Spin sensor, jig equipped with same, and device equipped with same

Abstract

Provided is a spin sensor comprising a single diamond particle, wherein: the maximum diameter of the diamond particle is 0.01 μm or more and less than 10 μm; the diamond particle has a color center; t

Description

TITLE OF INVENTION: Spin Sensor, Jig Equipped with Same, and Device Equipped with Same TECHNICAL FIELD

[0001] The present disclosure relates to a spin sensor, a jig equipped with the spin sensor, and a device equipped with the spin sensor. The present application claims priority to Japanese Patent Application No. 2023-120722 filed on July 25, 2023, the entire contents of which are incorporated herein by reference. BACKGROUND ART

[0002] Conventionally, diamond particles have been used in a jig or a device utilized in fields such as the semiconductor industry field, the vacuum apparatus industry field, the optical field, and the medical and biological field to measure the temperature of the jig or the device (NPL 1). CITATION LIST NON PATENT LITERATURE

[0003] NPL 1: L. Nie, et al., "Quantum monitoring of cellular metabolic activities in single mitochondria", Sci. Adv. 2021 May 19; 7 (21): eabf0573. SUMMARY OF INVENTION

[0004] The spin sensor of the present disclosure is a spin sensor formed of a single diamond particle, wherein a maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm, the diamond particle has a color center, an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, and a spin-spin relaxation time T2 of the diamond particle is 180 nsec or more. DETAILED DESCRIPTION

[0005] [Problem to be Solved by the Present Disclosure] In recent years, there has been a demand for such a spin sensor that is used in a jig or a device utilized in fields such as the semiconductor industry field, the vacuum apparatus industry field, the optical field, and the medical and biological field to measure a temperature of a minute measurement region with excellent sensitivity. By minimizing the maximum diameter of the particles constituting the spin sensor, it is possible for the spin sensor to measure the temperature of a minute measurement region. On the other hand, it is difficult for such a spin sensor to achieve sufficient temperature measurement accuracy (1 K / JHz or less), and it is also difficult for it to achieve excellent measurement sensitivity.

[0006] Therefore, an object of the present disclosure is to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region, a jig equipped with the spin sensor, and a device equipped with the spin sensor.

[0007] [Advantageous Effect of the Present Disclosure] According to the present disclosure, it is possible to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region, a jig equipped with the spin sensor, and a device equipped with the spin sensor.

[0008] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be described. (1) The spin sensor of the present disclosure is a spin sensor formed of a single diamond particle, wherein a maximum diameter of the diamond particle is 0.01 um or more and less than 10 um, the diamond particle has a color center, an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, and a spin-spin relaxation time T2 of the diamond particle is 180 nsec or more.

[0009] According to the present disclosure, it is possible to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0010] (2) In the above (1), a spin-lattice relaxation time T1 of the diamond particle may be 300 usee or more. Accordingly, it is possible to provide a spin sensor having better sensitivity in measuring the temperature of a minute measurement region.

[0011] (3) The spin sensor of the present disclosure is spin sensor formed of a powder that includes seven or more diamond particles, wherein the diamond particles include first diamond particles, a maximum diameter of each of the first diamond particles is 0.01 pm or more and less than 10 pm, each of the first diamond particles has a color center, an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, a spin-spin relaxation time T2 of each of the first diamond particles is 180 nsec or more, and in the spin sensor, a ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more.

[0012] According to the present disclosure, it is possible to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0013] (4) In the above (3), the spin-lattice relaxation time T1 of each of the first diamond particles may be 300 psec or more. Accordingly, it is possible to provide a spin sensor having better sensitivity in measuring the temperature of a minute measurement region.

[0014] (5) In the above (3) or (4), the first diamond particles include second diamond particles, the spin-spin relaxation time T2 of each of the second diamond particles is 1,000 nsec or more, and in the spin sensor, a ratio [(N2 / N)xl00] of the number N2 of the second diamond particles to the total number N of the diamond particles is 5% or more. Accordingly, it is possible to provide a spin sensor having better sensitivity in measuring the temperature of a minute measurement region.

[0015] (6) In any of the above (3) to (5), the first diamond particles include third diamond particles, the spin-lattice relaxation time T1 of each of the third diamond particles is 800 psec or more, and in the spin sensor, a ratio [(N3 / N)x 100] of the number N3 of the third diamond particles to the total number N of the diamond particles is 5% or more. Accordingly, it is possible to provide a spin sensor having better sensitivity in measuring the temperature of a minute measurement region.

[0016] (7) A jig of the present disclosure includes the spin sensor described in any of the above (1) to (6).

[0017] According to the present disclosure, it is possible to provide a jig including a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0018] (8) A device of the present disclosure includes the spin sensor described in any of the above (1) to (6).

[0019] According to the present disclosure, it is possible to provide a device including a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0020] [Details of Embodiments of the Present Disclosure] In the present specification, the expression in the form of "A to B" denotes an upper limit and a lower limit of a range (in other words, A or more and B or less), and if no unit is defined for A but a unit is defined for B, the unit of A is the same as the unit of B.

[0021] In the present specification, when a compound or the like is represented by a chemical formula without specifying the composition ratio of constituent elements, the chemical formula shall be deemed to include all composition ratios (element ratios) known in the prior art. Further, the chemical formula includes not only a stoichiometric composition but also a nonstoichiometric composition.

[0022] [First Embodiment: Spin Sensor (1)] A spin sensor according to an embodiment of the present disclosure will be described. The spin sensor according to an embodiment of the present disclosure (hereinafter also referred to as the present embodiment) is a spin sensor formed of a single diamond particle, wherein a maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm, the diamond particle has a color center, an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, and a spin-spin relaxation time T2 of the diamond particle is 180 nsec or more. The spin-related characteristic values (Tl, T2 and the like) of the present disclosure are not characteristic values of a single NV center, but characteristic values of an ensemble (a group of NV centers), and thereby the spin sensor can obtain sufficient light intensity.

[0023] The spin sensor according to the present embodiment can have excellent sensitivity in measuring the temperature of a minute measurement region. The possible reasons will be given in the following.

[0024] (a) In the spin sensor according to the present embodiment, the maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm. Since the maximum diameter of the diamond particle is suppressed to be small, the spin sensor according to the present embodiment may be used to measure the temperature of a minute measurement region.

[0025] (b) When the maximum diameter of the diamond particle is small, it would be difficult to distinguish the fluorescence intensity of the sensor required for calculating the temperature and the fluorescence intensity of the background during the temperature measurement. Therefore, it is difficult for the spin sensor to have excellent sensitivity in measuring the temperature of a minute measurement region.

[0026] In the spin sensor according to the present embodiment, the diamond particle has a color center, an electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, and a spin-spin relaxation time T2 of the diamond particle is 180 nsec or more. Since the noise during the temperature measurement is suppressed to a low level, the spin sensor can have excellent sensitivity in measuring the temperature of a minute measurement region.

[0027] Therefore, according to the present embodiment, it is possible to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0028] [Spin Sensor] In the present disclosure, the spin sensor refers to such a sensor that has an emission level with triplet electron spins. When excitation light is incident on the spin sensor, fluorescence is emitted from the spin sensor, and the fluorescence intensity changes in response to an external magnetic field applied to a spin. When a microwave resonant with a ground level and an excitation level is incident on the spin sensor, the change in the fluorescence intensity increases. Based on this principle, the spin sensor of the present disclosure can detect a temperature. Furthermore, the spin sensor of the present disclosure can detect not only a temperature but also a magnetic field, an electric field, a pressure, and the like.

[0029] The spin sensor according to the present embodiment is formed of a single diamond particle. Since the diamond particle has a high thermal conductivity, the spin sensor according to the present embodiment can instantly and efficiently equilibrate with the ambient temperature.

[0030] [Diamond Particle] <Shape> The maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm. If the maximum diameter of the diamond particle is less than 0.01 pm, the sensitivity of the spin sensor may decrease. If the maximum diameter of the diamond particle is 10 pm or more, the performance of the jig or the device may be impaired, which makes it difficult to measure the temperature of a minute measurement region. The maximum diameter of the diamond particle may be 0.05 pm or more, preferably 0.08 pm or more, and more preferably 0.1 pm or more. The maximum diameter of the diamond particle may be less than 5 pm, preferably less than 1 pm, and more preferably less than 0.5 pm. The maximum diameter of the diamond particle may be 0.05 pm or more and less than 5 pm, preferably 0.08 pm or more and less than 5 pm, more preferably 0.08 pm or more and less than 1 pm, and more preferably 0.1 pm or more and less than 0.5 pm.

[0031] The maximum diameter of the diamond particle may be determined using a scanning electron microscope (SEM).

[0032] <Color Center> The diamond particle has a color center. The color center may be an NV' center, for example.

[0033] The electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1. This enables the diamond particle to detect light, thereby suppressing noise generation as compared with any electrical temperature measurement method.

[0034] In the present embodiment, the "spin ground level of spin zero" may be paraphrased as the "spin ground level with a magnetic quantum number of 0". Similarly, the "spin excitation level of spin ±1" may be paraphrased as the "spin excitation level with a magnetic quantum number of ±1". The same applies to the second embodiment.

[0035] The fact that "the diamond particle has a color center, and the electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1" may be determined by the following method. First, an optical detection magnetic resonance (ODMR) spectrum is obtained by detecting fluorescence with a wavelength of 630 nm to 800 nm using excitation light with a wavelength of 530 nm. Next, by scanning the microwave frequency under a zero magnetic field in the spectrum, an ODMR resonance peak is obtained at 2.87 GHz. Observing the resonance peak confirms that "the diamond particle has a color center, and the electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1".

[0036] In the spectrum mentioned above, when a magnetic field is applied, two main peaks centered around 2.87 GHz are observed.

[0037] <Spin-Spin Relaxation Time T2 and Spin-Lattice Relaxation Time Tl> The spin-spin relaxation time T2 of the diamond particle is 180 nsec or more. Accordingly, it is possible to improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The lower limit of the spin-spin relaxation time T2 of the diamond particle may be 650 nsec or more, preferably 1,000 nsec or more, and more preferably 1,500 nsec or more. The upper limit of the spin-spin relaxation time T2 of the diamond particle is not particularly limited, but may be, for example, 100,000 nsec or less, 50,000 nsec or less, or 20,000 nsec or less. The spin-spin relaxation time T2 of the diamond particle may be 180 nsec or more and 100,000 nsec or less, preferably 650 nsec or more and 50,000 nsec or less, and more preferably 1,000 nsec or more and 20,000 nsec or less.

[0038] The spin-lattice relaxation time T1 of the diamond particle is preferably 300 psec or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. However, in general, the spin-lattice relaxation time T1 of the diamond particle may be 700 usee or more, 1,000 usee or more, or 1,300 usee or more. The upper limit of the spin-lattice relaxation time T1 of the diamond particle is not particularly limited, but may be, for example, 400,000 psec or less, 200,000 psec or less, or 100,000 psec or less. More preferably, the spin-lattice relaxation time T1 of the diamond particle may be 300 psec or more and 400,000 psec or less, 700 nsec or more and 200,000 psec or less, and 1,000 psec or more and 100,000 psec or less.

[0039] The spin-spin relaxation time T2 and the spin-lattice relaxation time T1 of the diamond particle may be determined by the following ODMR (Optically Detected Magnetic Resonance) measurement. The ODMR measurement is performed using a confocal fluorescence microscope equipped with a microwave excitation system. The microwaves are generated by a signal generator (SMB100A (registered trademark) by Rohde &Schwarz) and sent to a high frequency switch (ZYSWA-2-50DRS by MiniCircuits and F9160 by General Micro wave) triggered by a bit pattern generator (PulseBlasterESR-PRO-300 by SpinCore). The signals (specifically, the fluorescence signal and the ODMR signal) are amplified using a 45dB amplifier (ZHL-16W43+ by Mini-Circuits). The fluorescence signal is detected using a standard confocal microscope with a single-photon counting module (SPCM-AQRH-14 by Excelitas). The ODMR signal is measured in both a continuous wave (CW) mode and a pulsed mode. In the CW mode, the ON / OFF of microwave excitation is controlled to suppress noise. The ODMR measurement in the CW mode is performed on a sample placed directly on the antenna device. In the pulse mode, an external magnetic field is applied using a neodymium magnet to cancel the degeneracy of the magnetic sublevels. A small magnetic field is applied to split the magnetic sub-levels of the electrons in the color center sufficiently to achieve peak frequency separation. The Rabi measurement is performed to determine the jr-pulse duration for the electron spin in the color center. The n-pulse duration for measuring T1 and T2 is determined by the Rabi measurement. T2 is measured by measuring both the 7t / 2-7t-7t / 2 sequence and the 7t / 2-7t-37t / 2 sequence, and then subtracting these signals from each other to cancel common mode noise. T1 is measured by obtaining signals with and without 7t-pulse microwaves (referred to as the ON-signal and the OFF-signal, respectively), and then subtracting the ON-signal from the OFF-signal.

[0040] <First Plane> The diamond particle may have a first plane, and the maximum diameter of the first plane may be 0.3 times or more the maximum diameter of the diamond particle. This enables the spin sensor to have better sensitivity in measuring the temperature of a minute measurement region. The maximum diameter of the first plane may be preferably 0.5 times or more the maximum diameter of the diamond particle.

[0041] The fact that "the diamond particle has a first plane, and the maximum diameter of the first plane is 0.3 times or more the maximum diameter of the diamond particle" may be determined by the following method. Diamond particles or powder are extracted and deposited on a silicon substrate, and observed using SEM (scanning electron microscope) from the top side to determine the maximum diameter. Since the flat diamond particles are placed with the largest face facing downward, the maximum diameter corresponds to the maximum diameter observed from the top side. The difference in height (h) between the vertices of the maximum diameter and the distance (d) projected onto the plane may be measured using 3D-SEM, and the diameter (a) may be calculated as a=^(h2+d2). The first plane may be confirmed using 3D-SEM, and the maximum diameter of the first plane may be calculated geometrically.

[0042] [Composition] The diamond particle may be a single crystal diamond particle. The single crystal diamond particle may contain crystal defects (in other words, lattice defects).

[0043] The composition of the diamond particle may be determined by the following method. Diamond is cut into a bulk having a size of 1 mm or more and processed (surface polished) into a plate shape, and the concentration of substitutional nitrogen is calculated from an absorption spectrum with a peak at 270 nm. In addition, the concentration of Pl (concentration of substitutional nitrogen) or the concentration of NV’ is determined by an electron spin resonance (ESR) method. Further, the total amount of nitrogen is calculated from the same sample of a plate shape by SIMS (secondary ion mass spectrometry) method. Subsequently, the sample is pulverized to form particles or powder, and the value mentioned above represents the average value for a group of particles rather than the value for individual particles. Each particle exhibits variability, and the value for each particle may be estimated as a conversion value by comparing the fluorescence amount of NV’ and performing a relative comparison from the average value.

[0044] [Applications] The spin sensor according to the present embodiment may be suitably used in measuring the temperature of a semiconductor resist, measuring the temperature of a resin, measuring the temperature of an optical window (glass, ZnO), or measuring the temperature of a cell, for example.

[0045] [Producing Method of Spin Sensor] The spin sensor according to the present embodiment may be produced, for example, by the following method. First, in a spin sensor according to a second embodiment which will be described later, a single diamond particle is extracted, and for the diamond particle, the "maximum diameter of the diamond particle", the "presence or absence of a color center", and the "spin-spin relaxation time T2 of the diamond particle" are determined using the method described in the first embodiment (first step). The first step is repeated until it is determined that the extracted single diamond particle (in other words, the spin sensor according to the present embodiment) satisfies the following conditions: the single diamond particle has a maximum diameter of 0.01 pm or more and less than 10 pm, has a color center, and has a spin-spin relaxation time T2 of 180 nsec or more (second step).

[0046] As described above, it is possible to obtain a spin sensor formed of a single diamond particle, wherein the maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm, the diamond particle has a color center, the electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, and the spin-spin relaxation time T2 of the diamond particle is 180 nsec or more.

[0047] [Second Embodiment: Spin Sensor (2)] A spin sensor according to the present embodiment will be described. The spin sensor according to the present embodiment is a spin sensor formed of a powder that includes seven or more diamond particles, wherein the diamond particle include first diamond particles, a maximum diameter of each of the first diamond particles is 0.01 pm or more and less than 10 pm, each of the first diamond particles has a color center, an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, a spin-spin relaxation time T2 of each of the first diamond particles is 180 nsec or more, and in the spin sensor, a ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more.

[0048] The spin sensor according to the present embodiment can have excellent sensitivity in measuring the temperature of a minute measurement region. The possible reasons will be given in the following.

[0049] In the spin sensor according to the present embodiment, the ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more. As a result, the maximum diameter of the first diamond particles among the diamond particles may be suppressed to be small, and the noise during the temperature measurement may be easily suppressed to a low level, and thereby the spin sensor according to the present embodiment can have excellent sensitivity in measuring the temperature of a minute measurement region.

[0050] Therefore, according to the present embodiment, it is possible to provide a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0051] [Spin Sensor] The spin sensor is formed of a powder that includes seven or more diamond particles. The spin sensor may be formed of a powder that includes 10 or more diamond particles, preferably a powder that includes 20 or more diamond particles, and more preferably a powder that includes 50 or more diamond particles. In the powder, the upper limit of the number of diamond particles is not particularly limited, but may be, for example, 3xl014 or less, 3xl012 or less, or 3xl010 or less. The spin sensor may be formed of a powder that includes 7 to 3xl014 diamond particles, preferably a powder that includes 10 to 3xl012 diamond particles, and more preferably a powder that includes 20 to 3x 1010 diamond particles.

[0052] [First Diamond Particles] <(Nl / N)xl00> In the spin sensor, the diamond particles include first diamond particles. The maximum diameter of each of the first diamond particles is 0.01 pm or more and less than 10 pm. Each of the first diamond particle has a color center, and the electronic state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1. The spin-spin relaxation time T2 of each of the first diamond particles is 180 nsec or more. In the spin sensor, the ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles extracted for measurement is 40% or more. As a result, it is possible to improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [[Nl / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(Nl / N)xl00] may be preferably 40% or more and 100% or less. The spin-lattice relaxation time T1 of each of the first diamond particles may be 300 psec or more. As a result, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region.

[0053] |(N l / N)xl00] may be determined by the following method. First, seven or more diamond particles (maximum diameter: 0.01 pm or more and less than 10 pm) are arbitrarily extracted from the spin sensor. Next, for each of the seven or more diamond particles, the maximum diameter, the presence or absence of the color center, and the spin-spin relaxation time T2 are measured by the same method as that described in the first embodiment, and thereby the first diamond is determined. Next, the ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number of the diamond particles extracted for measurement is calculated.

[0054] [Second Diamond Particles] <(N2 / N)xl00> The first diamond particles may include second diamond particles. The spin-spin relaxation time T2 of each of the second diamond particles is 1,000 nsec or more. In the spin sensor, the ratio [(N2 / N)xl00] of the number N2 of the second diamond particles to the total number N of the diamond particles may be 5% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N2 / N)x 100] is not particularly limited, but may be, for example, 100% or less. [(N2 / N)xl00] may be preferably 5% or more and 100% or less.

[0055] [(N2 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "second diamond particles".

[0056] [Third Diamond Particles] <(N3 / N)xl00> The first diamond particles may include third diamond particles. The spinlattice relaxation time T1 of each of the third diamond particles is 800 psec or more. In the spin sensor, the ratio [(N3 / N)xl00] of the number N3 of the third diamond particles to the total number N of the diamond particles may be 5% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N3 / N)x 100] is not particularly limited, but may be, for example, 100% or less. [(N3 / N)xl00] may be preferably 5% or more and 100% or less.

[0057] [(N3 / N)xl00] may be determined by the following method. [(N3 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "third diamond particles" and that the third diamond particles are determined by measuring the spin-lattice relaxation time T1 in addition to the spin-spin relaxation time T2.

[0058] [Fourth Diamond Particles] <(N4 / N)xl00> The first diamond particles may include fourth diamond particles. The spinlattice relaxation time T2 of each of the fourth diamond particles is 500 nsec or more. In the spin sensor, the ratio [(N4 / N)xl00] of the number N4 of the fourth diamond particles to the total number N of the diamond particles may be 20% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N4 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N4 / N)x 100] may be preferably 20% or more and 100% or less.

[0059] [(N4 / N)x 100] may be determined by the following method. [(N4 / N)x 100] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "fourth diamond particles".

[0060] [Fifth Diamond Particles] <(N5 / N)xl00> The first diamond particles may include fifth diamond particles. The spinlattice relaxation time T1 of each of the fifth diamond particles is 500 psec or more. In the spin sensor, the ratio [(N5 / N)xl00] of the number N5 of the fifth diamond particles to the total number N of the diamond particles may be 20% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N5 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N5 / N)x 100] may be preferably 20% or more and 100% or less.

[0061] [(N5 / N)xl00] may be determined by the following method. [(N5 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "fifth diamond particles" and that the fifth diamond particles are determined by measuring the spin-lattice relaxation time T1 in addition to the spin-spin relaxation time T2.

[0062] [Sixth Diamond Particles] <(N6 / N)xl00> The first diamond particles may include sixth diamond particles. The spinlattice relaxation time T2 of each of the sixth diamond particles is 1,500 nsec or more. In the spin sensor, the ratio [(N6 / N)xl00] of the number N6 of the sixth diamond particles to the total number N of the diamond particles may be 3% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N6 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N6 / N)xl00] may be preferably 3% or more and 100% or less.

[0063] [(N6 / N)xl00] may be determined by the following method. [[N6 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "sixth diamond particles".

[0064] [Seventh Diamond Particles] <(N7 / N)xl00> The first diamond particles may include seventh diamond particles. The spin-lattice relaxation time T1 of each of the seventh diamond particles is 1,000 psec or more. In the spin sensor, the ratio [(N7 / N)xl00] of the number N7 of the seventh diamond particles to the total number N of the diamond particles may be 3% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N7 / N)x 100] is not particularly limited, but may be, for example, 100% or less. [(N7 / N)xl00] may be preferably 3% or more and 100% or less.

[0065] |(N7 / N)x 100] may be determined by the following method. [(N7 / N)x 100] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "seventh diamond particles" and that the seventh diamond particles are determined by measuring the spin-lattice relaxation time T1 in addition to the spin-spin relaxation time T2.

[0066] [Eighth Diamond Particles] <(N8 / N)xl00> The first diamond particles may include eighth diamond particles. The spinlattice relaxation time T2 of each of the eighth diamond particles is 750 nsec or more. In the spin sensor, the ratio [(N8 / N)xl00] of the number N8 of the eighth diamond particles to the total number N of the diamond particles may be 10% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N8 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N8 / N)xl00] may be preferably 10% or more and 100% or less.

[0067] [(N8 / N)xl00] may be determined by the following method. [(N8 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "eighth diamond particles".

[0068] [Ninth Diamond Particles] <(N9 / N)xl00> The first diamond particles may include ninth diamond particles. The spinlattice relaxation time T1 of each of the ninth diamond particles is 650 usee or more. In the spin sensor, the ratio [(N9 / N)x 100] of the number N9 of the ninth diamond particles to the total number N of the diamond particles may be 10% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N9 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N9 / N)x 100] may be preferably 10% or more and 100% or less.

[0069] f(N9 / N)xl00] may be determined by the following method. [(N9 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "ninth diamond particles" and that the ninth diamond particles are determined by measuring the spin-lattice relaxation time T1 in addition to the spin-spin relaxation time T2.

[0070] [Tenth Diamond Particles] <(N10 / N)xl00> The first diamond particles may include tenth diamond particles. The spinlattice relaxation time T1 of each of the tenth diamond particles is 300 psec or more. In the spin sensor, the ratio [(N10 / N)xl00] of the number N10 of the tenth diamond particles to the total number N of the diamond particles may be 40% or more. Accordingly, it is possible to further improve the measurement sensitivity of the spin sensor in measuring the temperature of a minute measurement region. The upper limit of [(N10 / N)xl00] is not particularly limited, but may be, for example, 100% or less. [(N10 / N)xl00] may be preferably 40% or more and 100% or less.

[0071] [(N10 / N)xl00] may be determined by the foilowing method. [(N10 / N)xl00] may be determined by the same method as [(Nl / N)xl00] except that the "first diamond particles" are replaced with the "tenth diamond particles" and that the third diamond particles are determined by measuring the spin-lattice relaxation time T1 in addition to the spin-spin relaxation time T2.

[0072] [Applications] The spin sensor according to the present embodiment may be suitably used in measuring the temperature of a semiconductor resist, measuring the temperature of a resin, measuring the temperature of an optical window (glass, ZnO), or measuring the temperature of a cell, for example.

[0073] [Producing Method of Spin Sensor] The spin sensor according to the present embodiment may be produced, for example, by the following method.

[0074] First, a bulky diamond sample is prepared. The bulky diamond may be synthesized according to a conventional high-temperature and high-pressure method, or may be purchased as a commercially available product. The diamond may be single crystal diamond. In the diamond, the concentration of nitrogen atoms may be about 50 ppm on atomic number basis.

[0075] Next, the diamond is subjected to electron beam irradiation and annealing in vacuum in this order to form a color center in the diamond. Thereafter, a portion of the diamond which is close to the seed substrate and is formed with the color center may be cut off by laser.

[0076] Next, the diamond formed with the color center is crushed to afford the spin sensor according to the present embodiment. The diamond is crushed using a mortarshaped iron base coated with resin or cellulose and an iron pestle-shaped rod coated with resin or cellulose and having a radius of curvature larger than that of the mortarshaped iron base by applying vibration to the iron pestle-shaped rod. The crushing of the diamond is performed until the maximum diameter of a half number of the diamond particles becomes less than 1 pm. The size of the mortar-shaped iron base may be 10 cmxlO cm. The radius of curvature of the mortar-shaped iron base may be 1 m. The radius of curvature of the tip of the iron pestle-shaped rod may be 10 cm. The mass of the iron pestle-shaped rod may be 0.5 kg or more and 2 kg or less. The frequency of vibration applied to the iron pestle-shaped rod may be 1 Hz or more and 5 Hz or less.

[0077] <Features of Producing Method of Spin Sensor of the Present Embodiment> The producing method described above can be used to produce a spin sensor formed of a powder that includes seven or more diamond particles, wherein the diamond particles include first diamond particles, the maximum diameter of each of the first diamond particles is 0.01 pm or more and less than 10 pm, each of the first diamond particles has a color center, the electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, the spin-spin relaxation time T2 of each of the first diamond particles is 180 nsec or more, and in the spin sensor, the ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more. The possible reasons will be given in the following.

[0078] Specifically, the producing method of the spin sensor according to the present embodiment is characterized in that the diamond formed with a color center (for example, an NV' center) is crushed using a mortar-shaped iron base coated with resin or cellulose and an iron pestle-shaped rod coated with resin or cellulose and having a radius of curvature larger than that of the mortar-shaped iron base by applying vibration to the iron pestle-shaped rod. As a result, it is possible to prevent any metal component derived from the container from being mixed into the spin sensor during the crushing, and it is possible to suppress the damage of the diamond particle to a low level, which makes it possible to increase the spin-spin relaxation time T2 of the diamond particle constituting the spin sensor. This finding was newly discovered by the inventors through diligent investigation.

[0079] [Third Embodiment: Jig] A jig according to the present embodiment includes the spin sensor according to the first embodiment or the second embodiment. The jig according to the present embodiment is not particularly limited as long as the jig includes the spin sensor according to the first embodiment or the second embodiment, and for example, the jig may be a bio-jig and a semiconductor jig. The bio-jig refers to such a jig that brings a spin sensor close to cells or microorganisms smaller than 10 pm in size. The semiconductor jig refers to such a jig that brings a spin sensor close to a specific minute region of a semiconductor.

[0080] According to the present embodiment, it is possible to provide a jig that includes a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region. [0081 ] [Producing Method of Jig] The producing method of the jig according to the present embodiment may be performed by the same method as a conventionally known method except that the spin sensor according to the first embodiment or the second embodiment is used.

[0082] [Fourth Embodiment: Device] A device according to the present embodiment includes the spin sensor according to the first embodiment or the second embodiment. The device according to the present embodiment is not particularly limited as long as the device includes the spin sensor according to the first embodiment or the second embodiment, and for example, the device may be a biodevice and a semiconductor device. The biodevice refers to such a device that includes the bio-jig according to the third embodiment and is configured to detect a temperature, a magnetic field, an electric field, a current or the like. The semiconductor device refers to such a device that includes the semiconductor jig according to the third embodiment and is configured to detect a temperature, a magnetic field, an electric field, a current or the like.

[0083] According to the present embodiment, it is possible to provide a device that includes a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement region.

[0084] [Producing Method of Device] The producing method of the device according to the present embodiment may be performed by the same method as a conventionally known method except that the spin sensor according to the first embodiment or the second embodiment is used. [Examples]

[0085] The embodiments will be described more specifically with reference to the following examples. However, the present embodiment is not limited to these examples.

[0086] [Production of Spin Sensor] < Product ion of Spin Sensor According to Sample 1 > First, a bulky single crystal diamond raw material (concentration of nitrogen: 10 to 30 ppm on atomic number basis, concentration of 13C: 1.1% by mass) was prepared by a conventional high-temperature and high-pressure method according to sample 1. Next, the bulky single crystal diamond raw material according to sample 1 was subjected to electron beam irradiation and annealing treatment in vacuum in this order to obtain a bulky single crystal diamond in which the concentration of NV’ (color center) is about 1 / 100 to 1 / 10 of the concentration of nitrogen.

[0087] Next, in the bulky single crystal diamond according to sample 1 in which the concentration of NV’ (color center) is about 1 / 100 to 1 / 10 of the concentration of nitrogen, a portion close to the seed substrate was cut off by laser to obtain a remaining portion. The remaining portion was used as a raw material for the spin sensor formed of a powder that includes seven or more diamond particles.

[0088] The mortar-shaped iron base and the iron pestle-shaped rod having a larger radius of curvature than the base were all coated with resin, and vibration was applied to the rod until the maximum diameter of a half number of the diamond particles becomes less than 1 pm. The size of the mortar-shaped iron base was 10 cmxlO cm, the radius of curvature of the mortar-shaped iron base was 1 m, the radius of curvature of the tip of the iron pestle-shaped rod was 10 cm, the mass of the iron pestle-shaped rod was 0.7 kg, and the frequency of the vibration applied to the iron pestle-shaped rod was 1 Hz or more and 5 Hz or less.

[0089] As described above, the spin sensor formed of a powder that includes seven or more diamond particles was produced according to sample 1. It was confirmed by a conventional method that almost no iron was contained in the obtained spin sensor.

[0090] <Production of Spin Sensor According to Sample 2> A spin sensor according to sample 2 was produced in the same manner as the producing method of the spin sensor formed of a powder that includes seven or more diamond particles according to sample 1, except that the concentration of nitrogen of the bulky single crystal diamond was 30 to 60 ppm on atomic number basis, that the concentration of 13C of the bulky single crystal diamond was 0.01% by mass, and that "cellulose was sandwiched between the mortar-shaped iron base and the iron pestleshaped rod" instead of "the mortar-shaped iron base and the iron pestle-shaped rod having a larger radius of curvature than the base were all coated with resin". As a result, the spin sensor formed of a powder that includes seven or more diamond particles was produced according to sample 2. It was confirmed by a conventional method that iron was prevented from being mixed into the obtained spin sensor (the powder).

[0091] <Produclion of Spin Sensor According to Sample 101 > A spin sensor formed of a powder that includes seven or more diamond nanoparticles (concentration of NV: 3 ppm), which are purchased as a commercially available product by Adamas Nanotechnologies, was produced according to sample 101.

[0092] [Characteristic Evaluation of Spin Sensor] <(Nl / N)xl00, (N2 / N)xl00, (N3 / N)xl00> Regarding the spin sensor according to each sample, the ratio [(Nl / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles was measured by the measurement method described in the second embodiment. Regarding sample 1, the spin-spin relaxation time T2 of each particle determined according to the measurement method is listed in the column of "T2 [nsec]" in Table 1. Regarding sample 2, the spin-spin relaxation time T2 of each particle determined according to the measurement method is listed in the column of "T2 [nsec]" in Table 2. Regarding sample 101, the spin-spin relaxation time T2 of each particle determined according to the measurement method is listed in the column of "T2 [nsec]" in Table 3. Further, the ratio [(Nl / N)xl00] determined according to the measurement method is listed in the column of "|(N l / N)xl00] [%]" in Table 4. Regarding the spin sensor of each sample, the ratio [(N2 / N)xl00] of the number N2 of the second diamond particles to the total number N of the diamond particles was measured by the measurement method described in the second embodiment. The obtained results are listed in the column of ”[(N2 / N)xl00] [%]" in Table 4. Regarding the spin sensor of each sample, the ratio [(N3 / N)x 100] of the number N3 of the third diamond particles to the total number N of the diamond particles was measured by the measurement method described in the second embodiment. Regarding sample 1, the spin-lattice relaxation time T1 of each particle determined according to the measurement method is listed in the column of "T1 [psec]" in Table 1. Regarding sample 2, the spin-lattice relaxation time T1 of each particle determined according to the measurement method is listed in the column of "T1 |pscc|" in Table 1. Regarding sample 101, the spin-lattice relaxation time T1 of each particle determined according to the measurement method is listed in the column of "T1 [psec]" in Table 3. Further, [(N3 / N)xl00] determined according to the measurement method is listed in the column of "[(N3 / N)xl00] [%]" in Table 4. Regarding the measurement of [(N3 / N)xl00], T1 was not measured for particle 1-10 and particle 1-11 in Table 1, particle 2-9, particle 2-10 and particle 2-11 in Table 2, and particle 101-10 in Table 3, the ratio [(N3 / N)xl00] was not measured for those particles mentioned above.

[0093] The spin sensor of sample 1 and the spin sensor of sample 2 correspond to examples. The spin sensor of sample 101 corresponds to a comparative example. The spin sensor of sample 1 and the spin sensor of sample 2 exhibit a remarkably higher [(Nl / N)xl00] than the spin sensor of sample 101. A relatively high [(Nl / N)xl00] indicates that the measurement sensitivity of the temperature of the spin sensor is relatively high. Therefore, it was confirmed that the spin sensor of sample 1 and the spin sensor of sample 2 exhibit particularly excellent sensitivity in the measurement of temperatures as compared with the spin sensor of sample 101.

[0094] In the measurement of [(Nl / N)xl00], [(N2 / N)xl00], and [(N3 / N)xl00], the spin-spin relaxation time T2 and the spin-lattice relaxation time T1 of each particle in sample 1 were listed in Table 1. In the measurement of [(NI / N )x 100]. [(N2 / N)x 100], and [(N3 / N)xl00], the spin-spin relaxation time T2 and the spin-lattice relaxation time T1 of each particle in sample 2 were listed in Table 2. In the measurement of [(Nl / N)xl00], [(N2 / N)xl00], and [(N3 / N)xl00], the spin-spin relaxation time T2 and the spin-lattice relaxation time T1 of each particle in sample 101 were listed in Table 3. In Tables 1 to 3,in the column of "T1 [usee]" indicates that the spin-lattice relaxation time T1 was not measured. In Tables 1 to 3, in the column of "T2 [nsec]" indicates that the spin-spin relaxation time T2 was not measured. In addition, it was confirmed by the method described in the first embodiment that the maximum diameter of each particle was 0.01 pm or more and less than 10 pm, each particle had a color center, and the electron state of the color center had a spin ground level of spin zero and a spin excitation level of spin ±1.

[0095] In Table 1, the spin-spin relaxation time T2 of the spin sensor according to each of the particles 1-1 to 1-7 and the particles 1-9 to 1-11 was 180 nsec or more. In Table 2, the spin-spin relaxation time T2 of the spin sensor according to each of the 5 particles 2-1 to 2-7 and the particles 2-9 to 2-11 was 180 nsec or more. On the other hand, in Table 3, the spin-spin relaxation time T2 of the spin sensor according to each of the particles 101-1 to 101-7, 101-9 and 101-10 was less than 180 nsec. The measurement sensitivity of temperatures by the spin sensor is inversely proportional to the square root of the spin-spin relaxation time T2 (in other words, for example, when 10 T2 is improved by 100 times, the lower limit of the measurement sensitivity becomes 1 / 10). Therefore, it was confirmed that the spin sensor according to each of the particles 1-1 to 1-7, 1-9 to 1-11, 2-1 to 2-7 and 2-9 to 2-11 has particularly excellent sensitivity in the measurement of temperatures as compared with the spin sensor according to each of the particles 101-1 to 101-7, 101-9 and 101-10. 15

[0096] [Table 1] Table 1 Particle No. T1 [psec] T2 [nsec] Particle 1-1 842 1066 Particle 1-2 442 1169 Particle 1-3 621 715 Particle 1-4 1075 768 Particle 1-5 216 463 Particle 1-6 419 529 Particle 1-7 270 711 Particle 1-9 621 776 Particle 1-10 — 484 Particle 1-11 — 672

[0097] [Table 2] Table 2 Particle No. T1 [gsec] T2 [nsec] Particle 2-1 342 689 Particle 2-2 431 797 Particle 2-3 918 1695 Particle 2-4 1297 699 Particle 2-5 710 1092 Particle 2-6 576 859 Particle 2-7 981 875 Particle 2-9 — 1598 Particle 2-10 — 1329 Particle 2-11 — 820

[0098] [Table 3] Table 3 Particle No. T1 [gsec] T2 [nsec] Particle 101-1 212 57 Particle 101-2 156 61 Particle 101-3 50 75 Particle 101-4 164 86 Particle 101-5 246 68 Particle 101-6 144 151 Particle 101-7 100 122 Particle 101-9 129 89 Particle 101-10 — 97

[0099] [Table 4] Table 4 Sample No. (Nl / N)xl00 [%] (N2 / N)xl00 [%] (N3 / N)xl00 [%] 1 100.0 20.0 25.0 2 100.0 40.0 42.9 101 0 0 0

[0100] It should be understood that the embodiments disclosed herein are illustrative 5 and non-restrictive in all respects. The scope of the present invention is defined not by the embodiments described above but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A spin sensor formed of a single diamond particle,a maximum diameter of the diamond particle is 0.01 pm or more and less than 10 pm,the diamond particle has a color center,an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1, anda spin-spin relaxation time T2 of the diamond particle is 180 nsec or more.

2. The spin sensor according to claim 1, whereina spin-lattice relaxation time T1 of the diamond particle is 300 psec or more.

3. A spin sensor formed of a powder that includes seven or more diamond particles,the diamond particles include first diamond particles,a maximum diameter of each of the first diamond particles is 0.01 pm or more and less than 10 pm,each of the first diamond particles has a color center,an electron state of the color center includes a spin ground level of spin zero and a spin excitation level of spin ±1,a spin-spin relaxation time T2 of each of the first diamond particles is 180 nsec or more, andin the spin sensor, a ratio [(N l / N)xl00] of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more.

4. The spin sensor according to claim 3, whereina spin-lattice relaxation time T1 of each of the first diamond particles is 300 psec or more.

5. The spin sensor according to claim 3 or 4, wherein the first diamond particles include second diamond particles, the spin-spin relaxation time T2 of each of the second diamond particles is 1,000 nsec or more, andin the spin sensor, a ratio [(N2 / N)xl00] of the number N2 of the second diamond particles to the total number N of the diamond particles is 5% or more.

6. The spin sensor according to any one of claims 3 to 5, wherein, the first diamond particles include third diamond particles,the spin-lattice relaxation time T1 of each of the third diamond particles is 800 psec or more, andin the spin sensor, a ratio [(N3 / N)x 100] of the number N3 of the third diamond particles to the total number N of the diamond particles is 5% or more.

7. A jig comprising the spin sensor according to any one of claims 1 to 6.

8. A device comprising the spin sensor according to any one of claims 1 to 6.INTERNATIONAL SEARCH REPORT International application No. PCT / JP2024 / 024736A. CLASSIFICATION OF SUBJECT MATTER G01K 11 / 20(2006.01)1; GOIN24 / 08(2006.01)1; G01R 33 / 20(2006.01)1 FI: G01K11 / 20; G01N24 / 08 510L; G01R33 / 20 According to International Patent Classification (IPC) or to both national classification and IPC B. FIELDS SEARCHED Minimum documentation searched (classification system followed by classification symbols) G01K1 / 00-19 / 00: G01N24 / 08; G01R33 / 20 Documentation searched other than minimum documentation to the extent that such documents are included in the fields searched Published examined utility model applications of Japan 1922-1996 Published unexamined utility model applications of Japan 1971-2024 Registered utility model specifications of Japan 1996-2024 Published registered utility model applications of Japan 1994-2024 Electronic data base consulted during the international search (name of data base and, where practicable, search terms used) C. DOCUMENTS CONSIDERED TO BE RELEVANT Category* Citation of document, with indication, where appropriate, of the relevant passages Relevant to claim No. X A JP 2015-529328 A (HARVARD COLLEGE) 05 October 2015 (2015-10-05) paragraphs [0015], [0019], [0035], [0036], [0081], [0082], fig. 1, 2 1-2, 7-8 3-6 P,X JP 2023-139660 A (KYOTO UNIVERSITY) 04 October 2023 (2023-10-04) paragraphs [0001]-[0010], [0014]-[0080], fig. 1, 2, 9 3-8 | | Further documents are listed in the continuation of Box C. | V | See patent family annex. * Special categories of cited documents: “A” document defining the general state of the art which is not considered to be of particular relevance “D” document cited by the applicant in the international application ‘4E” earlier application or patent but published on or after the international filing date *4L” document which may throw doubts on priority claim(s) or which is cited to establish the publication date of another citation or other special reason (as specified) “O” document referring to an oral disclosure, use, exhibition or other means “P” document published prior to the international filing date but later than the priority date claimed “T” later document published after the international filing date or priority date and not in conflict with the application but cited to understand the principle or theory underlying the invention “X” document of particular relevance; the claimed invention cannot be considered novel or cannot be considered to involve an inventive step when the document is taken alone “Y” document of particular relevance; the claimed invention cannot be considered to involve an inventive step when the document is combined with one or more other such documents, such combination being obvious to a person skilled in the art document member of the same patent family Date of the actual completion of the international search Date of mailing of the international search report 12 September 2024 24 September 2024 Name and mailing address of the ISA / JP Authorized officer Japan Patent Office (ISA / JP) 3-4-3 Kasumigaseki, Chiyoda-ku, Tokyo 100-8915 Japan Telephone No.Form PCT / ISA / 210 (second sheet) (July 2022)INTERNATIONAL SEARCH REPORT Information on patent family members International application No. PCT / JP2024 / 024736Patent document cited in search report Publication date (day / month / year) Patent family member)s) Publication date (day / month / year) JP 2015-529328 A 05 October 2015 US 2015 / 0253355 Al paragraphs [0015], [0019], [0071], [0072], [0117], [0118], fig- 1.2 JP 2017-75964 A US 2018 / 0246143 Al US 2022 / 0413007 Al US 2024 / 0044938 Al WO 2014 / 051886 Al EP 28885% Bl CN 104704375 A CN 109765257 A JP 2023-139660 A 04 October 2023 (Family: none)