A high-frequency vibrator driving device and a wafer cleaning equipment

Abstract

The application relates to a high-frequency vibrator driving device for wafer cleaning and a wafer cleaning equipment. The high-frequency vibrator driving device comprises an interaction module for establishing communication and control connection with an upper computer; a logic controller electrically connected with the interaction module; a signal processing module controlled by the logic controller and used for outputting a driving waveform signal to the high-frequency vibrator under the control of a control signal; an impedance adaptation module electrically connected with the signal processing module at one end and electrically connected with the logic controller at the other end, used for adjusting the impedance of the signal processing module; and a feedback device electrically connected with the signal processing module at one end and electrically connected with the logic controller at the other end, used for collecting the phase and amplitude of the driving waveform signal and feeding back to the logic controller. The wafer cleaning equipment for wafer cleaning comprises a cleaning tank, a high-frequency vibrator, an upper computer and the high-frequency vibrator driving device. The high-frequency vibrator driving device has high vibrator driving efficiency and small waveform distortion.

Description

Technical Field

[0001] This invention relates to the field of semiconductor cleaning technology, and in particular to a high-frequency oscillator driving device and wafer cleaning equipment for wafer cleaning. Background Technology

[0002] In semiconductor wafer cleaning processes, high-frequency oscillators are widely used to remove particulate contaminants from the wafer surface. They are typically driven by a combination of signal generator and power amplifier.

[0003] In existing technologies, high-frequency oscillators are typically driven using a combination of discrete devices, such as connecting independent signal generators and independent power amplifiers via cables. This approach suffers from large size and low integration; multiple discrete devices each have their own independent housing, power module, and heat dissipation structure, resulting in a large overall rack space requirement. This makes it difficult to adapt to the compact layout requirements of semiconductor cleaning equipment, leading to wasted space resources. Furthermore, the control methods for high-frequency oscillators are limited and difficult to adapt to various scenarios. In particular, existing devices typically only support a single communication control method and lack digital hard-wired control interfaces, resulting in insufficient flexibility in cleaning scenarios requiring rapid start-stop or simple gear switching, failing to meet cleaning needs. Simultaneously, the discrete configuration of existing drive devices leads to long signal links and numerous interfaces, resulting in significant signal attenuation and noise introduction. Moreover, existing general-purpose power amplifiers struggle to simultaneously achieve high bandwidth, high amplitude output, and low gain fluctuations under load conditions, resulting in low oscillator driving efficiency and high waveform distortion.

[0004] Therefore, it is necessary to provide a new high-frequency oscillator driving device and wafer cleaning equipment for wafer cleaning to solve the above-mentioned problems existing in the prior art. Summary of the Invention

[0005] The technical problem to be solved by this application is how to provide a high-frequency oscillator driving device and wafer cleaning equipment with high oscillator driving efficiency and low waveform distortion for wafer cleaning.

[0006] To address the aforementioned technical problems, according to embodiments of this application, a high-frequency oscillator driving device for wafer cleaning is provided, comprising: an interaction module for establishing a communication and control connection with a host computer to receive control commands from the host computer; a logic controller electrically connected to the interaction module to parse the control commands and generate control signals; a signal processing module controlled by the logic controller to output a driving waveform signal to the high-frequency oscillator under the control of the control signals; an impedance adaptation module, one end electrically connected to the signal processing module and the other end electrically connected to the logic controller to adjust the impedance of the signal processing module; and a feedback unit, one end electrically connected to the signal processing module and the other end electrically connected to the logic controller to acquire the phase and amplitude of the driving waveform signal and feed it back to the logic controller.

[0007] According to an embodiment of this application, the interaction module includes a communication device and an input signal device; the communication device and the input signal device are respectively connected to the host computer and electrically connected to the logic controller; the communication device is used to establish a communication network with the host computer, and the input signal device is used to receive control commands from the host computer.

[0008] According to an embodiment of this application, the signal processing module includes a signal generator, a programmable amplifier, a power amplifier, and a boost converter connected in sequence, and both the signal generator and the programmable amplifier are electrically connected to the logic controller; wherein, the signal generator is used to generate the driving waveform signal, the programmable amplifier is used to adjust the amplitude of the waveform signal, the power amplifier is used to amplify the power of the amplitude-adjusted driving waveform signal, and the boost converter is used to increase the output amplitude and provide electrical isolation to the power-amplified driving waveform signal.

[0009] According to an embodiment of this application, the output terminal of the signal generator is provided with a low-pass filter to make the driving waveform signal smooth; the programmable gain amplifier is a programmable gain amplifier to adjust the noise amplitude of the driving waveform signal under the control of the logic controller.

[0010] According to an embodiment of this application, the low-pass filter is a seventh-order passive elliptic low-pass filter circuit.

[0011] According to an embodiment of this application, the impedance adaptation module is a variable capacitor array, which is disposed between the programmable amplifier and the power amplifier and electrically connected to both respectively. The variable capacitor array is also electrically connected to the logic controller to adjust the equivalent capacitance value between the programmable amplifier and the power amplifier stage under the control of the logic controller.

[0012] According to an embodiment of this application, the variable capacitor array includes a plurality of fixed capacitors and a digital switch corresponding to each fixed capacitor; one end of each fixed capacitor is electrically connected to the line between the programmable amplifier and the power amplifier, and the other end is electrically connected to the ground terminal through the corresponding digital switch; wherein, the logic controller is controlled and connected to the digital switch, and is used to change the number and combination of fixed capacitors connected to the ground terminal by controlling the on / off state of each digital switch, so as to adjust the capacitance value of the output terminal of the programmable amplifier and achieve impedance matching between the programmable amplifier and the power amplifier.

[0013] According to an embodiment of this application, the feedback circuit includes a sampling circuit, a phase detection circuit, and an amplitude detection circuit; the input terminal of the sampling circuit is electrically connected to the output terminal of the boost converter to acquire the driving waveform signal; the input terminal of the phase detection circuit is electrically connected to the output terminal of the sampling circuit to detect the phase of the driving waveform and generate a phase feedback signal; the input terminal of the amplitude detection circuit is electrically connected to the output terminal of the sampling circuit to detect the amplitude of the driving waveform and generate an amplitude feedback signal; the output terminals of the phase detection circuit and the amplitude detection circuit are respectively electrically connected to the logic controller to transmit the phase feedback signal and the amplitude feedback signal to the logic controller.

[0014] According to an embodiment of this application, the sampling circuit includes a first resistor and a second resistor; one end of the first resistor is electrically connected to the output terminal of the boost converter; one end of the second resistor is electrically connected to the other end of the first resistor through a line to form a sampling node, and the other end of the second resistor is grounded; the input terminal of the phase detection circuit and the input terminal of the amplitude detection circuit are respectively electrically connected to the sampling node.

[0015] A wafer cleaning device includes a cleaning tank, a high-frequency oscillator, a host computer, and a high-frequency oscillator drive device. The cleaning tank contains cleaning fluid and a wafer to be cleaned. The high-frequency oscillator is disposed in the cleaning tank and electrically connected to the output terminal of the high-frequency oscillator drive device to generate high-frequency vibration under the drive of the high-frequency oscillator drive device to clean the wafer. The host computer is connected to the interaction module of the high-frequency oscillator drive device for communication and control, and is used to send control commands to the high-frequency oscillator drive device.

[0016] By adopting the above technical solution, the interaction module, logic controller, signal generator, programmable amplifier, power amplifier, boost converter, impedance adaptation module, and feedback unit are integrated into a single device, replacing the traditional combination of multiple discrete devices. This significantly reduces the system size and improves integration, while lowering hardware costs and space requirements. The high-resolution frequency output of the signal generator, combined with a seventh-order passive elliptic low-pass filter, low-noise gain adjustment of the programmable amplifier, high-bandwidth high-slew rate and low-gain fluctuation characteristics of the power amplifier, and high-amplitude output and electrical isolation of the boost converter, satisfies the requirements of the high-frequency oscillator for high amplitude and low loss of impedance. The requirement for true drive waveforms is met; by setting a variable capacitor array dynamically adjusted by a logic controller between the programmable amplifier and the power amplifier, impedance adaptive matching is achieved, effectively suppressing power reflection, VSWR degradation and signal distortion caused by gain switching, and ensuring efficient power transmission; the phase and amplitude of the output waveform are collected by the feedback device and the output frequency, gain and equivalent capacitance value are adjusted by the logic controller in a closed loop, so that the oscillator always works near the resonant point, which significantly improves the electroacoustic conversion efficiency and cleaning stability, while avoiding the risk of overheating damage to the oscillator due to detuning, thereby improving the uniformity and yield of wafer cleaning as a whole. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the internal component connection relationship of a high-frequency oscillator driving device according to an embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram showing the connection relationship of the internal components of an impedance adaptation module according to an embodiment of the present invention.

[0019] Figure 3 This is a schematic diagram showing the connection relationship of the internal components of a feedback device according to an embodiment of the present invention.

[0020] Figure label: C1, First capacitor; C2, Second capacitor; C3, Third capacitor; C4, Fourth capacitor; S1, First switch; S2, Second switch; S3, Third switch; S4, Fourth switch; 10, First resistor; 20, Second resistor; 30, Zero-crossing comparator; 40, Phase detector; 50, Detector diode; 60, Detector capacitor; 70, Detector resistor. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.

[0022] The following is in conjunction with the appendix Figures 1-3 The specific embodiments of the present invention will be further described in detail below.

[0023] In semiconductor wafer cleaning processes, high-frequency transducers (such as ultrasonic or megasonic transducers) are widely used to remove particulate contaminants from wafer surfaces. In existing technologies, the driving of high-frequency transducers typically employs a combination of discrete devices, such as connecting independent signal generators and independent power amplifiers via cables. This approach suffers from large size and low integration; multiple discrete devices each have independent housings, power modules, and heat dissipation structures, resulting in a large overall rack space requirement and making it difficult to adapt to the compact layout requirements of semiconductor cleaning equipment, thus wasting space resources. Furthermore, the control methods for high-frequency transducers are limited and difficult to adapt to various scenarios. In particular, existing devices typically only support a single communication control method and lack digital hard-wired control interfaces, resulting in insufficient flexibility in cleaning scenarios requiring rapid start / stop or simple gear switching, failing to meet cleaning needs. Simultaneously, the discrete configuration of existing drive devices leads to long signal links and numerous interfaces, resulting in significant signal attenuation and noise introduction. Moreover, existing general-purpose power amplifiers struggle to simultaneously achieve high bandwidth, high amplitude output, and low gain fluctuations under load conditions, leading to low transducer driving efficiency and significant waveform distortion.

[0024] To address the aforementioned deficiencies, embodiments of the present invention provide a high-frequency oscillator driving device and a wafer cleaning equipment for wafer cleaning. The wafer cleaning equipment is used to clean wafers, while the high-frequency oscillator driving device is used to drive the high-frequency oscillator within the wafer cleaning equipment to rotate, thereby facilitating the wafer cleaning process. Specifically, the high-frequency oscillator driving device includes an interaction module, a logic controller, a signal processing module, an impedance adaptation module, and a feedback unit. By integrating the above devices into a single device, the size is reduced, thus minimizing space requirements.

[0025] In some embodiments, the interaction module is used to establish a communication and control connection with the host computer to receive control commands from the host computer. The interaction module adopts existing communication methods to establish a communication connection with the host computer, solving the problem that existing high-frequency oscillator drive devices cannot be directly networked with existing equipment or require the addition of communication devices. At the same time, the interaction module is compatible with digital input and can adapt to more application scenarios. The logic controller is electrically connected to the interaction module to parse control commands and generate control signals. The logic controller interacts with the host computer through the interaction module or receives output commands from the host computer through digital input, which can achieve fast response. Through centralized scheduling by a single logic controller, the response delay between functional modules is reduced. The signal processing module is controlled by the logic controller to output drive waveform signals to the high-frequency oscillator under the control of the control signals. The signal processing module can perform waveform generation, amplitude adjustment, and other functions. Power amplification and boost isolation meet the requirements of high-frequency oscillators for high-amplitude (≥200Vpp) and low-distortion (≤1.2dB) drive waveforms, with a drive amplitude reaching up to 240Vpp. An impedance adaptation module is electrically connected to the signal processing module at one end and to the logic controller at the other to adjust the impedance of the signal processing module. This module dynamically adjusts the equivalent capacitance between components within the signal processing module to compensate for impedance mismatch caused by gain changes, suppressing power transmission loss and signal distortion, thereby ensuring efficient power transmission. A feedback unit is electrically connected to the signal processing module at one end and to the logic controller at the other to acquire the phase and amplitude of the drive waveform signal and feed it back to the logic controller. The feedback unit and logic controller form a closed loop, using phase detection to control the resonant frequency of the high-frequency oscillator, ensuring the oscillator always operates near the resonant point, thus improving the stability of wafer cleaning.

[0026] In some specific embodiments, the interaction module includes a communication device and an input signal device. The communication device and the input signal device are electrically connected to a host computer and also electrically connected to a logic controller. The communication device is used to establish a communication network with the host computer, and the input signal device is used to receive control commands from the host computer. Specifically, existing high-frequency oscillator drive devices mostly use dedicated communication protocols, such as RS-485 and CAN, which create protocol barriers with existing devices using industrial Ethernet protocols such as EtherCAT. This results in the inability to directly network or the need for additional protocol conversion gateways, increasing system complexity and communication latency. Therefore, in this embodiment, the communication device uses EtherCAT communication. Since the EtherCAT protocol is consistent with the communication methods of existing equipment in the semiconductor cleaning field, the high-frequency oscillator drive device in this embodiment can directly network with existing host computers without the need for additional protocol conversion gateways. This solves the problem that existing high-frequency oscillator drive devices cannot directly network with existing host computers or require additional communication devices, reducing system complexity and communication latency, and saving hardware costs. In addition, the input signal device is a digital input module. In this embodiment, the host computer sends control commands through 4 digital output channels to select the frequency and amplitude output by the high-frequency oscillator driver. This dual-interface design enables the high-frequency oscillator driver to support both process control under high-speed network communication and fast gear switching under hard-wiring, thereby adapting to different cleaning requirements of wafers.

[0027] In some embodiments, the signal processing module includes a signal generator, a programmable amplifier, a power amplifier, and a boost converter connected in sequence, with both the signal generator and the programmable amplifier electrically connected to the logic controller. The signal generator generates a drive waveform signal, the programmable amplifier adjusts the amplitude of the waveform signal, the power amplifier amplifies the amplitude-adjusted drive waveform signal, and the boost converter increases the output amplitude and provides electrical isolation to the power-amplified drive waveform signal. Specifically, the signal generator receives instructions from the logic controller and generates a corresponding drive waveform signal, which can be a sine wave, a triangle wave, or a square wave, with a frequency resolution of 0.1Hz and a maximum output frequency of 10MHz. Since the driving energy of the high-frequency oscillator is much higher than the output capability of the signal generator and the programmable amplifier, in order to meet the driving requirements of the high-frequency oscillator, the slew rate of the power amplifier is set to a range of 1500-2500V / us, preferably 2000V / us, and the bandwidth is set to a range of 25-35MHz, preferably 30MHz. Under load conditions, when the output voltage is 32Vpp, the gain fluctuation of the power amplifier is no greater than 1dB in the range of 0Hz to 15MHz; when the output voltage is 28Vpp, the gain fluctuation is no greater than 1.1dB in the range of 0Hz to 20MHz; and when the output voltage is 24Vpp, the gain fluctuation is no greater than 1dB in the range of 0Hz to 25MHz. The boost converter is used to amplify the output amplitude of the power amplifier to a higher amplitude range than the output amplitude of the power amplifier, such as 230-250Vpp, preferably 240Vpp, to meet the driving voltage requirements of the high-frequency oscillator. The boost converter includes an isolation transformer. The primary winding of the isolation transformer is electrically connected to the output terminal of the power amplifier, and the secondary winding of the isolation transformer is electrically connected to the high-frequency oscillator. Energy is transferred between the primary winding and the secondary winding through magnetic coupling, and there is no direct electrical connection between them. This electrically isolates the output terminal of the boost converter from the internal circuit of the high-frequency oscillator drive device, ensuring the stability and safety of the internal circuit of the high-frequency oscillator drive device, while preventing the chemical corrosion environment on the cleaning side from interfering with or damaging the internal circuit of the high-frequency oscillator drive device.

[0028] In some embodiments, the output of the signal generator is equipped with a low-pass filter to smooth the driving waveform signal. The programmable gain amplifier (PGA) is used to adjust the noise amplitude of the driving waveform signal under the control of the logic controller. Specifically, the waveform signal generated by the signal generator may contain high-frequency harmonics and spurious components. Direct power amplification would lead to waveform distortion and reduced power amplifier efficiency. Therefore, in this embodiment, a low-pass filter is provided at the output of the signal generator. The low-pass filter smooths the generated waveform and filters out high-frequency harmonics, thereby ensuring the purity of the waveform output and reducing the risk of distortion in the subsequent power amplification process. As a programmable gain amplifier, the PGA can be set with different amplitudes for different high-frequency oscillators or different cleaning requirements. The logic controller outputs amplitude control commands to control the PGA to reach the corresponding output amplitude. The bandwidth of the PGA is 85-95MHz, preferably 90MHz, and its gain adjustment range is -10dB to 30dB.

[0029] In some embodiments, the low-pass filter is a seventh-order passive elliptic low-pass filter circuit. Specifically, the cutoff frequency of the seventh-order passive elliptic low-pass filter circuit is 10MHz. It has controllable ripple characteristics in the passband, meaning the amplitude fluctuations of each frequency signal within the passband are controlled within a designed threshold range to ensure consistency when useful signals pass through. It also has high attenuation characteristics in the stopband, meaning the filter weakens signals above the cutoff frequency. This filter circuit consists of seven passive energy storage elements, including inductors and capacitors, connected in a predetermined topology to form an LC ladder network. Its principle for filtering high-frequency components is based on the difference in impedance frequency characteristics between inductors and capacitors: for low-frequency signals below 10MHz, the inductor exhibits low impedance, and the capacitor exhibits high impedance, allowing the signal to pass through almost unimpeded; for high-frequency signals above 10MHz, the inductor impedance increases with frequency, creating an obstruction, while the capacitor impedance decreases with frequency, bypassing the high-frequency components to the ground terminal. Therefore, signals below 10MHz can pass through with almost no attenuation, while high-frequency harmonics and spurious components above 10MHz are gradually weakened, thereby effectively filtering out high-frequency components above 10MHz and ensuring the smoothness and purity of the driving waveform signal.

[0030] In some embodiments, the impedance adaptation module is a variable capacitor array. This array is positioned between the programmable amplifier and the power amplifier and electrically connected to both. The variable capacitor array is also electrically connected to a logic controller to adjust the equivalent capacitance value between the programmable amplifier and the power amplifier stage under the control of the logic controller. Specifically, in the prior art, when the gain level of the programmable amplifier changes, its output impedance changes, leading to impedance mismatch with the power amplifier's input impedance. This causes power transmission loss, deterioration of the standing wave ratio (VSWR), signal distortion, and decreased power amplifier efficiency. Therefore, this embodiment sets a variable capacitor array between the programmable amplifier and the power amplifier. The parallel capacitor value is adjusted based on feedback from the feedback unit to achieve a discretely adjustable equivalent capacitance value, thereby dynamically compensating for impedance mismatch, suppressing power reflection and signal distortion caused by gain switching, and ensuring efficient power transmission to the subsequent power amplifier stage.

[0031] In some embodiments, the variable capacitor array includes multiple fixed capacitors and a digital switch corresponding to each fixed capacitor. One end of each fixed capacitor is electrically connected to the line between the programmable amplifier and the power amplifier, and the other end is electrically connected to ground through the corresponding digital switch. A logic controller is connected to the digital switches and controls the on / off states of the digital switches to change the number and combination of fixed capacitors connected to ground, thereby adjusting the capacitance value at the output of the programmable amplifier to achieve impedance matching between the programmable amplifier and the power amplifier. Specifically, in this embodiment, the fixed capacitors include a first capacitor C1, a second capacitor C2, a third capacitor C3, and a fourth capacitor C4, and the digital switches include a first switch S1, a second switch S2, a third switch S3, and a fourth switch S4. One end of each fixed capacitor is electrically connected to the line between the programmable amplifier and the power amplifier, and the other end is electrically connected to ground through the corresponding digital switch. The logic controller adjusts the equivalent capacitance at the output of the programmable amplifier by controlling the on / off states of various digital switches, thereby changing the number and combination of fixed capacitors connected in parallel to the main signal path. This, in turn, alters the output impedance of the programmable amplifier, matching it to the input impedance of the power amplifier, reducing power transmission losses and suppressing signal distortion. For example, when the logic controller changes the gain of the programmable amplifier from... When switching from 10dB to 30dB, the output impedance of the programmable amplifier changes accordingly, causing an impedance mismatch with the input impedance of the power amplifier. At this time, the logic controller determines the degree of impedance mismatch based on the amplitude change fed back from the feedback unit and outputs a switch control signal, turning on the first switch S1 and the second switch S2, and turning off the third switch S3 and the fourth switch S4. This connects the first capacitor C1 and the second capacitor C2 in parallel between the main signal path and the ground terminal. The equivalent capacitance of the variable capacitor array is then the sum of the capacitances of the first capacitor C1 and the second capacitor C2. This equivalent capacitance value forms a predetermined matching relationship with the changed output impedance of the programmable amplifier, compensating for the impedance drift caused by the gain switching and restoring the power transfer efficiency between the programmable amplifier and the power amplifier to a matched state. If the logic controller switches the gain to other levels, it correspondingly changes the on / off combination of the first switch S1 to the fourth switch S4, for example, turning on only the first switch S1, or turning on the first switch S1, the second switch S2, and the third switch S3 to obtain different equivalent capacitance values, thereby covering the input impedance of the programmable amplifier. Multi-stage impedance matching requirements within a gain range of 10dB to 30dB.

[0032] In some specific embodiments, the capacitance values ​​of each fixed capacitor range from 10pF to 10nF to cover the compensation capacitance values ​​required for impedance matching between the programmable amplifier and power amplifier stages in the 0Hz-30MHz operating frequency band of the high-frequency oscillator drive device. When the capacitance value of the fixed capacitor is less than 10pF, its adjustment effect on the output impedance is insufficient, making it difficult to compensate for impedance drift caused by gain switching. When the capacitance value of the fixed capacitor is greater than 10nF, the equivalent capacitance is too large, which can easily cause excessive bypassing of high-frequency signals, resulting in attenuation of high-frequency components and phase distortion in the main signal path. More specifically, in this embodiment, the first capacitor C1 is 100pF, the second capacitor C2 is 200pF, the third capacitor C3 is 400pF, and the fourth capacitor C4 is 800pF. The sum of these values ​​is 1.5nF, which is within the range of 10pF to 10nF. This can cover the compensation requirements of the programmable amplifier when the output impedance changes from about 150Ω to about 800Ω in the gain range of -10dB to 30dB. Based on an operating frequency of 10MHz, 100pF corresponds to a capacitive reactance of about 159Ω, and 800pF corresponds to a capacitive reactance of about 20Ω. Through 16 combinations of the four capacitors, discrete adjustment can be made in steps of about 20Ω within the range of 20Ω to 159Ω, thereby forming an effective conjugate match with the input impedance of the power amplifier (such as 50Ω or 75Ω) and suppressing power reflection and signal distortion caused by gain switching.

[0033] In some specific embodiments, each fixed capacitor is configured with an equal capacitance value. The first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 are all 200pF. In this case, the equivalent capacitance is adjusted in 4 levels in 200pF increments within the range of 0pF to 800pF. This scheme has a simpler switching control logic, but fewer adjustment levels, and is suitable for applications with fewer gain levels and a wide range of impedance variations.

[0034] In some embodiments, the feedback circuit includes a sampling circuit, a phase detection circuit, and an amplitude detection circuit. The input of the sampling circuit is electrically connected to the output of the boost converter to acquire the driving waveform signal. The input of the phase detection circuit is electrically connected to the output of the sampling circuit to detect the phase of the driving waveform and generate a phase feedback signal. The input of the amplitude detection circuit is electrically connected to the output of the sampling circuit to detect the amplitude of the driving waveform and generate an amplitude feedback signal. The outputs of the phase detection circuit and the amplitude detection circuit are respectively electrically connected to a logic controller to transmit the phase feedback signal and the amplitude feedback signal to the logic controller. Specifically, existing high-frequency oscillator drive devices are mostly open-loop controlled, which cannot detect the resonant frequency drift of the oscillator caused by changes in the temperature, level, or chemical ratio of the cleaning fluid. This results in the oscillator operating detuned for a long time, leading to low efficiency and easy damage. Therefore, in this embodiment, the feedback device acquires the phase and amplitude of the boost converter output waveform and transmits the acquisition results to the logic controller. The logic controller determines the offset direction of the high-frequency oscillator resonant frequency based on the phase and adjusts the output frequency of the signal generator. At the same time, it adjusts the gain of the programmable amplifier and the equivalent capacitance value of the variable capacitor array based on the amplitude to achieve frequency following and impedance matching, thereby ensuring that the oscillator always works near the resonant point, thus improving the stability of wafer cleaning.

[0035] In some embodiments, the sampling circuit includes a first resistor 10 and a second resistor 20. One end of the first resistor 10 is electrically connected to the output terminal of the boost converter. One end of the second resistor 20 is electrically connected to the other end of the first resistor 10 via a line to form a sampling node, and the other end of the second resistor 20 is grounded. The input terminals of the phase detection circuit and the amplitude detection circuit are respectively electrically connected to the sampling node. Specifically, one end of the first resistor 10 is electrically connected to the output terminal of the boost converter, and the other end is connected to the second resistor 20 via a line to form a sampling node. The first resistor 10 is used to withstand high voltage drops and limit the sampling current. The amplitude of the drive waveform signal output by the boost converter can reach 240Vpp. The first resistor 10 bears most of the voltage drop, limiting the high-amplitude signal to a low-amplitude sampling signal, preventing the subsequent detection circuit from being directly subjected to high voltage and damaged. At the same time, the first resistor 10 and the second resistor 20 work together to determine the voltage division ratio, so that the signal amplitude at the sampling node is within the safe input range of the phase detection circuit and the amplitude detection circuit. One end of the second resistor 20 is electrically connected to the first resistor 10 to form a sampling node, and the other end is grounded. The second resistor 20 is mainly used to provide a ground reference and establish a voltage divider reference. The second resistor 20 is connected in series with the first resistor 10 and then grounded to form a complete signal loop, so that the potential at the sampling node is referenced to ground to form a stable low-amplitude sampling signal. At the same time, the second resistor 20 provides a ground guiding path for the sampling node, avoiding charge accumulation that causes node potential drift, ensuring the stability of the DC operating point of the sampling signal, and enabling the phase detection circuit and amplitude detection circuit to accurately detect the phase and amplitude.

[0036] In some specific embodiments, the phase detection circuit includes a zero-crossing comparator 30 and a phase detector 40. The input of the zero-crossing comparator 30 is electrically connected to the sampling node and is used to convert the sampled drive waveform signal into a square wave signal of the same frequency. The first input of the phase detector 40 is electrically connected to the output of the zero-crossing comparator 30, and the second input is used to receive a reference signal. The phase detector 40 is used to compare the phase of the square wave signal with the reference signal and generate a phase error voltage. The output of the phase detector 40 is electrically connected to the logic controller to transmit the phase error voltage as a phase feedback signal to the logic controller. The reference signal is provided by a signal generator. While generating the drive waveform signal, the signal generator shapes an internally generated signal of the same frequency as the drive waveform signal into a square wave and outputs it to the second input of the phase detector 40 as the reference signal.

[0037] In some specific embodiments, the amplitude detection circuit includes a detector diode 50, a detector capacitor 60, and a detector resistor 70. The anode of the detector diode 50 is electrically connected to the sampling node and is used to perform half-wave rectification on the sampled drive waveform signal. One end of the detector capacitor 60 is electrically connected to the cathode of the detector diode 50, and the other end is grounded, used to store and maintain the rectified peak voltage. The detector resistor 70 is connected in parallel across the detector capacitor 60 and is used to provide a discharge path for the detector capacitor 60, so that the voltage across the detector capacitor 60 can follow the change in the amplitude of the drive waveform. The cathode of the detector diode 50 constitutes the output terminal of the amplitude detection circuit and is electrically connected to the logic controller to transmit the detected DC voltage as an amplitude feedback signal to the logic controller. Embodiments of this application also disclose a wafer cleaning device for wafer cleaning. The wafer cleaning device includes a cleaning tank, a high-frequency oscillator, a host computer, and the aforementioned high-frequency oscillator driving device. The cleaning tank is used to contain cleaning fluid and wafers to be cleaned. The high-frequency oscillator is disposed inside the cleaning tank, for example, on the inner side wall of the cleaning tank, which is known to those skilled in the art and will not be described in detail here. The high-frequency oscillator is electrically connected to the output terminal of the high-frequency oscillator driving device to generate high-frequency vibration under the drive of the high-frequency oscillator driving device to clean the wafer. The host computer (e.g., a central control computer) establishes a communication and control connection with the interaction module of the high-frequency oscillator driving device to send control commands to the high-frequency oscillator driving device.

[0038] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.

Claims

1. A high-frequency oscillator driving device for wafer cleaning, characterized in that, include: An interaction module is used to establish a communication and control connection with a host computer to receive control commands from the host computer. A logic controller, electrically connected to the interaction module, is used to parse the control commands and generate control signals; The signal processing module is connected to the logic controller to output a drive waveform signal to the high-frequency oscillator under the control of the control signal. An impedance adaptation module is electrically connected at one end to the signal processing module and at the other end to the logic controller to adjust the impedance of the signal processing module. as well as The feedback device is electrically connected at one end to the signal processing module and at the other end to the logic controller, so as to acquire the phase and amplitude of the driving waveform signal and feed it back to the logic controller.

2. The high-frequency oscillator driving device according to claim 1, characterized in that, The interaction module includes communication devices and input signal devices; The communication device and the input signal device are respectively connected to the host computer and electrically connected to the logic controller; the communication device is used to establish a communication network with the host computer, and the input signal device is used to receive control commands from the host computer.

3. The high-frequency oscillator driving device according to claim 1, characterized in that, The signal processing module includes a signal generator, a programmable amplifier, a power amplifier, and a boost converter connected in sequence, and both the signal generator and the programmable amplifier are electrically connected to the logic controller. The signal generator is used to generate the driving waveform signal, the programmable amplifier is used to adjust the amplitude of the waveform signal, the power amplifier is used to amplify the power of the amplitude-adjusted driving waveform signal, and the boost converter is used to increase the output amplitude and provide electrical isolation to the power-amplified driving waveform signal.

4. The high-frequency oscillator driving device according to claim 3, characterized in that, The output of the signal generator is equipped with a low-pass filter to smooth the driving waveform signal; the programmable gain amplifier is a programmable gain amplifier to adjust the noise amplitude of the driving waveform signal under the control of the logic controller.

5. The high-frequency oscillator driving device according to claim 4, characterized in that, The low-pass filter is a seventh-order passive elliptic low-pass filter circuit.

6. The high-frequency oscillator driving device according to claim 3, characterized in that, The impedance adaptation module is a variable capacitor array, which is located between the programmable amplifier and the power amplifier and electrically connected to both. The variable capacitor array is also electrically connected to the logic controller to adjust the equivalent capacitance value between the programmable amplifier and the power amplifier stage under the control of the logic controller.

7. The high-frequency oscillator driving device according to claim 6, characterized in that, The variable capacitor array includes, Multiple fixed capacitors and digital switches corresponding to each fixed capacitor; one end of each fixed capacitor is electrically connected to the line between the programmable amplifier and the power amplifier, and the other end is electrically connected to the ground terminal through the corresponding digital switch. The logic controller is connected to the digital switch control and is used to change the number and combination of fixed capacitors connected to the ground terminal by controlling the on / off state of each digital switch, so as to adjust the capacitance value of the output terminal of the programmable amplifier and achieve impedance matching between the programmable amplifier and the power amplifier.

8. The high-frequency oscillator driving device according to claim 3, characterized in that, The feedback circuit includes a sampling circuit, a phase detection circuit, and an amplitude detection circuit; The input terminal of the sampling circuit is electrically connected to the output terminal of the boost converter to acquire the drive waveform signal; The input terminal of the phase detection circuit is electrically connected to the output terminal of the sampling circuit, and is used to detect the phase of the driving waveform and generate a phase feedback signal. The input terminal of the amplitude detection circuit is electrically connected to the output terminal of the sampling circuit, and is used to detect the amplitude of the driving waveform and generate an amplitude feedback signal; the output terminals of the phase detection circuit and the amplitude detection circuit are respectively electrically connected to the logic controller to transmit the phase feedback signal and the amplitude feedback signal to the logic controller.

9. The high-frequency oscillator driving device according to claim 8, characterized in that, The sampling circuit includes a first resistor and a second resistor; One end of the first resistor is electrically connected to the output terminal of the boost converter; One end of the second resistor is electrically connected to the other end of the first resistor via a line to form a sampling node, and the other end of the second resistor is grounded; The input terminals of the phase detection circuit and the amplitude detection circuit are electrically connected to the sampling node, respectively.

10. A wafer cleaning apparatus for wafer cleaning, characterized in that, Includes a cleaning tank, a high-frequency vibrator, a host computer, and the high-frequency vibrator driving device according to any one of claims 1-9; The cleaning tank is used to hold the cleaning solution and the wafers to be cleaned. The high-frequency oscillator is disposed in the cleaning tank and electrically connected to the output terminal of the high-frequency oscillator driving device, so as to generate high-frequency vibration under the drive of the high-frequency oscillator driving device to clean the wafer. The host computer communicates and controls with the interaction module of the high-frequency oscillator drive device, and is used to send control commands to the high-frequency oscillator drive device.

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