that the thickness of the ground grinding film is the same as the thickness of the ground grinding film. The thickness of the ground grinding film is round and crystal-refined. It is far from the body to the semi-conductive. According to one embodiment of the present invention, the proposed chemical mechanical planarization Cheng's grinding endpoint detection device, including : (1) An acoustic / audio sensor is used to receive the vibration frequency and amplitude of a chemical mechanical polishing device that is polishing a semiconductor wafer film layer, and there is a structural layer under the film layer being polished It is adjacent to it. (2) A computer processing system records the characteristic data accompanying the end point of the film grinding 536454 V. Description of the invention (7) Whether the end point of the vibration mill of the (acoustic) grinding device is exposed to cause exposure Acoustic-Semiconductor wafer web according to the present process, in which a computer-processed material is used to determine whether the end point of the vibratory grinding device of the film-acoustic grinding device has reached the point where it leads to exposure) The semiconductor semiconductor wafer film data in the grinding and the semiconductor are analyzed and processed to determine whether the grinding end point / audio (and i 〇) frequency and amplitude are reached, in which part of the structural layer of this feature is polished by the structural layer and another implementation is shown Example point detection device, package / audio (aud i 〇) film chemical mechanical grinding system under the film layer, recording the film polishing end point Acoustic and audio (and i 〇) frequency and amplitude are achieved, in which part of the structural layer of this feature is polished by the structural layer to emit light onto the wafer film layer. (The anti-wafer film layer reflected from the layer is polished to obtain the grinding arrival. The chemical mechanical research materials included include part of the Japanese research grinding, and the layer produced by the exhaustion is used to guide the vibration characteristics. 'The proposed chemical wind includes: j chemical mechanical flattening. VU an acoustic sensor, Tian, m ^ u. To receive the twist of the grinding and grinding device ^ ^ a & broadcast frequency and vibration layer grinding End point; ϋ (2 The following # 符 二 accompanied feature information, 叼 sign data and sound, chemical mechanical research from the tester = theory and comparison, to confirm that the film research lean material contains part of the film Vibration characteristic data generated by being worn out and ground, and the film layer being worn out. (3 is being researched by chemical mechanical grinding equipment 4) A light sensor is used to receive the light and reflect the time of the light intensity The thickness of the film layer sent to the computer processing system, so the film layer is confirmed 536454 V. Description of the invention (8) In the above embodiment of the method and device, the acoustic / audio sensor includes acoustic emission , AE) sensor The microphone can be placed on a polishing platform or a polishing head of a chemical mechanical polishing device. The above-mentioned determination of the thickness of the film layer to be polished includes a first-order derivative function using the reflected light intensity relative to the time when the semiconductor wafer film layer is polished. It can be obtained through the analysis of the second-order derivative function relationship or the second-order derivative function relationship. In addition, the above-mentioned vibration characteristic data includes data on the change of volume intensity with time, as for the material of the film layer including copper, and the material of the structure layer including TaN or a low dielectric constant material (such as black diamond (B 1 ack D i am ο nd)). In addition, an acoustic / audio sensor may use a vibration sensor (such as a laser Doppler vibrator (Laser D ο pp 1 er Vibrometers) )) Replaced. Detailed description of the invention: The purpose of the present invention is to provide a grinding end detection device and method for a chemical mechanical planarization process, so that the wafer is insufficiently or excessively polished due to the end failure in the CMP sequence. The chance is minimized.

Page 12 536454 V. Description of Invention (9) Changes. In other words, the material type and film thickness of the film layer to be polished will affect the vibration frequency and amplitude of the CMP tool. Therefore, an acoustic (acoustic) / audio (aud i 〇) sensor system (for example: acoustic emission (AE) sensor or microphone) can be used to detect the end point of the CMP process. Compared with the traditional optical method for detecting the polishing end point of the CMP process, regardless of its processing condition, such an audio / audio sensor detection system can continuously monitor whether the polishing end point of the CMP process has been completed. The invention uses the characteristics that the friction between the semiconductor wafer and the polishing pad / belt (pad) will be changed due to different thin film materials and different surface flatness (topography). Different vibration conditions are generated to detect when the upper film layer of two vertically adjacent film layers is polished, when the interface between the two film layers is partially exposed (that is, part of the upper film layer is worn out and caused Part of the lower film layer is exposed) and when it is completely exposed (that is, the upper film layer is completely worn out, which causes the entire lower film layer to be exposed). Herein, a preferred embodiment details the method for detecting the polishing end point of the chemical mechanical planarization process proposed by the present invention as follows: Please refer to FIG. 2. When performing chemical mechanical polishing, a polishing head 4 8 is needed to hold the wafer. 4 6 and press the polishing head 4 8 to press the wafer 4 6 to the slurry layer 44 (the slurry layer 44 is made by continuously spraying the slurry to

Liguo _ II ··· _____ ΙΙΙηΙΙηΙ page 13 536454 V. Description of the invention (ίο) formed on a polishing pad) The wafer 4 6 is polished by the slurry layer 4 4 to make the upper surface of the wafer 4 6 to be polished. The film is flattened. The slurry layer 4 4 is driven by a belt 4 2, and there is a grinding platform 40 under the belt 4 2. The grinding platform 40 is designed in two types: fixed and mobile. If the design of the polishing platform 40 is fixed, there is an air bearing (not shown) between the polishing platform 40 and the belt 42 to support the wafer 46 above the belt 42. And if the design of the polishing platform 40 is mobile, the polishing platform 40 is linked with the belt 42 to support the wafer 46 above the belt 42. m On one of the grinding platform 40 and the grinding head 48, an acoustic / audio sensor system (for example, an acoustic emission (AE) sensor is placed Or microphone)-50 'to receive the vibration frequency and amplitude of the CMP tool. A computer processing system 52 is used to record the characteristic data accompanying the end point of grinding, and to combine this characteristic data with the cmp tool from the acoust ic / audio sensor system 50. The vibration frequency and the vibration age amplitude are processed and compared to confirm whether the grinding end point has been reached. The data from the sensor system 50 needs to be processed by signals (such as Fourier transform, pattern recognition, or filtering of noise, etc.). In the above embodiment, because the signal cannot be properly filtered or processed if

Page 14 536454 V. Description of the invention (11) The audio / audio sensor will suffer from background noise. Moreover, when the moving part of the CMP tool or the surface condition of the polishing pad changes, this signal will change. Therefore, the present invention also proposes a method (assuming an optical method) that combines the audio / audio grinding endpoint detection system with other endpoint detection systems to solve the disadvantage of using the CMP tool's vibration frequency and amplitude to perform the grinding endpoint detection. . Here is an example of a method combining an audio / audio grinding endpoint detection system and an optical method endpoint detection system, as follows: Because the audio / audio grinding endpoint detection system and the optical method endpoint detection system are in the same The reasons for the failure of the grinding endpoint detection at the time point are different. Therefore, using the dual grinding endpoint detection system combining these two systems to detect the grinding endpoint will avoid the lack of using the audio / audio grinding endpoint detection system or the optical endpoint detection system alone. This is because in the above dual-grind endpoint detection system, a normal (η 〇 r m a 1) or expected signal pattern can be recognized by each method. An end point can be detected by either method or by both methods. If the signal obtained by one method is far from the pre-set normal pattern, a warning signal will be sent to indicate that the detection method may fail, and then the grinding end point will be detected by another method.

Page 15 536454 V. Description of the invention (12) Please refer to Figure 3. When performing chemical mechanical polishing, a grinding head 80 is used to hold the wafer 7 8 and the grinding head 80 is pressed to press the wafer 7 8 The slurry layer 76 is pressed (the slurry layer 76 is formed by continuously spraying the slurry on a polishing pad), and the wafer 78 is polished by the slurry layer 76 to make the wafer 78 The film layer to be polished is flattened. The slurry layer 76 is driven by a belt 72, and there is a grinding platform 68 under the belt 72. The grinding platform 68 and the belt 72 have a first transparent window 70 and a second transparent window 74, respectively. The design of the grinding platform 6 8 is fixed or mobile. If the belt 72 is shown in the supporting diagram, then the position can pass through the gas belt 72 between the grinding platforms) and only when the first through the first through the first transparent window 7 8 surface of the first transparent window 7 0 Only 6 6 can pass through the first and the design located at the first through 6 8 can be fixed, then the grinding platform 6 8 and the air bearing (not shown), the square wafer 7 8. When the belt 72 is rotated along the two rollers (without restarting), the second transparent window 7 4 will then rotate along with the second transparent window 7 4 to be directly opposite the first transparent window 7 〇 directly below the bright f 7 0 The emitted light 6 4 from the light source 6 is the bright window 70, the second transparent window 74, and the mortar layer 76, and 1 is the same. 'Only when the second transparent window 7 4 is rotated to the same time, the second wafer 7 8 The reflected light transmitted back from the surface = window 70, the second transparent window 74 and the mortar layer 76, and the light sensor 6 2 directly under the bright window 70. In this case, the belt 7 2 is attached to support The crystal 7 2 above the belt 72 will be rotated simultaneously. If the grinding platform 68 is designed to move on the grinding platform 68, the grinding platform 6 is handsome and round 78, and when the grinding platform 68 rotates, the belt

Page 16 536454 V. Description of the invention (13) Turning, the second transparent window 74, the first transparent window 70, and the light source 60 and the light sensor 62 directly below the first transparent window 70 will also follow. Perform synchronous rotation. When the second transparent window 74 and the first transparent window 70 are rotated directly below the wafer 78 (measurement point position), the light 64 emitted from the first transparent window can pass through the first transparent window layer 76, and Reached the surface of the wafer 7 8. Same as 74. The first transparent window 70 is rotated until the reflected light 66 reflected from the wafer surface can pass through the window 74 and the ground layer 76, and is received by the detector 62. 70, 70 emitted by the light source 60 directly below the 70, the second transparent window 74, and the grind sample. Only when the second transparent window 78 is directly below, the first transparent window 70, the Light feeling directly below the second transparent first transparent window 70

failure. Because the above-mentioned hardware mechanism is out of the specification limit source 60 and emits light 64, the second transparent window 74 does not have the transparent window 70 in the position directly opposite it). The seal will be interfered, which will cause the end point detection of the grinding process. Because it takes a lot of time each time, the emitted light can pass through the first transparent window 70, the second transparent window 74, and the end point detection of the grinding. Therefore, the end point detection system is limited.

Among the grinding platform 68 and the grinding head 80, there are ~ F people, § an acoustic (tic) / audio (aud i 〇) sensor. The enemy has ~ .., Jin, Zhu (such as acoustic emission (acoustic emission 'AE) sensor Goru · 82, used to receive the vibration frequency and amplitude of the CMP tool. Xixianfeng) 536454 V. Description of the invention (14)' 一 '~ Two computer processing systems 8 4 are used for Record the characteristics associated with the end point of grinding, and process and compare the characteristic data with the vibration frequency and amplitude of the CMP tool transmitted from the acoust ic / audio sensor system 82. Check if the grinding end point is reached. Among them, the data from the sensor system 82 needs to be processed by signals (such as Fourier transform, pattern recognition, or filtering of noise, etc.). ^ Turn

The materials of the first transparent windows 20, 70 and the second transparent windows 24, 74 include resin. In summary, the polishing endpoint detection device and method for the chemical mechanical planarization process proposed by the present invention are summarized as follows: According to one embodiment of the present invention, the proposed polishing endpoint detection method for the chemical mechanical planarization process ( Please refer to Figure 2), including the following steps:

(1) An acoustic / audio sensor 50 'is used to receive the vibration frequency and amplitude of a chemical mechanical polishing device that is polishing a semiconductor wafer 28 film layer, and there is a layer below the film being polished. The structural layer is adjacent to it. (2) transmitting the vibration frequency and amplitude of the chemical mechanical polishing device received by the acoustic / audio sensor 50 to a computer processing system 52, wherein the computer processing system 5 2 has a film recorded Characteristic data accompanying the end point of layer grinding, and this characteristic data includes part of the film layer being worn out, which causes part of the exposed structural layer to be ground, and

536454 V. Description of the invention (15) Vibration characteristics of the exposed structure layer caused by the film layer being worn out. (3) Computer processing system 52. The characteristic data of I1 pass accompanied by the end point of the film polishing and the vibration frequency and amplitude of the chemical mechanical polishing device transmitted from the acoustic / audio sensor 5 are determined. A process and comparison to confirm whether the end point of film grinding has been reached. The method of measuring and testing is based on the method of leveling, and the measurement of the optical path of the machine is completed. The optical path of the wave path is used to improve the performance of the method. Investigate. The bright point comes} The final method III. The grinding chart According to the research test, Cheng Bo asked to make a sound {Detector 82, to receive the vibration frequency and the structural layer of the grinding device under development adjacent to it. audio) The rate and amplitude connected to the sensor 82 are transmitted to a computer 8 4 The end point of the film grinding is recorded, which includes vibration characteristics of a part of the film being worn out and the film being worn out. (The characteristic data accompanied by 3 points and the chemical-processing and comparison from the sensor 8 2 are used to confirm the sound (grind-amplitude [2]) The acoustic wave detection caused by the electro-acoustic sound machinery caused by the processing The method includes the following steps: Acoustic / audio sensing semiconductor wafer 7 8 film layer of chemical machinery 'wherein the polished film layer has an acoustic / audio (frequency) system of a chemical mechanical polishing device 84 Among them, the computer processes the characteristic data accompanying the system, and part of the structural layer exposed by this characteristic data is ground and the exposed structural layer is ground to produce the brain processing system 84. The membrane layer is ground to acoustic / audio ) The vibration frequency and amplitude of the grinding device do

536454

V. Description of the invention (16) Whether the film polishing end point is reached and the light wave detection method includes the following steps: (丨) using a light source 60, emitting light 64, to a semiconductor wafer 78 film being polished by a chemical mechanical polishing device On the floor. (2) A light sensor 62 is used to receive the reflected light 6 6 reflected from the semiconductor wafer 7 8 film layer. (3) Using the computer system Wangli system 84, analyze the relationship between the polishing time of the semiconductor wafer 78 film layer and the reflected light and the intensity of the line 66 to determine the thickness of the film layer being polished. Whether the layer grinding end point is reached. ^ According to Cheng Zhiyan, a speaker is currently researching frequency and connection. (Accompanying special sound (mechanical research film grinding as much as possible guide material 0) According to an embodiment of the present invention, the proposed chemical mechanical planarization grinding end point detection device (refer to Figure 2), including: (丨) (Acoustic) / audio sensor 50, used to receive the vibration amplitude of a chemical mechanical polishing device that grinds a film layer of a semiconductor wafer 46, wherein a structure layer and a phase are formed below the film layer being polished 2) — The computer processing system 52 records the data collected at the end point of the film grinding, and is used to compare the vibration frequency and the vibration frequency of the grinding device transmitted from the characteristic data / audio sensor 50 with the end point of the film grinding. Amplitude making-processing and comparison: whether the end of the grinding has been reached, where this characteristic data includes the part of the structural layer that has been exposed, which has been studied. 73, the layer was ^ / said to absorb the grinding, and the cavity: the temperature-induced exposure Vibration characteristics of structural layer caused by grinding & continuous breaking and grinding

536454 V. Description of the invention (17) According to another embodiment of the present invention, the polishing end-point detection device for the chemical mechanical planarization process (refer to FIG. 3) includes: (^ an acoustic / audio ( audio) A sensor 82 is used to control the vibration frequency and amplitude of a chemical mechanical polishing device that is polishing a film layer of a semiconductor wafer 78. A structure layer is adjacent to the polished film layer. (2) — The computer processing system 84 records the characteristic data accompanying the film polishing end point, and is used to combine the characteristic data accompanying the film polishing end point with the chemical mechanical polishing transmitted from the acoustic / audio sensor 82 The vibration frequency and amplitude of the device are processed and compared to reduce whether the polishing end point of the film layer is reached. The characteristic data includes that part of the film layer is worn out and the exposed structural layer is ground and the film layer is polished. Vibration characteristics of the exposed structural layer due to being worn out. (3) A light source 60, which emits light 64 and is being polished by a chemical mechanical polishing device. On the semiconductor wafer 78 film layer. (4) A light sensor 62 is used to receive the reflected light 6 6 reflected from the semiconductor wafer 7 8 film layer, and to reflect the intensity of the reflected light 6 6 to the semiconductor wafer. 7 8 The time when the film is polished is transmitted to the computer processing system 8 4 Analytical processing is performed to determine the thickness of the film being polished, so it is confirmed whether the end of the film polishing has been reached.

In the embodiment of the above method and device, the acoust ic / audio sensors 50 and 82 include an acoustic emission (AE) sensor or a microphone, which can be placed in a chemical mechanical polishing device. Grinding table 40, 68 or grinding head 48, 80 (or it can also be placed adjacent to grinding heads 48, 80). And the thickness of the film

Page 21 536454 V. Description of the invention (18)-^ -------- The request includes the use of reflected light 6 6 to produce a strong yield; |: day m-milling time-order derivative function off; The circle 7 8 film layer is obtained ... the above-mentioned vibration characteristics; the relationship is divided into two materials. As for the material of the film layer, the material of the film layer includes steel, low-k material with strength versus time (for example, the material of black diamond 7 9 contains T3 3 In addition, acoustic (acoustic / audio f Uck Diamond)). This uses vibration sensing II (for example, laser dob: 1〇) sensor 50, m 'Doppler Vibrometers)) instead of Buhler vibrator ( Laser in this value :: It is mentioned that the non-contact type (that is, the toilet grinding table is not in contact) is used to detect the vibration rate and amplitude of the film during grinding, which is susceptible to the acoustic signals of the adjacent grinding platform. Interference, and if a contact-type (that is, in contact with the grinding platform) acoustic emission sensor is used to detect the vibration frequency and amplitude of the film during grinding, only the grinding signal to be detected can be detected, so There will be microphones to detect interference problems. In addition, using laser Doppler vibration The vibration frequency and amplitude during the measurement of the film layer not only has the advantages of microphone detection, but also does not have the problem of interference with the acoustic signals of the adjacent polishing platform. In this application, the development has been attached to the original, and the exceptions are treated as if they were not applied. When it is true, it is better to decorate it than to modify it; The full version of the Ming Chengshu which is determined to be exclusive and only requested is the same as that of the Ming Cheng. It is necessary to publish its original spirit and set the guards

536454 Brief description of the drawings Using the following descriptions in conjunction with the following drawings will give a clearer understanding of the content and advantages of the present invention, of which: Figure 1 is a system architecture diagram of the grinding end point detection of the traditional chemical mechanical planarization process Figure 2 is a system architecture diagram of the polishing end point detection of a chemical mechanical planarization process according to a preferred embodiment of the present invention; Figure 3 is a proposed chemical system according to another preferred embodiment of the present invention System architecture diagram of grinding end point detection in mechanical planarization process. Drawing number: light source 10, 6 0; light sensor 1 2, 6 2; emitted light 14, 64; reflected light 1, 66, 66; grinding platform 18, 40, 68; first transparent window 2 0, 7 0; Belt 2 2, 4 2, 7 2; Second transparent windows 24, 74; Slurry layers 26, 44, 76; Wafers 2 8, 4 6, 7 8; Grinding heads 30, 48, 80 Acoustic / au di sensor system 50, 8 2; Computer processing system 5 2, 84.

Page 23

Claims (1)

536454 VI. Scope of patent application1. A method for detecting the polishing end point of a chemical mechanical planarization process, the method includes at least the following steps: using an acoustic / audio sensor to receive a semiconductor wafer film being honed Frequency and amplitude of the chemical mechanical polishing vibration of the layer, wherein a structural layer is connected below the film layer, and the vibration frequency and vibration towel of the chemical mechanical polishing device to the acoustic / audio sensor 5 ^ ,,, ° In the processing system, where the computer processing system records the characteristic data accompanying the: II, and the characteristic data contains part of the; and the exposed part of the structural layer is ground, ^ The resulting structure layer was ground is generated by moving = the computer processing system, the film and the sound material (acoustW / audio layer (grinding, point accompanying, the chemical mechanical grinding device) The vibration frequency is equal to 20 sensing states, so it is confirmed whether the polishing end point of the film layer has reached the x field to do a treatment and 2 · As the method of the first scope of the patent application (acoustic) / On the grinding platform or grinding head of the audio-sensing grinding device 3. The method of item 1 in the scope of the patent application, wherein the above-mentioned acoustic / audio sensor includes sound ^^^ 1 , The adjacent device received a computer-compared comparison of the end-milled layer of the end-of-mill layer and the characteristics of the material. “The above-mentioned acoustic detector can be placed on the chemical machine. 536454 6. Acoustic emission (AE) sensor or microphone. 4. The method according to item 1 of the scope of patent application, wherein the above-mentioned vibration characteristic data includes data on changes in volume intensity with time. 5. The method according to item 1 of the scope of patent application, wherein the above method further includes, if the computer processing system cannot rely on the vibration of the chemical mechanical polishing device transmitted from the ac ustic / audio sensor Frequency and amplitude to confirm whether the film polishing end point is reached, then the following steps are performed: using a light source to emit light onto the semiconductor wafer film layer being polished by the chemical mechanical polishing device; using a light sensor A device for receiving the reflected light reflected from the semiconductor wafer film layer; using the computer processing system, analyzing the relationship between the time when the semiconductor wafer film layer is polished and the intensity of the reflected light to obtain the polished film Layer thickness, it was confirmed whether the polishing end point of the film layer was reached. 6. The method according to item 1 of the patent application range, wherein the material of the above-mentioned film layer includes copper, and the material of the structural layer includes TaN or a low dielectric constant material. 7. The method according to item 1 of the scope of patent application, wherein the above-mentioned acoustic (ac 0u s t i c) / audio (aud i 0) sensor can be replaced by a vibration sensor. Page 25 536454 VI. Application for Patent Scope 8 · As in the method for applying for Scope 5 of the Patent Application, wherein the thickness of the film to be polished includes the time for polishing the semiconductor wafer film using the reflected light intensity It is obtained by analyzing the first-order derivative function relationship or the second-order derivative function relationship. 9. The method according to item 6 of the patent application, wherein the low-dielectric-constant material includes black diamond. 10. The method according to item 7 in the scope of patent application, wherein the vibration sensor includes a laser Doppler Vibrometer (Laser Doppler Vibrometers 1 1). A method for detecting a polishing end point of a chemical mechanical planarization process, the method at least The method includes the following steps: The light wave detection method and the sound wave detection method are used simultaneously to perform the grinding end point detection of the chemical mechanical planarization process, wherein the sound wave detection method includes: using an acoustic / audio sensing To receive the vibration frequency and amplitude of a chemical mechanical polishing device that is polishing a semiconductor wafer film layer, wherein a structural layer is adjacent to the film layer below the film layer; and the acoustic (ac 〇ustic) / audio (aud i 〇) The vibration frequency and amplitude of the chemical mechanical polishing device received by the sensor are transmitted to an electric Page 26 536454 6. In the patent processing brain processing system, the computer processing system records the characteristic data accompanying the polishing end point of the film layer, and the characteristic data includes part of the film layer being worn out and exposed. Part of the structure layer is ground, and the film layer is worn out, which causes the exposed structure layer to be ground and the vibration characteristic data generated by the grinding; the computer processing system, the characteristic data accompanying the end point of the film layer grinding and the The vibration frequency and amplitude of the chemical mechanical polishing device transmitted from the acoustic (ac 〇ustic) / audio (audi 〇) sensor are processed and compared to confirm whether the film polishing end point has been reached; and the light wave detection The measuring method includes: ° using a light source to emit light onto the semiconductor wafer film layer being polished by the chemical mechanical polishing device; using a light sensor to receive the reflected light reflected from the semiconductor wafer film layer; The computer processing system is used to analyze the relationship between the polishing time of the semiconductor wafer film layer and the intensity of the reflected light. The film thickness obtained was polished, the polishing layer thus confirmed that the end point has arrived. 1 2. The method according to item 11 of the scope of patent application, wherein the above-mentioned acoustic / audible sensor can be placed on a grinding platform or a grinding head of the chemical mechanical grinding device. 1 3. The method according to item 11 of the scope of patent application, wherein the above-mentioned acoustic (acous t i c) / audio (aud i 〇) sensor includes acoustic emission Page 27 536454 VI. Acoustic emission (AE) sensor or microphone. 14. The method according to item 11 of the scope of patent application, wherein the above-mentioned vibration characteristic data includes data on changes in volume intensity with time. 15. The method according to item 11 of the scope of patent application, wherein the obtaining of the thickness of the film layer to be polished includes using a first-order derivative function relationship of the intensity of the reflected light relative to the time when the semiconductor wafer film layer is polished or It is obtained by analyzing the second-order derivative function. 16. The method according to item 11 of the scope of patent application, wherein the material of the film layer includes copper, and the material of the structure layer includes Ta N or a low dielectric constant material. 1 7. The method according to item 11 of the scope of patent application, wherein the above-mentioned acoustic (a c0 u s t c) / audio (a u d i) sensor can be replaced by a vibration sensor. 18. The method according to item 16 of the scope of patent application, wherein the low-dielectric-constant material includes black diamond. 19. The method according to item 17 of the scope of patent application, wherein the vibration sensor includes a laser Doppler Vibrometer (Laser Doppler Vibrometers) Page 28 536454 VI. Patent application scope 20 · —A kind of grinding end point detection device for chemical mechanical flattening process, the device includes at least: an audio (receiving the frequency and amplitude of a moving while grinding, a computer processing sign data, used to The end point of the vibrating film layer of the acoustic mechanical grinding device is that the material layer is worn out, which leads to the exhaustion of the violent layer, which results in characteristic data. Acoustic / audio semiconductor wafer film layer There is a system under the film layer, which records The end of the film layer grinding / audio (aud i 〇) touch frequency and amplitude do not reach, in which the part of the structure that is exposed by the junction is exposed. The processing and comparison data transmitted by the accompanying special tester, the structure layer, the ground layer, is ground by the grinding sensor, and the pair comes from the accompanying data of the phase point. The vibration is adjacent; the special and the sonic chemical machine confirm the vibration of the film layer and the film 2 1. The device of scope 20 of the patent application, in which the above. us t i c) / audio (aud i 〇) sensor can be placed on the grinding table or grinding head of the chemical mechanical grinding device. 22. The device of claim 20 in the scope of patent application, wherein the above-mentioned acoustic (au c i s) / audio (au d i 〇) sensor comprises an acoustic emission (AE) sensor or a microphone. 2 3 · The device according to item 20 of the scope of patent application, wherein the above-mentioned vibration characteristic data includes data on changes in volume intensity with time. Page 29 536454 6. Application scope of patent 24. The device of scope 20 of the patent application, wherein the above-mentioned device further includes: a light source for emitting light to the semiconductor wafer being polished by the chemical mechanical polishing device Film layer A light sensor is used for receiving the reflected light reflected from the semiconductor wafer film layer, and transmitting the reflected light intensity data and the time when the semiconductor wafer film layer is polished to the computer processing system for analysis and processing, The thickness of the film layer to be polished is determined, so it is confirmed whether the polishing end point of the film layer has been reached. 25. The device according to the scope of application for patent No. 20, wherein the material of the film layer includes copper, and the material of the structure layer includes TaN or a low dielectric constant material. 26. For the device in the scope of application for patent No. 20, the above-mentioned acoustic (ac0u s t c) / audio (aud i 0) sensor can be replaced by a vibration sensor. 2 7. The device according to item 24 of the scope of patent application, wherein the obtaining of the thickness of the film layer to be polished includes using a first-order derivative function relationship of the intensity of the reflected light relative to the time when the semiconductor wafer film layer is polished or It is obtained by analyzing the second-order derivative function. 28. The device according to item 25 of the scope of patent application, in which the above-mentioned low dielectric constant is 536454. 6. Scope of patent application The material includes black diamond. Fan Zhenliler ’s special instructions are to shoot the device. The device containing 9 2 packs 26 items, among which the above-mentioned vibration sensor (Laser Doppler Vibrometers 3 〇 — a type of chemical machine includes at least: a Acoustic (receiving a frequency and amplitude of grinding, a computer-processed sign data, used to end the grinding of the diaphragm layer of an acoustic mechanical grinding device is characterized by being worn out, resulting in the erosion of the storm layer, resulting in characteristic data; a light source A polishing end point detection device for mechanical planarization process, which is equipped with acoustic) / audio semiconductor wafer film layer, and there is a system under the film layer, which records the film polishing end point of the film layer / audio (aud i 〇) moved Whether the frequency and amplitude reach, in which the exposed part of the junction, the structure (audio) is sensed by chemical mechanical polishing, a structural layer and a characteristic layer accompanying the end point of the straight layer grinding. For processing and comparison, the materials include parts produced by grinding the layers and grinding the layers, which are used to connect the vibration of the device; the accompanying special materials and the sound should be confirmed by the chemical machine. The film layer and the vibration generated by the film are used to emit light onto the semiconductor wafer film layer being polished; and a mechanical polishing device is used to receive the semiconductor wafer makeup Xi Mosi # 绿绿 译 5 The intensity of the falling reflected light reflected from the ®m layer is negative. * Inversely, it seems that the multi-layer, lambda semiconductor wafer film layer is suitable for the embedded electronic fine processing system, and the Bayi light sensor reflects the light. And pass the time of grinding to analysis and analysis, in order to 536454 VI. Scope of patent application The thickness of the film layer to be polished is obtained, so it is confirmed whether the grinding end point of the film layer has been reached. 31. The device according to item 30 of the scope of patent application, wherein the above-mentioned acoustic (a c o s t c) / audio (au d i 〇) sensor can be placed on a grinding platform or a grinding head of the chemical mechanical grinding device. 32. The device according to item 30 of the scope of patent application, wherein the above-mentioned acoustic (a c o u s t i c) / audio (au d i 〇) sensor comprises an acoustic emission (AE) sensor or a microphone. 33. The device according to item 30 of the scope of patent application, wherein the above-mentioned vibration characteristic data includes data on changes in volume intensity versus time. 3 4. The device according to item 30 of the scope of patent application, wherein the obtaining of the thickness of the film layer to be polished includes a first-order derivative function relationship or a second-order function using the reflected light intensity with respect to the time when the semiconductor wafer film layer is polished. Derived function relationship analysis. 35. For the device in the scope of patent application No. 30, wherein the material of the film layer includes copper, and the material of the structure layer includes TaN or a low dielectric constant material. 36. For the device in the 30th scope of the patent application, the above-mentioned acoustic (ac 〇u s t i c) / audio (aud i 〇) sensor can use a vibration sensor Page 32 To replace it. 37. Materials such as the patent application range include the device of the 35th diamond factory, including the above-mentioned low-dielectric Black Diamond) constant f. Such as the patent application ^ device including the laser doppler range of the 36th item, where the above Vibration sensing vibrator (Laser Doppler Vibrometers 2 g, one method at least 3, 2 grinds the end point detection method of mechanical flattening process) The following steps are included: 1. Learning of the film layer: to receive the semiconductor wafer being polished Adjacent to the bottom: vibration frequency and amplitude, ... The film layer transmits the dynamic frequency and amplitude received by the vibration sensor to a computer-made, vibrating system of a mechanical grinding device, which records the film polishing final processing system. Among them, the computer-processed data includes some characteristic data of the film layer being abraded, and the characteristic layer is abraded, and part of the film layer exposed by vf is the vibration characteristic data generated by the abrasion of the structure. As a result, the computer processing system of the structural layer that is exposed will process and compare the characteristic rate and amplitude of the characteristic data and amplitudes that come from the vibration sensor with the two = 1 endpoint. Two sub-vibration frequency of the mechanical milling apparatus. Confirm that the film layer to the polishing end point Fan Zhenliler on page 33, please refer to all -φ- Sherui • Contains οο 4 packets} 536454 6. Method of applying for 39 items of patents, among which the above-mentioned vibration sensor (Laser Doppler V i brometers 4 1. A polishing endpoint detection device for a chemical mechanical planarization process, the device includes at least: a vibration sensor for receiving the vibration frequency and amplitude of the chemical mechanical polishing device that is polishing a semiconductor wafer film layer A computer processing system records the characteristic data accompanying the polishing end point of the film layer, and is used to detect the characteristic data accompanying the polishing end point of the film layer and the vibration sensing. The vibration frequency and amplitude of the chemical mechanical polishing device transmitted from the device are processed and compared to confirm whether the polishing end point of the film layer has been reached. The characteristic data includes part of the film layer that is worn out and exposed. Part of the structural layer is ground, and the film layer is worn out, which results in the vibration characteristics of the exposed structural layer being ground. 4 2. Lee scope of a fourth apparatus, wherein the vibration sensor comprises a Doppler laser oscillator (Laser Doppler Vibrometers Page 34