Spectral resolution optical excitation scanning probe electric signal extraction device and method

Abstract

The invention relates to the technical field of material electrical signal detection, in particular to a spectral resolution optical excitation scanning probe electrical signal extraction device which comprises a light source unit, a light path unit, a measurement unit and a management control unit. The light source unit and the measuring unit are electrically connected to the management control unit. The management control unit configures working parameters of the light source unit. Under the control of the management control unit, light beams emitted by the light source unit are guided to irradiate the surface of a sample through the light path unit. The control management unit further controls the measuring unit to collect electrical information of the sample irradiated by the light beams and transmits the electrical information to the management control unit for further processing and storage. The invention also comprises a method. According to the invention, the electrical response of the material under the excitation of light with different wavelengths can be accurately obtained, and the photoelectric characteristics and the microscopic physical mechanism of the material can be deeply researched. A more accurate and effective detection means is provided for research and development of novel materials, performance optimization of semiconductor devices and the like, and technical progress and innovative development are promoted.

Description

Technical Field

[0001] The invention relates to the technical field of material electrical signal detection, in particular to a spectrally resolved optical excitation scanning probe electrical signal extraction device and method. Background Art

[0002] In the field of material electrical properties research, photocurrent extraction technology has always been a key means to deeply explore the internal carrier behavior and photoelectric conversion mechanism of materials. Traditional photocurrent extraction methods mainly include the use of Fourier spectrometer combined with device electrical signal extraction and the use of monochromator spectrometry combined with device electrical signal extraction.

[0003] During the photocurrent extraction process, the Fourier spectrometer performs spectral analysis on light through its unique interference principle. It can cover a wide spectral range and perform accurate spectral resolution of optical signals. However, when the Fourier spectrometer is combined with the device electrical signal extraction, due to the limitations of its optical path design and measurement principle, the spatial resolution can only reach the micron level. At this micron-level spatial resolution, it is difficult to perform a detailed characterization of the carrier transport process at the microscopic scale inside the material. The transport behavior of carriers in nanoscale material structures is often significantly affected by multiple factors such as quantum size effects and interface states, and the micron-level resolution cannot accurately capture these detailed changes at the nanoscale, thus limiting the in-depth understanding of the carrier transport mechanism.

[0004] Similarly, the method of combining monochromator spectroscopy with device electrical signal extraction also faces a similar dilemma. The monochromator decomposes composite light into monochromatic light of different wavelengths through optical elements such as gratings, and then studies the electrical response of the device under the excitation of light of different wavelengths. However, in terms of spatial resolution, it can only reach the micron level. When studying materials or devices with nanostructures, it is impossible to meet the demand for accurate detection of carrier behavior in nanoscale regions, and it is difficult to obtain photocurrent spectrum information in local nanoscale regions, which makes the research on the microscopic photoelectric properties of materials have great limitations.

[0005] On the other hand, the currently commercialized scanning probe microscope has unique advantages in the extraction of electrical signals from materials. It can realize the extraction of current and potential signals with nanoscale spatial resolution. This makes it play an important role in studying the inhomogeneity of electrical properties on the surface of materials at the nanoscale and the electrical properties of nanostructures. However, it mainly focuses on the extraction of intrinsic carrier signals of materials and lacks effective means of light excitation. Moreover, since its original design was not aimed at spectral resolution, it has obvious deficiencies in spectral resolution. This leads to the inability to take into account both nanoscale spatial resolution and spectral resolution when studying the optoelectronic properties of materials. It is difficult to fully and deeply explore the dynamic processes of carrier generation, transport and recombination in nanoscale regions of materials under light excitation of different wavelengths, and it is impossible to meet the needs of modern materials science and nanotechnology for high-precision and multifunctional electrical signal detection technology.

[0006] In summary, the existing photocurrent extraction technology has obvious defects in the integration of spatial resolution and spectral resolution. There is an urgent need for a new technology to extract material electrical signals using a photoexcitation probe that has both nanoscale spatial resolution and spectral resolution capabilities to fill this technological gap and promote the research on material electrical properties in a more microscopic and precise direction. Summary of the invention

[0007] The purpose of the present invention is to provide a spectrally resolved photoexcitation scanning probe electrical signal extraction device and method, which mainly solves the problems existing in the above-mentioned prior art. It can obtain the photocurrent spectrum of the material under nanoscale spatial resolution, so as to deeply study the electrical properties of the material when excited by light of different wavelengths.

[0008] In order to achieve the above-mentioned object, the technical solution adopted by the present invention is to provide a spectrally resolved optical excitation scanning probe electrical signal extraction device, characterized in that it comprises a light source unit, an optical path unit, a measurement unit and a management control unit;

[0009] The light source unit and the measuring unit are both electrically connected to the management control unit;

[0010] The management and control unit configures the working parameters of the light source unit; under the control of the management and control unit, the light beam emitted by the light source unit is guided through the optical path unit to illuminate the surface of the sample; the control and management unit also controls the measuring unit to collect electrical information of the sample at the point where the light beam illuminates, and transmits it to the management and control unit for further processing and storage.

[0011] Further, the light source unit comprises a wide spectrum light source and a monochromator;

[0012] The light beam output by the wide spectrum light source enters the monochromator, and the monochromator selects one of the monochromatic light beams as the output of the illumination unit according to the working parameters; the monochromator is electrically connected to the management control unit, and the management control unit sets the working parameters.

[0013] Furthermore, the broad spectrum light source is a white light source having a focusing function.

[0014] Furthermore, the optical path unit includes a beam expanding optical path module and a focusing optical path module; the beam expanding optical path module is connected to the light source unit, receives the light beam and expands the diameter of the light beam; the focusing optical path module is installed after the beam expanding optical path module, and is used to focus the light beam with expanded diameter onto the surface of the sample.

[0015] Furthermore, the focusing optical path module comprises a reflector and a concave mirror; the reflector projects the light beam onto the top of the sample, and the concave mirror focuses the light beam onto the surface of the sample.

[0016] Further, the measuring unit comprises a driving module and a probe;

[0017] The probe is connected to the driving module and, under the action of the driving module, is brought close to the surface of the sample; the probe is electrically connected to the management and control unit and is responsible for collecting the electrical information of the sample surface in contact with it and transmitting it to the management and control unit.

[0018] Furthermore, the electrical information includes current and potential.

[0019] Furthermore, the management control unit includes a control module and a modulation and demodulation module;

[0020] The control module is electrically connected to the light source unit and the measuring unit, and is used to configure the working parameters and synchronize the actions of the light source unit and the measuring unit; the modulation and demodulation module receives the electrical information from the measuring unit, and saves it after further processing.

[0021] Further, the control module includes a lock-in amplifier and a controller;

[0022] The controller is connected to the light source unit and the measuring unit through the phase-locked amplifier; the controller adjusts the light beam output by the light source unit by adjusting the working parameters, and also uses the control signal amplified by the phase-locked amplifier to synchronize the measurement unit with the light source unit to ensure the synchronization of the illumination timing and the measurement timing.

[0023] The present invention also discloses a signal extraction method using the above-mentioned optical excitation scanning probe electrical signal extraction device with spectral resolution, characterized in that it comprises the steps of:

[0024] Step S1, installing the sample;

[0025] Step S2, turning on the light source unit;

[0026] Step S3, configuring the operating parameters of the light source unit through the management control unit;

[0027] Step S4, adjusting the optical path unit so that the light beam is focused on the surface of the sample below the measuring unit;

[0028] Step S5, controlling the measuring unit to read the electrical information of the sample under test through the management control unit;

[0029] Step S6, the management control unit records the electrical information;

[0030] Step S7, if data collection is completed, jump to step S9, otherwise go to step S8;

[0031] Step S8, configuring the new working parameters through the management control unit to change the wavelength of the light beam; jumping to step S5;

[0032] Step S9, generating a photocurrent spectrum using the electrical information recorded under different operating parameters.

[0033] In view of the above technical features, compared with the prior art, the present invention has the following advantages:

[0034] 1. The spectrally resolved light-excitation scanning probe electrical signal extraction device and method of the present invention can accurately obtain the electrical response of materials under light excitation of different wavelengths, which is helpful for in-depth research on the photoelectric properties and microscopic physical mechanisms of materials.

[0035] 2. The spectrally resolved light-excited scanning probe electrical signal extraction device and method of the present invention provide a more accurate and effective detection means for the research and development of new materials, optimization of semiconductor device performance, etc., which is conducive to promoting technological progress and innovative development in related fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of a preferred embodiment of the optical excitation scanning probe electrical signal extraction device with spectral resolution of the present invention;

[0037] Figure 2 It is a method flow chart of a preferred embodiment of the measurement method of the present invention using a light excitation scanning probe electrical signal extraction device with spectral resolution;

[0038] Figure 3 The data are measured data of a preferred embodiment of the measurement method of the present invention using a light-excitation scanning probe electrical signal extraction device with spectral resolution.

[0039] In the figure: 100 - light source unit, 200 - optical path unit, 300 - measurement unit, 400 - management control unit, 500 - sample;

[0040] 101-broad spectrum light source, 102-monochromator; 201-beam expansion optical path module, 202-focusing optical path module;

[0041] 301 - driving module, 302 - probe; 410 - control module, 420 - modulation and demodulation module; 411 - phase-locked amplifier, 412 - controller. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0043] See also Figure 1 The present invention discloses a spectrally resolved optical excitation scanning probe electrical signal extraction device. As shown in the figure, a preferred embodiment thereof includes a light source unit 100, an optical path unit 200, a measurement unit 300 and a management control unit 400.

[0044] The light source unit 100 includes a wide spectrum light source 101 and a monochromator 102. In the present embodiment, the wide spectrum light source is a white light source. The wide spectrum light source 101 also has a focusing function, so that the light beam can be directed to the monochromator 102 more effectively. Because the photoelectric effect is related to the incident frequency of light, when measuring the photocurrent spectrum of the sample 500, it is necessary to irradiate the sample 500 one by one at different frequencies and then measure. Therefore, the grating in the monochromator 102 can separate light of different wavelengths, which is used to select a wavelength from the light beam output by the wide spectrum light source 101 to form a monochromatic light beam, and then irradiate the sample 500. The monochromator 102 is connected to the management control unit 400, and the management control unit 400 configures the working parameters for it. Different working parameters of the monochromator 102 correspond to different output wavelengths. During the measurement process, the management control unit 400 inputs different working parameters in sequence, and finally traverses all wavelengths corresponding to the entire wide spectrum light source 101.

[0045] The optical path unit 200 includes a beam expansion optical path module 201 and a focusing optical path module 202, which are used to accurately introduce the light beam separated by the monochromator 102 into the measuring unit 300. The beam expansion optical path module 201 receives the light beam from the monochromator 102, and then expands the diameter of the light beam using an optical lens. The focusing optical path module 202 is installed after the beam expansion optical path module 201. It can adjust the optical path of the light beam after the diameter is expanded so that it converges to different positions on the surface of the sample 500, and is used to measure the photoelectric properties of different positions on the sample 500. The focusing optical path module 202 is composed of a reflector and a concave mirror. Among them, a combination of multiple reflectors projects the light beam onto the top of the sample 500, and finally converges the light beam through the concave mirror to form a small diameter light spot on the surface of the sample 500.

[0046] The measuring unit 300 includes a clamping module 301 and a probe 302, which is used to collect electrical information of the sample 500 under the irradiation of the light beam. Specifically, the probe 302 is installed on the driving module 301, and is pushed and close to the surface of the sample 500 by the driving module. The contact surface between the probe 302 and the sample 500 is smaller than the spot diameter of the light beam. The probe 302 is also electrically connected to the management and control unit 400. When the light beam excites the sample 500 under the probe 302, carriers are excited in the sample 500, and the probe 302 collects electrical information of the contact surface by physically contacting the surface of the sample 500, and then transmits it to the management and control unit 400 for further processing. The collected electrical information includes the current and potential of the sample 500.

[0047] The management control unit 400 includes a control module 410 and a modulation and demodulation module 420. The control module 410 is used to manage and schedule the entire system. It is electrically connected to the light source unit 100 and the measuring unit 300 and is composed of a phase-locked amplifier 411 and a controller 412. The control signal of the controller 412 is amplified by the phase-locked amplifier 411 and sent to the light source unit 100 and the measuring unit 300. Specifically, for the light source unit 100, the controller 412 is connected to the monochromator 102, configures the working parameters of the monochromator 102, and selects the wavelength of the light beam output by the light source unit 100. For the measuring unit 300, the controller 412 is used to synchronize the actions of the measuring unit 300 and the light source unit 100 to ensure that the illumination timing and the measurement timing are synchronized. That is, when the light source unit 100 outputs, the probe 302 is notified to act and collect electrical information. The electrical information collected by the probe 302 is transmitted to the modulation and demodulation module 420. After the modulation and demodulation module 420 obtains the electrical information, it organizes the electrical information in a data format and saves it, and can generate a photocurrent spectrum of the sample 500 based on the previously saved historical data.

[0048] See also Figure 2The present invention also discloses a signal extraction method using the above-mentioned optical excitation scanning probe electrical signal extraction device with spectral resolution. A preferred embodiment thereof comprises the steps of:

[0049] Step S100, installing a sample.

[0050] Step S200, turning on the light source unit.

[0051] Turn on the broad spectrum light source and use the default configuration of the monochromator to output a single wavelength beam.

[0052] Step S300, configuring a monochromator.

[0053] Use the control module in the management control unit to configure the working parameters of the monochromator and select the beam wavelength suitable for the current sample.

[0054] Step S400, focusing the light beam onto the sample.

[0055] Adjust the optical path unit so that the monochromatic light beam is focused on the sample surface below the probe in the measurement unit.

[0056] Step S500, reading electrical information.

[0057] The control module in the management control unit is used to control the probe in the measurement unit to read the electrical information of the sample surface irradiated by the monochromatic light beam, including the potential and current, and then send the electrical information to the modulation and demodulation module in the management control unit.

[0058] Step S600, saving electrical information.

[0059] The modulation and demodulation module in the management control unit performs pre-processing including format conversion on the received electrical information and then saves it.

[0060] Step S700, determining whether the measurement is completed.

[0061] If all data measurements for the sample are completed, jump to step S900; otherwise, go to step S800.

[0062] Step S800, adjusting working parameters.

[0063] The control module in the management control unit is used to adjust the working parameters of the monochromator, thereby changing the wavelength of the monochromator output light beam, and then jumps to step S500 to continue the next measurement.

[0064] Step S900: generating a photocurrent spectrum.

[0065] Using the electrical information recorded under different measurement parameters, a photocurrent spectrum is plotted based on the potential and current. A photocurrent spectrum of this embodiment, such as Figure 3shown.

[0066] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A spectrally resolved optical excitation scanning probe electrical signal extraction device, characterized in that: It includes a light source unit, an optical path unit, a measuring unit and a management control unit; The light source unit and the measuring unit are both electrically connected to the management control unit; The management and control unit configures the working parameters of the light source unit; under the control of the management and control unit, the light beam emitted by the light source unit is guided through the optical path unit to illuminate the surface of the sample; the control and management unit also controls the measuring unit to collect electrical information of the sample at the point where the light beam illuminates, and transmits it to the management and control unit for further processing and storage.

2. The optical excitation scanning probe electrical signal extraction device with spectral resolution according to claim 1, characterized in that: The light source unit comprises a wide spectrum light source and a monochromator; The light beam output by the wide spectrum light source enters the monochromator, and the monochromator selects one of the monochromatic light beams as the output of the illumination unit according to the working parameters; the monochromator is electrically connected to the management control unit, and the management control unit sets the working parameters.

3. The optical excitation scanning probe electrical signal extraction device with spectral resolution as claimed in claim 2, characterized in that: The broad spectrum light source is a white light source including a focusing function.

4. The optical excitation scanning probe electrical signal extraction device with spectral resolution according to claim 1, characterized in that: The optical path unit includes a beam expanding optical path module and a focusing optical path module; the beam expanding optical path module is connected to the light source unit, receives the light beam and expands the diameter of the light beam; the focusing optical path module is installed after the beam expanding optical path module, and is used to converge the light beam with expanded diameter onto the surface of the sample.

5. The optical excitation scanning probe electrical signal extraction device with spectral resolution as claimed in claim 4, characterized in that: The focusing optical path module comprises a reflecting mirror and a concave mirror; the reflecting mirror projects the light beam onto the top of the sample, while the concave mirror focuses the light beam onto the surface of the sample.

6. The optical excitation scanning probe electrical signal extraction device with spectral resolution according to claim 1, characterized in that: The measuring unit comprises a driving module and a probe; The probe is connected to the driving module and, under the action of the driving module, is brought close to the surface of the sample; the probe is electrically connected to the management and control unit and is responsible for collecting the electrical information of the sample surface in contact with it and transmitting it to the management and control unit.

7. The optical excitation scanning probe electrical signal extraction device with spectral resolution according to claim 1, characterized in that: The electrical information includes current and potential.

8. The optical excitation scanning probe electrical signal extraction device with spectral resolution as claimed in claim 1, characterized in that: The management control unit comprises a control module and a modulation and demodulation module; The control module is electrically connected to the light source unit and the measuring unit, and is used to configure the operating parameters and synchronize the actions of the light source unit and the measuring unit; The modulation and demodulation module receives the electrical information from the measurement unit and stores it after further processing.

9. The optical excitation scanning probe electrical signal extraction device with spectral resolution according to claim 8, characterized in that: The control module includes a lock-in amplifier and a controller; The controller is connected to the light source unit and the measuring unit through the phase-locked amplifier; the controller adjusts the light beam output by the light source unit by adjusting the working parameters, and also uses the control signal amplified by the phase-locked amplifier to synchronize the measurement unit with the light source unit to ensure the synchronization of the illumination timing and the measurement timing.

10. A signal extraction method using the optical excitation scanning probe electrical signal extraction device with spectral resolution as claimed in claim 1, characterized in that: Contains steps: Step S1, installing the sample; Step S2, turning on the light source unit; Step S3, configuring the operating parameters of the light source unit through the management control unit; Step S4, adjusting the optical path unit so that the light beam is focused on the surface of the sample below the measuring unit; Step S5, controlling the measuring unit to read the electrical information of the sample under test through the management control unit; Step S6, the management control unit records the electrical information; Step S7, if data collection is completed, jump to step S9, otherwise go to step S8; Step S8, configuring new operating parameters and changing the wavelength of the light beam through the management control unit; Jump to step S5; Step S9, generating a photocurrent spectrum using the electrical information recorded under different operating parameters.

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