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; the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ± 1; and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more.

Description

Spin sensor, jig including same, and device including same

[0001] The present disclosure relates to a spin sensor, a jig including the same, and an apparatus including the same. This application claims priority to Japanese Patent Application No. 2023-120722, filed on July 25, 2023. The entire contents of the Japanese patent application are incorporated herein by reference.

[0002] Diamond particles have been used in the past to measure the temperature of tools and devices used in fields such as semiconductors, vacuum equipment, optics, and medical and biological sciences (Non-Patent Document 1).

[0003] L. Nie, et al. , “Quantum monitoring of cellular metabolic activities in single mitochondria”, Sci Adv. 2021 May 19;7(21): eabf0573.

[0004] The spin sensor of the present disclosure is a spin sensor consisting of a single diamond particle, wherein the diamond particle has a maximum diameter of 0.01 μm or more and less than 10 μm, the diamond particle has a color center, the electronic state of the color center has a spin ground level of spin zero and a spin excited level of spin ±1, and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more.

[0005] [Problem to be Solved by the Present Disclosure] In recent years, in the fields of semiconductors, vacuum equipment industry, optics, and medical / biological science, there has been a demand for spin sensors that can measure the temperature of a minute measurement area and have excellent sensitivity as spin sensors used in jigs and devices. Temperature measurement in a minute measurement area becomes possible by keeping the maximum diameter of the particles that make up the spin sensor small. On the other hand, such spin sensors tend to have difficulty measuring temperature with sufficient accuracy (1 K / √Hz or less), and it has sometimes been difficult 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 area, a jig including the spin sensor, and an apparatus including the spin sensor.

[0007] 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 area, a jig including the spin sensor, and an apparatus including the spin sensor.

[0008] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. (1) A spin sensor of the present disclosure is a spin sensor consisting of a single diamond particle, wherein the diamond particle has a maximum diameter of 0.01 μm or more and less than 10 μm, the diamond particle has a color center, the electronic state of the color center has a spin ground level of spin zero and a spin excited level of spin ±1, and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more.

[0009] According to the present disclosure, a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement area can be provided.

[0010] (2) In the above (1), the longitudinal spin relaxation time T1 of the diamond particles may be 300 μsec or more, thereby providing a spin sensor with superior sensitivity in measuring the temperature of a minute measurement area.

[0011] (3) The spin sensor of the present disclosure is a spin sensor consisting of a powder of seven or more diamond particles, wherein the diamond particles include first diamond particles, each of which has a maximum diameter of 0.01 μm or more and less than 10 μm, the first diamond particles have a color center, and the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ±1, the spin transverse relaxation time T2 of the first diamond particles is 180 nsec or more, and in the spin sensor, the proportion (N1 / N) x 100 of the number N of the first diamond particles to the total number N of the diamond particles is 40% or more.

[0012] According to the present disclosure, a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement area can be provided.

[0013] (4) In the above (3), the first diamond particles may have a longitudinal spin relaxation time T1 of 300 μsec or more, thereby providing a spin sensor with superior sensitivity in measuring the temperature of a minute measurement area.

[0014] (5) In the above (3) or (4), the first diamond particles may include second diamond particles, the second diamond particles may have a spin transverse relaxation time T2 of 1,000 nsec or more, and the ratio (N2 / N) x 100 of the number N2 of the second diamond particles to the total number N of the diamond particles may be 5% or more. This makes it possible to provide a spin sensor with better sensitivity in measuring the temperature of a fine measurement region.

[0015] (6) In any of the above (3) to (5), the first diamond particles may include third diamond particles, the third diamond particles may have a spin longitudinal relaxation time T1 of 800 μsec or more, and in the spin sensor, the ratio (N3 / N)×100 of the number N3 of the third diamond particles to the total number N of the diamond particles may be 5% or more. This makes it possible to provide a spin sensor with better sensitivity in measuring the temperature of a fine measurement region.

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

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

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

[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 area.

[0020] [Details of the embodiment of the present disclosure] In this specification, the expression "A to B" means the upper and lower limits of a range (i.e., A or more and B or less), and when no unit is specified for A and a unit is specified only for B, the unit of A and the unit of B are the same.

[0021] In this specification, when a compound is expressed by a chemical formula that does not limit the composition ratio of the constituent elements, the chemical formula is considered to include any conventionally known composition ratio (element ratio). Furthermore, the chemical formula includes not only stoichiometric compositions but also non-stoichiometric compositions.

[0022] [Embodiment 1: Spin Sensor (1)] A spin sensor according to one embodiment of the present disclosure will be described. A spin sensor according to one embodiment of the present disclosure (hereinafter also referred to as "the present embodiment") is a spin sensor consisting of a single diamond particle, wherein the diamond particle has a maximum diameter of 0.01 μm or more and less than 10 μm, the diamond particle has a color center, and the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ±1, and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more. The spin-related characteristic values ​​(T1, T2, etc.) of the present disclosure are not characteristic values ​​of a single NV, but values ​​of an ensemble (collected NV), which allows for a sufficient amount of light to be obtained as a sensor.

[0023] A spin sensor according to an embodiment of the present disclosure can have excellent sensitivity in measuring the temperature of a minute measurement area, the reason for which is presumed to be as follows.

[0024] (a) In the spin sensor according to this embodiment, the maximum diameter of the diamond particles is 0.01 μm or more and less than 10 μm. This keeps the maximum diameter of the diamond particles small, so the spin sensor according to this embodiment can be used to measure the temperature of a minute measurement area.

[0025] (b) When the maximum diameter of diamond particles is small, it tends to be difficult to distinguish between the fluorescence intensity of the sensor part, which is necessary for calculating the temperature, and the background fluorescence intensity during temperature measurement. Therefore, it tends to be difficult for the spin sensor to have excellent sensitivity when measuring the temperature of a small measurement area.

[0026] In the spin sensor according to this embodiment, the diamond particle has a color center, and the electronic state of the color center has a spin ground level of spin zero and a spin excited level of spin ±1, and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more. This makes it easier to keep noise low during temperature measurement, and the spin sensor can have excellent sensitivity in measuring the temperature of a minute measurement area.

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

[0028] <Spin Sensor> In the present disclosure, a spin sensor refers to a sensor having an emission level with triplet electron spin. When excitation light is incident on a spin sensor, the spin sensor emits fluorescence, and the fluorescence intensity changes depending on the magnetic field outside the spin. When microwaves resonating with the ground level and excited level are incident, the change in fluorescence intensity increases. Utilizing this principle, the spin sensor of the present disclosure can sense temperature. Furthermore, the spin sensor of the present disclosure can also sense magnetic fields, electric fields, pressure, and the like in addition to temperature.

[0029] The spin sensor according to this embodiment is made of a single diamond particle, and since the diamond particle has high thermal conductivity, the spin sensor according to this embodiment can quickly and efficiently assimilate with the ambient temperature.

[0030] <Diamond Particles> <Shape> The maximum diameter of the diamond particles is 0.01 μm or more and less than 10 μm. If the maximum diameter of the diamond particles is less than 0.01 μm, the sensitivity of the spin sensor tends to decrease. If the maximum diameter of the diamond particles is 10 μm or more, it tends to hinder the performance of the jig and the device and make it difficult to measure fine areas. The maximum diameter of the diamond particles may be 0.05 μm or more, preferably 0.08 μm or more, and more preferably 0.1 μm or more. The maximum diameter of the diamond particles may be less than 5 μm, preferably less than 1 μm, and more preferably less than 0.5 μm. The maximum diameter of the diamond particles may be 0.05 μm or more and less than 5 μm, preferably 0.08 μm or more and less than 5 μm, more preferably 0.08 μm or more and less than 1 μm, and more preferably 0.1 μm or more and less than 0.5 μm.

[0031] The maximum diameter of the diamond particles can be determined by carrying out measurements using a scanning electron microscope (SEM).

[0032] <Color Center> Diamond particles have a color center. For example, NV － The center is mentioned.

[0033] The electronic state of the color center has a spin ground level of spin zero and spin excited levels of spin ±1. This allows the diamond particle to detect light, which reduces noise generation compared to when measuring temperature electrically.

[0034] Here, the "spin ground level of spin zero" can be rephrased as "spin ground level of magnetic quantum number 0." Also, the "spin excitation level of spin ±1" can be rephrased as "spin excitation level of magnetic quantum number ±1." The same applies to the second embodiment.

[0035] The fact that "diamond particles have color centers, and the electronic state of the color centers has a spin ground level of spin zero and a spin excited level of spin ±1" can be identified by the following method. First, an optically detected magnetic resonance (ODMR) spectrum is obtained by detecting fluorescence with wavelengths of 630 nm to 800 nm using excitation light with a wavelength of 530 nm. Next, an ODMR resonance peak is obtained at 2.87 GHz by sweeping the microwave frequency in zero magnetic field in the spectrum. Observation of the above resonance peak confirms that "diamond particles have color centers, and the electronic state of the color centers has a spin ground level of spin zero and a spin excited level of spin ±1."

[0036] In the above spectrum, when a magnetic field is applied, two peaks are observed, with the microwave frequency at 2.87 GHz as the center.

[0037] <Spin transverse relaxation time T2 and spin longitudinal relaxation time T1> The spin transverse relaxation time T2 of diamond particles is 180nsec or more.Therefore, when measuring the temperature of a minute measurement area, the measurement sensitivity of the spin sensor can be improved.The lower limit of the spin transverse relaxation time T2 of diamond particles can be 650nsec or more, preferably 1,000nsec or more, more preferably 1,500nsec or more.The upper limit of the spin transverse relaxation time T2 of diamond particles is not particularly limited, but can be, for example, 100,000nsec or less, 50,000nsec or less, or 20,000nsec or less. The transverse spin relaxation time T2 of the diamond particles 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 longitudinal relaxation time T1 of the diamond particle is preferably 300 μsec or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. However, usually, the spin longitudinal relaxation time T1 of the diamond particle may be 700 μsec or more, 1,000 μsec or more, or 1,300 μsec or more. The upper limit of the spin longitudinal relaxation time T1 of the diamond particle is not particularly limited, but may be, for example, 400,000 μsec or less, 200,000 μsec or less, or 100,000 μsec or less. More preferably, the spin longitudinal relaxation time T1 of the diamond particle may be 300 μsec or more and 400,000 μsec or less, 700 nsec or more and 200,000 μsec or less, or 1,000 μsec or more and 100,000 μsec or less.

[0039] The transverse spin relaxation time T2 and longitudinal spin relaxation time T1 of diamond particles can be determined by the following ODMR measurement. The ODMR measurement is performed using a confocal fluorescence microscope equipped with a microwave excitation system. Microwaves are generated by a signal generator (Rohde & Schwarz "SMB100A" (trademark)) and sent to high-frequency switches (Mini-circuit, ZYSWA-2-50DRS and General Microwave, F9160) triggered by a bit pattern generator (SpinCore, PBESRPRO-300). The signals (i.e., fluorescence and ODMR signals) are amplified using a 45 dB amplifier (Mini-circuit, ZHL-16W43+). Fluorescence signals were detected using a standard confocal microscope with a single photon counting module (Excelitas, SPCM-AQRH-14). ODMR signals were measured in both continuous wave (CW) and pulsed modes. In CW mode, microwave excitation was controlled on and off to suppress noise. CW-mode ODMR measurements were performed on samples placed directly on the antenna device. In pulsed mode, an external magnetic field was applied using a neodymium magnet to remove the degeneracy of the magnetic sublevels. A small magnetic field was applied to split the magnetic sublevels of the color center electrons to such an extent that the peaks were separated in frequency. Rabi measurements were performed to determine the duration of the π pulse on the color center electron spin. The Rabi measurements determined the duration of the π pulse used for T1 and T2 measurements. T2 measurements are performed by measuring both the π / 2-π-π / 2 and π / 2-π-3π / 2 sequences and subtracting these signals from each other to cancel common-mode noise, while T1 measurements are performed by obtaining signals with and without the π-pulsed microwave (ON-signal and OFF-signal, respectively) and subtracting the ON-signal from the OFF-signal.

[0040] <First Plane> The diamond particle has 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 allows the spin sensor to have better sensitivity in measuring the temperature of a fine measurement area. The maximum diameter of the first plane may preferably be 0.5 times or more the maximum diameter of the diamond particle.

[0041] The fact that "diamond particles have a first plane, and the maximum diameter of the first plane is 0.3 times or more the maximum diameter of the diamond particles" can be specified by the following method. Diamond particles or powder are extracted and scattered on a silicon substrate, and the maximum diameter is observed from the top using SEM observation (scanning electron microscope observation). Since the flat diamond is placed with its maximum surface facing downwards, the maximum diameter is the same as the maximum diameter from the top. By using 3D-SEM to measure the difference in height (h) between the vertices of the maximum diameter and the distance (d) projected onto a plane, the diameter (a) can be calculated as a = √(h ２ +d ２ The first plane can be confirmed using a 3D-SEM, and its maximum diameter can be calculated geometrically.

[0042] Composition The diamond particles may be made of single-crystal diamond, which may contain crystal defects (in other words, lattice defects).

[0043] The composition of diamond particles can be specified by the following method. Diamond is prepared in bulk form of 1 mm or more, processed into a plate (surface polished), and the substitutional nitrogen concentration is calculated from the absorption spectrum with a peak at 270 nm. In addition, the P1 concentration (substitutional nitrogen concentration) and NV concentration are calculated by the ESR method (electron spin resonance method). － The concentration is measured. The total nitrogen content is also calculated from the same plate-shaped sample by SIMS (Secondary Ion Mass Spectroscopy). After that, the sample is crushed to form particles and powder, but the above value is not the value of each particle, but the average value of the group. Each particle has its own variation, and the value of each particle is calculated by NV －The fluorescence intensity can be compared and a rough conversion value can be obtained by relative comparison from the average value.

[0044] <<Uses>> The spin sensor of this embodiment can be suitably used for, for example, measuring the temperature of semiconductor resist, resin, optical window (glass, ZnO), or cell temperature.

[0045] <<Manufacturing Method of Spin Sensor>> The spin sensor according to this embodiment can be manufactured by, for example, the following method. First, in the spin sensor according to the second embodiment described later, any one diamond particle is extracted, and the "maximum diameter of the diamond particle", "presence or absence of a color center", and "spin transverse relaxation time T2 of the diamond particle" are identified for this diamond particle by the method described in the first embodiment (first step). In any one extracted diamond particle, the "maximum diameter of the diamond particle" is 0.01 μm or more and less than 10 μm, a "color center" is present, and the "spin transverse relaxation time T2 of the diamond particle" is 180 nsec or more (in other words, the spin sensor according to this embodiment) is identified (second step).

[0046] As a result of the above, a spin sensor can be obtained which consists of one 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, the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ±1, and the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more.

[0047] [Embodiment 2: Spin sensor (2)] The spin sensor according to this embodiment will be described. The spin sensor according to this embodiment is a spin sensor made of a powder of 7 or more diamond particles, wherein the diamond particles include first diamond particles, and the maximum diameter of each of the first diamond particles is 0.01 μm or more and less than 10 μm, the first diamond particles have a color center, and the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ±1, the spin transverse relaxation time T2 of the first diamond particles is 180 nsec or more, and in this spin sensor, the proportion (N1 / N) × 100 of the number N of the first diamond particles to the total number N of the diamond particles is 40% or more.

[0048] The spin sensor according to this embodiment can have excellent sensitivity in measuring the temperature of a minute measurement area, and the reason for this is presumed to be as follows.

[0049] In the spin sensor according to this embodiment, the ratio (N1 / N) x 100 of the number N1 of the first diamond particles to the total number N of the diamond particles is 40% or more. This makes it possible to keep the maximum diameter of the first diamond particles among the diamond particles small, and also makes it easy to keep noise low during temperature measurement, so that the spin sensor according to this embodiment can have excellent sensitivity even when measuring the temperature of a minute measurement area.

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

[0051] <Spin Sensor> The spin sensor is made of a powder consisting of 7 or more diamond particles. The spin sensor may be made of a powder consisting of 10 or more diamond particles, preferably 20 or more diamond particles, and more preferably 50 or more diamond particles. The upper limit of the number of diamond particles in the powder is not particularly limited, but may be, for example, 3 × 10１４ It may be 3 × 10 or less. １２ It may be 3 × 10 or less. １０ The number of spin sensors may be 7 or more and 3×10 １４ The powder may be composed of diamond particles of 10 or less, and preferably 10 or more and 3×10 １２ The powder may be composed of diamond particles of 20 or less, more preferably 20 or more and 3×10 １０ It may be made of a powder consisting of diamond particles or less.

[0052] <First Diamond Particles> <(N1 / N) x 100> In the spin sensor, the diamond particles include first diamond particles. The maximum diameter of each of the first diamond particles is 0.01 μm or more and less than 10 μm. The first diamond particles have a color center, and the electronic state of the color center has a spin ground level of spin zero and a spin excitation level of spin ±1. The spin transverse relaxation time T2 of the first diamond particles is 180 nsec or more. In the spin sensor, the proportion (N1 / N) x 100 of the number N1 of first diamond particles to the total number N of diamond particles extracted for measurement is 40% or more. This improves the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. The upper limit of (N1 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N1 / N) x 100 may preferably be 40% or more and 100% or less. The longitudinal spin relaxation time T1 of the first diamond grains may be 300 μsec or more, thereby further improving the measurement sensitivity of the spin sensor when measuring the temperature of a minute measurement area.

[0053] (N1 / N) × 100 can be determined by the following method. First, any seven or more diamond particles (maximum diameter: 0.01 μm or more and less than 10 μm) are extracted from the spin sensor. Next, for each of the seven or more diamond particles, the maximum diameter, the presence or absence of a color center, and the spin transverse relaxation time T2 are measured using the same method as in embodiment 1, to identify the first diamond. Next, the proportion (N1 / N) × 100 of the number N1 of first diamond particles to the total number of extracted and measured diamond particles is calculated.

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

[0055] (N2 / N)×100 can be determined in the same manner as (N1 / N)×100, except that "first diamond particles" are read as "second diamond particles".

[0056] <Third Diamond Particles> <(N3 / N) x 100> The first diamond particles may include third diamond particles. The spin longitudinal relaxation time T1 of the third diamond particles is 800 μsec or more. In the spin sensor, the proportion (N3 / N) x 100 of the number N3 of third diamond particles to the total number N of diamond particles measured may be 5% or more. This makes it possible to further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. The upper limit of (N3 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N3 / N) x 100 may preferably be 5% or more and 100% or less.

[0057] (N3 / N) x 100 can be determined by the following method: The "first diamond particle" is replaced with the "third diamond particle", and the third diamond particle is determined by measuring the longitudinal spin relaxation time T1 in addition to the transverse spin relaxation time T2, etc., and can be determined by the same method as (N1 / N) x 100.

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

[0059] (N4 / N) x 100 can be determined by the following method: It can be determined in the same way as (N1 / N) x 100, except that the "first diamond particle" is replaced with the "fourth diamond particle".

[0060] <Fifth Diamond Particles> <(N5 / N) x 100> The first diamond particles may include fifth diamond particles. The fifth diamond particles have a spin longitudinal relaxation time T1 of 500 μsec or more. In the spin sensor, the ratio (N5 / N) x 100 of the number N5 of fifth diamond particles to the total number N of diamond particles may be 20% or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement region. The upper limit of (N5 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N5 / N) x 100 may preferably be 20% or more and 100% or less.

[0061] (N5 / N) x 100 can be determined by the following method: The "first diamond particle" is replaced with the "fifth diamond particle", and the fifth diamond particle is determined by measuring the longitudinal spin relaxation time T1 in addition to the transverse spin relaxation time T2, etc., and can be determined by the same method as (N1 / N) x 100.

[0062] <Sixth Diamond Particles> <(N6 / N) x 100> The first diamond particles may include sixth diamond particles. The spin longitudinal relaxation time T2 of the sixth diamond particles is 1,500 nsec or more. In the spin sensor, the ratio (N6 / N) x 100 of the number N6 of sixth diamond particles to the total number N of diamond particles may be 3% or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. The upper limit of (N6 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N6 / N) x 100 may preferably be 3% or more and 100% or less.

[0063] (N6 / N) x 100 can be determined in the following manner: (N6 / N) x 100 can be determined in the same manner as (N1 / N) x 100, except that the "first diamond particle" is replaced with the "sixth diamond particle".

[0064] <Seventh Diamond Particles> <(N7 / N) x 100> The first diamond particles may include seventh diamond particles. The seventh diamond particles have a spin longitudinal relaxation time T1 of 1,000 μsec or more. In the spin sensor, the ratio (N7 / N) x 100 of the number N7 of seventh diamond particles to the total number N of diamond particles may be 3% or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. The upper limit of (N7 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N7 / N) x 100 may preferably be 3% or more and 100% or less.

[0065] (N7 / N) x 100 can be determined by the following method: The "first diamond particle" is replaced with the "seventh diamond particle", and the seventh diamond particle is determined by measuring the longitudinal spin relaxation time T1 in addition to the transverse spin relaxation time T2, etc., and can be determined by the same method as (N1 / N) x 100.

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

[0067] (N8 / N) x 100 can be determined in the following manner: (N8 / N) x 100 can be determined in the same manner as (N1 / N) x 100, except that the "first diamond particle" is replaced with the "eighth diamond particle".

[0068] <Ninth Diamond Particles> <(N9 / N) x 100> The first diamond particles may include ninth diamond particles. The ninth diamond particles have a spin longitudinal relaxation time T1 of 650 μsec or more. In the spin sensor, the ratio (N9 / N) x 100 of the number N9 of ninth diamond particles to the total number N of diamond particles may be 10% or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement area. The upper limit of (N9 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N9 / N) x 100 may preferably be 10% or more and 100% or less.

[0069] (N9 / N) x 100 can be determined by the following method: The "first diamond particle" is replaced with the "ninth diamond particle" and the ninth diamond particle is determined by measuring the longitudinal spin relaxation time T1 in addition to the transverse spin relaxation time T2. The same method as (N1 / N) x 100 can be used to determine the ninth diamond particle.

[0070] <Tenth Diamond Particle> <(N10 / N) x 100> The first diamond particle may include a tenth diamond particle. The spin longitudinal relaxation time T1 of the tenth diamond particle is 300 μsec or more. In the spin sensor, the ratio (N10 / N) x 100 of the number N10 of tenth diamond particles to the total number N of diamond particles may be 40% or more. This can further improve the measurement sensitivity of the spin sensor when measuring the temperature of a fine measurement region. The upper limit of (N10 / N) x 100 is not particularly limited, but may be, for example, 100% or less. (N10 / N) x 100 may preferably be 40% or more and 100% or less.

[0071] (N10 / N) x 100 can be determined by the following method: The third diamond particle can be determined by the same method as (N1 / N) x 100, except that the "first diamond particle" is replaced with the "tenth diamond particle" and the longitudinal spin relaxation time T1 is measured in addition to the transverse spin relaxation time T2.

[0072] <<Uses>> The spin sensor of this embodiment can be suitably used for, for example, measuring the temperature of semiconductor resist, resin, optical window (glass, ZnO), or cell temperature.

[0073] <<Method of Manufacturing Spin Sensor>> The spin sensor according to this embodiment can be manufactured by, for example, the following method.

[0074] First, a bulk diamond sample is prepared. The bulk diamond may be prepared by synthesizing it using a conventional high-temperature and high-pressure method, or by purchasing a commercially available product. The diamond may be a single crystal diamond. The nitrogen atom concentration in the diamond may be about 50 ppm based on the number of atoms.

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

[0076] Next, the diamond with the color center formed thereon is crushed to obtain the spin sensor according to this embodiment. The diamond is crushed using a "mortar-shaped iron base" coated with resin or cellulose and an "iron pestle-shaped rod" with a larger radius of curvature than the "mortar-shaped iron base" and coated with resin or cellulose, and the diamond is crushed by applying vibration to the "iron pestle-shaped rod." The diamond is crushed until the maximum diameter of half of the diamond particles is less than 1 μm. The size of the mortar-shaped iron base may be 10 cm square. 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 vibration applied to the "iron pestle-shaped rod" may be 1 Hz or more and 5 Hz or less.

[0077] <Features of the manufacturing method of the spin sensor of this embodiment> By the manufacturing method described above, can manufacture a spin sensor that is made of powder that is made up of 7 or more diamond particles, this diamond particle comprises first diamond particle, the maximum diameter of each of this first diamond particle is 0.01 μm or more and less than 10 μm, this first diamond particle has color center, the electronic state of this color center has spin ground level of spin zero and spin excitation level of spin ±1, the spin transverse relaxation time T2 of this first diamond particle is 180nsec or more, and in this spin sensor, the ratio (N1 / N) x 100 that the number N1 of this first diamond particle occupies to the total number N of this diamond particle is 40% or more.The reason for this is presumed to be as follows.

[0078] The method for manufacturing the spin sensor of this embodiment is particularly － The diamond having a center formed thereon is placed on a "mortar-shaped iron base" coated with resin or cellulose and an "iron pestle-like rod" with a larger radius of curvature than the "iron pestle-like rod" also coated with resin or cellulose, and the diamond is crushed by vibrating the "iron pestle-like rod." This prevents metal components from the container used during crushing from being mixed into the spin sensor, and also minimizes damage to the diamond particles, thereby increasing the spin transverse relaxation time T2 of the diamond particles that make up the spin sensor. This was a new discovery made by the inventors after extensive research.

[0079] [Embodiment 3: Jig] The jig according to this embodiment includes the spin sensor according to embodiment 1 or embodiment 2. The jig according to this embodiment is not particularly limited as long as it includes the spin sensor according to embodiment 1 or embodiment 2, and examples thereof include a bio jig and a semiconductor jig. The bio jig refers to a jig for bringing a spin sensor close to cells or microorganisms less than 10 μm in size. The semiconductor jig refers to a jig for bringing a spin sensor close to a specific microscopic location on a semiconductor.

[0080] According to this embodiment, it is possible to provide a jig equipped with a spin sensor having excellent sensitivity in measuring the temperature of a minute measurement area.

[0081] <Method of Manufacturing Jig> The method of manufacturing the jig according to this embodiment can be carried out in the same manner as a conventionally known method, except that the spin sensor according to the first or second embodiment is used.

[0082] [Embodiment 4: Device] The device according to this embodiment includes the spin sensor according to embodiment 1 or embodiment 2. The device according to this embodiment is not particularly limited as long as it includes the spin sensor according to embodiment 1 or embodiment 2, and examples thereof include a biodevice and a semiconductor device. The biodevice refers to a device that includes the biotool according to embodiment 3 and is capable of detecting temperature, magnetic field, electric field, current, etc. The semiconductor device refers to a device that includes the semiconductor tool according to embodiment 3 and is capable of detecting temperature, magnetic field, electric field, current, etc.

[0083] According to this embodiment, it is possible to provide a device equipped with a spin sensor that has excellent sensitivity in measuring the temperature of a minute measurement area.

[0084] <Device Manufacturing Method> The device manufacturing method according to this embodiment can be carried out in the same manner as a conventionally known method, except that the spin sensor according to the first or second embodiment is used.

[0085] The present embodiment will be described in more detail with reference to examples, although the present embodiment is not limited to these examples.

[0086] <<Fabrication of Spin Sensor>> <Fabrication of Spin Sensor According to Sample 1>> First, a bulk single crystal diamond according to Sample 1 (nitrogen concentration: 10 to 30 ppm based on the number of atoms, １３ Next, the bulk single crystal diamond of Sample 1 was subjected to electron beam irradiation and vacuum annealing in this order to obtain NV. －A bulk single crystal diamond was obtained in which the concentration of color centers was about 1 / 100 to 1 / 10 of the nitrogen concentration.

[0087] Next, the "NV" for sample 1 － The remainder was obtained by cutting off a portion of a bulk single-crystal diamond "in which the concentration of color centers is about 1 / 100 to 1 / 10 of the nitrogen concentration" near the seed substrate with a laser. The remainder was used as the raw material for a "spin sensor made of powder consisting of seven or more diamond particles."

[0088] A mortar-shaped iron base and an iron pestle-shaped rod with a larger radius of curvature than the base were each coated with resin, and the rod was vibrated until half of the particles in the powder had a diameter of less than 1 μm. The base was 10 cm square, the rod had an overall radius of curvature of 1 m, a radius of curvature at the tip of the rod was 10 cm, the rod had a mass of 0.7 kg, and the vibration frequency was 1 to 5 Hz.

[0089] As a result of the above, a spin sensor made of powder consisting of seven or more diamond particles was obtained, which is sample 1. It was confirmed by a conventional method that the obtained spin sensor contained almost no iron.

[0090] <Fabrication of spin sensor according to sample 2> The fabrication of the spin sensor according to sample 2 was carried out by taking into consideration the fact that the nitrogen concentration of the bulk single crystal diamond was 30 to 60 ppm on the basis of the number of atoms, and １３ The same method as for the "spin sensor made of powder consisting of seven or more diamond particles" relating to Sample 1 was used, except that the C concentration was 0.01% by mass and that instead of "a mortar-shaped iron base and an iron pestle-shaped rod with a larger radius of curvature than the base being each resin-coated," "cellulose was sandwiched between the base and the rod." This resulted in a spin sensor made of powder consisting of seven or more diamond particles relating to Sample 1. It was confirmed by conventional methods that the resulting spin sensor (powder) was free of iron contamination.

[0091] <Preparation of Spin Sensor Concerning Sample 101> Seven or more diamond nanoparticles (NV) manufactured by Adams Nanotechnologies were purchased commercially as sample 101. － A spin sensor was prepared using a powder of ZnO (concentration: 3 ppm).

[0092] <<Spin sensor characteristic evaluation>> <(N1 / N) x 100, (N2 / N) x 100, (N3 / N) x 100> For the spin sensor of each sample, the ratio (N1 / N) x 100 of the number N1 of first diamond particles to the total number N of diamond particles was measured by the method described in embodiment 2. For sample 1, the spin transverse relaxation time T2 of each particle identified through the measurement is recorded in the "T2 [nsec]" column of Table 1. For sample 2, the spin transverse relaxation time T2 of each particle identified through the measurement is recorded in the "T2 [nsec]" column of Table 2. For sample 101, the spin transverse relaxation time T2 of each particle identified through the measurement is recorded in the "T2 [nsec]" column of Table 3. Furthermore, the (N1 / N) x 100 determined by the measurement is recorded in the "(N1 / N) x 100 [%]" column of Table 4. Furthermore, for the spin sensors of each sample, the ratio (N2 / N) x 100 of the number N2 of second diamond particles to the total number N of diamond particles was measured using the method described in embodiment 2. The results obtained are recorded in the "(N2 / N) x 100 [%]" column of Table 4. Furthermore, for the spin sensors of each sample, the ratio (N3 / N) x 100 of the number N3 of third diamond particles to the total number N of diamond particles was measured using the method described in embodiment 2. For sample 1, the spin longitudinal relaxation time T1 of each particle determined through the measurement is recorded in the "T1 [μsec]" column of Table 1. For sample 2, the spin longitudinal relaxation time T1 of each particle determined through the measurement is recorded in the "T1 [μsec]" column of Table 1. For sample 101, the spin longitudinal relaxation time T1 of each particle determined through the measurement is shown in the "T1 [μsec]" column of Table 3. In addition, (N3 / N) × 100 determined through the measurement is shown in the "(N3 / N) × 100 [%]" column of Table 4. Note that, since T1 was not measured in the measurement of (N3 / N) × 100, particles 1-10 and 1-11 in Table 1, particles 2-9, 2-10 and 2-11 in Table 2, and particle 101-10 in Table 3 were excluded from the measurement.

[0093] The spin sensors of Samples 1 and 2 correspond to Examples. The spin sensor of Sample 101 corresponds to a Comparative Example. The spin sensors of Samples 1 and 2 exhibit significantly higher (N1 / N)×100 than the spin sensor of Sample 101. Here, a relatively high (N1 / N)×100 means that the temperature measurement sensitivity of the spin sensor is relatively high. Therefore, it was confirmed that the spin sensors of Samples 1 and 2 exhibit significantly superior sensitivity in temperature measurement compared to the spin sensor of Sample 101.

[0094] In the above measurements of (N1 / N) × 100, (N2 / N) × 100, and (N3 / N) × 100, the spin transverse relaxation time T2 and spin longitudinal relaxation time T1 of each particle in Sample 1 were as shown in Table 1. In addition, in the above measurements of (N1 / N) × 100, (N2 / N) × 100, and (N3 / N) × 100, the spin transverse relaxation time T2 and spin longitudinal relaxation time T1 of each particle in Sample 2 were as shown in Table 2. In addition, in the above measurements of (N1 / N) × 100, (N2 / N) × 100, and (N3 / N) × 100, the spin transverse relaxation time T2 and spin longitudinal relaxation time T1 of each particle in Sample 101 were as shown in Table 3. In Tables 1 to 3, a "-" in the "T1 [μsec]" column means that measurement of the spin longitudinal relaxation time T1 was not performed. In Tables 1 to 3, a "-" in the "T2 [nsec]" column means that measurement of the spin transverse relaxation time T2 was not performed. It was confirmed by the method described in embodiment 1 that each particle had a maximum diameter of 0.01 μm or more and less than 10 μm, each particle had a color center, and the electronic state of the color center had a spin ground level with spin zero and a spin excited level with spin ±1.

[0095] In Table 1, the spin transverse relaxation times T2 of the spin sensors for particles 1-1 to 1-7 and 1-9 to 1-11 were 180 nsec or longer. Furthermore, in Table 2, the spin transverse relaxation times T2 of the spin sensors for particles 2-1 to 2-7 and 2-9 to 2-11 were 180 nsec or longer. In contrast, in Table 3, the spin transverse relaxation times T2 of the spin sensors for particles 101-1 to 101-7, 101-9, and 101-10 were shorter than 180 nsec. The temperature measurement sensitivity of a spin sensor is inversely proportional to the square root of the spin transverse relaxation time T2 (i.e., if T2 is improved by 100 times, for example, the lower limit of the measurement sensitivity becomes 1 / 10). Therefore, it was confirmed that the spin sensors of particles 1-1 to 1-7, 1-9 to 1-11, 2-1 to 2-7, and 2-9 to 2-11 have significantly superior sensitivity in measuring temperature compared to the spin sensors of particles 101-1 to 101-7, 101-9, and 101-10.

[0096]

[0097]

[0098]

[0099]

[0100] The embodiments disclosed herein are illustrative in all respects and should not be considered limiting. The scope of the present invention is defined by the claims, not by the above-described embodiments, and is intended to include meanings equivalent to the claims and all modifications within the scope thereof.

Claims

1. A spin sensor consisting of a single diamond particle, The maximum diameter of the diamond particles is 0.01 μm or more and less than 0.5 μm. The diamond particles have color centers, The electronic state of the aforementioned color center has a spin ground state with zero spin and a spin excited state with ±1 spin. The spin sensor wherein the spin transverse relaxation time T2 of the diamond particle is 180 nsec or more.

2. The spin sensor according to claim 1, wherein the spin longitudinal relaxation time T1 of the diamond particle is 300 μsec or more.

3. A spin sensor made of powder consisting of seven or more diamond particles, The diamond particles include a first diamond particle, The maximum cross-sectional diameter of each of the first diamond particles is 0.01 μm or more and less than 10 μm. The first diamond particle has a color center, The electronic state of the aforementioned color center has a spin ground state with zero spin and a spin excited state with ±1 spin. The spin transverse relaxation time T2 of the first diamond particle is 180 nssec or more. The spin sensor wherein the ratio (N1 / N) × 100 of the number of first diamond particles to the total number of diamond particles N is 40% or more.

4. The spin sensor according to claim 3, wherein the spin longitudinal relaxation time T1 of the first diamond particle is 300 μsec or more.

5. The first diamond particle includes a second diamond particle. The spin transverse relaxation time T2 of the second diamond particle is 1,000 nsec or more. The spin sensor according to claim 3 or claim 4, wherein the ratio (N2 / N) × 100 of the number of second diamond particles to the total number of diamond particles N is 5% or more.

6. The first diamond particle includes a third diamond particle. The spin longitudinal relaxation time T1 of the third diamond particle is 800 μsec or more. The spin sensor according to claim 3 or claim 4, wherein the ratio (N3 / N) × 100 of the number of third diamond particles to the total number of diamond particles N is 5% or more.

7. A jig comprising the spin sensor according to any one of claim 1 or claim 4.

8. An apparatus comprising a spin sensor according to any one of claim 1 or claim 4.