Metal film thickness detection device

Abstract

The utility model relates to the technical field of metal film thickness monitoring, and discloses a metal film thickness detection device, which comprises a control module, a waveform generation module, a sensor, a sampling module and a signal modulation module, and is characterized in that a communication end of the control module receives command signals, and a first output end of the control module is connected with an input end of the waveform generation module; the second output end is connected with the first input end of the signal modulation module; the input end of the waveform generation module inputs driving signals, and the output end of the waveform generation module is connected with the control end of the sensor; the detection end of the sensor covers a detected metal film; the input end of the sampling module is connected with the output end of the sensor, and the output end of the sampling module is connected with the second input end of the signal modulation module; the first input end of the signal modulation module inputs modulation signals, and the output end of the signal modulation module is connected with the input end of the control module. According to the utility model, the bias and amplification parameters of the detection device can be adjusted, so that the detection device can be matched with sensors with different resolutions.

Description

Technical Field

[0001] The utility model relates to the technical field of metal film thickness monitoring, in particular to a metal film thickness detection device. Background Art

[0002] In the integrated circuit manufacturing process, after the wafer substrate conductive film is deposited, it is processed by chemical mechanical inspection process, which can effectively improve the overlay accuracy of the photolithography process. Therefore, the thickness of the conductive film needs to be monitored in real time during the chemical mechanical inspection process, and grinding is stopped at the predetermined thickness value. The chemical mechanical inspection device that detects the real-time ultra-thin film thickness and surface morphology is a special equipment for integrated circuit manufacturing that can optimize the flattening process online.

[0003] At present, the detection methods used for real-time monitoring of chemical mechanical detection devices include light detection, eddy current phase difference and amplitude difference detection, etc. These detection methods all require parameter calibration and matching between hardware, metal film thickness value and sensor.

[0004] When the existing eddy current phase difference and amplitude difference detection device is used, the thickness resolution cannot be adaptively adjusted after calibration, and the detection device cannot flexibly adjust the bias parameters and amplification parameters according to sensors with different resolutions, which has limitations. Utility Model Content

[0005] Therefore, the technical problem to be solved by the present invention is to solve the problem that the metal film thickness detection device in the prior art cannot flexibly adjust the bias parameters and the amplification parameters, thereby providing a metal film thickness detection device.

[0006] In order to achieve the above object, the utility model provides the following technical solutions:

[0007] The utility model provides a metal film thickness detection device, comprising: a control module, a waveform generating module, a sensor, a sampling module and a signal modulation module, wherein the control module, whose communication end receives a command signal, whose first output end is connected to the input end of the waveform generating module, whose second output end is connected to the first input end of the signal modulation module, is used to generate a drive signal and a modulation signal based on the command signal, wherein the command signal represents the need to detect the thickness of the metal film to be measured; the waveform generating module, whose input end inputs the drive signal, whose output end is connected to the control end of the sensor, is used to output an excitation signal of a preset frequency based on the drive signal; the sensor, whose detection end covers the A measuring metal film is used to detect the thickness of the measured metal film based on the excitation signal and then output a corresponding current detection signal; a sampling module, whose input end is connected to the output end of the sensor, and whose output end is connected to the second input end of the signal modulation module, and is used to collect the current detection signal and then output a voltage detection signal; a signal modulation module, whose first input end inputs a modulation signal, and whose output end is connected to the input end of the control module, and is used to adjust its internal bias parameters based on the modulation signal, and after amplifying the voltage detection signal based on the modulation signal and the bias parameter, output an output voltage signal within a preset interval; the control module obtains the thickness of the measured metal film based on the output voltage signal.

[0008] The utility model provides a metal film thickness detection device, in which the signal modulation module can flexibly adjust its internal bias parameters and amplification parameters according to the modulation signal, so as to realize different degrees of bias and amplification of the voltage detection signal, so that the output voltage signal is fixed within a preset voltage. Even when the sensor is replaced with a sensor with a different resolution, the output voltage signal received by the detection device is also within the preset range, that is, sensors of different processes can use the same threshold window of the detection device, which improves the matching degree of the detection device and avoids the problem that the output voltage signal is too large to damage the control module, or the output voltage signal is too small to cause inaccurate detection results.

[0009] In an optional embodiment, the waveform generating module includes: a waveform generating unit, an amplifying unit and an amplitude stabilizing unit, wherein the waveform generating unit, the amplifying unit and the amplitude stabilizing unit are connected in series in sequence, the input end of the waveform generating unit is connected to the first output end of the control module, and the output end of the amplitude stabilizing unit is connected to the control end of the sensor; the waveform generating unit is used to output a sine wave of a preset frequency based on a driving signal, the amplifying unit is used to amplify the amplitude of the sine wave, and the amplitude stabilizing unit is used to control the amplitude of the sine wave to be stable within a preset range.

[0010] The utility model provides a metal film thickness detection device, in which the waveform generation module can stably output a sine wave to the sensor, so that the sensor can stably measure the thickness of the metal film being measured, thereby improving the reliability of the sensor operation.

[0011] In an optional embodiment, the waveform generating module further includes: an adjustable reference unit, whose output end is connected to the first end of the amplitude stabilizing unit and outputs a reference value, so that the amplitude stabilizing unit controls the amplitude of the sine wave to be stable within a preset range based on the reference value.

[0012] The metal film thickness detection device provided by the utility model can flexibly adjust the reference value of the adjustable reference unit according to the resolution of the sensor, thereby controlling the amplitude of the sine wave output by the amplitude stabilization unit to match the normal working state of the sensor, ensuring that different sensors can work under appropriate sinusoidal wave excitation.

[0013] In an optional embodiment, the sensor is an eddy current sensor.

[0014] The metal film thickness detection device provided by the utility model can generate a current related to the thickness of the metal film to be measured under the action of a sine wave. The current size is easy to detect, and it is easier to obtain the corresponding thickness of the metal film to be measured through the current.

[0015] In an optional embodiment, the sampling module includes: a sampling resistor, an amplifier circuit and a first diode, wherein the sampling resistor has a first end connected to the output end of the sensor and a second end connected to the input end of the amplifier circuit, and is used to collect the current detection signal and then input the sampling voltage at its second end into the amplifier circuit; the amplifier circuit has an output end connected to the anode of the first diode and is used to amplify the sampling voltage; the first diode has a cathode connected to the second input end of the signal modulation module and is used to convert the sampling voltage into a DC voltage detection signal.

[0016] In an optional embodiment, the amplification circuit includes: a first operational amplifier, a first resistor, a second resistor and a first capacitor, wherein the first operational amplifier has a positive input terminal connected to the second end of the sampling resistor, the first end of the first resistor and the first end of the first capacitor, a negative input terminal connected to the first end of the second resistor, and an output terminal connected to the anode of the first diode, the second end of the first resistor and the second end of the first capacitor; the second resistor has a second end connected to ground.

[0017] In an optional embodiment, the signal modulation module includes: an analog-to-digital converter, a bias modulation circuit and an amplification modulation circuit, wherein the analog-to-digital converter, whose input end is connected to the second output end of the control module, whose first output end is connected to the first input end of the bias modulation circuit, the output end of the bias modulation circuit and the first input end of the amplification modulation circuit, whose second output end is connected to the second input end of the amplification modulation circuit, and whose power supply end is connected to the first power supply, is used to convert the modulation signal into a first reference voltage signal and a second reference voltage signal; the bias modulation circuit, whose second input end is connected to the output end of the sampling module, is used to output a bias voltage based on the voltage detection signal and the first reference voltage signal; the amplification modulation circuit, whose output end is connected to the input end of the control module, and whose first end is connected to the first end of the analog-to-digital converter, is used to amplify the bias voltage based on the second reference voltage signal and output an output voltage signal.

[0018] The utility model provides a metal film thickness detection device, in which an analog-to-digital converter generates a corresponding first reference voltage signal and a second reference voltage signal based on a modulation signal of a control module, and adjusts a bias parameter of a bias modulation circuit and an amplification parameter of an amplification modulation circuit, thereby biasing and amplifying the voltage detection signal output by the sensor to different degrees, so that the output voltage signal received by the control module is within a preset range, thereby improving the matching degree between the detection device and different sensors, and avoiding the problem of the control module being damaged by overvoltage or the detection result being inaccurate due to an output voltage signal that is too small.

[0019] In an optional embodiment, the bias modulation circuit includes: a second operational amplifier, a second diode, a third resistor, a fourth resistor and a second capacitor, wherein the second operational amplifier, a first input end of which is connected to the cathode of the second diode, the first output end of the analog-to-digital converter, the output end of the second operational amplifier and the first input end of the amplification modulation circuit, and a second input end of which is connected to the first end of the third resistor and the first end of the fourth resistor; the second diode, an anode of which is connected to the second end of the third resistor and then grounded; the fourth resistor, a second end of which is connected to the first end of the second capacitor and the output end of the sampling module; the second capacitor, a second end of which is grounded.

[0020] In an optional embodiment, the amplification and modulation circuit includes: a third operational amplifier and a third capacitor, wherein the third operational amplifier has a first input terminal connected to the output terminal of the second operational amplifier, a second input terminal connected to the second output terminal of the analog-to-digital converter and the first terminal of the third capacitor, and an output terminal connected to the input terminal of the control module; the third capacitor has a second terminal connected to the first terminal of the analog-to-digital converter.

[0021] In an optional implementation, the signal modulation module further includes: a collection unit, whose input end is connected to the output end of the third operational amplifier, and whose output end is connected to the input end of the control module, and is used to convert the output voltage signal into a digital signal.

[0022] In the metal film thickness detection device provided by the utility model, the acquisition unit can convert the output voltage signal of the analog signal into a digital signal, which is convenient for the control module to process. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 A composition diagram of a specific example of a metal film thickness detection device according to an embodiment of the utility model;

[0025] Figure 2 It is a composition diagram of another specific example of the metal film thickness detection device according to the embodiment of the utility model;

[0026] Figure 3 This is a structural diagram of a specific circuit of a metal film thickness detection device according to an embodiment of the utility model. DETAILED DESCRIPTION

[0027] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] This embodiment provides a metal film thickness detection device, such as Figure 1 As shown, it includes: a control module 1, a waveform generating module 2, a sensor 3, a sampling module 4 and a signal modulation module 5.

[0032] like Figure 1 As shown, the control module 1, whose communication end receives the command signal, whose first output end is connected to the input end of the waveform generating module 2, and whose second output end is connected to the first input end of the signal modulation module 5, is used to generate a driving signal and a modulation signal based on the command signal, and the command signal represents the need to detect the thickness of the metal film to be measured.

[0033] Specifically, Figure 1 In the embodiment, the control module 1 is connected to the host computer through the communication interface. When the thickness of the metal film to be measured needs to be detected, the operator sends a driving signal and a modulation signal corresponding to the sensor to the control module 1 through the host computer according to the specifications of the sensor. The driving signal is used to control the operation of the waveform generating module 2, and the modulation signal is used to adjust the internal parameters of the signal modulation module 5 so that the metal film thickness detection device matches the sensor 3.

[0034] Figure 1 In the waveform generating module 2, the input end thereof inputs the driving signal, and the output end thereof is connected to the control end of the sensor 3, and is used for outputting an excitation signal of a preset frequency based on the driving signal.

[0035] Figure 1 In the figure, the sensor 3, whose detection end covers the metal film to be measured, is used to detect the thickness of the metal film to be measured based on the excitation signal and then output a corresponding current detection signal.

[0036] Optionally, Figure 1 In the figure, the sensor 3 is a mature eddy current sensor in the prior art, the excitation signal is a sine wave signal, and the waveform generating module 2 outputs an excitation signal of a preset frequency according to the driving signal.

[0037] Specifically, Figure 1 In the figure, sensor 3 maintains a resonant state under the action of a sinusoidal wave signal. When sensor 3 is close to the metal film to be measured, sensor 3 excites the metal film to be measured to generate eddy current. At the same time, the eddy current in the metal film will again generate an induced electromotive force inside sensor 3. Sensor 3 then outputs a current detection signal corresponding to the induced electromotive force. That is, when the thickness of the metal film to be measured is different, the magnitude of the induced electromotive force is different, and the corresponding current detection signal output by sensor 3 is also different.

[0038] Figure 1 In the example, the sampling module 4 has an input end connected to the output end of the sensor 3 and an output end connected to the second input end of the signal modulation module 5, and is used to collect the current detection signal and then output a voltage detection signal.

[0039] Figure 1 In the figure, the signal modulation module 5 has a first input terminal that inputs a modulation signal, and an output terminal that is connected to the input terminal of the control module 1. The signal modulation module 5 is used to adjust its internal bias parameters based on the modulation signal, and amplify the voltage detection signal based on the modulation signal and the bias parameters, and then output an output voltage signal within a preset interval. The control module 1 obtains the thickness of the metal film to be measured based on the output voltage signal.

[0040] Specifically, Figure 1 In the embodiment, when the sensor 3 fails or needs to be replaced with a sensor of other resolutions due to other reasons, the relationship between the voltage detection signal output by the sensor 3 and the thickness of the metal film to be measured will change, and the output voltage signal received by the control module 1 may exceed the tolerance range of its receiving end. In order to avoid the output voltage signal being too high to damage the control module 1, or the output voltage signal being too low to cause the control module 1 to be unable to recognize, the operator can control the control module 1 to output the corresponding modulation signal according to the resolution or other parameters of the sensor 3. The signal modulation module 5 adjusts the internal bias parameters and amplification parameters according to the modulation signal, thereby amplifying the voltage detection signal to different degrees, so that the output voltage signal after amplification is within the preset range of the input end of the control module 1, that is, the control module 1 can adapt to the process requirements of sensors with different resolutions, and use the same threshold window to receive the detection parameters of the metal film thickness to be measured by sensors with different resolutions, thereby improving the adaptability of the metal film thickness detection device and expanding the scope of use.

[0041] It should be noted that the control module 1 in this embodiment has a built-in program control method for metal film thickness detection in the prior art. Those skilled in the art can control the control module 1 to output a suitable drive signal and modulation signal according to the mature metal film thickness detection program in the prior art, combined with the process parameters of the sensor 3, adjust the sine wave frequency and amplitude output by the waveform generation module 2, and adjust the bias parameters and amplification parameters of the signal modulation module 5. At the same time, the corresponding relationship between the output voltage signal and the thickness of the metal film to be measured is pre-stored in the detection program, so that the control module 1 can obtain the thickness of the metal film to be measured according to the output voltage signal. That is, this embodiment only protects the structure of the metal film thickness detection device, and does not protect the detection method involved in the metal film thickness detection device.

[0042] The metal film thickness detection device provided in this embodiment has a signal modulation module that can flexibly adjust its internal bias parameters and amplification parameters according to the modulation signal, thereby realizing different degrees of bias and amplification of the voltage detection signal, so that the output voltage signal is fixed within a preset voltage. Even when the sensor is replaced with a sensor of a different resolution, the output voltage signal received by the detection device is also within the preset range, that is, sensors of different processes can use the same threshold window of the detection device, thereby improving the matching degree of the detection device and avoiding the problem of the output voltage signal being too large to damage the control module, or the output voltage signal being too small to cause inaccurate detection results.

[0043] In some optional embodiments, such as Figure 2 As shown, the waveform generating module 2 includes: a waveform generating unit 21, an amplifying unit 22 and an amplitude stabilizing unit 23, wherein the waveform generating unit 21, the amplifying unit 22 and the amplitude stabilizing unit 23 are connected in series in sequence, the input end of the waveform generating unit 21 is connected to the first output end of the control module 1, and the output end of the amplitude stabilizing unit 23 is connected to the control end of the sensor 3; the waveform generating unit 21 is used to output a sine wave of a preset frequency based on a driving signal, the amplifying unit 22 is used to amplify the amplitude of the sine wave, and the amplitude stabilizing unit 23 is used to control the amplitude of the sine wave to be stable within a preset range.

[0044] Optionally, Figure 2 In the figure, the waveform generating unit 21 is an arbitrary waveform generator based on direct digital synthesis technology (Direct Digital Synthesis, DDS), the amplifying unit 22 is a power amplifier, and the amplitude stabilizing unit 23 is an automatic gain control (Automatic Generation Control, AGC). The types and models of each unit in the waveform generating module 2 are only used as examples and are not limited in sequence.

[0045] Specifically, Figure 2In the embodiment, the waveform generating unit 21 outputs a sine wave of a preset frequency according to the driving signal of the control module 1. The sine wave is power-amplified by the amplifying unit 22 in turn, and the amplitude of the amplified sine wave is stabilized within a suitable range by the amplitude stabilizing unit 23, thereby ensuring that the sensor 3 can work normally under the action of the sine wave.

[0046] Optionally, Figure 2 In the waveform generating module 2, the waveform generating module 2 also includes: an adjustable reference unit 24, whose output end is connected to the first end of the amplitude stabilizing unit 23 and outputs a reference value, so that the amplitude stabilizing unit 23 controls the amplitude of the sine wave to be stable within a preset range based on the reference value. The operator can adjust the amplitude stabilizing interval of the amplitude stabilizing unit 23 by adjusting the reference value of the adjustable reference unit 24, thereby adjusting the amplitude of the sine wave to adapt to sensors 3 of different processes.

[0047] In some optional embodiments, such as Figure 3 As shown, the sampling module 4 includes: a sampling resistor R0, an amplifier circuit 41 and a first diode D1, wherein the sampling resistor R0, a first end of which is connected to the output end of the sensor 3, and a second end of which is connected to the input end of the amplifier circuit 41, is used to collect the current detection signal and then input the sampling voltage at its second end to the amplifier circuit 41; the amplifier circuit 41, an output end of which is connected to the anode of the first diode D1, is used to amplify the sampling voltage; the first diode D1, a cathode of which is connected to the second input end of the signal modulation module 5, is used to convert the sampling voltage into a DC voltage detection signal Usi.

[0048] Specifically, Figure 3 As shown, the amplifier circuit 41 includes: a first operational amplifier U1, a first resistor R1, a second resistor R2 and a first capacitor C1, wherein the first operational amplifier U1 has a positive input terminal connected to the second end of the sampling resistor R0, the first end of the first resistor R1 and the first end of the first capacitor C1, a negative input terminal connected to the first end of the second resistor R2, and an output terminal connected to the anode of the first diode D1, the second end of the first resistor R1 and the second end of the first capacitor C1; the second resistor R2 has a second end connected to ground.

[0049] Specifically, Figure 3 In the figure, when the sensor 3 outputs a current detection signal, the current detection signal passes through the sampling resistor R0, and an AC sampling voltage is generated at both ends of the sampling resistor R0. The sampling voltage is input to the positive input end of the first operational amplifier U1 for amplification, and then rectified by the first diode D1 and converted into a voltage detection signal Usi.

[0050] In some optional embodiments, such as Figure 3As shown, the signal modulation module 5 includes: an analog-to-digital converter 51, a bias modulation circuit 52 and an amplification modulation circuit 53, wherein the analog-to-digital converter 51 has its input end connected to the second output end of the control module 1, its first output end connected to the first input end of the bias modulation circuit 52, the output end of the bias modulation circuit 52 and the first input end of the amplification modulation circuit 53, its second output end connected to the second input end of the amplification modulation circuit 53, and its power supply end A connected to the first power supply 2.5V, which is used to convert the modulation signal into a first reference voltage signal Ua and a second reference voltage signal Ub.

[0051] Specifically, Figure 3 In the embodiment, the bias modulation circuit 52 includes: a second operational amplifier U2, a second diode D2, a third resistor R3, a fourth resistor R4 and a second capacitor C2, wherein the second operational amplifier U2, a first input end thereof is connected to the cathode of the second diode D2, the first output end of the analog-to-digital converter 51, the output end of the second operational amplifier U2 and the first input end of the amplification modulation circuit 53, and a second input end thereof is connected to the first end of the third resistor R3 and the first end of the fourth resistor R4; the second diode D2, an anode thereof is connected to the second end of the third resistor R3 and then grounded; the fourth resistor R4, a second end thereof is connected to the first end of the second capacitor C2 and the output end of the sampling module 4; the second capacitor C2, a second end thereof is grounded.

[0052] Specifically, Figure 3 In the embodiment, the operator can set the control module 1 to output the modulation signal to the analog-to-digital converter 51 according to the process parameters of the sensor 3 and the required bias amount. The analog-to-digital converter 51 converts the modulation signal into a first reference voltage signal Ua and inputs it to the reverse input terminal of the second operational amplifier U2 through the CHA channel. At the same time, the voltage detection signal Usi is input to the positive input terminal of the second operational amplifier U2 after being divided by the third resistor R3 and the fourth resistor R4. At this time, the output terminal of the second operational amplifier U2 outputs the bias voltage U2o.

[0053]

[0054]

[0055] Among them, Amax_code is the maximum design range of the analog-to-digital converter 51, Aset_code is the required bias value set by the operator through the control module 1, Usi is the empty stability value, and the operator can adjust the size of the first reference voltage signal Ua by controlling the modulation signal output by the control module 1, thereby controlling the size of the bias voltage U2o.

[0056] Figure 3In the figure, the bias modulation circuit 52, whose second input terminal is connected to the output terminal of the sampling module 4, is used to output the bias voltage U2o based on the voltage detection signal Usi and the first reference voltage signal Ua; the amplification modulation circuit 53, whose output terminal is connected to the input terminal of the control module 1, and whose first terminal is connected to the first terminal of the analog-to-digital converter 51, is used to amplify the bias voltage U2o based on the second reference voltage signal Ub and output the output voltage signal Usio.

[0057] Specifically, Figure 3 In the figure, the amplification modulation circuit 53 includes: a third operational amplifier U3 and a third capacitor C3, wherein the third operational amplifier U3 has a first input terminal connected to the output terminal of the second operational amplifier U2, a second input terminal connected to the second output terminal of the analog-to-digital converter 51 and a first terminal of the third capacitor C3, and an output terminal connected to the input terminal of the control module 1; the third capacitor C3 has a second terminal connected to the first terminal B of the analog-to-digital converter 51.

[0058] Specifically, Figure 3 In the embodiment, the bias voltage U2o is input to the positive input terminal of the third operational amplifier U3. The operator can set the control module 1 to output the modulation signal to the analog-to-digital converter 51 according to the process parameters of the sensor 3 and the required amplification amount. The analog-to-digital converter 51 also converts the modulation signal into a second reference voltage signal Ub and inputs it to the reverse input terminal of the third operational amplifier U3 through the CHB channel. The third capacitor C4 is connected between the reverse input terminal and the output terminal of the third operational amplifier U3 as an isolation device. At this time, the output terminal of the third operational amplifier U3 outputs the output voltage signal Usio.

[0059]

[0060] Among them, Bmax_code is the maximum design range of the analog-to-digital converter 51, which is equal to Amax_code, and Bset_code is the required amplification amount set by the operator through the control module 1. The operator can adjust the size of the second reference voltage signal Ub by controlling the modulation signal output by the control module 1, thereby controlling the size of the output voltage signal Usio.

[0061] Optionally, Figure 3 In the figure, the signal modulation module also includes: an acquisition unit 54, whose input end is connected to the output end of the third operational amplifier U3, and whose output end is connected to the input end of the control module 1, which is used to convert the output voltage signal Usio into a digital signal and then combine it into the measured metal film parameters in the control module 1. The measured metal film parameters include the thickness value, eddy current size, phase difference, amplitude and other information of the measured metal film. The measured metal film parameters are then sent to the host computer through the communication interface, so that the operator can obtain relevant information of the measured metal film through the host computer.

[0062] For example, in combination Figure 3 When replacing the sensor 3 in the metal film thickness detection device, since the resolution and other process parameters of the sensor 3 change, in order to make the sensor 3 match with other devices in the metal film thickness detection device and avoid the output voltage signal Usio exceeding the limit value of the input end of the control module 1, the operator can perform the following calibration steps on the metal film thickness detection device:

[0063] (1) Connect the new sensor 3 to the waveform generating module 2 and the sampling module 4, install the sensor 3 in the metal film thickness detection device, keep the detection plane of the sensor 3 level with the detection platform plane, and keep the sensor 3 free of metal objects outside. At this time, do not place the metal film to be measured.

[0064] (2) The operator controls the control module 1 through the host computer to send a modulation signal, so that the bias parameter of the signal modulation module 5 read by the host computer is 0 and the amplification parameter is 1, and then reads the air data Uair of the host computer.

[0065] (3) The bias voltage U2o of the signal modulation module 5 is adjusted by the modulation signal, so that the value of the air data Uair in the host computer becomes 0 or close to 0.

[0066] (4) A metal film with a known maximum process detection thickness value ΔH is taken to cover the sensor 3, completely shielding the sensor 3, and the pressure plate is evenly pressed on the surface of the metal film using the gravity equivalent to the pressure during the polishing process. After ensuring that the detection distance between the metal film and the sensor 3 is consistent with the detection distance in the subsequent polishing process, the maximum range data Uhigh of the host computer is read. Uhigh is the detected data corresponding to the maximum metal film thickness value ΔH of the process detection.

[0067] (5) Calculate the amplification parameter value, Umax is the maximum supported range value of the hardware design of the metal film thickness detection device, and the amplification parameter X = 0.8Umax / Uhigh.

[0068] (6) Adjust the amplification parameter X and set the amplification parameter of the signal modulation module 5.

[0069] (7) Check the air data Uair and the maximum range data Uhigh. If the parameters set by the control module 1 have been sent down and executed correctly, the air data Uair should be 0, and the maximum range data Uhigh should be close to 0.8 times the maximum supported range value Umax. After that, the calibration is completed and the subsequent metal film thickness detection process is started.

[0070] It should be noted that the control module 1 has a built-in program control method for metal film thickness detection in the prior art. Those skilled in the art can control the control module 1 to output a suitable drive signal and modulation signal according to the mature metal film thickness detection program in the prior art, combined with the process parameters of the sensor 3, to adjust the sine wave frequency and amplitude output by the waveform generation module 2, and to adjust the bias parameters and amplification parameters of the signal modulation module 5. And the control module 1 obtains the measured metal film parameters according to the output voltage signal Usio, which is a mature function in the relevant metal film thickness detection program, that is, this embodiment only protects the structure of the metal film thickness detection device, and does not protect the detection method involved in the metal film thickness detection device.

[0071] Although the embodiments of the present invention are 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 appended claims.

Claims

1. A metal film thickness detection device, characterized in that: include: Control module, waveform generation module, sensor, sampling module and signal modulation module, wherein: A control module, whose communication end receives a command signal, whose first output end is connected to the input end of the waveform generating module, and whose second output end is connected to the first input end of the signal modulating module, and which is used to generate a driving signal and a modulation signal based on the command signal, wherein the command signal indicates that the thickness of the metal film to be measured needs to be detected; A waveform generating module, whose input end is input with the driving signal, whose output end is connected with the control end of the sensor, and which is used to output an excitation signal of a preset frequency based on the driving signal; A sensor, whose detection end covers the metal film to be detected, and is used to detect the thickness of the metal film to be detected based on the excitation signal and then output a corresponding current detection signal; A sampling module, whose input end is connected to the output end of the sensor, and whose output end is connected to the second input end of the signal modulation module, and is used to output a voltage detection signal after collecting the current detection signal; a signal modulation module, wherein the modulation signal is input to a first input terminal thereof, and an output terminal thereof is connected to an input terminal of the control module, and is used for adjusting an internal bias parameter thereof based on the modulation signal, and amplifying the voltage detection signal based on the modulation signal and the bias parameter, and then outputting an output voltage signal within a preset range; The control module obtains the thickness of the measured metal film based on the output voltage signal.

2. The metal film thickness detection device according to claim 1, characterized in that: The waveform generation module includes: a waveform generation unit, an amplification unit and an amplitude stabilization unit, wherein: The waveform generating unit, the amplifying unit and the amplitude stabilizing unit are connected in series in sequence, the input end of the waveform generating unit is connected to the first output end of the control module, and the output end of the amplitude stabilizing unit is connected to the control end of the sensor; The waveform generating unit is used to output a sine wave of a preset frequency based on the driving signal, the amplifying unit is used to amplify the amplitude of the sine wave, and the amplitude stabilizing unit is used to control the amplitude of the sine wave to be stable within a preset range.

3. The metal film thickness detection device according to claim 2, characterized in that: The waveform generation module also includes: The adjustable reference unit has an output end connected to the first end of the amplitude stabilizing unit and outputs a reference value, so that the amplitude stabilizing unit controls the amplitude of the sine wave to be stable within a preset range based on the reference value.

4. The metal film thickness detection device according to claim 1, characterized in that: The sensor is an eddy current sensor.

5. The metal film thickness detection device according to claim 1, characterized in that: The sampling module includes: a sampling resistor, an amplifier circuit and a first diode, wherein: A sampling resistor, a first end of which is connected to the output end of the sensor, and a second end of which is connected to the input end of the amplifier circuit, and is used to input the sampling voltage at its second end into the amplifier circuit after collecting the current detection signal; an amplifier circuit, whose output end is connected to the anode of the first diode, and is used to amplify the sampled voltage; The first diode, whose cathode is connected to the second input end of the signal modulation module, is used for converting the sampling voltage into the direct current voltage detection signal.

6. The metal film thickness detection device according to claim 5, characterized in that: The amplifying circuit includes: a first operational amplifier, a first resistor, a second resistor and a first capacitor, wherein: a first operational amplifier, wherein a positive input terminal of the first operational amplifier is connected to the second end of the sampling resistor, the first end of the first resistor and the first end of the first capacitor, a negative input terminal of the first operational amplifier is connected to the first end of the second resistor, and an output terminal of the first operational amplifier is connected to the anode of the first diode, the second end of the first resistor and the second end of the first capacitor; The second resistor has a second end connected to the ground.

7. The metal film thickness detection device according to claim 1, characterized in that: The signal modulation module includes: an analog-to-digital converter, a bias modulation circuit and an amplification modulation circuit, wherein: an analog-to-digital converter, whose input end is connected to the second output end of the control module, whose first output end is connected to the first input end of the bias modulation circuit, the output end of the bias modulation circuit and the first input end of the amplification modulation circuit, whose second output end is connected to the second input end of the amplification modulation circuit, and whose power supply end is connected to the first power supply, and which is used to convert the modulation signal into a first reference voltage signal and a second reference voltage signal; a bias modulation circuit, whose second input terminal is connected to the output terminal of the sampling module, and which is used to output a bias voltage based on the voltage detection signal and the first reference voltage signal; The amplification modulation circuit has an output end connected to the input end of the control module and a first end connected to the first end of the analog-to-digital converter, and is used to amplify the bias voltage based on the second reference voltage signal and then output an output voltage signal.

8. The metal film thickness detection device according to claim 7, characterized in that: The bias modulation circuit includes: a second operational amplifier, a second diode, a third resistor, a fourth resistor and a second capacitor, wherein: A second operational amplifier, a first input end of which is connected to the cathode of the second diode, the first output end of the analog-to-digital converter, the output end of the second operational amplifier and the first input end of the amplification modulation circuit, and a second input end of which is connected to the first end of the third resistor and the first end of the fourth resistor; a second diode, an anode of which is connected to the second end of the third resistor and then grounded; a fourth resistor, a second end of which is connected to the first end of the second capacitor and the output end of the sampling module; The second capacitor has a second terminal connected to the ground.

9. The metal film thickness detection device according to claim 8, characterized in that: The amplification modulation circuit includes: a third operational amplifier and a third capacitor, wherein: a third operational amplifier, wherein a first input terminal of the third operational amplifier is connected to the output terminal of the second operational amplifier, a second input terminal of the third operational amplifier is connected to the second output terminal of the analog-to-digital converter and the first terminal of the third capacitor, and an output terminal of the third operational amplifier is connected to the input terminal of the control module; A third capacitor has a second end connected to the first end of the analog-to-digital converter.

10. The metal film thickness detection device according to claim 9, characterized in that: The signal modulation module also includes: The acquisition unit has an input end connected to the output end of the third operational amplifier and an output end connected to the input end of the control module, and is used to convert the output voltage signal into a digital signal.

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