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

Abstract

The invention provides a device and method for measuring the channel temperature of a silicon-based transistor, and relates to the technical field of temperature measurement, and the device comprises a superconducting coil which is used for providing a magnetic field for the transistor so as to form two spin-state energy levels; the low-temperature thermostat 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 meets Boltzmann distribution related to the temperature value of the channel; the tunable laser module is used for generating first laser in a near-infrared band; the current processing module is used for collecting tunneling current; the processor is used for determining the photo ionization signal intensity; based on the photoionization signal intensity, determining a second ratio of the probabilities of photoionization events on the two spin state energy levels; determining a first ratio based on the second ratio; and obtaining the temperature value of the channel according to the Boltzmann distribution and the first ratio.

Description

Technical Field

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

[0002] Silicon-based micro-nano devices are widely used in daily life and production. Silicon-based micro-nano devices include silicon-based transistors in mobile phone processor chips, silicon optical modulators in integrated photonics chips, etc. With the rapid development of quantum information technology, micro-nano devices such as silicon-based transistors and silicon-based photonic crystal cavities also play an indispensable role in the field of frontier science. Devices that can be fabricated using silicon-based micro-nano devices, such as: scalable spin quantum computers constructed based on silicon-based transistors, high-performance solid-state quantum light sources realized using silicon-based photonic transistor cavities. In the above important applications, the characteristics of silicon-based micro-nano devices in a low-temperature environment (below the liquid helium temperature of 4.2 K) are particularly important, especially the temperature of their internal channels affects key parameters or performances such as spin-lattice relaxation and spin-coherent manipulation. However, at present, the precise measurement technology for the channel temperature of silicon-based micro-nano devices in a low-temperature environment is not yet perfect. Summary of the Invention

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

[0004] According to a first aspect of the present invention, there is provided a device for measuring the channel temperature of a silicon-based transistor. The measuring device includes: a superconducting coil for providing a magnetic field for the 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 in the low-temperature environment, a first ratio of the particle populations on the two spin state energy levels 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 the 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 modulation stage, determining the photoionization signal intensity; based on the photoionization signal intensity, determining a second ratio of the probabilities of photoionization events occurring on the two spin state energy levels; based on the second ratio, determining the first ratio; and according to the Boltzmann distribution and the first ratio, obtaining the temperature value of the channel.

[0005] According to an embodiment of the present invention, the above-mentioned current processing module includes: a circuit board for supporting and electrically connecting the above-mentioned transistor; a voltage source for providing a voltage to the above-mentioned circuit board to supply a preset gate voltage, a preset source voltage, and a preset drain voltage to the above-mentioned transistor, so as to drive the above-mentioned transistor to generate the above-mentioned tunneling current when the above-mentioned low-temperature environment and the above-mentioned first laser are incident on the above-mentioned channel position; a collection unit for collecting the above-mentioned tunneling current and converting the above-mentioned tunneling current into a voltage signal to facilitate observing the jump of the above-mentioned tunneling current.

[0006] According to an embodiment of the present invention, the above-mentioned measuring device further includes: a lens group for focusing the above-mentioned first laser onto the above-mentioned transistor and receiving the second laser reflected from the above-mentioned transistor; a cryogenic nano-positioning module for fixedly positioning the above-mentioned circuit board non-adjustably and positioning the above-mentioned lens group adjustably, and adjusting the position of the focused first laser spot to be incident on the above-mentioned channel position by adjusting the position of the above-mentioned lens group.

[0007] According to an embodiment of the present invention, the above-mentioned tunable laser module includes: an optical fiber circulator for inputting the above-mentioned first laser into the above-mentioned cryostat and receiving the above-mentioned second laser; a photoelectric detection unit connected to the above-mentioned optical fiber circulator for detecting the optical power of the above-mentioned second laser.

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

[0009] According to an embodiment of the present invention, the above-mentioned cryogenic nano-positioning module includes: a nano-displacement stage configured to be connected to the above-mentioned lens group for adjusting the position of the above-mentioned lens group within the nano-scale range; a first mounting member configured to be fixedly connected to the above-mentioned circuit board; a cold plate configured to be connected to the above-mentioned nano-displacement stage and the above-mentioned first mounting member for reducing the temperature of the above-mentioned circuit board.

[0010] According to an embodiment of the present invention, the above lens group includes: an optical fiber ceramic head for transmitting the above first laser and the above second laser; a second mounting member for fixedly connecting the above optical fiber ceramic head and the above nano-displacement stage; an aspherical lens assembly installed in the second mounting member for focusing the above first laser on the above transistor and receiving the above second laser from the above transistor.

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

[0012] Another aspect of the present invention provides a method for measuring the channel temperature of a silicon-based transistor, which is applied to the above measurement device. The above measurement method includes: providing a magnetic field for the transistor so that the spin defects in the transistor channel undergo spin energy level splitting to form two spin state energy levels; providing a low-temperature environment for the above transistor, wherein, in the above low-temperature environment, the first ratio of the population numbers of the particles on the above two spin state energy levels satisfies the Boltzmann distribution related to the temperature value of the above channel; generating a first laser in the near-infrared band; collecting the tunneling current generated by the above transistor when the above first laser is incident on the above channel; recording the number of jumps of the above tunneling current per unit time under the action of the first laser in the microwave frequency modulation stage to determine the photoionization signal intensity; determining the second ratio of the probabilities of photoionization events occurring on the above two spin state energy levels based on the above photoionization signal intensity; determining the above first ratio based on the above second ratio; and obtaining the temperature value of the above channel according to the above Boltzmann distribution and the above first ratio.

[0013] According to an embodiment of the present invention, the above measurement method further includes: making the above first laser incident on the above channel; wherein, making the above first laser incident on the above channel includes: adjusting the position of the lens group to a first position so that the spot of the focused first laser moves from other positions of the above transistor to the surface of the above transistor; when the position of the lens group is adjusted to the above first position, the optical power of the above second laser is a first target value; adjusting the position of the lens group from the above first position to a second position so that the spot of the focused first laser moves from the surface of the above transistor to the above channel; when the position of the lens group is adjusted to the above second position, the above tunneling current is a second target value under the action of the first laser in the frequency-stabilized state and not within the resonance frequency.

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

[0015] The above content and other objects, features, and advantages of the present invention will become clearer through the following description of the embodiments of the present invention with reference to the accompanying drawings.

[0016] Figure 1 FIG. shows a schematic diagram of the principle of a measuring device for the channel temperature of a silicon-based transistor according to an embodiment of the present invention.

[0017] Figure 2 FIG. shows a schematic diagram of the principle of a measuring device for the channel temperature of a silicon-based transistor according to an embodiment of the present invention.

[0018] Figure 3 FIG. shows a schematic diagram of the principle of a measuring device for the channel temperature of a silicon-based transistor according to another embodiment of the present invention.

[0019] Figure 4 FIG. shows a schematic diagram of the principle of a measuring device for the channel temperature of a silicon-based transistor according to still another embodiment of the present invention.

[0020] Figure 5 FIG. shows an operation flowchart of a method for measuring the channel temperature of a silicon-based transistor according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0022] The terms used herein are for describing specific embodiments only and are not intended to limit the present invention. The terms "comprising", "including" and the like used herein indicate the presence of the described features, steps, operations and / or components, but do not preclude the presence or addition of one or more other features, steps, operations or components.

[0023] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0024] In the case of using expressions such as "at least one of A, B, and C, etc.", generally it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but not be limited to a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0025] The measurement of the temperature of micro-nano devices in a low-temperature environment poses stringent requirements on temperature sensors: it is necessary to be compatible with existing devices and be able to measure the temperature of the internal channels of the devices, and at the same time, it is necessary to have a spatial resolution at the nanoscale.

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

[0027] The principle of an optical temperature sensor is to deduce the magnitude of the temperature by using the change of optical quantities such as the resonance frequency of the resonant cavity and the intensity of the transmission spectrum caused by the thermo-optic effect. However, an optical temperature sensor only has good sensitivity at relatively high temperatures (such as room temperature). Because in a low-temperature environment below liquid helium, the thermo-optic coefficient decreases sharply (less than one ten-thousandth), which in turn leads to a significant reduction in its sensitivity and cannot give an accurate temperature value.

[0028] A fluorescence temperature sensor usually gives the temperature value by using the dependence relationship between the fluorescence spectrum and the temperature of materials such as solid-state color centers (such as diamond and silicon carbide), quantum dots, and rare-earth ion-doped organic powders. 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, etc., and thus cannot give the actual temperature inside the device. In addition, the excitation light wavelength required by a fluorescence thermometer is usually in the visible light wavelength range (such as the common 532 nm green light), which is within the bandgap of silicon. More light absorption brings extra heat, further increasing 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 present invention provides a device and method for measuring the channel temperature of a silicon-based transistor. By using the Boltzmann distribution of spin populations directly related to the temperature value, the temperature value of the silicon-based transistor can be measured at liquid helium temperature.

[0031] Figure 1 The schematic diagram of the principle of the device for measuring the channel temperature of a silicon-based transistor according to an embodiment of the present invention is shown.

[0032] As Figure 1 shown, the device 100 for measuring the channel temperature of a silicon-based transistor includes a superconducting coil 110, a cryostat 130, a tunable laser module 140, a current processing module 150, and a processor 160.

[0033] According to an embodiment of the present invention, the superconducting coil 110 is used to provide a magnetic field for the transistor 120, so that the spin defects in the channel of the transistor 120 undergo spin energy level splitting to form two spin state energy levels. The cryostat 130 is used to provide a low-temperature environment for the transistor 120. Among them, in the low-temperature environment, the first ratio of the particle populations on the two spin state energy levels satisfies the Boltzmann distribution related to the temperature value of the channel. The tunable laser module 140 is used to generate a first laser in the near-infrared band. The current processing module 150 is used to collect the tunneling current generated by the transistor 120 when the first laser is incident on the channel. The processor 160 is used to record 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 determine the photoionization signal intensity; based on the photoionization signal intensity, determine the second ratio of the probabilities of photoionization events occurring on the two spin state energy levels; based on the second ratio, determine the first ratio; according to the Boltzmann distribution and the first ratio, obtain the temperature value of the channel.

[0034] Spin defects in silicon materials are usually caused by impurity atoms, vacancies or other defects, and some of these defects can contain spin states. Spin energy level splitting means that due to the interaction between an external magnetic field and the magnetic moment of electrons in an atom, the energy levels of electrons split, which is called the Zeeman effect and can be used to control the electron spin state. In structures such as silicon-based quantum dots, under the action of an external magnetic field of a certain magnitude, the spin states of electrons undergo energy splitting, splitting into spin states and spin In this state, the energy levels of the two spin states can form a good two-level system. The Boltzmann distribution is a formula in statistical physics that describes the population distribution of particles at different energy levels. At low temperatures, particles tend to populate the lower energy levels. At high temperatures, the number of particles in the two energy levels tends to be equal. In 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 particle populations on the two spin state energy levels and the temperature value of the channel satisfy the formula of the Boltzmann distribution and can be expressed as:

[0036] (1);

[0037] (2);

[0038] Wherein, represents the first ratio of the particle populations on the two spin state energy levels (spin state and spin state), is the Boltzmann constant, represents the Bohr magneton constant, represents the Zeeman factor, represents the magnetic field. represents the splitting magnitude of the spin energy level and can be determined by formula (2).

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

[0040] (3).

[0041] The photoionization defect in the silicon material refers to a point defect with atomic size in the silicon crystal. Under the excitation of external resonance light, its charge will be ionized. The photoionization defects of the silicon material include, but are not limited to, the defects introduced by high-energy electron / proton irradiation, ion implantation, crystal growth, etc., and some of the defects are in the near-infrared band. Under the excitation of the first laser in the band at the resonance frequency and the action of an external voltage, photoionization events will occur in the transistor prepared based on the silicon material, thereby causing a jump in the tunneling current of the transistor. There are spin states and photoionizable defects in the channel of the transistor of the silicon material, and the change in the tunneling current caused by the photoionization defect can reflect the intensity of the optical transition. By applying a magnetic field of a certain magnitude through a superconducting coil, due to the Zeeman effect, for the defects containing electron spins, the optical transition energy levels will be further split, resulting in the splitting of the photoionization signal of the photoionization defect.

[0042] According to an embodiment of the present invention, the low-temperature environment provided by the cryostat 130 can set a preset temperature of the low-temperature environment according to the usage scenario. The range of the preset temperature can be less than or equal to 10 K.

[0043] According to an embodiment of the present invention, the frequency stabilization of the first laser can be performed first to prevent the wavelength of the first laser from drifting, and then the rapid tuning of the first laser can be achieved by performing microwave frequency modulation on the first laser. When the first laser in the microwave frequency modulation stage sweeps through 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 the photoionization of the charge of the photoionization defect will cause a jump in the tunneling current of the device. According to the wavelength of the first laser in the frequency-stabilized state, the frequency of the first laser in the microwave frequency modulation stage, and the tunneling current at this time, 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 expressed as the photoionization signal intensity.

[0044] According to an embodiment of the present invention, the number of jumps in the tunneling current per unit time is determined as the photoionization signal intensity. The photoionization signal intensity can characterize the second ratio of the probabilities of photoionization events occurring on two spin state energy levels. In a low-temperature environment, only the lowest optical transition energy level has population, and the second ratio of the probabilities of photoionization events occurring on two spin state energy levels is equal to the first ratio of the population numbers on two spin state energy levels, and the temperature value of the channel of the transistor can be obtained.

[0045] According to an embodiment of the present invention, based on the spin population thermal distribution of photoionization defects in silicon materials, 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 obtained. The measuring device for the temperature of the channel of the silicon-based transistor according to the embodiment of the present invention uses the near-infrared light band in the optical fiber communication band to excite the photoionization defects of the silicon-based transistor, avoiding the additional heating of the silicon-based device by visible light; using the excitation of the first laser to generate tunneling current, avoiding the fluorescence collection in a low-temperature environment, and reducing the complexity of the measuring device; using the photoionization defects in silicon materials, it can be highly integrated with existing silicon-based devices, so as to directly measure the temperature of the channel of the silicon-based transistor.

[0046] Figure 2 The schematic diagram of the principle of the measuring device for the temperature of the channel of the silicon-based transistor according to an embodiment of the present invention is shown.

[0047] As Figure 2 shown, 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, the circuit board 151 is used to support and electrically connect the transistor 120. The voltage source 152 is used to provide a preset gate voltage, a preset source voltage, and a preset drain voltage for the transistor 120 by supplying voltage to the circuit board 151, so as to drive the transistor 120 to generate a tunneling current in a low-temperature environment and at the position of the first laser incident channel. The acquisition unit 153 is used to acquire the tunneling current and convert the tunneling current into a voltage signal for facilitating the observation of the jump of the tunneling current.

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

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

[0051] In one example, the acquisition unit 153 can include a current amplifier and can also include a data acquisition card. The current amplifier can convert the tunneling current of the transistor 120 into a voltage signal and amplify and output it. The current amplifier can provide a variable gain of 10 6 ~ 10 9 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 more than 1 MHz. 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 deduced. The first filter 154 and the second filter 155 can be cryogenic low-pass filters.

[0052] According to an embodiment of the present invention, by providing appropriate source voltage, drain voltage, and gate voltage to the transistor through the voltage source, it is ensured that a tunneling current appears between the source and drain of the transistor in a low-temperature environment. By setting appropriate gain and bandwidth for the acquisition unit, a high signal-to-noise ratio reading of the tunneling current of the transistor is ensured.

[0053] As Figure 2 shown, the measuring device 100 for the channel temperature of the silicon-based transistor further includes a lens group 170 and a cryogenic nano-positioning module 180.

[0054] According to an embodiment of the present invention, the lens group 170 is configured to focus the first laser onto the transistor 120 and receive the second laser reflected from the transistor 120. The cryogenic nano-positioning module 180 is configured to fixedly position the circuit board 151 non-adjustably and position the lens group 170 adjustably, and adjust the incident channel position of the spot of the focused first laser by adjusting the position of the lens group 170.

[0055] As Figure 2 shown, the tunable laser module 140 includes an optical fiber circulator 141 and a photoelectric detection unit 142.

[0056] According to an embodiment of the present invention, the optical fiber circulator 141 is configured to input the first laser into the cryostat 130 and receive the second laser. The photoelectric detection unit 142 is connected to the optical fiber circulator 141 and is configured to detect the optical power of the second laser.

[0057] In one example, the photoelectric detection unit 142 may be a photodetector, and the optical response range of the photodetector may be 900 nm - 1700 nm.

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

[0059] In one example, a bare-fiber single-mode optical fiber may be used inside the cryostat 130 to transmit the first laser and the second laser.

[0060] According to an embodiment of the present invention, the optical fiber circulator can separate the first laser incident on the cryostat and the second laser output from the cryostat. Based on the different reflectivities of light by different structures or materials on the silicon-based micro-nano transistor, the second laser is sent into the photoelectric detection unit through the optical fiber circulator. Based on the magnitude of the reflectivity, a rough image of the surface of the transistor can be obtained.

[0061] According to an embodiment of the present invention, as Figure 2As shown, the cryogenic nano-positioning module 180 adjusts the position of the lens group 170 to the first position, so that the spot of the first laser after focusing moves from other positions of the transistor 120 to the surface of the transistor 120; when 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 cryogenic nano-positioning module 180 adjusts the position of the lens group 170 from the first position to the second position, so that the spot of the first laser after focusing moves from the surface of the transistor 120 to the channel; when the position of the lens group 170 is adjusted to the second position, the tunneling current is the second target value under the action of the first laser that is in the frequency stabilization state and not within the resonance frequency.

[0062] According to an embodiment of the present invention, the tunable laser module 140 obtains the first laser in the frequency stabilization state, controls the wavelength of the first laser to be stable near the resonance frequency band and appropriately reduces the optical power of the first laser. The cryogenic nano-positioning module 180 adjusts the position of the lens group 170 according to the magnitude of the optical power of the reflected 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, and the spot of the first laser after focusing 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 an embodiment of the present invention, the tunable laser module 140 obtains the first laser in the frequency stabilization state, controls the wavelength of the first laser to be outside the resonance frequency band and appropriately increases the optical power of the first laser. The cryogenic nano-positioning module 180 adjusts the position of the lens group 170 according to the magnitude of the tunneling current. When the tunneling current is the second target value, it can be considered that the spot of the first laser after focusing 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 an embodiment of the present invention, the cryogenic nano-positioning module can change the distance between the lens group and the transistor, can also change the position of the spot of the first laser after focusing on the transistor, and can also position the second position. Roughly judging the first position through the optical power of the second laser and finely adjusting the second position through the tunneling current, so that the spot of the first laser after focusing falls on the position of the channel of the transistor. The accurate measurement position can provide more reliable measurement data, improve the accuracy of the temperature measurement of the transistor channel, ensure the repeatability of the temperature measurement, and provide a basis for real-time monitoring of the temperature of the transistor channel.

[0065] According to an embodiment of the present invention, based on the temperature of the channel of a transistor capable of obtaining an accurate position, the temperature gradient or temperature distribution of the transistor can be obtained, and it is expected to achieve nanoscale spatial resolution by means of defects of atomic size.

[0066] As Figure 2 shown, the tunable laser module 140 further includes a laser frequency stabilization unit 143 and an electro-optic modulation unit 144.

[0067] According to an embodiment of the present invention, the laser frequency stabilization unit 143 is used to generate a first laser in the near-infrared band and perform frequency stabilization processing so that the first laser is in a frequency-stabilized state. The electro-optic modulation unit 144 is used to load a microwave modulation signal on the frequency-stabilized first laser to perform microwave frequency modulation on the first laser so that the first laser is in the microwave frequency modulation stage.

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

[0069] In one example, the electro-optic modulation unit 144 may include a microwave signal source and an electro-optic modulator. The microwave signal source can drive the electro-optic modulator to generate sidebands, quickly change the microwave frequency, and achieve rapid tuning of the wavelength of the first laser.

[0070] According to an embodiment of the present invention, the wavelength of the first laser can be stabilized at a desired wavelength through the laser frequency stabilization unit to prevent wavelength drift. Through the electro-optic modulation unit, rapidly changing excitation sidebands can be generated to achieve rapid frequency scanning of the first laser.

[0071] According to an embodiment of the present invention, the tunable laser module 140 may further include a laser pretreatment unit 145.

[0072] In one example, the laser pretreatment unit 145 may include a fiber optic attenuator, a fiber optic polarization controller, a photodetector, etc. The fiber optic attenuator can control the power of the first laser, the fiber optic 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. By adjusting the fiber optic attenuator and observing the value of the photodetector, the optical power of the first laser input to the cryostat 130 can be controlled at a lower level to avoid intense heating of the transistor 120 by a high level of optical power and damage to the low-temperature environment of the cryostat 130. The optical response range of the photodetector can be 900 nm - 1700 nm.

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

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

[0075] According to an embodiment of the present invention, the nano-displacement stage 181 is configured to be connected to a lens group for adjusting the position of the lens group within the nano-scale range. The first mounting member 182 is configured to be fixedly connected to the circuit board 151. The cold plate 183 is configured to connect the nano-displacement stage 181 and the first mounting member 182 for reducing the temperature of the circuit board 151.

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

[0077] In one example, the first mounting member 182 may be a machined part made of oxygen-free copper.

[0078] According to an embodiment of the present invention, the nano-displacement stage can provide a moving ability at the nano-scale. The first mounting member can keep a good contact between the circuit board and the cold plate to cool the transistor to a low temperature. The cold plate can also cool the nano-displacement stage well.

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

[0080] According to an embodiment of the present invention, the optical 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 optical fiber ceramic head 171 and the nano-displacement stage 181. The aspherical lens assembly 173 is installed in the second mounting member 172 for focusing the first laser on the transistor 120 and receiving the second laser from the transistor 120.

[0081] In one example, the second mounting member 172 may be a mechanical mounting member machined from titanium material. The titanium material has a low density, a large 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 Figure 3 shown, the end of the single-mode optical fiber of the bare fiber inside the cryostat 130 is fixed by the optical fiber ceramic head 171. The aspherical lens assembly 173 and the optical fiber ceramic head 171 are fixed to the second mounting member 172. The aspherical lens assembly 173 may include two low-temperature aspherical lenses coated with an antireflection film.

[0083] According to an embodiment of the present invention, the aspherical lens assembly can converge the first laser emitted from the fiber ceramic head onto the channel of the transistor, and at the same time, can also incident 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 group by detecting the optical power of the second laser.

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

[0085] As Figure 4 shown, in one example, the tunable laser module may include a near-infrared tunable laser 1, a laser frequency stabilizer 2, a beam splitter 3, a microwave signal source 4, an electro-optic modulator 5, an optical fiber polarization controller 6, an optical fiber attenuator 7, an optical 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 beam splitter 3, and the wavelength of the first laser can be stabilized near the resonance frequency band. After the output frequency of the near-infrared tunable laser 1 is stabilized, the frequency-stabilized first laser after passing through the beam splitter 3 passes through the electro-optic modulator 5. In the microwave frequency modulation stage, the microwave signal source 4 can drive the intensity electro-optic modulator 5 to generate two sidebands. Among them, the carrier component can be weakened by applying an appropriate bias voltage so that the first laser realizes fast frequency sweeping in the microwave frequency modulation stage. Then, the first laser sequentially passes through the optical fiber polarization controller 6 and the optical fiber attenuator 7. The optical fiber polarization controller 6 can control the polarization state of the first laser, and the optical 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 optical fiber beam splitter 8. The splitting ratio of the optical fiber beam splitter 8 can be 99:1, or can also be 90:10. One end of the high splitting ratio of the optical fiber beam splitter 8 is connected to the first photodetector 9. 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 Figure 4 shown, 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 can also receive the second laser reflected from the transistor 120 and incident the second laser on the second photodetector 11 to detect the optical power of the second laser.

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

[0089] In one example, as Figure 4 shown, the current processing module may 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 enters the interior of the cryostat 130 through the first port 131 via a room temperature cable, establishes a connection with the circuit board 151, and thus establishes a connection with the transistor 120. The first filter 154 and the second filter 155 are provided 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 acquires the amplified tunneling current.

[0090] In one example, as Figure 4 shown, the processor 160 may be a computer, connected to the data acquisition card 13, for analyzing and processing experimental data, and also for controlling related devices, etc.

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

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

[0093] As Figure 5 shown, 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 the spin defects in the channel of the transistor undergo spin energy level splitting to form two spin state energy levels.

[0095] In operation S520, a low-temperature environment is provided for the transistor, wherein, in the low-temperature environment, the first ratio of the particle populations 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 band is generated.

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

[0098] In operation S550, the number of jumps 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 intensity is determined.

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

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

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

[0102] Before operation S540, the method for measuring the temperature of the silicon-based transistor channel further includes: irradiating the first laser onto the channel.

[0103] According to an embodiment of the present invention, irradiating the first laser onto the channel includes: adjusting the position of the lens group to a first position so that the spot of the focused first laser 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; adjusting the position of the lens group from the first position to a second position so that the spot of the focused first laser 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 the frequency-stabilized state and not within the resonance frequency.

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

[0105] The above describes the embodiments of the present invention. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present invention. Although the embodiments are described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. A device for measuring the channel temperature of a silicon-based transistor, characterized in that: The measuring device comprises: A superconducting coil is used to provide a magnetic field for the transistor, so that the spin defect in the channel of the transistor undergoes spin energy level splitting to form two spin state energy levels; A cryostat, configured to provide a low temperature environment for the transistor, wherein, in the low temperature environment, a first ratio of the particle populations at the two spin state energy levels satisfies a Boltzmann distribution associated with a temperature value of the channel; A tunable laser module, used for generating a first laser in a near-infrared band; a current processing module, used for collecting a tunneling current generated by the transistor when the first laser is incident on the channel; The processor is used to record the number of jumps of the tunneling current per unit time under the action of the first laser in the microwave frequency modulation stage to determine the intensity of the photoionization signal; based on the intensity of the photoionization signal, determine the second ratio of the probability of photoionization events occurring at the two spin state energy levels; based on the second ratio, determine the first ratio; and obtain the temperature value of the channel according to the Boltzmann distribution and the first ratio.

2. The measuring device according to claim 1, characterized in that The current processing module comprises: A circuit board, used for supporting and electrically connecting the transistor; A voltage source, used 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; The acquisition unit is used to acquire the tunneling current and convert the tunneling current into a voltage signal so as to observe the jump of the tunneling current.

3. The measuring device according to claim 2, characterized in that The measuring device also includes: A lens group, used for focusing the first laser onto the transistor and receiving a second laser reflected from the transistor; The low-temperature nanopositioning module is used to fix the position of the circuit board in an unadjustable manner and to fix the position of the lens group in an adjustable manner, and to adjust the position of the focused first laser spot incident on the channel by adjusting the position of the lens group.

4. The measuring device according to claim 3, characterized in that The tunable laser module comprises: an optical fiber circulator for inputting the first laser into the cryostat and receiving the second laser; A photoelectric detection unit is connected to the optical fiber circulator and is used to detect the optical power of the second laser.

5. The measuring device according to claim 4, characterized in that: The low-temperature nanopositioning module adjusts the position of the lens group to a first position so that the spot of the focused first laser 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 nanopositioning module adjusts the position of the lens group from the first position to the second position so that the spot of the focused first laser 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 at a second target value under the action of the first laser which is in a stable frequency state and is not within the resonance frequency.

6. The measuring device according to claim 5, characterized in that The cryogenic nanopositioning module comprises: A nano-displacement stage, configured to be connected to the lens group and used to adjust the position of the lens group within a nanometer range; A first mounting member configured to be fixedly connected to the circuit board; A cold plate is configured to connect the nano displacement stage and the first mounting member and is used to reduce the temperature of the circuit board.

7. The measuring device according to claim 6, characterized in that The lens assembly comprises: An optical fiber ceramic head, used for transmitting the first laser and the second laser; A second mounting member, used for fixedly connecting the optical fiber ceramic head and the nano displacement stage; An aspheric lens assembly is mounted in the second mounting member and is used to focus the first laser on the transistor and receive the second laser from the transistor.

8. The measuring device according to claim 1, characterized in that The tunable laser module also includes: A laser frequency stabilization unit, used for generating a first laser in a near-infrared band and performing frequency stabilization processing so that the first laser is in a frequency-stabilized state; The electro-optical modulation unit is used to load a microwave modulation signal to the first laser after the frequency stabilization process, so as to perform microwave frequency modulation on the first laser, so that the first laser is in the microwave frequency modulation stage.

9. A method for measuring the channel temperature of a silicon-based transistor, applied to the measuring device as claimed in any one of claims 1 to 8, characterized in that: The measuring method comprises: Providing a magnetic field to the transistor so that a spin defect in a channel of the transistor undergoes spin level splitting to form two spin state energy levels; Providing a low temperature environment for the transistor, wherein, in the low temperature environment, a first ratio of the particle populations at the two spin state energy levels satisfies a Boltzmann distribution related to a temperature value of the channel; generating a first laser in a near-infrared band; collecting a 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 stage to determine the intensity of the photoionization signal; Determining a second ratio of probabilities of photoionization events occurring at the two spin state energy levels based on the photoionization signal intensity; determining the first ratio based on the second ratio; A temperature value of the channel is obtained according to the Boltzmann distribution and the first ratio.

10. The measuring method according to claim 9, characterized in that: The measuring method further comprises: injecting the first laser into the channel; Wherein, injecting the first laser into the channel comprises: The position of the lens group is adjusted to a first position, so that the light spot of the focused first laser 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 position of the lens group is adjusted from the first position to the second position so that the spot of the focused first laser 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 that is in a stable frequency state and not in the resonant frequency.

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