A standard sample carrier lifetime calibration method and traceability system

Abstract

This application relates to the field of semiconductor testing and metrology technology, and discloses a method and traceability system for determining the carrier lifetime of a standard sample. The method includes the following steps: positioning the sample under test, stabilizing the environment, and initializing the system; constructing a periodically modulated acoustic potential well within the sample and exciting the coherent quantum state at the center of the potential well using a coherent double-pulse sequence; acquiring the returned optical signal and extracting its attenuation envelope using differential lock-in demodulation technology; verifying physical self-consistency by rotating the acoustic field stress axis and fitting the attenuation envelope to extract carrier lifetime parameters; statistically analyzing multiple sets of parameters to determine the final value and constructing a traceability chain to a frequency reference. This invention uses a three-dimensional acoustic standing wave field to construct an acoustic potential well within the sample material, trapping photogenerated carriers without contact within the sample, thus achieving direct measurement of carrier lifetime and overcoming the deficiency that the measurement results are severely affected by the sample surface state.

Description

Technical Field

[0001] This invention relates to the field of semiconductor testing and metrology technology, specifically to a method for determining the carrier lifetime of a standard sample and a traceability system. Background Technology

[0002] Semiconductors are the cornerstone of the modern electronics industry. From chips in smartphones to solar cells powering green energy, the core performance of these devices profoundly depends on the intrinsic quality of their semiconductor materials. Carrier lifetime is a key physical parameter for measuring this quality, directly determining the material's response efficiency and loss rate to light and electrical signals. Therefore, precise measurement of carrier lifetime is essential throughout the entire semiconductor supply chain, creating a demand for a high-precision "ruler"—a carrier lifetime standard sample. Using this standard sample to calibrate various measuring instruments on the production line ensures the uniformity and comparability of product quality globally.

[0003] To meet the industry's need for rapid quality assessment of semiconductor materials, a series of non-contact measurement methods have been developed, such as microwave photoconductivity attenuation (μ-PCD) technology. This technology can quickly provide quality assessment results without damaging the wafer. Before measurement, the sample surface is typically chemically passivated, which has become a standard pretreatment process. Thanks to its ease of operation and high measurement speed, this technology is widely used in quality monitoring during industrial production, providing an effective means to ensure the yield of semiconductor materials.

[0004] However, when the goal shifts from rapid screening at the industrial level to absolute determination at the metrological level, the fundamental flaws of existing technologies become apparent. First, the measurement results are always subject to interference from the physical surface of the sample. The chemical passivation layer itself is extremely unstable, highly sensitive to ambient light and temperature, and may even fail over time. This causes the measured values ​​to be mixed with volatile surface composite information, resulting in a value that is not a pure volumetric lifetime of the material. As a result, a value used as a "standard" will drift. Second, the high-purity materials necessary for manufacturing standard samples have extremely weak optical signal responses. This signal is easily drowned out by detector noise and stray light from the environment. Extracting an accurate lifetime value from a bunch of data mixed with huge noise results in a high degree of randomness and uncertainty, which is difficult to meet metrological requirements. The most fundamental problem is that the existing technology lacks a clear traceability path for measurement values. Its measurement results mostly rely on comparison with other samples rather than absolute measurement based on the first principles of physics. The entire measurement system is suspended in the air, and its values ​​cannot be traced back to the basic physical constants in the International System of Units (SI). This means that this "ruler" itself has no precise scale, and its accuracy cannot be fundamentally guaranteed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and traceability system for determining the carrier lifetime of a standard sample, thereby solving the fundamental problems in existing technologies, such as the interference of surface recombination instability, low signal-to-noise ratio of weak signals, and the lack of a metrological standard traceable to SI base units.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method and traceability system for determining the carrier lifetime of a standard sample, comprising the following steps:

[0007] Loading, positioning, and environmental stabilization of the sample under test are performed, and system initialization parameters are configured.

[0008] A three-dimensional acoustic standing wave field is generated in the target region of the sample under test to construct an acoustic potential well, and the driving frequency of the three-dimensional acoustic standing wave field is periodically modulated.

[0009] A coherent double-pulse sequence with a specific time delay and polarization state is focused toward the central region of the acoustic potential well to excite a coherent quantum state within the acoustic potential well;

[0010] The polarization-resolved photoluminescence signal returned from the coherent quantum state is acquired, and the photoluminescence signal is differentially locked demodulated based on the periodic modulation to extract the attenuation envelope of the signal.

[0011] Physical self-consistency was verified by rotating the stress principal axis of the three-dimensional acoustic standing wave field and analyzing the polarization correlation of the signal, and the attenuation envelope was fitted to extract the carrier lifetime parameters.

[0012] Statistical analysis was performed on multiple sets of carrier lifetime parameters to determine the final values, and a traceability chain of values ​​based on frequency reference was constructed.

[0013] Preferably, the step of generating a three-dimensional acoustic standing wave field in the target region within the sample under test to construct an acoustic potential well, and applying periodic modulation to the driving frequency of the three-dimensional acoustic standing wave field, includes:

[0014] Multiple radio frequency signals with preset phase, frequency and amplitude relationships are generated, and a periodically changing modulation signal is superimposed on the center driving frequency of the radio frequency signals.

[0015] A three-dimensional piezoelectric transducer array is driven to emit coherent ultrasonic waves, which interfere within the sample under test to form the three-dimensional acoustic standing wave field. The three-dimensional acoustic standing wave field induces spatially periodic stress and strain distribution in the lattice of the sample under test.

[0016] The stress and strain distribution in the target region forms a local energy minimum point, which constitutes the acoustic potential well.

[0017] Preferably, focusing a coherent double-pulse sequence with a specific time delay and polarization state onto the central region of the acoustic potential well to excite a coherent quantum state within the acoustic potential well includes:

[0018] The ultrafast laser pulse sequence is split into two beams, and one of the beams is passed through an optical delay line to introduce a controllable time delay. The two beams are then recombined to form the coherent double pulse sequence.

[0019] The polarization state of the coherent double pulse sequence is set to a preset incident polarization vector by a polarization controller;

[0020] The coherent double-pulse sequence is focused on the central region of the acoustic potential well to drive the exciton states that have undergone energy level splitting due to local stress to the coherent quantum states formed by coherent superposition.

[0021] Preferably, the step of acquiring the polarization-resolved photoluminescence signal returned from the coherent quantum state and performing differential-locked demodulation of the photoluminescence signal based on the periodic modulation includes:

[0022] The photoluminescence signal generated by the recombination of the coherent quantum states is collected and polarization-resolved using a polarization analyzer;

[0023] The polarization-resolved optical signal is converted into a raw electrical signal that includes exponential decay and quantum beat frequency oscillation.

[0024] The original electrical signal and the periodically modulated modulation signal are respectively fed into a lock-in amplifier as signal input and reference input. The original electrical signal is demodulated by phase-sensitive detection and low-pass filtering to output the attenuation envelope of the signal that contains only the exponential decay information.

[0025] Preferably, fitting the attenuation envelope to extract carrier lifetime parameters includes:

[0026] The experimental data points of the signal attenuation envelope were compared with those of the single exponential attenuation model function using the nonlinear least squares method. Perform fitting;

[0027] in, The initial amplitude of the attenuating signal, The carrier lifetime to be extracted. A background baseline constant;

[0028] Through iterative adjustments , and The optimal parameter value is obtained when the sum of squared residuals between the model function and the experimental data points is minimized, and this optimal parameter value is used as the carrier lifetime parameter.

[0029] Preferably, the step of statistically analyzing multiple sets of carrier lifetime parameters to determine the final value includes:

[0030] Repeated measurements were performed at different spatial locations of the sample under test to obtain a carrier lifetime dataset containing multiple independent measurement results;

[0031] The weighted average of the carrier lifetime dataset is calculated as the final value, where the weighting factor is the reciprocal of the square of the uncertainty of each measurement.

[0032] The Type A and Type B uncertainties in the measurement process are evaluated and combined to obtain the expanded uncertainty of the final value.

[0033] Preferably, the loading, positioning, and environmental stabilization of the sample under test, and the configuration of system initialization parameters, include:

[0034] The selected bulk material target measurement area on the sample under test is precisely positioned at the optical focusing point and the acoustic field target center using a three-dimensional displacement platform.

[0035] The temperature control chamber and vibration isolation system are activated to isolate external environmental temperature fluctuations and mechanical vibrations;

[0036] Set the center driving frequency and modulation frequency of the acoustic field, the delay time and incident polarization state of the optical system, and the lock-in amplifier parameters and data acquisition mode of the signal processing system.

[0037] Preferably, the differential lock-lock demodulation extracts the attenuation envelope of the signal by calculating the cross-correlation between the original electrical signal and the periodically modulated signal, outputting only the envelope of the signal components that are locked with the periodic modulation in frequency and phase, and filtering out all signal components that are not related to the periodic modulation.

[0038] Preferably, the physical self-consistency verification includes:

[0039] Non-mechanical rotation of the stress principal axis direction is achieved by programmatically changing the relative phase between multiple radio frequency signals used to generate the three-dimensional acoustic standing wave field.

[0040] In each of the principal stress axes, the initial amplitude of the photoluminescence signal is recorded in response to the outgoing polarization direction to generate an experimental response spectrum.

[0041] The experimental response spectrum is compared with the theoretical response spectrum calculated based on semiconductor band theory. If the two are consistent in terms of symmetry and extreme value positions, the verification is successful.

[0042] A system for tracing the carrier lifetime of a standard sample includes:

[0043] The sample and environment control module is used to carry and precisely position the standard sample to be tested, and to provide a highly stable physical measurement environment for the standard sample.

[0044] The dynamic acoustic field driving module is used to generate a three-dimensional acoustic standing wave field within the standard sample and to dynamically adjust the parameters of the three-dimensional acoustic standing wave field.

[0045] The coherent optical path and detection module is used to optically excite the potential well region formed by the three-dimensional acoustic standing wave field within the sample under test, and to collect the photoluminescence signal returned from the region.

[0046] The signal processing and verification module coordinates the operation of the dynamic acoustic field driving module and the coherent optical path and detection module, and receives the electrical signal output by the coherent optical path and detection module, and performs differential lock demodulation and fitting processing on the electrical signal.

[0047] The frequency reference and traceability module is electrically connected to the dynamic acoustic field drive module and is used to output a frequency reference signal with high stability and high accuracy to lock the core clock of the dynamic acoustic field drive module.

[0048] This invention provides a method and traceability system for determining the carrier lifetime of a standard sample. It offers the following advantages:

[0049] 1. This invention employs a three-dimensional acoustic standing wave field to construct an acoustic potential well within the sample material, confining photogenerated carriers within the sample without contact. This enables direct measurement of the carrier lifetime. Compared to existing technologies that rely on microwave photoconductivity attenuation, this invention overcomes the shortcomings of measurement results being severely affected by the sample surface condition. Existing technologies use chemical passivation treatment, which suffers from instability and time-sensitivity. This invention fundamentally eliminates surface recombination interference, ensuring the authenticity and accuracy of the measurement results.

[0050] 2. This invention innovatively combines quantum beat frequency detection technology with periodic modulation of acoustic fields and uses differential lock-in demodulation technology to extract signals. It can non-destructively separate the pure attenuation signal that is only related to the recombination of charge carriers in the acoustic potential well from extremely strong noise background. Compared with conventional time-resolved spectral measurements in existing technologies, this scheme effectively avoids the serious interference caused by detector dark noise, environmental stray light and non-trapped area fluorescence in traditional methods, and solves the technical bottleneck of low fitting accuracy and large measurement uncertainty due to insufficient signal-to-noise ratio.

[0051] 3. This invention constructs a complete traceability chain for measurement values. The time reference of the measurement process is strictly locked to a first-level frequency standard source through a phase-locked loop, so that the final carrier lifetime determination value can be directly traced back to the International System of Units (SI) base unit "second". Compared with the existing technology that relies on standard materials or cyclic comparisons for measurement value transfer, this invention solves the fundamental defects of unclear traceability path and lack of absolute metrological significance of determination results, and endows the measurement values ​​of standard samples with long-term stability and authority. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the system structure according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the method flow according to an embodiment of the present invention.

[0054] Explanation of icon numbers:

[0055] 10. Sample and environmental control module; 20. Dynamic acoustic field driving module; 30. Coherent optical path and detection module; 40. Signal processing and verification module; 50. Frequency reference and traceability module. Detailed Implementation

[0056] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and 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.

[0057] See attached document Figure 1 , Figure 1 This is a schematic diagram of a system structure according to an embodiment of the present invention. The present invention provides a method for determining the carrier lifetime of a standard sample and a traceability system, which may include: a sample and environment control module 10, a dynamic acoustic field driving module 20, a coherent optical path and detection module 30, a signal processing and verification module 40, and a frequency reference and traceability module 50.

[0058] The sample and environment control module 10 is used to carry and precisely position the standard sample to be tested, and to provide it with a highly stable physical measurement environment. Specifically, the sample and environment control module 10 includes a high-precision three-dimensional displacement platform, a sample fixture adapted to the sample to be tested, a passive or active vibration isolation system, and an integrated temperature-controlled chamber. The three-dimensional displacement platform is used to realize the translation and rotation of the sample to be tested in three-dimensional space to select the target measurement area within the sample. The sample fixture is used to securely fix the sample to be tested. The vibration isolation system and the temperature-controlled chamber are used to isolate the mechanical vibration and temperature fluctuations of the external environment from interference with the measurement process, respectively.

[0059] The dynamic acoustic field driving module 20, electrically connected to the signal processing and verification module 40 and the frequency reference and tracing module 50, is used to generate a three-dimensional acoustic standing wave field within the sample under test and to dynamically and precisely control the parameters of this standing wave field. The dynamic acoustic field driving module 20 includes a multi-channel direct digital frequency synthesizer (DDS), a set of radio frequency power amplifiers, and a three-dimensional piezoelectric transducer array. The multi-channel DDS receives instructions from the signal processing and verification module 40 and generates multiple radio frequency signals with independently controllable frequency, phase, and amplitude. These radio frequency signals are amplified by the radio frequency power amplifier group and then drive corresponding units in the three-dimensional piezoelectric transducer array arranged around the sample under test. A three-dimensional piezoelectric transducer array can be composed of three pairs of orthogonally arranged planar piezoelectric transducers, each pair facing each other along a Cartesian coordinate axis (e.g., X, Y, Z axes). By emitting coherent ultrasonic waves propagating in opposite directions, a standing wave is formed along that axis. The three pairs of transducers work together to ultimately superimpose in the central region to form a three-dimensional acoustic standing wave field. By precisely controlling the parameters of each radio frequency signal, the three-dimensional piezoelectric transducer array forms interference in the target region within the sample under test, thereby constructing the desired three-dimensional acoustic standing wave field. The dynamic acoustic field driving module 20 is also responsible for applying a preset low-frequency modulation to the central driving frequency and can achieve non-mechanical rotation of the principal stress axis direction of the acoustic standing wave field by changing the relative phase of the signals in each channel.

[0060] The coherent optical path and detection module 30 is used to optically excite the potential well region formed by the acoustic field within the sample under test and to collect the photoluminescence signal returned from this region. It includes a femtosecond laser source and an optical path control subsystem consisting of a beam splitter, a high-precision optical delay line, an acousto-optic modulator, and a polarization controller. This subsystem is responsible for preparing the laser pulses generated by the femtosecond laser source into a coherent double-pulse sequence with a specific time delay and a preset polarization state, and focusing it onto the target measurement region. The coherent optical path and detection module 30 also includes a photoluminescence collection and detection subsystem consisting of a high numerical aperture objective lens, a spectral filter, a polarization analyzer, and a high temporal resolution photodetector (e.g., a time-correlated single-photon counting module or a single-photon avalanche diode). This subsystem efficiently collects the photoluminescence signal emitted from the sample, performs spectral filtering and polarization state selection on it, and finally, the high temporal resolution photodetector records the attenuation information of the signal photons over time, outputting the corresponding electrical signal to the signal processing and verification module 40.

[0061] The signal processing and verification module 40 is the core of the entire system's control and data processing. Its hardware mainly includes a high-frequency lock-in amplifier, a high-speed data acquisition card, and a central control and analysis computer. The raw electrical signal output from the coherent optical path and detection module 30 is fed into the high-frequency lock-in amplifier. Simultaneously, the reference signal used for acoustic field modulation in the dynamic acoustic field drive module 20 is also fed into this high-frequency lock-in amplifier. The lock-in amplifier performs differential lock-in demodulation on the raw signal, extracting the signal component synchronized with the acoustic modulation, and transmits the demodulated signal to the central control and analysis computer via the high-speed data acquisition card. Dedicated software within the central control and analysis computer is responsible for exponentially fitting the demodulated attenuated signal to extract the carrier lifetime. Furthermore, the signal processing and verification module 40 is also responsible for performing physical self-consistency verification, i.e., analyzing and comparing the consistency between the signal characteristics measured under different stress field vectors and polarization states and the theoretical model. Simultaneously, the central control and analysis computer issues commands to coordinate the operation of the dynamic acoustic field drive module 20 and the coherent optical path and detection module 30.

[0062] The frequency reference and traceability module 50 is the fundamental guarantee for ensuring the accuracy of the system's measurement results and establishing its traceability chain. This module includes a primary frequency standard source (e.g., a rubidium or cesium atomic clock) and a phase-locked loop (PLL) circuit. The primary frequency standard source outputs a highly stable and accurate frequency reference signal. The core clock of the multi-channel direct digital frequency synthesizer in the dynamic acoustic field drive module 20 is strictly locked to this frequency reference signal through the PLL circuit. In this way, the accuracy of all frequency-related operations in the system, especially the center drive frequency and modulation frequency of the acoustic field, is directly traceable to this primary frequency standard source, thus constructing a complete and reliable traceability path to the International System of Units (SI) "second" for the final lifetime determination result.

[0063] See attached document Figure 2 , Figure 2 This is a flowchart of a method according to an embodiment of the present invention. The present invention provides a method for determining the carrier lifetime of a standard sample, which can be implemented using the aforementioned system, and specifically includes the following steps:

[0064] S100 loads, positions, and stabilizes the environment of the sample under test, and initializes the system parameters.

[0065] S200 generates a three-dimensional acoustic standing wave field in the target region within the sample under test to construct an acoustic potential well, and applies periodic modulation to the driving frequency of the acoustic standing wave field.

[0066] S300, prepare a coherent double pulse sequence with specific time delay and polarization state, and focus it on the central region of the acoustic potential well to excite the generation of coherent quantum state;

[0067] S400 acquires the polarization-resolved photoluminescence signal returned from the target area and performs differential lock demodulation on the photoluminescence signal based on periodic modulation to extract the signal attenuation envelope.

[0068] The S500 verifies physical self-consistency by rotating the principal stress axis of the acoustic standing wave field and analyzing the polarization correlation of the signal, and fits the attenuation envelope to extract carrier lifetime parameters.

[0069] S600 performs statistical analysis on multiple sets of carrier lifetime parameters to determine the final values ​​and constructs a traceability chain of values ​​based on frequency reference.

[0070] To enable those skilled in the art to better understand the technical solution of the present invention, the technical details and implementation methods of the above steps will be described in detail below.

[0071] In step S100, the sample under test is loaded, positioned, and stabilized in the environment, and the system initialization parameters are configured. This preparation stage is the foundation for subsequent accurate measurements, aiming to place the sample under test in a precisely known and highly stable physical and system environment.

[0072] Specifically, this step may include the following sub-steps:

[0073] S101, Perform loading and precise three-dimensional positioning of the sample to be tested. The operator places and fixes the standard sample to be tested on the sample fixture within the sample and environment control module 10. Subsequently, the high-precision three-dimensional displacement platform in the sample and environment control module 10 is controlled by the central control and analysis computer within the signal processing and verification module 40. According to the pre-set coordinates, the platform precisely moves the selected bulk material target measurement area on the sample to be tested to the optical focusing point of the coherent optical path and detection module 30, and the target center position of the acoustic field generated by the dynamic acoustic field drive module 20. To ensure precise alignment between the optical focus and the acoustic field center, during the system calibration stage, acousto-optic effects or by monitoring the characteristic effects of the acoustic field on the photoluminescence signal (such as changes in signal intensity or spectral line position) can be used for auxiliary alignment, controlling the alignment error within a specific proportion (e.g., 1 / 10) of the optical diffraction limit or acoustic wavelength.

[0074] S102, stabilization control of the measurement environment is performed. After the sample to be tested is positioned, the isothermal control chamber and vibration isolation system in the sample and environment control module 10 are activated. The temperature control unit in the isothermal control chamber, such as a controller based on a proportional-integral-derivative (PID) algorithm, drives the thermoelectric cooler (TEC) and other heating or cooling elements by reading feedback from temperature sensors (such as platinum resistance thermometers) to stabilize the internal temperature of the chamber at a preset temperature value. and maintains a very small fluctuation range ± This approach aims to eliminate changes in the optical and acoustic properties of materials caused by temperature drift. Simultaneously, it activates vibration isolation systems (such as passive air rafts or active piezoelectric feedback isolation platforms) to maximally suppress mechanical vibrations from the external environment, ensuring the stability of optical focusing and the morphology of the acoustic standing wave field remain undisturbed.

[0075] S103, execute system hardware initialization and parameter preset. Initial configuration commands are issued to each functional module via the central control and analysis computer of the signal processing and verification module 40. For the dynamic acoustic field drive module 20, the center drive frequency of its multi-channel direct digital frequency synthesizer (DDS) is set. Modulation frequency of periodic modulation With modulation amplitude The system loads the initial phase and amplitude data for each channel used to generate the initial three-dimensional acoustic standing wave field. For the coherent optical path and detector module 30, the output power of the femtosecond laser source is set, and the delay time of the optical delay line in the optical path control subsystem is set. And set the polarization controller to generate the preset incident light polarization state. For the signal processing and verification module 40 itself, the operating parameters of the high-frequency lock-in amplifier (such as reference frequency, time constant, filter slope, etc.) and the data acquisition mode of the high-speed data acquisition card (such as sampling rate, acquisition duration, etc.) are set. After all parameters are preset, a system baseline measurement can be performed, for example, recording the dark count background of the detector without laser excitation, to provide a noise reference for subsequent signal processing.

[0076] In step S200, a three-dimensional acoustic standing wave field is generated in the target region within the sample body to construct an acoustic potential well, and the driving frequency of the acoustic standing wave field is periodically modulated. This step is one of the core aspects of the present invention, and its purpose is to create a dynamically adjustable virtual measurement space without a physical surface within the sample body material.

[0077] This step may specifically include the following sub-steps:

[0078] S201, construct the three-dimensional acoustic standing wave field. The signal processing and verification module 40 issues a command to the dynamic acoustic field driving module 20 to start its internal multi-channel direct digital frequency synthesizer (DDS). This DDS, based on the parameters initially configured in step S103, including the center drive frequency... Modulation frequency Modulation amplitude The system generates multiple radio frequency (RF) signals with precise phase, frequency, and amplitude relationships, based on the initial phase and amplitude data of each channel. These signals are amplified by an RF power amplifier array and then drive the corresponding units in the three-dimensional piezoelectric transducer array. The coherent ultrasonic waves emitted by each transducer propagate within the sample under test and interfere with each other in the target measurement area, thus superimposing to form a stable three-dimensional acoustic standing wave field. This standing wave field induces a spatially periodic stress and strain distribution in the sample lattice.

[0079] S202, based on stress and strain distribution, forms an acoustic potential well within the sample. According to continuum mechanics and deformation potential theory, the strain tensor generated by the acoustic standing wave field... In spatial location This causes a stress tensor. The relationship is as follows:

[0080] ;

[0081] in, Let be the fourth-order elastic stiffness tensor of the sample material under test. This localized stress field alters the band structure of the semiconductor, causing changes in the energy at the conduction band bottom or valence band top. An offset occurred; the offset amount for: ;

[0082] in, Let be the deformation potential tensor of the semiconductor material. Through precise design of the three-dimensional acoustic standing wave field morphology, a local energy minimum point can be formed in the target measurement region (e.g., at the antinodes or nodes of the standing wave field). This energy minimum point constitutes a three-dimensional acoustic levitation potential well (ALPW). This acoustic potential well, like a trap without physical boundaries, can trap electron-hole pairs generated by subsequent photoexcitation within the potential well through the restoring force generated by the potential energy gradient, effectively preventing them from diffusing to the physical surface of the sample and undergoing surface recombination. This creates the physical prerequisite for directly measuring the carrier lifetime.

[0083] It is worth noting that this acoustic potential well effectively confines both electrons in the conduction band and holes in the valence band. Although the deformation potential tensors of electrons and holes may differ, resulting in differences in the potential well depths they experience, by rationally designing the morphology of the acoustic standing wave field (e.g., selecting specific interference nodes or antinodes as confinement centers), it can be ensured that both types of charge carriers are effectively confined within the same spatial region and participate together in the subsequent recombination process.

[0084] S203 performs dynamic periodic modulation of the acoustic standing wave field drive frequency. This is done at the center drive frequency during the generation of the RF signal by the multi-channel direct digital frequency synthesizer. Based on this, a low-frequency, periodically varying modulation signal is superimposed. This, in turn, drives the instantaneous frequency of the three-dimensional piezoelectric transducer array. Over time Changes can take the following forms:

[0085] ;

[0086] in, The amplitude of the frequency modulation. The modulation frequency is [value]. Periodic changes in this driving frequency will cause synchronized changes in the intensity of the acoustic standing wave field and the depth of the acoustic potential well at a frequency of [value]. The periodic variation. More importantly, the local energy level splitting energy subsequently used to generate quantum beat frequency signals, caused by the stress field of this potential well. It will also be synchronously modulated, that is This periodic modulation provides the necessary reference for extracting a clean signal from a high-noise background using differential locking technology in step S400.

[0087] In step S300, a coherent double-pulse sequence with specific time delay and polarization state is prepared and focused onto the central region of the acoustic potential well to excite coherent quantum states. This step aims to actively prepare a quantum coherent system that can be used for subsequent measurements on a localized energy level structure created by an acoustic field through precise optical manipulation.

[0088] This step may specifically include the following sub-steps:

[0089] S301, performs the preparation of a coherent double-pulse sequence. The femtosecond laser source in the coherent optical path and detector module 30 generates a stable ultrafast laser pulse sequence. This pulse sequence is split into two beams by a beam splitter in the optical path. One beam passes through a high-precision optical delay line, which introduces a precisely controllable time delay. Then the two beams of light are recombined. This creates a beam composed of two beams spaced apart in time. A two-pulse sequence consisting of laser pulses that maintain a stable phase relationship.

[0090] S302, precisely setting the polarization state of the incident pulse. Before entering the sample under test, the dual-pulse sequence passes through the coherent optical path and the polarization controller (e.g., composed of a Pockels cell and a waveplate group) in the detection module 30. Based on instructions from the signal processing and verification module 40, the polarization controller sets the polarization state of the dual-pulse sequence to a preset, defined polarization vector. Since the optical transition selection rules in semiconductors are closely related to the polarization state of the excitation light, the crystal axis, and the stress direction, this step provides the necessary conditions for selectively exciting specific transitions and for subsequent verification of physical self-consistency.

[0091] S303, a coherent quantum state is excited within the acoustic potential well. The processed double-pulse sequence is then precisely focused onto the central region of the single acoustic potential well constructed in step S200 using a high numerical aperture objective lens in the photoluminescence collection and detection subsystem. Within this region, the localized stress generated by the acoustic standing wave field has caused the degenerate energy levels (e.g., the valence band top) of the semiconductor to split, forming two states with an energy difference of... The neighboring energy levels have the following energies: and When the first pulse (pump pulse) in the double-pulse sequence arrives, it excites electron-hole pairs within the potential well. Immediately following, with a delay of... The second pulse (probe pulse or second pump pulse), due to its coherence with the first pulse, drives the system to an exciton state corresponding to these two split energy levels. and quantum state formed by coherent superposition The wave function of this coherent superposition state can be expressed as:

[0092] ;

[0093] in, and The amplitude is complex, determined by the excitation conditions. To reduce Planck's constant. The time evolution of this coherent superposition state will lead to the appearance of a frequency in the subsequent photoluminescence signal. The oscillation of the quantum beat frequency is called the quantum beat frequency. The angular frequency of this quantum beat frequency is determined by the energy difference between the energy level splits. The only certainty:

[0094] ;

[0095] Due to energy level splitting energy It has been periodically modulated by the acoustic field in step S203, that is Therefore, the quantum beat frequency generated by the excited quantum state here will also be synchronously modulated, that is... This establishes a direct physical link between the optical signal and the acoustic modulation, which forms the basis for subsequent differential locking detection.

[0096] In step S400, the polarization-resolved photoluminescence signal returned from the target region is acquired, and differential lock-lock demodulation is performed on the photoluminescence signal based on periodic modulation to extract the signal attenuation envelope. This step is crucial for achieving high signal-to-noise ratio measurements, as it directly obtains attenuation information related to carrier lifetime by separating the weak physical signal from the complex noise background.

[0097] This step may specifically include the following sub-steps:

[0098] S401, polarization-resolved collection of the photoluminescence signal is performed. The photoluminescence (PL) signal generated by the evolution and recombination of the coherent quantum state excited in step S303 is collected by a high numerical aperture objective lens in the coherent optical path and detector module 30. The collected light signal is sequentially passed through a spectral filter to remove residual excitation laser scattered light, and then through a polarization analyzer (e.g., a Gran-Thompson prism). This polarization analyzer is configured to allow only one specific, preset polarization direction vector. The optical signal passes through. After polarization resolution, the optical signal is finally recorded by a high time-resolution photodetector, which converts the signal of light intensity changing with time into a corresponding electrical signal.

[0099] S402 acquires the raw electrical signal containing quantum beat frequency and recombination attenuation information. The electrical signal output by the high time-resolution photodetector. Its intensity is proportional to the incident photon flux. This signal, in time... The functional form of this includes the exponential decay caused by carrier recombination within the acoustic potential well, as well as the quantum beat oscillations generated by the evolution of coherent quantum states. Its complete mathematical expression is:

[0100] ;

[0101] in, The overall detection efficiency factor of the system includes the collection efficiency of the optical signal, the transmittance of the optical elements, and the quantum efficiency of the photodetector. The initial amplitude of the signal depends on the polarization state of the incident light. Polarization state of emitted light and the stress principal axis direction vector generated by the acoustic field ; The lifetime of the pure charge carriers to be measured; It is in time The instantaneous quantum beat frequency, as in step S303, is a frequency that changes periodically with time due to the acoustic field modulation applied in step S203. ; This represents the initial phase of the quantum beat signal.

[0102] S403, Perform differential lock-lock demodulation to extract a clean attenuation envelope. The raw electrical signal obtained in step S402 is then... The signal is input to the high-frequency lock-in amplifier within the signal processing and verification module 40. Simultaneously, the signal used in the dynamic acoustic field driving module 20 to modulate the acoustic field, with a frequency of... The periodically modulated signal is used as a reference signal and input to the reference input terminal of the high-frequency lock-in amplifier. The lock-in amplifier uses its internal core components—a phase-sensitive detector (PSD) and a low-pass filter—to analyze the input signal. The process involves differential lock-in demodulation. The physical essence of this process is calculating the cross-correlation between the input signal and the reference signal. Since only the quantum beat frequency signal component generated by carriers periodically modulated by the acoustic field within the acoustic potential well has a strict lock-in relationship with the reference signal in both frequency and phase, only this part of the signal can produce a non-zero, slowly changing DC output. All signal components unrelated to acoustic modulation, including detector noise, ambient stray light interference, and background fluorescence generated by carriers not trapped in the acoustic potential well, are averaged out after low-pass filtering because they are uncorrelated with the reference signal. Therefore, the lock-in amplifier ultimately outputs a demodulated signal. The amplitude of this signal no longer includes high-frequency quantum beat frequency oscillations, but is directly proportional to the envelope of the signal component associated with acoustic modulation. This envelope is the pure recombination decay curve of charge carriers within the acoustic potential well, and its form is as follows:

[0103] ;

[0104] This step successfully and losslessly extracted a pure exponential decay signal with a very high signal-to-noise ratio, containing only carrier lifetime information, from the complex original signal, laying the foundation for subsequent high-precision parameter fitting.

[0105] In step S500, physical self-consistency is verified by rotating the principal stress axis of the acoustic standing wave field and analyzing the polarization correlation of the signal. The attenuation envelope is then fitted to extract the carrier lifetime parameters. This step ensures the physical authenticity of the measurement results through internal cross-validation, and based on this validity, the final physical quantities are accurately extracted from the purified signal.

[0106] This step may specifically include the following sub-steps:

[0107] S501 performs a non-mechanical rotation of the acoustic stress field vector. The central control and analysis computer within the signal processing and verification module 40 issues a series of preset control commands to the dynamic acoustic field drive module 20. These commands are used to programmatically and continuously change the relative phase between the various radio frequency signals output by its internal multi-channel direct digital frequency synthesizer (DDS). Since the spatial morphology of the three-dimensional acoustic standing wave field and the direction of its stress tensor are determined by the interference of various coherent ultrasonic waves, the direction vector of the principal axis of the acoustic standing wave field stress within the sample under test can be realized through electronic control of this relative phase. Precise rotation without requiring any physical mechanical movement of the sample or the three-dimensional piezoelectric transducer array.

[0108] S502, perform signal polarization-stress correlation mapping and physical model self-consistency verification. This is done in each principal stress axis direction defined in step S501. Next, the excitation and demodulation process of steps S300 to S400 is repeated. During the detection process, the angles of the coherent optical path and the polarization analyzer in the detection module 30 can be further systematically rotated to achieve the desired effect in each step. The following data was collected, corresponding to different emission polarization directions. The signal. Recorded in each combination. The initial amplitude of the quantum beat frequency signal measured below (This can be obtained from the initial values ​​of the original signal or the demodulated signal). This generates a two-dimensional response spectrum of the experimentally determined signal amplitude with respect to the stress direction and the outgoing polarization direction. Meanwhile, the central control and analysis computer, based on the band theory of the semiconductor material (e.g., k·p perturbation theory) and the selection rules of piezoelectric spectroscopy, calculates the theoretically expected response spectrum. In this calculation, k·p perturbation theory is used to accurately calculate the changes in the semiconductor band structure and the specific values ​​of energy level splitting caused by the acoustic stress field, while the selection rules of piezoelectric spectroscopy are used to determine the optical transition probabilities between light of different polarization states and these split energy levels. Together, they constitute the complete physical model for calculating the theoretical response spectrum. This is achieved by using experimental spectra... With theoretical map If the two measurements show a high degree of consistency in key features (such as symmetry, the location of maxima and minima), then the measurement provides strong physical self-consistency verification. This verification confirms that the detected signal does indeed originate from the expected quantum beat frequency effect generated by stress-splitting energy levels, thus verifying the physical correctness of the entire measurement method chain.

[0109] S503, perform numerical fitting and extraction of carrier lifetime parameters. After passing physical self-consistency verification, the central control and analysis computer of the signal processing and verification module 40 processes one or more sets of high signal-to-noise ratio attenuated envelope signals obtained in step S403. The data points are then processed. A numerical fitting algorithm (such as nonlinear least squares) is used to process the experimental data points. With the following single exponential decay model function Perform fitting:

[0110] ;

[0111] in, The initial amplitude of the attenuating signal; The lifetime of the charge carriers to be extracted; This is a background baseline constant. The fitting algorithm adjusts iteratively. , and The values ​​of these three parameters are used to find an optimal solution that makes the model function... With experimental data The sum of squared residuals is minimized. The optimal parameter values ​​obtained after the fitting process converges are the set of high-precision carrier lifetimes extracted from this measurement. The value of . During the fitting process, the standard error of the fitting parameters will also be obtained simultaneously. This standard error is the main basis for assessing the Type A uncertainty of this measurement.

[0112] In step S600, statistical analysis is performed on multiple sets of carrier lifetime parameters to determine the final value, and a traceability chain of values ​​based on a frequency reference is constructed. This final step aims to integrate a series of independent measurement results into a reliable value with definite uncertainty, and fundamentally establish the metrological status of this value.

[0113] This step may specifically include the following sub-steps:

[0114] S601, Perform statistical analysis and uncertainty assessment of the measurement results. To ensure the representativeness and reliability of the set values, the three-dimensional displacement platform of the manipulator sample and environmental control module 10 is used to repeatedly execute the complete measurement process of steps S200 to S500 at different spatial positions of the sample under test, or under different system parameter configurations (e.g., different stress field vector directions), thereby obtaining a result containing... Carrier lifetime dataset of individual measurements Perform statistical processing on the dataset and calculate its weighted average. As the final value for the carrier lifetime of the standard sample:

[0115] ;

[0116] Among them, weighting factors Typically, the uncertainty of each measurement is taken as . The reciprocal of the square, that is This assigns greater weight to measurement results with higher accuracy. Simultaneously, all sources of uncertainty in the measurement process are assessed, including Type A uncertainty (statistical uncertainty) introduced by data fitting and Type B uncertainty (systematic uncertainty) introduced by various system modules (such as temperature stability, time delay line accuracy, frequency source stability, etc.), and finally, the expanded uncertainty of the given value is obtained by combining these factors. Finally, output a document containing a constant value. and its expanded uncertainty A complete setpoint report.

[0117] When assessing the uncertainty of measurement results, the guidelines for the expression of measurement uncertainty (GUM) published by the International Bureau of Weights and Measures are followed. Type A uncertainty is an uncertainty component assessed through statistical analysis of the observation series. In this invention, it mainly originates from statistical errors generated when statistically averaging multiple sets of carrier lifetime measurement data and numerically fitting decay curves. Type B uncertainty is an uncertainty component assessed using methods different from statistical analysis. In this invention, it mainly originates from systematic errors related to the measurement equipment given in instrument calibration certificates, technical specifications, or previous measurement data, such as the stability of the frequency reference source, the temperature control accuracy of the isothermal chamber, and the positioning accuracy of the optical delay line.

[0118] S602, Construct and declare the traceability chain of the measurement values. The accuracy and reliability of the carrier lifetime determination values ​​measured in this invention are ultimately traced back to the International System of Units (SI) base unit "second" through a complete, clear, and purely physical comparison chain. The construction logic of this traceability chain is as follows:

[0119] 1. The constant value of carrier lifetime Its unit is seconds, and it is directly derived from a physical decay process with time as the independent variable. It was obtained through fitting.

[0120] 2. The signal during this attenuation process The reliability and high signal-to-noise ratio depend on the processing of the original photoluminescence signal in step S403. Differential lock-in demodulation.

[0121] 3. The reference for the differential lock demodulation process is the frequency of the periodic modulation signal applied to the acoustic standing wave field in step S203. This frequency The accuracy of the data directly determines the accuracy of the investigation process.

[0122] 4. The modulation frequency and the center driving frequency of the acoustic field All frequencies are precisely generated by the multi-channel direct digital frequency synthesizer (DDS) in the dynamic acoustic field drive module 20.

[0123] 5. The core clock of the multi-channel direct digital frequency synthesizer (DDS) is strictly locked to the frequency reference signal output by the frequency reference and traceability module 50 through a phase-locked loop (PLL) circuit.

[0124] 6. The frequency reference and traceability module 50 contains a primary frequency standard source, such as a rubidium atomic clock. The output frequency of this atomic clock, based on the principles of quantum physics, is directly related to the hyperfine transition period of the ground state of the cesium-133 atom, which is the definition reference of the "second" in the International System of Units (SI).

[0125] Through the aforementioned uninterrupted traceability chain, the carrier lifetime determination obtained by this method is... Its value is ultimately anchored to the highest physical reference representing the unit of time. This traceability path is entirely based on the precise measurement and transmission of the physical quantity of frequency, without relying on any consumable standard materials or intermediate reference samples that require periodic calibration, thus ensuring the long-term stability and authority of the determination results.

[0126] To further illustrate the collaborative working process of the technical solution of this invention, a specific working scenario example will be used below.

[0127] The objective of this embodiment is to determine the absolute value of the carrier lifetime on a high-purity floating zone (FZ) single-crystal silicon standard sample with a (100) crystal orientation used for high-order metrology calibration. After determination, this standard sample will be used as a transfer standard to calibrate conventional lifetime measurement equipment such as microwave photoconductivity attenuation (μ-PCD) widely used in industrial production lines.

[0128] First, specific parameter configurations are performed for the system of this invention. In the sample and environment control module 10, the temperature of the constant temperature control chamber is set to 300K, and its stability is required to be better than ±0.01K. In the dynamic acoustic field driving module 20, the center driving frequency for generating the three-dimensional acoustic standing wave field is set. The frequency is 100MHz, and a modulation frequency is applied to it. 10kHz, modulation amplitude The frequency modulation is 50 kHz periodicly. In the coherent optical path and detector module 30, a femtosecond laser source with a center wavelength of 800 nm and a pulse width of 100 fs is selected, and the time delay between the coherent double pulses generated by its optical path control subsystem is set. The time constant is 1 ns. In the signal processing and verification module 40, the time constant of the high-frequency lock-in amplifier is set to 1 ms to match the expected lifespan of the sample under test, which is in the millisecond range, and the high-speed data acquisition card is set to record data at a sampling rate of 1 MS / s.

[0129] After configuration, the setting process begins. The operator loads the (100) crystal orientation high-purity single-crystal silicon standard sample onto the sample fixture of the sample and environmental control module 10 and initiates environmental stabilization control. Subsequently, the system runs automatically according to steps S200 to S500. The dynamic acoustic field driving module 20 generates an acoustic potential well modulated by a 10kHz frequency in a preset target area within the sample. Immediately afterwards, the coherent optical path and detection module 30 emits a polarization-controlled 800nm ​​coherent double pulse sequence to excite the carriers in the acoustic potential well, causing them to enter a coherent superposition state.

[0130] The photoluminescence collection and detection subsystem acquires the photoluminescence signal containing quantum beat frequency information and converts it into an electrical signal, which is then sent to the signal processing and verification module 40. A high-frequency lock-in amplifier, using a modulation frequency of 10 kHz as a reference, performs differential lock-in demodulation on the original electrical signal, outputting a pure exponential decay curve with a very high signal-to-noise ratio. Simultaneously with data acquisition, the system automatically performs physical self-consistency verification: by non-mechanically rotating the principal axis of the acoustic stress field and simultaneously recording the change in signal amplitude with the outgoing polarization state, the obtained experimental spectrum is compared with the calculation results based on silicon band theory, confirming their agreement and thus verifying the physical validity of the measurement process. Finally, the central control and analysis computer performs nonlinear least squares fitting on the demodulated decay curve to extract the carrier lifetime at the measurement point. value.

[0131] To obtain the final value, the above complete process was repeated multiple times in different areas of the sample to obtain a set of independent lifetime measurement values.

[0132] Finally, statistical analysis and uncertainty assessment were performed on this set of measurement data. The final calculated carrier lifetime of the standard sample was determined to be... =1.254ms, combined expanded uncertainty is =0.008ms (confidence factor k=2). The system outputs a formal determination report, which clearly states the determination result and its uncertainty, and includes a traceability statement: This determination result, through locking the acoustic field modulation frequency, can be directly traced to the frequency reference and the rubidium atomic clock frequency standard built into the traceability module 50, thus establishing a direct correlation with the International System of Units (SI) "second". This determination report is delivered along with the standard sample, providing an authoritative metrological basis for its use as a measurement standard.

[0133] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of setting the value of the carrier lifetime of a standard wafer, characterized by, Includes the following steps: Loading, positioning, and environmental stabilization of the sample under test are performed, and system initialization parameters are configured. A three-dimensional acoustic standing wave field is generated in the target region within the sample under test to construct an acoustic potential well, and the driving frequency of the three-dimensional acoustic standing wave field is periodically modulated. Specifically, this includes: generating multiple radio frequency signals with preset phase, frequency, and amplitude relationships, and superimposing a periodically changing modulation signal on the center driving frequency of the radio frequency signals; driving a three-dimensional piezoelectric transducer array to emit coherent ultrasonic waves, which interfere within the sample under test to form the three-dimensional acoustic standing wave field, which induces a spatially periodic stress and strain distribution in the lattice of the sample under test; and forming a local energy minimum point in the target region based on the stress and strain distribution to constitute the acoustic potential well. Focusing a coherent double-pulse sequence with a specific time delay and polarization state onto the central region of the acoustic potential well to excite a coherent quantum state within the acoustic potential well; specifically including: splitting an ultrafast laser pulse sequence into two beams, passing one beam through an optical delay line to introduce a controllable time delay, and then recombining the two beams to form the coherent double-pulse sequence; setting the polarization state of the coherent double-pulse sequence to a preset incident polarization vector using a polarization controller; focusing the coherent double-pulse sequence onto the central region of the acoustic potential well to drive the exciton states that undergo energy level splitting due to local stress to the coherent quantum state formed by coherent superposition; The polarization-resolved photoluminescence signal returned from the coherent quantum state is acquired, and the photoluminescence signal is differentially locked demodulated based on the periodic modulation to extract the attenuation envelope of the signal. Physical self-consistency was verified by rotating the stress principal axis of the three-dimensional acoustic standing wave field and analyzing the polarization correlation of the signal, and the attenuation envelope was fitted to extract the carrier lifetime parameters. Statistical analysis was performed on multiple sets of carrier lifetime parameters to determine the final values, and a traceability chain of values ​​based on frequency reference was constructed.

2. The method for determining the carrier lifetime of a standard sample according to claim 1, characterized in that, The acquisition of the polarization-resolved photoluminescence signal returned from the coherent quantum state, and the differential-locked demodulation of the photoluminescence signal based on the periodic modulation, includes: The photoluminescence signal generated by the recombination of the coherent quantum states is collected and polarization-resolved using a polarization analyzer; The polarization-resolved optical signal is converted into a raw electrical signal that includes exponential decay and quantum beat frequency oscillation. The original electrical signal and the periodically modulated modulation signal are respectively fed into a lock-in amplifier as signal input and reference input. The original electrical signal is demodulated by phase-sensitive detection and low-pass filtering to output the attenuation envelope of the signal that contains only the exponential decay information.

3. The method for determining the carrier lifetime of a standard sample according to claim 1, characterized in that, The process of fitting the attenuation envelope to extract carrier lifetime parameters includes: The experimental data points of the signal attenuation envelope were compared with those of the single exponential attenuation model function using the nonlinear least squares method. Perform fitting; in, The initial amplitude of the attenuating signal, The carrier lifetime to be extracted. A background baseline constant; Through iterative adjustments , and The optimal parameter value is obtained when the sum of squared residuals between the model function and the experimental data points is minimized, and this optimal parameter value is used as the carrier lifetime parameter.

4. The method for determining the carrier lifetime of a standard sample according to claim 1, characterized in that, The statistical analysis of multiple sets of carrier lifetime parameters to determine the final value includes: Repeated measurements were performed at different spatial locations of the sample under test to obtain a carrier lifetime dataset containing multiple independent measurement results; The weighted average of the carrier lifetime dataset is calculated as the final value, where the weighting factor is the reciprocal of the square of the uncertainty of each measurement. The Type A and Type B uncertainties in the measurement process are evaluated and combined to obtain the expanded uncertainty of the final value.

5. The method for determining the carrier lifetime of a standard sample according to claim 1, characterized in that, The process of loading, positioning, and stabilizing the test sample, and configuring system initialization parameters includes: The selected bulk material target measurement area on the sample under test is precisely positioned at the optical focusing point and the acoustic field target center using a three-dimensional displacement platform. The temperature control chamber and vibration isolation system are activated to isolate external environmental temperature fluctuations and mechanical vibrations; Set the center driving frequency and modulation frequency of the acoustic field, the delay time and incident polarization state of the optical system, and the lock-in amplifier parameters and data acquisition mode of the signal processing system.

6. The method for determining the carrier lifetime of a standard sample according to claim 2, characterized in that, The differential locked demodulation extracts the attenuation envelope of the signal by calculating the cross-correlation between the original electrical signal and the periodically modulated signal, outputting only the envelope of the signal components that are locked with the periodic modulation in frequency and phase, and filtering out all signal components that are not related to the periodic modulation.

7. The method for determining the carrier lifetime of a standard sample according to claim 3, characterized in that, The physical self-consistency verification includes: Non-mechanical rotation of the stress principal axis direction is achieved by programmatically changing the relative phase between multiple radio frequency signals used to generate the three-dimensional acoustic standing wave field. In each of the principal stress axes, the initial amplitude of the photoluminescence signal is recorded in response to the outgoing polarization direction to generate an experimental response spectrum. The experimental response spectrum was compared with the theoretical response spectrum calculated based on semiconductor band theory to verify the consistency between the experimental response spectrum and the theoretical response spectrum in terms of symmetry and extreme value location characteristics.

8. A traceability system for carrier lifetime of a standard sample, applied to the method for determining the carrier lifetime of a standard sample as described in any one of claims 1-7, characterized in that, include: The sample and environment control module is used to carry and precisely position the standard sample to be tested, and to provide a highly stable physical measurement environment for the standard sample. The dynamic acoustic field driving module is used to generate a three-dimensional acoustic standing wave field within the standard sample and to dynamically adjust the parameters of the three-dimensional acoustic standing wave field. The coherent optical path and detection module is used to optically excite the potential well region formed by the three-dimensional acoustic standing wave field within the sample under test, and to collect the photoluminescence signal returned from the region. The signal processing and verification module coordinates the operation of the dynamic acoustic field driving module and the coherent optical path and detection module, and receives the electrical signal output by the coherent optical path and detection module, and performs differential lock demodulation and fitting processing on the electrical signal. The frequency reference and traceability module is electrically connected to the dynamic acoustic field drive module and is used to output a frequency reference signal with high stability and high accuracy to lock the core clock of the dynamic acoustic field drive module.

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