Apparatus and method for measuring temperature of silicon-based transistor channel

Abstract

The application provides a silicon-based transistor channel temperature measuring device and method, and relates to the technical field of temperature measurement. The measuring device comprises: a superconducting coil, which is used for providing a magnetic field for a transistor to form two spin state energy levels; a low-temperature thermostat, which is used for providing a low-temperature environment for the transistor, and in the low-temperature environment, a first ratio of particle population numbers on the two spin state energy levels satisfies a Boltzmann distribution related to a temperature value of the channel; a tunable laser module, which is used for generating a first laser in a near-infrared wave band; a current processing module, which is used for collecting a tunneling current; a processor, which is used for determining a photoionization signal strength; based on the photoionization signal strength, a second ratio of probabilities of photoionization events occurring on the two spin state energy levels is determined; based on the second ratio, the first ratio is determined; and according to the Boltzmann distribution and the first ratio, the temperature value of the channel is obtained.

Description

TECHNICAL FIELD

[0001] At least one embodiment of the present application relates to the technical field of temperature measurement, and more particularly to a silicon-based transistor channel temperature measurement device and method. BACKGROUND

[0002] Silicon-based micro-nano devices are widely used in daily life and production, including silicon-based transistors in mobile phone processor chips, silicon light modulators in integrated photonics chips, etc. With the rapid development of quantum information technology, silicon-based transistors and silicon-based photonic crystal cavities and other micro-nano devices also play an indispensable role in frontier scientific fields. Devices that can be prepared using silicon-based micro-nano devices, such as scalable spin quantum computers based on silicon-based transistors and high-performance solid-state quantum light sources using silicon-based photonic crystal transistors. In the above important applications, the characteristics of silicon-based micro-nano devices in a low-temperature environment (below 4.2 K of liquid helium temperature) are particularly important, especially the temperature of the internal channel, which affects key parameters or performance such as spin-lattice relaxation and spin coherence control. However, the current precise measurement technology for the temperature of the channel of silicon-based micro-nano devices in a low-temperature environment is not perfect. SUMMARY

[0003] In view of the above problems, the present application provides a silicon-based transistor channel temperature measurement device and method for measuring the temperature of micro-nano devices in a low-temperature environment.

[0004] According to a first aspect of the present application, a silicon-based transistor channel temperature measurement device is provided, the measurement device comprising: a superconducting coil for providing a magnetic field for a transistor, so that spin defects in the transistor channel undergo spin energy level splitting to form two spin state energy levels; a cryostat for providing a low-temperature environment for the transistor, wherein the first ratio of the population of particles on the two spin state energy levels in the low-temperature environment satisfies the Boltzmann distribution related to the temperature value of the channel; a tunable laser module for generating a first laser in the near-infrared band; a current processing module for collecting tunneling current generated by the transistor when the first laser is incident on the channel; a processor for recording the number of jumps of the tunneling current per unit time under the action of the first laser in the microwave frequency stage, and determining the photoionization signal strength; determining the second ratio of the probability of photoionization events on the two spin state energy levels based on the photoionization signal strength; determining the first ratio based on the second ratio; and obtaining the temperature value of the channel according to the Boltzmann distribution and the first ratio.

[0005] According to an embodiment of the present application, the current processing module comprises: a circuit board for supporting and electrically connecting the transistor; a voltage source for providing a preset gate voltage, a preset source voltage and a preset drain voltage for the transistor by providing a voltage to the circuit board, so as to drive the transistor to generate the tunneling current in the case that the transistor is in the low-temperature environment and the first laser is incident on the channel position; and a collection unit for collecting the tunneling current and converting the tunneling current into a voltage signal, so as to facilitate observation of the jump of the tunneling current.

[0006] According to an embodiment of the present application, the measuring device further comprises: a lens group for focusing the first laser on the transistor and receiving the second laser reflected from the transistor; and a low-temperature nano-positioning module for non-adjustably fixing the position of the circuit board and adjustably fixing the position of the lens group, and adjusting the position of the focused first laser spot on the channel position by adjusting the position of the lens group.

[0007] According to an embodiment of the present application, the tunable laser module comprises: a fiber loop for inputting the first laser into the low-temperature thermostat and receiving the second laser; and a photoelectric detection unit connected to the fiber loop for detecting the optical power of the second laser.

[0008] According to an embodiment of the present application, the low-temperature nano-positioning module adjusts the position of the lens group to a first position, so that the focused first laser spot moves from other positions of the transistor to the surface of the transistor; in the case that the position of the lens group is adjusted to the first position, the optical power of the second laser is a first target value; the low-temperature nano-positioning module adjusts the position of the lens group from the first position to a second position, so that the focused first laser spot moves from the surface of the transistor to the channel; in the case that the position of the lens group is adjusted to the second position, the tunneling current is a second target value under the action of the first laser which is in a stable frequency state and is not in a resonance frequency.

[0009] According to an embodiment of the present application, the low-temperature nano-positioning module comprises: a nano-displacement stage configured to be connected to the lens group for adjusting the position of the lens group in a nano-scale range; a first mounting member configured to fixedly connect the circuit board; and a cold plate configured to be connected to the nano-displacement stage and the first mounting member for reducing the temperature of the circuit board.

[0010] According to the embodiment of the present application, the lens group comprises: a fiber ceramic head for transmitting the first laser and the second laser; a second mounting member for fixedly connecting the fiber ceramic head and the nanometer displacement table; and an aspheric lens assembly installed in the second mounting member, and the aspheric lens assembly is used for focusing the first laser on the transistor and receiving the second laser from the transistor.

[0011] According to the embodiment of the present application, the tunable laser module further comprises: a laser frequency stabilization unit for generating a first laser in a near-infrared wave band and performing frequency stabilization processing, so that the first laser is in a frequency stabilization state; and an electro-optical modulation unit for loading a microwave modulation signal on the first laser after the frequency stabilization processing, so as to perform microwave frequency modulation on the first laser, so that the first laser is in a microwave frequency modulation stage.

[0012] Another aspect of the present application provides a silicon-based transistor channel temperature measurement method applied to the measurement device, and the measurement method comprises: providing a magnetic field for the transistor, so that spin defects in the transistor channel are spin energy level split to form two spin state energy levels; providing a low-temperature environment for the transistor, wherein the first ratio of the particle population numbers on the two spin state energy levels satisfies the Boltzmann distribution related to the temperature value of the channel in the low-temperature environment; generating a first laser in a near-infrared wave band; collecting a tunneling current generated by the transistor under the condition that the first laser is incident on the channel; recording the number of jumps of the tunneling current per unit time under the action of the first laser in the microwave frequency modulation stage, and determining the photoionization signal strength; determining the second ratio of the probability of photoionization events occurring on the two spin state energy levels based on the photoionization signal strength; determining the first ratio based on the second ratio; and obtaining the temperature value of the channel according to the Boltzmann distribution and the first ratio.

[0013] According to the embodiment of the present application, the measurement method further comprises: incident the first laser on the channel; wherein the incident of the first laser on the channel comprises: adjusting the position of the lens group to a first position, so that the focal spot of the focused first laser moves from other positions of the transistor to the surface of the transistor; under the condition that the position of the lens group is adjusted to the first position, the optical power of the second laser is a first target value; adjusting the position of the lens group from the first position to a second position, so that the focal spot of the focused first laser moves from the surface of the transistor to the channel; under the condition that the position of the lens group is adjusted to the second position, the tunneling current under the action of the first laser in the frequency stabilization state and not in the resonance frequency is a second target value.

[0014] According to the embodiment of the present application, based on the spin occupation thermal distribution of the photoionization defects in the silicon material, and the wavelength of the spin defect resonance laser of the silicon material is in the near infrared light waveband, according to the magnetic field information, the photoionization signal intensity and the Boltzmann distribution formula, the temperature of the channel of the silicon-based transistor can be directly obtained. The measuring device for the channel temperature of the silicon-based transistor in the embodiment of the present application uses the near infrared light waveband of the optical fiber communication waveband to excite the photoionization defects of the silicon-based transistor, avoiding the additional heating of the visible light to the silicon-based device; the tunneling current is generated by the excitation of the first laser, avoiding the fluorescence collection in the low temperature environment, and reducing the complexity of the measuring device; the photoionization defects in the silicon material can be highly integrated with the existing silicon-based device, so as to directly measure the temperature of the channel of the silicon-based transistor. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the present application will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 A principle schematic diagram of the measuring device for the channel temperature of the silicon-based transistor according to an embodiment of the present application is shown.

[0017] Figure 2 A principle schematic diagram of the measuring device for the channel temperature of the silicon-based transistor according to an embodiment of the present application is shown.

[0018] Figure 3 A principle schematic diagram of the measuring device for the channel temperature of the silicon-based transistor according to another embodiment of the present application is shown.

[0019] Figure 4 A principle schematic diagram of the measuring device for the channel temperature of the silicon-based transistor according to another embodiment of the present application is shown.

[0020] Figure 5 An operation flow chart of the measuring method for the channel temperature of the silicon-based transistor according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present application will be described with reference to the accompanying drawings. It is to be understood, however, that the description is merely exemplary and is intended to provide a thorough understanding of the present application. The following description, given by way of example, is not to be construed as limiting the present application. In the following detailed description of embodiments of the present application, numerous specific details are set forth in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that one or more embodiments of the present application can be practiced without these specific details. In other instances, well-known structures and functions have not been described in detail in order to avoid obscuring aspects of the present application.

[0022] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "comprising" or "comprises" is used in the sense of "including" or "includes" and not in the sense of "consisting only of" or "consists only of."

[0023] All terms used herein including technical and scientific terms have the meanings commonly understood by one of ordinary skill in the art unless otherwise specified. It should be noted that the use of any terms herein should not be interpreted to limit the scope of the present disclosure, but rather to enhance the understanding thereof.

[0024] In the case of using expressions similar to "at least one of A, B, and C, etc.", it is generally understood that the expression is intended to include at least one of the items, but not only including the items listed one by one. For example, "a system having at least one of A, B, and C" is understood as including, for example, a system having only A, a system having only B, a system having only C, a system having both A and B, a system having both A and C, a system having both B and C, and a system having all of A, B, and C, etc.

[0025] The measurement of the temperature of micro-nano devices in a low-temperature environment imposes stringent requirements on temperature sensors: compatibility with existing devices and the ability to measure the temperature of the channel inside the device, as well as nanoscale spatial resolution.

[0026] In the related art, the measurement method of the internal temperature of a low-temperature micro-nano device structure can be achieved by an optical temperature sensor and a fluorescent temperature sensor.

[0027] The principle of the optical temperature sensor is to inversely deduce the temperature from the change of optical quantities such as the resonant frequency of the resonant cavity and the intensity of the transmission spectrum caused by the thermo-optic effect. However, the optical temperature sensor only has good sensitivity at a relatively high temperature (such as room temperature). Because the thermo-optic coefficient sharply decreases (below one ten-thousandth) in a low-temperature environment below liquid helium, the sensitivity is greatly reduced, and an accurate temperature value cannot be given.

[0028] The fluorescent temperature sensor usually uses materials such as solid color centers of diamond and silicon carbide, quantum dots, and rare earth ion-doped organic powders to give a temperature value based on the dependence of the fluorescence spectrum on temperature. Although it can give an accurate temperature in a low-temperature environment, it cannot be well compatible and integrated with current silicon-based micro-nano devices, and thus cannot give the actual temperature inside the device. In addition, the excitation light wavelength required by the fluorescent thermometer is usually in the visible light wavelength range (such as common 532 nm green light), which is located in the forbidden band of silicon. Excessive light absorption further increases the internal temperature and instability of the silicon-based device.

[0029] The above two temperature measurement methods usually rely on the relationship between temperature and a given physical quantity (such as resonance frequency, fluorescence spectrum intensity), and are an indirect measurement method.

[0030] The application provides a silicon transistor channel temperature measurement device and method, which adopts a spin-occupied Boltzmann distribution directly related to a temperature value, and can realize measurement of the temperature value of a silicon transistor at a liquid helium temperature.

[0031] Figure 1 A principle schematic diagram of a silicon transistor channel temperature measurement device according to an embodiment of the application is shown.

[0032] As shown in Figure 1 , the silicon transistor channel temperature measurement device 100 includes a superconducting coil 110, a low-temperature thermostat 130, a tunable laser module 140, a current processing module 150, and a processor 160.

[0033] According to an embodiment of the application, the superconducting coil 110 is configured to provide a magnetic field for the transistor 120, so that spin defects in a channel of the transistor 120 are subjected to spin energy level splitting, and two spin state energy levels are formed. The low-temperature thermostat 130 is configured to provide a low-temperature environment for the transistor 120, wherein, in the low-temperature environment, a first ratio of particle populations on the two spin state energy levels satisfies a Boltzmann distribution related to a temperature value of the channel. The tunable laser module 140 is configured to generate a first laser in a near-infrared waveband. The current processing module 150 is configured to collect a tunneling current generated by the transistor 120 in a case where the first laser is incident on the channel. The processor 160 is configured to record a number of jumps of the tunneling current per unit time under the action of the first laser in a microwave frequency modulation phase, determine a photoionization signal strength; determine a second ratio of probabilities of photoionization events occurring on the two spin state energy levels based on the photoionization signal strength; determine the first ratio based on the second ratio; and obtain the temperature value of the channel according to the Boltzmann distribution and the first ratio.

[0034] Spin defects in silicon material are usually caused by impurity atoms, vacancies or other defects, and some of the defects can contain spin states. Spin energy level splitting means that the energy level of an electron is split due to the interaction between an external magnetic field and the magnetic moment of the electron in the atom, which is called Zeeman effect, and can be used to regulate the spin state of the electron. In a structure such as a silicon quantum dot, under the action of a certain size of external magnetic field, the spin state of the electron is subjected to energy splitting, and the splitting is spin and spin The two spin state energy levels can constitute a good two-level system. The Boltzmann distribution is a formula for describing the distribution of particles on different energy levels in statistical physics. At low temperatures, particles tend to occupy lower energy levels. At high temperatures, the number of particles on the two energy levels tends to be equal. In a state of thermal equilibrium, the distribution of the two spin states of the two-level system conforms to the Boltzmann distribution.

[0035] The first ratio of the number of particles on the two spin state energy levels and the temperature value of the channel satisfying the formula of the Boltzmann distribution can be expressed as:

[0036] (1);

[0037] (2);

[0038] wherein, the first ratio of the number of particles on the two spin state energy levels (spin state and spin state) is represented, B is the Boltzmann constant, μB represents the Bohr magneton constant, g represents the g-factor, B represents the magnetic field. Δ represents the spin level splitting size, which can be determined by formula (2).

[0039] The temperature value of the channel of the transistor can be derived as:

[0040] (3).

[0041] The photoionization defect in the silicon material refers to a point defect with atomic size in the silicon crystal, and the charge of the point defect will be ionized under the excitation of external resonant light. The photoionization defect of the silicon material includes but is not limited to defects introduced by high-energy electron / proton irradiation, ion implantation, crystal growth and the like, and part of the defects are in the near-infrared waveband. Under the excitation of the first laser in the resonant frequency band and the action of the external voltage, the photoionization event will occur in the transistor prepared based on the silicon material, and then the tunneling current of the transistor will jump. The transistor of the silicon material has defects with spin states and photoionizable in the channel of the transistor, and the change of the tunneling current of the transistor caused by the photoionization defect can reflect the light transition intensity. By applying a magnetic field of a certain size through a superconducting coil, due to the Zeeman effect, the photoionization level of the defect containing electron spin will be further split, and the photoionization signal of the photoionization defect will also be split.

[0042] According to the embodiment of the application, the low-temperature environment provided by the low-temperature thermostat 130 can set the preset temperature of the low-temperature environment according to the use scene. The preset temperature range can be less than or equal to 10 K.

[0043] According to the embodiment of the present application, the first laser can be first subjected to frequency stabilization to prevent wavelength drift of the first laser, and then subjected to microwave frequency modulation to realize rapid tuning of the first laser. When the first laser in the microwave frequency modulation stage sweeps the resonance frequency band (resonance excitation wavelength), the wavelength of the first laser resonates with the optical transition energy level of the photoionization defect in the transistor channel, and photoionization of the charge of the photoionization defect causes a jump in the tunneling current of the device. According to the wavelength of the first laser in the frequency stabilization state at this time, the frequency of the first laser in the microwave frequency modulation stage, and the tunneling current, the tunneling current jump probability of the transistor under the action of the first laser in the resonance frequency band can be obtained, which is the photoionization signal of the photoionization defect, and the optical transition intensity can be represented as the photoionization signal intensity.

[0044] According to the embodiment of the present application, the number of jumps of the tunneling current per unit time is determined as the photoionization signal intensity. The photoionization signal intensity can represent the second ratio of the probability of photoionization events occurring on the two spin state energy levels. In a low-temperature environment, only the lowest optical transition energy level is occupied by particles, and the second ratio of the probability of photoionization events occurring on the two spin state energy levels is equal to the first ratio of the number of particles occupying the two spin state energy levels, so that the temperature value of the channel of the transistor can be obtained.

[0045] According to the embodiment of the present application, based on the spin occupation thermal distribution of the photoionization defect of the silicon material, the temperature of the channel of the silicon-based transistor can be obtained according to the magnetic field information, the photoionization signal intensity, and the Boltzmann distribution formula. The silicon-based transistor channel temperature measurement device of the embodiment of the present application uses the near-infrared light wave band of the optical fiber communication wave band to excite the photoionization defect of the silicon-based transistor, avoiding additional heating of the silicon-based device by visible light; the tunneling current generated by the excitation of the first laser avoids fluorescence collection in a low-temperature environment, and reduces the complexity of the measurement device; the photoionization defect in the silicon material can be highly integrated with the existing silicon-based device, so as to directly measure the temperature of the channel of the silicon-based transistor.

[0046] Figure 2 A principle schematic diagram of a silicon-based transistor channel temperature measurement device according to an embodiment of the present application is shown.

[0047] As shown in Figure 2 The current processing module 150 includes a circuit board 151, a voltage source 152, and an acquisition unit 153.

[0048] According to an embodiment of the present invention, circuit board 151 is used to support and electrically connect transistor 120. Voltage source 152 is used to provide a preset gate voltage, preset source voltage, and preset drain voltage to transistor 120 by supplying voltage to circuit board 151, so as to drive transistor 120 to generate tunneling current under low temperature environment and first laser incident channel position. Acquisition unit 153 is used to acquire tunneling current and convert tunneling current into voltage signal to facilitate observation of tunneling current transitions.

[0049] In one example, voltage source 152 can be a precision voltage source that can be connected to circuit board 151 via a cable to provide high-precision voltage to circuit board 151 and to provide transistor 120 with a highly stable, low-drift preset gate voltage, preset source voltage and preset drain voltage.

[0050] In one example, such as Figure 2 As shown, voltage source 152 can be connected to circuit board 151 via first port 131 of cryogenic thermostat 130. First port 131 can be an electrical vacuum feedthrough. The cable inside cryogenic thermostat 130 can be a cryogenic cable, and electrical noise can be filtered out by setting first filter 154 and second filter 155. Acquisition unit 153 can be connected to circuit board 151 via first port 131.

[0051] In one example, the acquisition unit 153 may include a current amplifier and a data acquisition card. The current amplifier can convert the tunneling current of transistor 120 into a voltage signal and amplify it for output. The current amplifier can provide 10 6 ~10 9 The gain is variable (V / A). The data acquisition card can collect the amplified voltage signal and input it into the processor 160. The data acquisition card can have a bandwidth of 1 MHz or more. By combining the real-time voltage value of the data acquisition card and the gain of the current amplifier, the tunneling current of the transistor 120 can be calculated. The first filter 154 and the second filter 155 can be low-temperature low-pass filters.

[0052] According to embodiments of the present invention, a voltage source provides suitable source, drain, and gate voltages to the transistor, ensuring that tunneling current occurs between the source and drain of the transistor at low temperatures. A suitable gain and bandwidth are set in the acquisition unit to ensure high signal-to-noise ratio readout of the transistor's tunneling current.

[0053] like Figure 2 As shown, the silicon-based transistor channel temperature measuring device 100 also includes a lens group 170 and a low-temperature nanopositioning module 180.

[0054] According to an embodiment of the present application, the lens group 170 is used to focus the first laser to the transistor 120 and receive the second laser reflected from the transistor 120. The low-temperature nano-positioning module 180 is used to fix the position of the circuit board 151 unadjustably and fix the position of the lens group 170 adjustably, and adjust the spot of the focused first laser to be incident to the channel position by adjusting the position of the lens group 170.

[0055] As shown in Figure 2 , the tunable laser module 140 includes a fiber circulator 141 and a photodetector unit 142.

[0056] According to an embodiment of the present application, the fiber circulator 141 is used to input the first laser to the cryostat 130 and receive the second laser. The photodetector unit 142 is connected to the fiber circulator 141 and is used to detect the optical power of the second laser.

[0057] In one example, the photodetector unit 142 can be a photodetector, and the light response range of the photodetector can be 900 nm-1700 nm.

[0058] In one example, as shown in Figure 2 , the fiber circulator 141 can be connected through the second port 132 of the cryostat 130. The second port 132 can be a vacuum fiber feedthrough. The transmission of the first laser and the second laser can be performed through a single-mode fiber. The core diameter of the single-mode fiber is extremely small, can have a pinhole function similar to a confocal optical system, and can improve the spatial resolution of ordinary lens imaging.

[0059] In one example, the inside of the cryostat 130 can use a bare fiber single-mode fiber to transmit the first laser and the second laser.

[0060] According to an embodiment of the present application, the fiber circulator can separate the first laser incident to the cryostat and the second laser output from the cryostat. Based on the different reflectivity of different structures or materials on the silicon-based micro-nano transistor to light, the second laser is sent to the photodetector unit through the fiber circulator. Based on the size of the reflectivity, the surface of the transistor can be roughly imaged.

[0061] According to an embodiment of the present application, as shown in Figure 2As shown, the low-temperature nano-positioning module 180 adjusts the position of the lens group 170 to the first position, so that the focused spot of the first laser is moved from other positions of the transistor 120 to the surface of the transistor 120; in the case that the position of the lens group 170 is adjusted to the first position, the optical power of the second laser is the first target value. The low-temperature nano-positioning module 180 adjusts the position of the lens group 170 from the first position to the second position, so that the focused spot of the first laser is moved from the surface of the transistor 120 to the channel; in the case that the position of the lens group 170 is adjusted to the second position, the tunneling current under the first laser in the frequency stabilization state and not in the resonance frequency is the second target value.

[0062] According to the embodiment of the present application, the tunable laser module 140 obtains the first laser in the frequency stabilization state, controls the wavelength of the first laser to be stabilized near the waveband of the resonance frequency and appropriately reduces the optical power of the first laser. The low-temperature nano-positioning module 180 adjusts the position of the lens group 170 according to the size of the reflected optical power of the second laser, when the optical power of the second laser is the first target value, it can be considered that the reflectivity is the largest at this time, the focused spot of the first laser falls on the surface of the transistor 120, and the position of the lens group 170 is the first position. The first target value can be the maximum value of the optical power of the second laser, or a preset optical power threshold.

[0063] According to the embodiment of the present application, the tunable laser module 140 obtains the first laser in the frequency stabilization state, controls the wavelength of the first laser to be stabilized outside the waveband of the resonance frequency and appropriately increases the optical power of the first laser. The low-temperature nano-positioning module 180 adjusts the position of the lens group 170 according to the size of the tunneling current, when the tunneling current is the second target value, it can be considered that the focused spot of the first laser falls on the channel of the transistor 120 at this time, and the position of the lens group 170 is the second position. The second target value can be the maximum value of the tunneling current, or a preset current threshold.

[0064] According to the embodiment of the present application, the low-temperature nano-positioning module can change the distance between the lens group and the transistor, also can change the position of the focused spot of the first laser on the transistor, and also can position the second position. The first position is roughly judged by the optical power of the second laser and the second position is finely adjusted by the tunneling current, so that the focused spot of the first laser falls on the position of the channel of the transistor, the accurate measurement position can provide more reliable measurement data, improves the accuracy of the temperature measurement of the channel of the transistor, ensures the repeatability of the temperature measurement, and provides a basis for real-time monitoring the temperature of the channel of the transistor.

[0065] According to the embodiments of the present application, on the basis of the temperature of the channel of the transistor which can obtain the accurate position, the temperature gradient or temperature distribution of the transistor can be obtained, and the spatial resolution of nanometer scale can be expected to be realized by means of the defects of atomic size.

[0066] As shown in Figure 3 The tunable laser module 140 further includes a laser frequency stabilization unit 143 and an electro-optical modulation unit 144.

[0067] According to the embodiments of the present application, the laser frequency stabilization unit 143 is configured to generate a first laser in a near-infrared waveband and perform frequency stabilization processing, so that the first laser is in a frequency stabilized state. The electro-optical modulation unit 144 is configured to load a microwave modulation signal on the first laser after the frequency stabilization processing, so as to perform microwave frequency modulation on the first laser, so that the first laser is in a microwave frequency modulation stage.

[0068] In one example, the laser frequency stabilization unit 143 can include a laser and a frequency stabilizer. The laser can be a near-infrared tunable laser, and the wavelength of the output first laser can be tunable between a preset wavelength range. The preset wavelength range includes a waveband of a resonance frequency corresponding to a photoionization defect of a silicon material, and the preset wavelength range can be 1300nm-1600nm.

[0069] In one example, the electro-optical modulation unit 144 can include a microwave signal source and an electro-optical modulator. The microwave signal source can drive the electro-optical modulator to generate a sideband, rapidly change the microwave frequency, and realize rapid tuning of the wavelength of the first laser.

[0070] According to the embodiments of the present application, the laser frequency stabilization unit can stabilize the wavelength of the first laser at a required wavelength, so as to prevent the wavelength from drifting. The electro-optical modulation unit can generate a rapidly changing excitation sideband, so as to realize rapid frequency sweeping of the first laser.

[0071] According to the embodiments of the present application, the tunable laser module 140 can further include a laser preprocessing unit 145.

[0072] In one example, the laser preprocessing unit 145 can include a fiber attenuator, a fiber polarization controller, a photodetector, and the like. The fiber attenuator can control the power of the first laser, the fiber polarization controller can control the polarization state of the first laser, and the photodetector can detect and monitor the optical power of the first laser. The optical power of the first laser input into the cryostat 130 can be controlled at a low level by adjusting the fiber attenuator, observing the value of the photodetector, so as to avoid the severe heating of the transistor 120 caused by the high level of optical power, and to avoid the destruction of the low-temperature environment of the cryostat 130. The optical response range of the photodetector can be 900nm-1700nm.

[0073] Figure 3A schematic diagram of a device for measuring the temperature of a silicon-based transistor channel according to another embodiment of the present application is shown.

[0074] As shown in Figure 3 , the low-temperature nano-positioning module can include a nano-positioning stage 181, a first mounting member 182, and a cold plate 183.

[0075] According to an embodiment of the present application, the nano-positioning stage 181 is configured to connect the lens group for adjusting the position of the lens group in the nanometer range. The first mounting member 182 is configured to fixedly connect the circuit board 151. The cold plate 183 is configured to connect the nano-positioning stage 181 and the first mounting member 182 for reducing the temperature of the circuit board 151.

[0076] In one example, the nano-positioning stage 181 can be a three-axis spatial movement, and the nano-positioning stage 181 can have a movement step size of less than 10 nm and can work in a low-temperature environment and a magnetic field environment.

[0077] In one example, the first mounting member 182 can be an oxygen-free copper workpiece.

[0078] According to an embodiment of the present application, the nano-positioning stage can provide nanometer-scale movement capability. The first mounting member can enable good contact between the circuit board and the cold plate to cool the transistor to a low temperature. The cold plate can also provide good cooling for the nano-positioning stage.

[0079] As shown in Figure 3 , the lens group can include a fiber ceramic head 171, a second mounting member 172, and an aspheric lens assembly 173.

[0080] According to an embodiment of the present application, the fiber ceramic head 171 is used to transmit the first laser and the second laser. The second mounting member 172 is used to fixedly connect the fiber ceramic head 171 and the nano-positioning stage 181. The aspheric lens assembly 173 is mounted in the second mounting member 172 and is used to focus the first laser on the transistor 120 and receive the second laser from the transistor 120.

[0081] In one example, the second mounting member 172 can be a mechanical mounting member made of titanium material. Titanium material has low density, high mechanical strength, and is a non-magnetic material, which is suitable for use in a low-temperature environment under a magnetic field.

[0082] In one example, as shown in Figure 4 , the end of the bare fiber single-mode fiber inside the low-temperature thermostat 130 is fixed with the fiber ceramic head 171. The aspheric lens assembly 173 and the fiber ceramic head 171 are fixed in the second mounting member 172. The aspheric lens assembly 173 can include two low-temperature aspheric lenses coated with an anti-reflection film.

[0083] According to an embodiment of the present application, the aspherical lens assembly can converge the first laser emitted from the fiber-ceramic head to the channel of the transistor, and also can inject the second laser reflected by the transistor into the fiber-ceramic head, map the reflectivity of the transistor to the optical power of the second laser, and facilitate the determination of the second position of the lens assembly by detecting the optical power of the second laser.

[0084] Figure 4 A schematic diagram of a device for measuring the temperature of a silicon-based transistor channel is shown according to another embodiment of the present application.

[0085] As shown in Figure 4 one example, the tunable laser module can include a near-infrared tunable laser 1, a laser frequency stabilizer 2, a fiber beam splitter 3, a microwave signal source 4, an electro-optical modulator 5, a fiber polarization controller 6, a fiber attenuator 7, a fiber beam splitter 8, a first photodetector 9, a circulator 10, and a second photodetector 11. The first laser emitted by the near-infrared tunable laser 1 is sent into the laser frequency stabilizer 2 after passing through the fiber beam splitter 3, and the wavelength of the first laser can be stabilized near the resonant frequency. After the output frequency of the near-infrared tunable laser 1 is stabilized, the first laser after frequency stabilization passes through the electro-optical modulator 5. In the microwave frequency modulation stage, the microwave signal source 4 can drive the intensity electro-optical modulator 5 to generate two sidebands, and the carrier component can be weakened by applying a suitable bias voltage, so that the first laser in the microwave frequency modulation stage realizes rapid frequency sweeping. Then, the first laser passes through the fiber polarization controller 6 and the fiber attenuator 7 in turn, the fiber polarization controller 6 can control the polarization state of the first laser, and the fiber attenuator 7 can change the optical power of the first laser. Before the first laser is sent into the cryostat 130, it can also pass through the fiber beam splitter 8, and the splitting ratio of the fiber beam splitter 8 can be 99:1 or 90:10. The high splitting ratio end of the fiber beam splitter 8 is connected to the first photodetector 9, and the first photodetector 9 can be a near-infrared photodetector for monitoring and estimating the optical power irradiated on the transistor 120.

[0086] In one example, the first laser is transmitted in the tunable laser module through a single-mode optical fiber.

[0087] In one example, as shown in Figure 4 the circulator 10 is connected to the cryostat 130 through the second port 132. The circulator 10 can input the first laser into the cryostat 130, and also can receive the second laser reflected by the transistor 120, and inject the second laser into the second photodetector 11 for optical power detection of the second laser.

[0088] In one example, as shown in Figure 4As shown, the superconducting coil 110 is arranged inside the cryostat 130, and the transistor 120 is arranged at the position of the magnetic field center of the superconducting coil 110. The first laser enters the inside of the cryostat 130 through the second port 132. The transmission of the first laser inside the cryostat 130 can use a bare fiber single-mode optical fiber which can be sequentially thermally fixed on the cold plate 183 of the cryostat 130 for sufficient heat exchange to achieve cooling.

[0089] In one example, as shown in Figure 4 The current processing module can include a circuit board 151, a voltage source 152, a current amplifier 12, a data acquisition card 13, a first filter 154 and a second filter 155. The voltage source 152 is connected to the inside of the cryostat 130 through the room temperature cable connected to the first port 131, and is connected to the circuit board 151, thereby being connected to the transistor 120. The first filter 154 and the second filter 155 are arranged to reduce electrical noise. The current amplifier 12 receives the tunneling current of the transistor 120 through the first port 131, and the data acquisition card 13 collects the amplified tunneling current.

[0090] In one example, as shown in Figure 5 The processor 160 can be a computer connected to the data acquisition card 13, used for analyzing and processing experimental data, and also used for controlling related equipment, etc.

[0091] Another aspect of the present application provides a method for measuring the channel temperature of a silicon-based transistor, applied to a device for measuring the channel temperature of a silicon-based transistor.

[0092] Figure 5 An operation flowchart of the method for measuring the channel temperature of a silicon-based transistor according to an embodiment of the present application is shown.

[0093] As shown in ​ The method for measuring the channel temperature of a silicon-based transistor includes operations S510-S580.

[0094] In operation S510, a magnetic field is provided for the transistor, so that spin defects in the channel of the transistor undergo spin energy level splitting, forming two spin state energy levels.

[0095] In operation S520, a low-temperature environment is provided for the transistor, wherein, under the low-temperature environment, the first ratio of the particle population numbers on the two spin state energy levels satisfies the Boltzmann distribution related to the temperature value of the channel.

[0096] In operation S530, a first laser in the near-infrared waveband is generated.

[0097] In operation S540, the tunneling current generated by the transistor when the first laser is incident on the channel is collected.

[0098] In operation S550, the number of times of jumping of the tunneling current per unit time under the action of the first laser in the microwave frequency modulation stage is recorded, and the photoionization signal strength is determined.

[0099] In operation S560, the second ratio of the probabilities of the photoionization events occurring on the two spin state energy levels is determined based on the photoionization signal strength.

[0100] In operation S570, the first ratio is determined based on the second ratio.

[0101] In operation S580, the temperature value of the channel is obtained according to the Boltzmann distribution and the first ratio.

[0102] Before operation S540, the method for measuring the temperature of the silicon-based transistor channel further includes: causing the first laser to be incident on the channel.

[0103] According to an embodiment of the present application, causing the first laser to be incident on the channel includes: adjusting the position of the lens group to a first position so that the focal spot of the focused first laser moves from other positions of the transistor to the surface of the transistor; in the case where the position of the lens group is adjusted to the first position, the optical power of the second laser is a first target value; adjusting the position of the lens group from the first position to a second position so that the focal spot of the focused first laser moves from the surface of the transistor to the channel; in the case where the position of the lens group is adjusted to the second position, the tunneling current under the action of the first laser in the frequency stabilization state and not in the resonance frequency is a second target value.

[0104] Those skilled in the art can understand that the features described in various embodiments of the present application can be combined and / or integrated in various combinations, even if such combinations or integrations are not explicitly described in the present application. In particular, the features described in various embodiments of the present application can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present application. All such combinations and / or integrations fall within the scope of the present application.

[0105] The embodiments of the present application are described above. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present application. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present application, and these substitutions and modifications should all fall within the scope of the present application.

Claims

1. A device for measuring the temperature of a silicon-based transistor channel, comprising: The measuring device comprises: a superconducting coil for providing a magnetic field for the transistor to cause spin defects in a channel of the transistor to have spin energy level splitting to form two spin state energy levels; a cryostat for providing a low-temperature environment for the transistor, wherein a first ratio of particle populations on the two spin state energy levels satisfies a Boltzmann distribution related to a temperature value of the channel in the low-temperature environment; a tunable laser module for generating a first laser in a near-infrared waveband; a current processing module for collecting a tunneling current generated by the transistor when the first laser is incident on the channel; a processor for recording a number of jumps of the tunneling current per unit time under the action of the first laser in a microwave frequency modulation phase, determining an ionization signal strength, determining a second ratio of probabilities of ionization events on the two spin state energy levels based on the ionization signal strength, determining the first ratio based on the second ratio, and obtaining the temperature value of the channel according to the Boltzmann distribution and the first ratio.

2. The measuring device of claim 1, wherein, The current processing module comprises: a circuit board for supporting and electrically connecting the transistor; a voltage source for providing a preset gate voltage, a preset source voltage and a preset drain voltage for the transistor by providing a voltage to the circuit board, so as to drive the transistor to generate the tunneling current in the low-temperature environment and when the first laser is incident on the channel position; a collection unit for collecting the tunneling current and converting the tunneling current into a voltage signal to facilitate observation of the jumps of the tunneling current.

3. The measuring device of claim 2, wherein, The measuring device further comprises: a lens group for focusing the first laser to the transistor and receiving a second laser reflected from the transistor; a low-temperature nanometer positioning module for non-adjustably fixing the position of the circuit board and adjustably fixing the position of the lens group, and adjusting the position of the focused first laser spot to be incident on the channel position by adjusting the position of the lens group.

4. The measuring device of claim 3, wherein, The tunable laser module comprises: a fiber loop for inputting the first laser into the cryostat and receiving the second laser; a photodetector unit connected to the fiber loop for detecting the optical power of the second laser.

5. The measuring device according to claim 4, wherein: the low-temperature nanometer positioning module adjusts the position of the lens group to a first position, so that the focused first laser spot moves from other positions of the transistor to the surface of the transistor; when the position of the lens group is adjusted to the first position, the optical power of the second laser is a first target value; the low-temperature nanometer positioning module adjusts the position of the lens group from the first position to a second position, so that the focused first laser spot moves from the surface of the transistor to the channel; when the position of the lens group is adjusted to the second position, the tunneling current is a second target value under the action of the first laser in a frequency stabilization state and not in a resonance frequency.

6. The measuring device of claim 5, wherein, The low-temperature nanometer positioning module comprises: A nanometer displacement stage configured to be connected to the lens group, for adjusting the position of the lens group in a nanometer range; A first mounting member configured to be fixedly connected to the circuit board; A cold plate configured to be connected to the nanometer displacement stage and the first mounting member, for reducing the temperature of the circuit board.

7. The measuring device of claim 6, wherein, The lens group comprises: A fiber ceramic head for transmitting the first laser and the second laser; A second mounting member for fixedly connecting the fiber ceramic head and the nanometer displacement stage; An aspheric lens assembly installed in the second mounting member, for focusing the first laser on the transistor and receiving the second laser from the transistor.

8. The measuring device of claim 1, wherein, The tunable laser module further comprises: A laser frequency stabilization unit for generating a first laser in a near-infrared wave band and performing frequency stabilization processing, so that the first laser is in a frequency stabilized state; An electro-optical modulation unit for loading a microwave modulation signal on the first laser after frequency stabilization processing, to perform microwave frequency modulation on the first laser, so that the first laser is in a microwave frequency modulation phase.

9. A method of measuring the temperature of a silicon-based transistor channel, applied to a measuring device as claimed in any one of claims 1-8, characterized in that, The measurement method comprises: Providing a magnetic field for the transistor, so that spin defects in the channel of the transistor undergo spin energy level splitting, forming two spin state energy levels; Providing a low-temperature environment for the transistor, wherein the first ratio of the population of particles on the two spin state energy levels under the low-temperature environment satisfies the Boltzmann distribution related to the temperature value of the channel; Generating a first laser in a near-infrared wave band; Collecting the tunneling current generated by the transistor when the first laser is incident on the channel; Recording the number of jumps of the tunneling current per unit time under the action of the first laser in the microwave frequency modulation phase, to determine the photoionization signal strength; Based on the photoionization signal strength, determining the second ratio of the probability of photoionization events occurring on the two spin state energy levels; Based on the second ratio, determining the first ratio; According to the Boltzmann distribution and the first ratio, obtaining the temperature value of the channel.

10. The measurement method according to claim 9, characterized by, The measurement method further comprises: incident the first laser on the channel; Wherein, the incident the first laser on the channel comprises: Adjusting the position of the lens group to a first position, so that the focal spot of the focused first laser moves from other positions of the transistor to the surface of the transistor; under the condition that the position of the lens group is adjusted to the first position, the optical power of the second laser is a first target value; Adjusting the position of the lens group from the first position to a second position, so that the focal spot of the focused first laser moves from the surface of the transistor to the channel; under the condition that the position of the lens group is adjusted to the second position, the tunneling current under the action of the first laser in the frequency stabilized state and not in the resonance frequency is a second target value.

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