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Article Cite This: ACS Omega 2019, 4, 7459−7466
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Operando Analysis of Electron Devices Using Nanodiamond Thin Films Containing Nitrogen-Vacancy Centers Haruki Uchiyama,† Soya Saijo,‡ Shigeru Kishimoto,† Junko Ishi-Hayase,‡ and Yutaka Ohno*,†,§ †
Department of Electronics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan § Institute of Materials and Systems for Sustainability, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan ‡
ACS Omega 2019.4:7459-7466. Downloaded from pubs.acs.org by 46.161.62.156 on 04/25/19. For personal use only.
S Supporting Information *
ABSTRACT: Operando analysis of electron devices provides key information regarding their performance enhancement, reliability, thermal management, etc. For versatile operando analysis of devices, the nitrogen-vacancy (NV) centers in diamonds are potentially useful media owing to their excellent sensitivity to multiple physical parameters. However, in single crystal diamond substrates often used for sensing applications, placing NV centers in contiguity with the active channel is difficult. This study proposes an operando analysis method using a nanodiamond thin film that can be directly formed onto various electron devices by a simple solution-based process. The results of noise analysis of luminescence of the NV centers in nanodiamonds show that the signal-to-noise ratio in optically detected magnetic resonance can be drastically improved by excluding the large 1/f noise of nanodiamonds. Consequently, the magnetic field and increase in temperature caused by the device current could be simultaneously measured in a lithographically fabricated metal microwire as a test device. Moreover, the spatial mapping measurement is demonstrated and shows a similar profile with the numerical calculation.
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the optically detected magnetic resonance (ODMR) method.32 Ensembles of NV centers in a single crystal diamond have been adopted for the operando analysis of integrated circuits,33 graphene devices,34 and diamond power devices.35 In these studies, a single crystal diamond containing NV centers was placed on the integrated circuits or graphene, and diamond devices were directly fabricated on single crystal diamonds. Although the NV centers in single crystal diamonds generally have a long coherence time36 and hence a high sensitivity during the magnetic field detection, placing NV centers in contiguity with the active channel of the device is difficult, thus limiting the variety of devices on which operando analysis can be conducted. Therefore, a universal method to configure NV centers on various types of electron devices is required. Scanning probe microscopy with the tip attached to NV centers is a powerful tool for analyzing nanoscale devices,37 however, the scan area is limited for microscale electron devices. This study proposes a method for the operando analysis of various electron devices using nanodiamonds. A nanodiamond thin film can be directly formed onto various electron devices by simple solution-based processes such as drop casting and spin coating.38−42 Moreover, because nanodiamond thin films
INTRODUCTION Operando analysis is a powerful tool for understanding the operation and failure mechanisms of electron devices such as transistors1−3 and diodes.4,5 Various techniques such as scanning probe microscopies,6−9 electron microscopies,10−12 and optical spectroscopies13 have been adopted to measure the potential,14−17 temperature,2−5,18−20 and defect distributions13,21−23 in electron devices under operation and thus obtain important information regarding reliability and thermal management. Moreover, the spatially resolved measurement of the current in the channel is important, particularly for electron devices with inhomogeneous channels, such as thin-film transistors based on poly-Si, amorphous Si, recently developed semiconducting carbon nanotubes, and other low-dimensional materials. Although the measurement of current distribution is important, reports on this topic are fewer than those on the measurement of other physical parameters such as potential and temperature because the direct measurement of current is difficult. Indirect measurements of current distribution have been realized by magnetic field measurements using scanning magnetic force microscopy;24 however, this method is not sensitive when the magnetic field is vertical to the direction of magnetization of the probe. The nitrogen-vacancy (NV) centers25 in diamonds are recently attracting considerable research interest as media for sensing multiple physical parameters such as magnetic field, potential, and temperature with ultrahigh sensitivity26−31 via © 2019 American Chemical Society
Received: February 6, 2019 Accepted: April 15, 2019 Published: April 24, 2019 7459
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Figure 1. Test device and measurement setup for operando analysis using a nanodiamond thin film. (a) Schematic, (b) optical micrograph, and (c) scanning electron microscopy image of the test device covered with a nanodiamond thin film. (d) Setup for optically detected magnetic resonance (ODMR) measurement. For the lock-in method, a microwave or voltage source is modulated at 1 kHz, and the lock-in amplifier is synchronized with the frequency. In the operando measurement, the bias voltage was applied to the sample by a function generator through the probing needles settled on the XYZ stage.
are neither conductive nor magnetized, they do not affect the measurement when the device is under operation. To avoid the blinking phenomenon of NV centers in nanodiamonds,43−48 this study introduces a lock-in method for ODMR measurements on the basis of the detailed analysis of the noise spectrum of luminescence. Furthermore, the magnetic field and increase in temperature owing to the current flowing through a metal microwire lithographically fabricated on a quartz substrate with a high signal-to-noise ratio (SNR) are successfully measured.
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RESULTS AND DISCUSSION Figure 1 illustrates the test device and experimental setup. A metal wire with a width of 11.3 μm fabricated on a quartz substrate was used as the test device (Figure 1a). The nanodiamond film was directly formed on the sample by dropping the nanodiamond suspension (see the Experimental Section for the device fabrication and nanodiamond film formation). An area of ∼5 mm in diameter was covered with a nanodiamond film. The thickness and surface roughness of the nanodiamond film were approximately 1.2 and 0.5 μm, respectively. A nanodiamond film was uniformly formed on both quartz and metal wire surfaces, as observed in the micrograph and scanning electron microscopy images (Figure 1b,c, respectively). The optical measurements were performed using a home-built setup with a confocal microscope configuration as shown in Figure 1d (see the Experimental Section for the details of optical measurement). The photoluminescence spectrum of the nanodiamond film shows that negatively charge NV centers are dominant emission center (see Supporting Information, Figure S1). Noise Spectrum of Photoluminescence of Nanodiamonds. First, we investigated the blinking phenomenon in the photoluminescence of nanodiamonds as this may degrade the sensitivity of the magnetic field detection. Photoluminescence was measured by the photon counting method using an avalanche photodiode (APD), and the noise spectrum related to the blinking phenomenon was characterized by a vector signal analyzer (see the Experimental Section for the details). Figure 2a compares the fluctuation in the photoluminescence of a nanodiamond thin film and a single crystal diamond (Element six, 145-500-0248). Here, the time evolutions of the photoluminescence intensity normalized by the average intensity were plotted. The thickness of the
Figure 2. Characterization of photoluminescence of the NV centers. (a) Time evolutions of luminescence intensity and (b) their noise spectra for the single crystal diamond and nanodiamond thin film.
nanodiamond was adjusted such that its average luminescence intensity was comparable with that of the single crystal diamond. The fluctuation in the photoluminescence intensity of the nanodiamond film was larger than that of the single crystal diamond. The standard deviation in the fluctuation was 1.7 and 0.7% for the nanodiamond film and single crystal diamond, respectively. We further investigated the blinking phenomenon by measuring the noise spectrum of photoluminescence. Figure 2b shows the noise spectra of photoluminescence for the nanodiamond film and single crystal diamond. In the case of nanodiamond film, three noise components were observed in the noise spectrum: (i) 1/f noise (2−200 Hz), (ii) spike-like noises (30−200 Hz), and (iii) white noise (>200 Hz). In the case of single crystal diamond, 1/f noise was not observed; 7460
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moreover, compared with the nanodiamond film, the spike-like noises were lower, and white noise was approximately equal. The surface traps of nanodiamonds are a plausible cause of 1/f noise. Trap sites catch and release the charge of NV centers,43,45,49 and the charge state (neutral or negative) determines the luminescence intensity of the NV center because the lifetime of both states are different,44,50 causing fluctuations in the luminescence intensity. Although a single trap level generates a Lorentzian noise spectrum, the 1/f noise spectrum is observed from multilevel traps with different time constants. The nanodiamonds surfaces containing disorders (ex., primal sp2 defects, sp2−sp3 hybridization, functional groups, and adsorbed species) may be the sources of charge traps.43,51,52 The spike-like noises were caused by the mechanical vibrations of the measurement setup and by the fluctuation of excitation laser intensity. The larger noise observed for the nanodiamond film is attributable to the nonuniformity of the film, that is, the number of NV centers under the excitation laser spot fluctuated due to mechanical vibration. The white noise was the shot noise caused by the random statistical fluctuations of the number of photons detected by the APD, which was dependent on the luminescence intensity and not on the type of samples. Therefore, we expect ODMR measurements with high SNRs using nanodiamonds, similar to those using single crystal diamonds, by utilizing the shotnoise region. ODMR Measurement in the Shot-Noise Region. For ODMR measurement with high SNR in the shot-noise region, we employed the lock-in configuration shown in Figure 1d. In this case, the microwave was modulated at 1 kHz for the lockin detection of the ODMR signal (see the Experimental Section for the details). Based on the noise spectrum analysis, the modulation frequency was determined to be in the shotnoise region. Figure 3a,b shows the ODMR spectra measured
intensity to the microwave can be detected (in this study, we call this response “differential ODMR signal”), and the 1/f and vibrational noises observed in Figure 2b are excluded. The signal SNRs (SNR = σ , where signal and σerr are the signal err
voltage and standard deviation of error between the measured spectrum and Gaussian fitting at 2870 MHz, respectively) were evaluated to be 54.8 and 1.53 for the lock-in and photon counting methods, respectively, showing a significant improvement in the SNR when the shot-noise region is used. Operando Measurement. We examined the possibility of operando analysis with a nanodiamond film by measuring the ODMR response to the current flowing through the metal microwire fabricated on the quartz substrate. In this case, continuous microwave was the input; however, a square-wave voltage of 0 to the maximum voltage (Vmax) with a duty cycle of 50% and a frequency of 1 kHz was applied to the metal wire. Vmax was varied from 0 to 5 V. The current flowing through the metal wire was 3.6 mA at 1 V. The differential ODMR signal, that is, the change in the luminescence caused by the device current, was detected by the lock-in amplifier synchronized with the applied square-wave voltage at 1 kHz. This current modulation method for the lock-in measurement simulates the device operation in the pulse width modulation (PWM), which is normally used for power transistors in inverters and converters.53 Alternatively, the microwave modulation method can be chosen for the lock-in technique in the case if a tested device is normally operated at a static DC voltage. Figure 4a shows the differential ODMR spectra at six different current values, where the signal voltage (lock-in output) was normalized by the luminescence intensity measured by the single-photon counter for each data point. With the increasing device current, the amplitude of the differential ODMR spectra increased and the peak frequency slightly down-shifted, showing a clear response to the device current. The spectral profile of the differential ODMR signal can be explained by the peak splitting of the Gaussian-shaped ODMR spectrum of an ensemble of randomly oriented NV centers, as illustrated in Figure 4b. A resonant dip observed for an individual NV center in ODMR splits owing to the Zeeman effect under the influence of a finite magnetic field, and the separation depends on the inner product of the magnetic field and NV axis.26,54 The resonant frequency also depends on temperature.31 At a low magnetic field regime below ∼1 mT, it can be considered that the resonant dip separation and frequency depend linearly on the magnetic field and temperature, respectively.55 These phenomena also occur in the case of the Gaussian spectrum of an ensemble of randomly oriented NV centers in the nanodiamond film. In addition, owing to the random orientation of the NV centers, broadening of the Gaussian spectrum may occur under a magnetic field. The profiles of the measured and illustrated differential ODMR spectra are presented in Figure 4a,b, respectively. Assuming the Gaussian function, the ODMR spectrum of an NV center ensemble can be expressed as
Figure 3. ODMR spectra measured using the (a) photon counting method and (b) lock-in method in the shot-noise region.
using the photon counting and lock-in methods, respectively. Here, the time required to measure the ODMR spectra was almost the same (5 s/point) for both methods. A clear Gaussian-shaped resonant dip, originating from an ensemble of randomly oriented NV centers in the nanodiamond film, was obtained in the ODMR spectrum measured using the lock-in method, whereas the significant noise was detected in the ODMR spectrum measured using the photon counting method. Note that the ODMR spectrum measured using the present lock-in method represents the difference in the luminescence intensities with and without the microwave input. Therefore, only the response of the luminescence
ij (f − f )2 yz A0 c z zz + y S(f , fc ) = − expjjjj−2 0 j w w 2 zz k {
(1)
where A0, w, and fc are the amplitude at zero magnetic field, width, and center frequency of the resonant dip of the ODMR spectrum, respectively. y0 is the luminescence intensity at off 7461
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Figure 4. Operando analysis of metal wires with current flow. (a) Differential ODMR spectra at various current values. The solid curves are the fitted curve with eq 2. (b) Schematic of the differential ODMR spectrum. The upper graph represents a normal ODMR spectra with and without a device current. The lower graph represents the differential ODMR spectrum. (c) Intensity of the differential ODMR signal as a function of device current at a microwave frequency of 2870 MHz. The solid curve is the fitted curve with eq 2. (d) Peak frequency of the differential ODMR spectrum as a function of device current. The solid line is the fitted line.
32.2 μT/Hz1/2) from the standard deviation of error between the measured data and fitted curve with eq 2 in the calibration curve. Even though the sensitivity is poorer than that obtained by the dynamical decoupling ODMR method (140 nT/Hz1/2 for nanodiamonds),56 the measurement setup based on the lock-in technique is simpler and applicable for devices with a high current driving ability such as power transistors. A small peak shift was observed in the differential ODMR spectra with increasing device current. Figure 4d depicts the peak frequencies as a function of current. The frequency shift is probably attributable to the increase in temperature owing to Joule heating generated by the current flow. The increase in temperature was estimated to be ∼32 K at 17.7 mA by the shift of peak frequency.31 The measured change in temperature is comparable to that calculated from a steady-state solution of t the heat equation, ΔT ≈ Q κS = 28.8 K , where Q is the heat dissipation, S is the area of the wire, and κ and t are the thermal conductivity and thickness of the quartz, respectively. The resolution for temperature measurement was estimated to be 1.6 K from the standard deviation of error between the measured data and linear fitting in the peak frequency−current plot as shown in Figure 4d. Here, we used the coefficient of −72.4 kHz/K for the relation between temperature and the resonant frequency.31 It should be noted that the heat flow through the nanodiamond film may affect the temperature of device under test. The thermal conductivity of nanodiamonds sintered at a high pressure and high temperature (7 GPa and 740 °C, respectively) has been reported to be 5 W/mK;57 however, we expect a lower thermal conductivity for the asdeposited nanodiamond film by the drop-casting method because of a lot of voids existing in the film. In order to avoid the influence of the nanodiamond film, the film thickness
resonance. The differential ODMR spectrum, dS, as a function of device current, I, is given as dS(f , I ) = S(f , fc − αI − βI 2) + S(f , fc + αI − βI 2) − 2S(f , fc )
(2)
assuming a low magnetic field regime. Here, the first and second terms represent the spectra splitting due to the magnetic field formed by the device current, and their separation is proportional to I with a coefficient α. The effect of temperature owing to the power dissipation can be considered by adding the term βI2 to the center frequency. This model agrees well with the differential ODMR spectra experimentally obtained with fitting parameters of α = 1.4 MHz/mA, β = 7.0 kHz/mA2, and w from 15.5 to 29.3 MHz, as observed in Figure 4a. Figure 4c shows the signal intensities as a function of current at a microwave frequency of 2870 MHz. The signal intensity exhibited a nonlinear increase with increasing device current. The nonlinear response to the current originates from the Gaussian-shaped ODMR spectrum. The solid gray curve in the figure is the fitted curve with eq 2 and shows good agreement. The minimum current detectable using the present method is 210 μA for an acquisition time of 5 s/point. Further improvement in sensitivity can be achieved by optimizing the thickness of the nanodiamond thin film. The magnetic field strength can be estimated from the signal intensity by using the calibration curve as shown in the Supporting Information (Figure S2). The procedure to obtain the calibration curve is also described in the Supporting Information. The magnetic field strength at 10 mA was estimated to be 1.0 mT in the magnetic field strength. The sensitivity for magnetic field was estimated to be 14.4 μT (or 7462
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Figure 5. Spatial distributions of the magnetic field strength in the vicinity of the metal wire. (a−c) Mapping data and (d) cross-sectional data measured at device currents of 0, 7.4, and 14.8 mA. (e−g) Mapping data and (h) cross-sectional data of the calculated magnetic field formed by 0, 7.4, and 14.8 mA of the current input.
increased with increasing device current. We observed peak profiles at the edges of the metal wire and gradual decays with increasing distance from the metal wire. A similar two-peak profile was obtained from the calculated magnetic field distributions, as shown in Figure 5e−h. Here, to consider half of the thickness of the nanodiamond film, the magnetic field strengths that are 0.6 μm away from the surface were plotted. The microscopic images of the measured and calculated magnetic field strength showed a similarity. The peak magnetic field was ∼1.2 mT at 14.8 mA, which was in the same order as the simulated value. These results suggest the possibility of the microscopic operando analysis of microdevices. Taking a closer look, there are some differences between the measured and calculated magnetic field profiles, especially, more significant droop can be seen at the center of the wire in the experimental data than in the calculated data. The reason is not clear at this moment; however, it was found that the magnetic field profile strongly depended on the distance from the metal wire surface in the calculation, and that more significant droop appeared at the position closer to the surface (see Supporting Information, Figure S9). Because of the drop-casting method, the thickness of the nanodiamond film may fluctuate in the experiment. For a better accuracy in this operando measurement technique, an improvement of the film formation technique is necessary.
should be thin enough, so that, the thermal resistance is sufficiently higher than that of the device or substrate. For the semiconductor substrates, which normally have a thermal conductivity of >100 W/mK, the heat flow through the 1.2 μm-thick nanodiamond film can be negligible (see Supporting Information, Figure S8). In the case of power semiconductor devices, it is quite important to measure the temperature and current distributions to detect the formation of hot spots and current filaments for the reliability.58 The temperature under operation rises up to ∼150 °C due to the large Joule heating. It is known as the median time of failure (MTTF), an important reliability index of power devices, exponentially decreases with temperature. The NV centers can be used as a temperature sensor in a wide range from 100 to 700 K.59,60 The temperature range and sensitivity of the present technique is applicable for analysis of power devices under operation. Microscopic imaging can be achieved using a confocal microscope system. To demonstrate two-dimensional microscopic imaging, we measured the differential ODMR signal at a microwave frequency of 2870 MHz, scanning the motor-driven XY stage. Figure 5a−c presents the mapping results of the differential ODMR signal at 0, 7.4, and 14.8 mA, respectively. The profiles perpendicular to the metal wire are displayed in Figure 5d. Here, the differential ODMR signal was converted to the magnetic field strength by using the calibration curve (Supporting Information, Figure S2). The magnetic field 7463
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CONCLUSIONS This study demonstrated the possibility of simultaneous operando analysis of current and temperature in electron devices using a nanodiamond film containing NV centers. Results of the detailed noise analysis show that ODMR measurements with high SNRs could be achieved in the shotnoise region, excluding the large 1/f noise and spike-like noises attributable to the NV centers of the nanodiamond. The SNR using lock-in detection in the shot-noise region was improved by a factor of 36 compared with the SNR using the photon counting method. The magnetic field formed by the current and increase in temperature owing to Joule heating could be evaluated for the metal wire under bias from the differential ODMR measurement. The spatial mapping data showed a similar profile for the calculated magnetic field distribution. Because a nanodiamond thin film can be easily formed at room temperature by a solution-based process directly onto the device surface without disturbing the device property, the proposed method presents the possibility of operando analysis of various types of electron devices.
generator. For both cases, the time constant of the lockamplifier was set to be 1 s. In the measurement of ODMR spectrum, the microwave frequency was changed with 0.5 MHz step, then after 5 s, the lock-in output voltage was acquired.
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ASSOCIATED CONTENT
S Supporting Information *
The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acsomega.9b00344. Photoluminescence spectrum of nanodiamond film, calibration curve for magnetic field, procedure to obtain calibration curve, effect of thermal conductance of nanodiamond film on temperature of device under operando analysis, and dependence of magnetic field profile on the distance from the metal wire surface (PDF)
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AUTHOR INFORMATION
Corresponding Author
*E-mail:
[email protected].
EXPERIMENTAL SECTION Device Fabrication. Metal wires of Ti/Au (50/200 nm) were fabricated on a 2 × 2 cm2 quartz substrate with a thickness of 500 μm using photolithography, electron-beam evaporation, and a lift-off process. The contact pads were also formed simultaneously on the fringe of the sample for the electrical contact with probing needles. Nanodiamond Film Formation. The nanodiamond film was directly formed on the sample by dropping the nanodiamond suspension (Sigma Aldrich, 798134-5ML) with diamond nanoparticles containing ∼800 NV centers with a diameter of ∼100 nm. The nanodiamond suspension of 30 μL was dropped with a pipette and left to dry in air at room temperature. Photoluminescence Measurement. The optical measurement was performed using a home-built setup with a confocal microscope configuration comprising an objective lens (100×, NA = 0.8). An Ar-ion laser (Spectra physics, Stabilite 2017) with a wavelength of 514.5 nm was used as the excitation light source. The measured excitation power at the surface of the device was 100 μW. The emission light was detected by an APD (Laser components, COUNT-10C-FC) and counted by the single-photon counter (AUREA technology, SPD-TDC). Noise analysis of the photoluminescence related to the blinking phenomenon of nanodiamonds was performed using a vector signal analyzer (Hewlett Packard, 89410A). ODMR Measurement. The fundamental optical setup for ODMR measurement is the same as that for photoluminescence measurement described above. The sample was mounted on an epoxy glass equipped with a microwave planar ring antenna that was connected to a microwave generator (Tektronix, TSG4104A) and placed on a motor-driven XYZ stage equipped with probing needles. Furthermore, we used a digital lock-in amplifier (NF Corporation, LI5640) for high SNR measurement in the shot-noise region. The microwave was modulated at 1 kHz for the lock-in measurement. For the operando device measurement, the bias voltage was applied to the device through probing needles by a function generator (Agilent, 33250A). In this case, the device was driven by a square wave (duty ratio, 50%) at 1 kHz with a function
ORCID
Yutaka Ohno: 0000-0002-4577-1533 Funding
This work was partially supported by the MEXT Grant-in-Aid for Scientific Research on Innovative Areas “Science of hybrid quantum systems” (grant nos. 15H05867 and 15H05868) and Spin-NRJ. Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Gribelyuk, M. A.; McCartney, M. R.; Li, J.; Murthy, C. S.; Ronsheim, P.; Doris, B.; McMurray, J. S.; Hegde, S.; Smith, D. J. Mapping of electrostatic potential in deep submicron CMOS devices by electron holography. Phys. Rev. Lett. 2002, 89, No. 025502. (2) Kuball, M.; Rajasingam, S.; Sarua, A.; Uren, M. J.; Martin, T.; Hughes, B. T.; Hilton, K. P.; Balmer, R. S. Measurement of temperature distribution in multifinger AlGaN/GaN heterostructure field-effect transistors using micro-Raman spectroscopy. Appl. Phys. Lett. 2003, 82, 124−126. (3) Lin, C. H.; Merz, T. A.; Doutt, D. R.; Hetzer, M. J.; Joh, J.; del Alamo, J. A.; Mishra, U. K.; Brillson, L. J. Nanoscale mapping of temperature and defect evolution inside operating AlGaN/GaN high electron mobility transistors. Appl. Phys. Lett. 2009, 95, No. 033510. (4) Chen, N. C.; Wang, Y. N.; Tseng, C. Y.; Yang, Y. K. Determination of junction temperature in AlGaInP/GaAs light emitting diodes by self-excited photoluminescence signal. Appl. Phys. Lett. 2006, 89, 101114. (5) Luo, K.; Herrick, R. W.; Majumdar, A.; Petroff, P. Scanning thermal microscopy of a vertical-cavity surface-emitting laser. Appl. Phys. Lett. 1997, 71, 1604−1606. (6) García, R.; Pérez, R. Dynamic atomic force microscopy methods. Surf. Sci. Rep. 2002, 47, 197−301. (7) Melitz, W.; Shen, J.; Kummel, A. C.; Lee, S. Kelvin probe force microscopy and its application. Surf. Sci. Rep. 2011, 66, 1−27. (8) Majumdar, A. SCANNING THERMAL MICROSCOPY. Annu. Rev. Mater. Sci. 1999, 29, 505−585. (9) Hansma, P. K.; Tersoff, J. Scanning tunneling microscopy. J. Appl. Phys. 1987, 61, R1−R24. (10) Leamy, H. J. Charge Collection Scanning Electron-Microscopy. J. Appl. Phys. 1982, 53, R51−R80. (11) Midgley, P. A.; Dunin-Borkowski, R. E. Electron tomography and holography in materials science. Nat. Mater. 2009, 8, 271−280.
7464
DOI: 10.1021/acsomega.9b00344 ACS Omega 2019, 4, 7459−7466
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Article
vacancy magnetic resonance in diamond. Phys. Rev. Lett. 2010, 104, No. 070801. (32) Gruber, A.; Dräbenstedt, A.; Tietz, C.; Fleury, L.; Wrachtrup, J.; Von Borczyskowski, C. Scanning confocal optical microscopy and magnetic resonance on single defect centers. Science 1997, 276, 2012−2014. (33) Nowodzinski, A.; Chipaux, M.; Toraille, L.; Jacques, V.; Roch, J. F.; Debuisschert, T. Nitrogen-Vacancy centers in diamond for current imaging at the redistributive layer level of Integrated Circuits. Microelectron. Reliab. 2015, 55, 1549−1553. (34) Tetienne, J. P.; Dontschuk, N.; Broadway, D. A.; Stacey, A.; Simpson, D. A.; Hollenberg, L. C. L. Quantum imaging of current flow in graphene. Sci. Adv. 2017, 3, No. e1602429. (35) Iwasaki, T.; Naruki, W.; Tahara, K.; Makino, T.; Kato, H.; Ogura, M.; Takeuchi, D.; Yamasaki, S.; Hatano, M. Direct Nanoscale Sensing of the Internal Electric Field in Operating Semiconductor Devices Using Single Electron Spins. ACS Nano 2017, 11, 1238− 1245. (36) Balasubramanian, G.; Neumann, P.; Twitchen, D.; Markham, M.; Kolesov, R.; Mizuochi, N.; Isoya, J.; Achard, J.; Beck, J.; Tissler, J.; Jacques, V.; Hemmer, P. R.; Jelezko, F.; Wrachtrup, J. Ultralong spin coherence time in isotopically engineered diamond. Nat. Mater. 2009, 8, 383−387. (37) Chang, K.; Eichler, A.; Rhensius, J.; Lorenzelli, L.; Degen, C. L. Nanoscale Imaging of Current Density with a Single-Spin Magnetometer. Nano Lett. 2017, 17, 2367−2373. (38) Fox, N. A.; Youh, M. J.; Wang, W. N.; Steeds, J. W.; Cheng, H.F.; Lin, I.-N. Properties of electron field emitters prepared by selected area deposition of CVD diamond carbon films. Diamond Relat. Mater. 2000, 9, 1263−1269. (39) Girard, H. A.; Perruchas, S.; Gesset, C.; Chaigneau, M.; Vieille, L.; Arnault, J.-C.; Bergonzo, P.; Boilot, J.-P.; Gacoin, T. Electrostatic grafting of diamond nanoparticles: a versatile route to nanocrystalline diamond thin films. ACS Appl. Mater. Interfaces 2009, 1, 2738−2746. (40) Hanada, K.; Matsuzaki, K.; Sano, T. Nanocrystalline diamond films fabricated by sol−gel technique. Surf. Sci. 2007, 601, 4502− 4505. (41) Scorsone, E.; Saada, S.; Arnault, J. C.; Bergonzo, P. Enhanced control of diamond nanoparticle seeding using a polymer matrix. J. Appl. Phys. 2009, 106, No. 014908. (42) Williams, O. A.; Douhéret, O.; Daenen, M.; Haenen, K.; O̅ sawa, E.; Takahashi, M. Enhanced diamond nucleation on monodispersed nanocrystalline diamond. Chem. Phys. Lett. 2007, 445, 255−258. (43) Bradac, C.; Gaebel, T.; Naidoo, N.; Sellars, M. J.; Twamley, J.; Brown, L. J.; Barnard, A. S.; Plakhotnik, T.; Zvyagin, A. V.; Rabeau, J. R. Observation and control of blinking nitrogen-vacancy centres in discrete nanodiamonds. Nat. Nanotechnol. 2010, 5, 345−349. (44) Aslam, N.; Waldherr, G.; Neumann, P.; Jelezko, F.; Wrachtrup, J. Photo-induced ionization dynamics of the nitrogen vacancy defect in diamond investigated by single-shot charge state detection. New J. Phys. 2013, 15, No. 013064. (45) Bradac, C.; Gaebel, T.; Pakes, C. I.; Say, J. M.; Zvyagin, A. V.; Rabeau, J. R. Effect of the nanodiamond host on a nitrogen-vacancy color-centre emission state. Small 2013, 9, 132−139. (46) Gu, M.; Cao, Y.; Castelletto, S.; Kouskousis, B.; Li, X. Superresolving single nitrogen vacancy centers within single nanodiamonds using a localization microscope. Opt. Express 2013, 21, 17639−17646. (47) Inam, F. A.; Steel, M. J.; Castelletto, S. Effects of the hosting nano-environment modifications on NV centres fluorescence emission. Diamond Relat. Mater. 2014, 45, 64−69. (48) Kaviani, M.; Deák, P.; Aradi, B.; Frauenheim, T.; Chou, J.-P.; Gali, A. Proper surface termination for luminescent near-surface NV centers in diamond. Nano Lett. 2014, 14, 4772−4777. (49) Manson, N. B.; Harrison, J. P. Photo-ionization of the nitrogenvacancy center in diamond. Diamond Relat. Mater. 2005, 14, 1705− 1710.
(12) Vendelbo, S. B.; Kooyman, P. J.; Creemer, J. F.; Morana, B.; Mele, L.; Dona, P.; Nelissen, B. J.; Helveg, S. Method for local temperature measurement in a nanoreactor for in situ high-resolution electron microscopy. Ultramicroscopy 2013, 133, 72−79. (13) Fuyuki, T.; Kondo, H.; Yamazaki, T.; Takahashi, Y.; Uraoka, Y. Photographic surveying of minority carrier diffusion length in polycrystalline silicon solar cells by electroluminescence. Appl. Phys. Lett. 2005, 86, 262108. (14) McCartney, M. R.; Smith, D. J.; Hull, R.; Bean, J. C.; Voelkl, E.; Frost, B. Direct observation of potential distribution across Si/Sip− njunctions using off-axis electron holography. Appl. Phys. Lett. 1994, 65, 2603−2605. (15) Nonnenmacher, M.; O’boyle, M. P.; Wickramasinghe, H. K. Kelvin Probe Force Microscopy. Appl. Phys. Lett. 1991, 58, 2921− 2923. (16) Arakawa, M.; Kishimoto, S.; Mizutani, T. Kelvin probe force microscopy for potential distribution measurement of cleaved surface of GaAs devices. Jpn. J. Appl. Phys., Part 1 1997, 36, 1826−1829. (17) Rau, W. D.; Schwander, P.; Baumann, F. H.; Hoppner, W.; Ourmazd, A. Two-dimensional mapping of the electrostatic potential in transistors by electron holography. Phys. Rev. Lett. 1999, 82, 2614− 2617. (18) Brintlinger, T.; Qi, Y.; Baloch, K. H.; Goldhaber-Gordon, D.; Cumings, J. Electron thermal microscopy. Nano Lett. 2008, 8, 582− 585. (19) Wu, X.; Hull, R. A novel nano-scale non-contact temperature measurement technique for crystalline materials. Nanotechnology 2012, 23, 465707. (20) Majumdar, A.; Lai, J.; Chandrachood, M.; Nakabeppu, O.; Wu, Y.; Shi, Z. Thermal Imaging by Atomic-Force Microscopy Using Thermocouple Cantilever Probes. Rev. Sci. Instrum. 1995, 66, 3584− 3592. (21) Shiota, T.; Nakayama, K. Atom-Resolved Imaging of the Potential Distribution at Si (111) 7 × 7 Surfaces. Jpn. J. Appl. Phys. 2002, 41, L1178−L1180. (22) Chen, J.; Sekiguchi, T.; Yang, D.; Yin, F.; Kido, K.; Tsurekawa, S. Electron-beam-induced current study of grain boundaries in multicrystalline silicon. J. Appl. Phys. 2004, 96, 5490−5495. (23) Trupke, T.; Bardos, R. A.; Schubert, M. C.; Warta, W. Photoluminescence imaging of silicon wafers. Appl. Phys. Lett. 2006, 89, No. 044107. (24) Saida, D.; Takahashi, T. Magnetic field observation around current path by magnetic force microscopy. Jpn. J. Appl. Phys. 2004, 43, 4643−4646. (25) Doherty, M. W.; Manson, N. B.; Delaney, P.; Jelezko, F.; Wrachtrup, J.; Hollenberg, L. C. L. The nitrogen-vacancy colour centre in diamond. Phys. Rep. 2013, 528, 1−45. (26) Dolde, F.; Fedder, H.; Doherty, M. W.; Nöbauer, T.; Rempp, F.; Balasubramanian, G.; Wolf, T.; Reinhard, F.; Hollenberg, L. C. L.; Jelezko, F.; Wrachtrup, J. Electric-field sensing using single diamond spins. Nat. Phys. 2011, 7, 459−463. (27) Doherty, M. W.; Struzhkin, V. V.; Simpson, D. A.; McGuinness, L. P.; Meng, Y.; Stacey, A.; Karle, T. J.; Hemley, R. J.; Manson, N. B.; Hollenberg, L. C. L.; Prawer, S. Electronic properties and metrology applications of the diamond NV- center under pressure. Phys. Rev. Lett. 2014, 112, No. 047601. (28) Balasubramanian, G.; Chan, I. Y.; Kolesov, R.; Al-Hmoud, M.; Tisler, J.; Shin, C.; Kim, C.; Wojcik, A.; Hemmer, P. R.; Krueger, A.; Hanke, T.; Leitenstorfer, A.; Bratschitsch, R.; Jelezko, F.; Wrachtrup, J. Nanoscale imaging magnetometry with diamond spins under ambient conditions. Nature 2008, 455, 648−651. (29) Doherty, M. W.; Manson, N. B.; Delaney, P.; Hollenberg, L. C. L. The negatively charged nitrogen-vacancy centre in diamond: the electronic solution. New J. Phys. 2011, 13, No. 025019. (30) Maze, J. R.; Gali, A.; Togan, E.; Chu, Y.; Trifonov, A.; Kaxiras, E.; Lukin, M. D. Properties of nitrogen-vacancy centers in diamond: the group theoretic approach. New J. Phys. 2011, 13, No. 025025. (31) Acosta, V. M.; Bauch, E.; Ledbetter, M. P.; Waxman, A.; Bouchard, L. S.; Budker, D. Temperature dependence of the nitrogen7465
DOI: 10.1021/acsomega.9b00344 ACS Omega 2019, 4, 7459−7466
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(50) Storteboom, J.; Dolan, P.; Castelletto, S.; Li, X.; Gu, M. Lifetime investigation of single nitrogen vacancy centres in nanodiamonds. Opt. Express 2015, 23, 11327−11333. (51) Stacey, A.; Dontschuk, N.; Chou, J.-P.; Broadway, D. A.; Schenk, A. K.; Sear, M. J.; Tetienne, J.-P.; Hoffman, A.; Prawer, S.; Pakes, C. I.; Tadich, A.; de Leon, N. P.; Gali, A.; Hollenberg, L. C. L. Evidence for Primal sp2 Defects at the Diamond Surface: Candidates for Electron Trapping and Noise Sources. Adv. Mater. Interfaces 2019, 6, 1801449. (52) Bluvstein, D.; Zhang, Z.; Jayich, A. C. B. Identifying and Mitigating Charge Instabilities in Shallow Diamond Nitrogen-Vacancy Centers. Phys. Rev. Lett. 2019, 122, No. 076101. (53) Okumura, H. Present status and future prospect of widegap semiconductor high-power devices. Jpn. J. Appl. Phys. 2006, 45, 7565−7586. (54) Steinert, S.; Dolde, F.; Neumann, P.; Aird, A.; Naydenov, B.; Balasubramanian, G.; Jelezko, F.; Wrachtrup, J. High sensitivity magnetic imaging using an array of spins in diamond. Rev. Sci. Instrum. 2010, 81, No. 043705. (55) Tetienne, J.-P.; Rondin, L.; Spinicelli, P.; Chipaux, M.; Debuisschert, T.; Roch, J.-F.; Jacques, V. Magnetic-field-dependent photodynamics of single NV defects in diamond: an application to qualitative all-optical magnetic imaging. New J. Phys. 2012, 14, 103033. (56) Knowles, H. S.; Kara, D. M.; Atatüre, M. Observing bulk diamond spin coherence in high-purity nanodiamonds. Nat. Mater. 2014, 13, 21−25. (57) Kidalov, S. V.; Shakhov, F. M.; Vulˈ, A. Y.; Ozerin, A. N. Grainboundary heat conductance in nanodiamond composites. Diamond Relat. Mater. 2010, 19, 976−980. (58) Trew, R. J.; Green, D. S.; Shealy, J. B. AlGaN/GaN HFET Reliability. IEEE Microw. Mag. 2009, 10, 116−127. (59) Toyli, D. M.; Christle, D. J.; Alkauskas, A.; Buckley, B. B.; Van de Walle, C. G.; Awschalom, D. D. Measurement and Control of Single Nitrogen-Vacancy Center Spins above 600 K. Phys. Rev. X 2012, 2, No. 031001. (60) Chen, X.-D.; Dong, C.-H.; Sun, F.-W.; Zou, C.-L.; Cui, J.-M.; Han, Z.-F.; Guo, G.-C. Temperature dependent energy level shifts of nitrogen-vacancy centers in diamond. Appl. Phys. Lett. 2011, 99, 161903.
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