A comparative analysis of radiation-induced defect formation in the gallium and nitrogen sublattices of gallium nitride is conducted under irradiation by 15-MeV protons and 0.9-MeV electrons. Numerical modeling using the SRIM software is performed for proton deceleration, while analytical calculations are applied for electrons. The analysis shows that, under proton irradiation, the total vacancy-generation rate in the gallium sublattice ηFP(Ga) is approximately 560 cm–1, while in the nitrogen sublattice, ηFP(N) is approximately 1340 cm–1. Detailed numerical calculations using the Full Cascade mode indicate that the vacancy-formation rate due to protons in the gallium sublattice is 110 cm–1, with an additional 450 cm–1 generated by cascade processes. In the nitrogen sublattice, this disparity is even more pronounced, with 60 cm–1 attributed to direct proton interaction and 1280 cm–1 to cascade processes. Under electron irradiation, the vacancy-generation rate in the gallium sublattice ηFP(Ga) is approximately 4.7 cm–1, while in the nitrogen sublattice, ηFP(N) is approximately 2.0 cm–1. For the experimental study of radiation-induced defects in n-GaN, which create deep levels and compensate for the material’s conductivity, the forward current–voltage characteristics of Schottky diodes based on n-GaN are recorded. The analysis demonstrates that the charge-carrier removal rates in n-GaN are 0.47 cm–1 under electron irradiation and 150 cm–1 under proton irradiation. A comparison of the calculated and experimental parameters of radiation-induced defect formation provides insights into the compensation mechanism and the radiation-induced defects responsible for this process.

The effect of proton irradiation (proton energy 15 MeV) on the parameters of high-voltage 4H-SiC integrated Schottky diodes (JBS) was studied for the first time in the operating temperature range Ti (23 and 175°C). The blocking voltage of the diodes under study, Ub, was 600 and 1700 V. For devices with Ub = 600 V, the fluence range was 5 × 1013–1 × 1014 cm–2; for devices with Ub = 1700 V, the fluence range was 3 × 1013–6 × 1013 cm–2. An increase in the irradiation temperature leads to a noticeable decrease in the effect of irradiation on the current–voltage characteristics of the diodes. The effect of annealing on the current-voltage characteristics of irradiated devices is studied.

The spectra of anticrossing of spin sublevels have been recorded and spin-3/2 color centers have been identified for the first time in commercially available 4H-SiC Schottky diodes irradiated with 0.9-MeV electrons or 15-MeV protons. The effect of the irradiation density on the defect formation has been shown. It has been demonstrated that the increase in the temperature at which proton irradiation is carried out acts as a short-term annealing, leading to a decrease in the concentration of point defects.

The effect of high-temperature electron and proton irradiation on the characteristics of devices based on SiC has been studied. For the study, industrial 4H-SiC integrated Schottky diodes with an n-type base with a blocking voltage of 600, 1200, and 1700 V manufactured by CREE are used. Irradiation is carried out by electrons with an energy of 0.9 MeV and protons with an energy of 15 MeV. It is found that the radiation resistance of SiC Schottky diodes under high-temperature irradiation significantly exceeds the resistance of diodes under irradiation at room temperature. It is shown that this effect arises due to the annealing of compensating radiation defects under high-temperature irradiation. It is revealed that this effect arises due to the annealing of compensating radiation defects under high-temperature irradiation. The parameters of radiation defects are determined by the method of transient capacitance spectroscopy. Under high-temperature (“hot”) irradiation, the spectrum of radiation-induced defects introduced into SiC differs significantly from the spectrum of defects introduced at room temperature. The radiation resistance of silicon and silicon carbide is compared. The relatively small difference in the rate of carrier removal in SiC and Si upon irradiation at room temperature is due to the fact that in SiC, in contrast to Si, there is practically no annealing of primary radiation defects during irradiation.

The processes of long-term (persistent) conductivity relaxation in n-type silicon carbide irradiated with protons in a wide range irradiation temperatures Ti from 23 to 500°C are studied. It is shown for the first time that as a result of the proton irradiation with the fluence of 1014 cm–2, two “competing” long-term processes of conductivity relaxation can be observed. The characteristics of both processes significantly depend on the irradiation temperature and bias, at which the dynamics of conductivity changes is studied. After applying a relatively small constant voltage to the sample, the decrease in current during persistent relaxation process is replaced by persistent increase in current and establishing of the steady state. Both processes are characterized by a very wide range of time constants. When irradiation is performed at room temperature (Ti = 23°C), the time constants range from milliseconds to hundreds of seconds. When the samples are irradiated at elevated temperatures, the time constants are in the range from milliseconds to hundreds of milliseconds. The higher the bias applied, the faster the decrease in current is replaced by its increase. The possible nature of the observed effects is discussed.

The carrier removal rates during proton and electron irradiations of n-type GaN grown by metal-organic vapor phase epitaxy were determined. Irradiation was carried out with protons with energy of 15 MeV in the fluence range 0 ≤ Фр ≤ 5 × 1014 cm–2; the range of fluences when irradiated with electrons with energy of 0.9 MeV was 0 ≤ Фn ≤ 5 × 1016 cm–2. The value of the removal rate during proton irradiation, ηp ≈ 140 cm–1, is close to the lower limit of currently known values of ηp and indicates a sufficiently high level of radiation resistance of the studied material with respect to proton irradiation. The rate of carrier removal under the influence of electron irradiation, ηe is ≈0.47 cm–1 and corresponds to the typical values of ηe for type gallium nitride obtained by various methods.

The effect of proton irradiation (proton energy 15 MeV) on the parameters of high-voltage 4H-SiC integrated Schottky diodes (JBS) was studied for the first time in the operating temperature range Ti (23 and 175oC). The blocking voltage of the diodes under study, Ub, was 600 and 1700 V. For devices with U_b = 600 V, the fluence range was 5·1013-1·1014 cm-2; for devices with U_b=1700 V, the fluence range was 3·1013-6·1013 cm-2. An increase in the irradiation temperature leads to a noticeable decrease in the effect of irradiation on the current-voltage characteristics of the diodes. The effect of annealing on the current-voltage characteristics of irradiated devices is studied. Keywords: Silicon carbide, Schottky diodes, proton irradiation, current-voltage characteristics, annealing.

The effect of proton irradiation (proton energy 15 MeV) on the parameters of high-voltage 4H-SiC integrated Schottky diodes (JBS) was studied for the first time in the operating temperature range Ti (23 and 1750C). The blocking voltage of the diodes under study, Ub, was 600 and 1700 V. For devices with Ub = 600 V, the fluence range was 5×1013–1×1014 cm-2; for devices with Ub = 1700 V, the fluence range was 3×1013 – 6×1013 cm-2. An increase in the irradiation temperature leads to a noticeable decrease in the effect of irradiation on the current-voltage characteristics of the diodes. The effect of annealing on the current-voltage characteristics of irradiated devices is studied.

We study the low frequency noise in infra-red InAs photodiodes (PDs) in the frequency range 1 – 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> Hz at room and cryogenic temperatures. We compare noise characteristics of two types of photodiodes: Single Heterostructure PDs and Double Heterostructure PDs and demonstrate the advantages of Double Heterostructure technology. We find that for comparable size, composition, and thickness of the photosensitive layers, the current noise in Double Heterostructure PD is significantly lower than in Single Heterostructure PD at both room and cryogenic temperatures. In addition, we measure the optical output noise in InAsSbP/InAs LEDs at 300K and find that its intensity is less than the intensity of the photodiode reverse bias current noise by ~4 orders of magnitude.

Using the mathematical modeling of a displacement cascade in two wide-gap semiconductors based on gallium, gallium oxide (Ga 2 O 3 ), and gallium nitride (GaN), the features of the generation of Frenkel pairs during the scattering of protons with energies of 8 and 15 MeV are considered. The number of displacements created not only by primary knocked-out atoms, but also by recoil atoms generated in displacement cascades is calculated for the first time. Calculations show that under the proton irradiation of Ga 2 O 3 , for example, the fraction of vacancies in the oxygen sublattice created directly by protons is only 12%. The remaining 88% are created by recoil atoms in cascade processes. For the gallium sublattice, these fractions are 25 and 75%, respectively. Therefore, the processes of compensating the conductivity of GaN and Ga 2 O 3 observed under proton irradiation will be determined by deep centers created not by primary knocked-out atoms, but by recoil atoms formed in displacement cascades. A comparison with experimental data is made, and the fraction of Frenkel pairs dissociating during irradiation is estimated.

The effect of the electron-irradiation temperature on radiation-defect formation in silicon carbide is studied for the first time. Commercial high-voltage 4H-SiC Schottky diodes are studied. Irradiation is carried out by electrons with an energy of 0.9 MeV at temperatures of 20°C and 200°C. The spectra of radiation-induced defects are measured using nonstationary capacitance spectroscopy. It is established that with an increase in the temperature of irradiated silicon carbide, not only the number of introduced radiation defects decreases, but also their spectrum changes. If cold irradiation leads to the formation of six deep traps, then hot irradiation leads to the formation of only three traps: Z1/Z2 (0.68 eV), EH5 (1.08 eV), and EH6/EH7 (1.58 eV). During hot irradiation the number of induced radiation defects also sharply decreases, which leads to a decrease in the rate of removal of charge carriers (compensation of semiconductor conductivity) by almost four times: from 0.25 to 0.065 cm–1. It is noted that nonlinear effects in radiation-defect formation are observed in silicon carbide. At a fixed dose of irradiation of silicon carbide by electrons, the number of introduced radiation defects depends on the electron-flux density (dose-accumulation time).

low frequency noise and electrical characteristics of the p-InAsSbP/n-InAs single photodiode heterostructures grown onto n+-InAs substrates have been measured in the presence of atmosphere containing ethanol vapor. Correlation between ethanol vapor density and electrical noise spectral density, as well as the heterostructure resistance, has been estimated, and possible reasons for such correlation have been discussed.

The effect of annealing on the parameters of 4H-SiC Schottky diodes irradiated with electrons at high temperatures has been studied for the first time. The electron energy was 0.9 MeV. The irradiation was carried out at temperatures of 23, 300, and 500oС at fluences  in the range 1×1016 – 1.3×1017 cm-2. The results of annealing after the irradiation at high temperatures are qualitatively different from the results of annealing after conventional irradiation at room temperature with the same fluencies. The results obtained indicate that the spectrum of radiation defects introduced into SiC under a high-temperature (“hot”) irradiation differs significantly from that of defects introduced by irradiation at room temperature. At irradiation temperatures of 300 and 500°C and large, the effect of "reverse annealing" was revealed, when the base resistance grows rather than falling as a result of annealing.

The effect of annealing on the parameters of 4H-SiC Schottky diodes irradiated with electrons at a high temperature is studied for the first time. The electron energy is 0.9 MeV, irradiation is carried out at temperatures of 23, 300, and 500°C with fluences Φ in the 1 × 1016–1.3 × 1017 cm–2 range. The results of annealing samples irradiated at high temperatures differ qualitatively from the results of annealing samples irradiated with the same fluence at room temperature. The results indicate that, under high-temperature (“hot”) irradiation, the spectrum of radiation-induced defects introduced in SiC differs significantly from the spectrum of defects introduced at room temperature. The effect of reverse annealing, when the resistance of the base of the diode does not fall but increases as a result of annealing, was discovered for large values of Φ at irradiation temperatures of 300 and 500°C.

For the first time, a comparative study of the effect of electron and proton irradiation at a temperature of 20–500°C on the characteristics of semiconductor devices based on silicon carbide, i.e., commercial high-voltage 4H-SiC Schottky diodes, is carried out. The diodes are irradiated with 15-MeV protons and 0.9‑MeV electrons. It is found that the most sensitive parameter, which determines the radiation resistance of devices, is the base resistance, which monotonically increases with the radiation dose D. It is shown that, under low-temperature (“cold”) irradiation, the efficiency of compensation of a semiconductor by proton irradiation is about 400 times higher than the efficiency of electron irradiation. Under “hot” (high temperature) irradiation, the radiation resistance of diodes is several times higher than the resistance of diodes under “cold” irradiation. The rate of formation of deep centers in the upper half of the band gap of silicon carbide decreased with increasing irradiation temperature.

Впервые исследовано влияние облучения электронами с энергией 0.9 МэВ на параметры 4H-SiC диодов Шоттки с предельным блокирующим напряжением Ub=600 и 1700 В в диапазоне рабочих температур Ti (23 и 175oС). Диапазон флюенсов Phi составлял 1·1016-2·1016 см-2 для приборов c Ub=600 В и 5·1015-1.5·1016 cм-2 для приборов c Ub=1700 В. Облучение при комнатной температуре значительно увеличивает дифференциальное сопротивление базы диодов. Облучение теми же дозами при Ti=175oС --- предельной рабочей температуре приборов практически не сказывается на параметрах вольтамперных характеристик. Тем не менее DLTS-спектры демонстрируют значительное увеличение концентрации глубоких уровней в верхней половине запрещенной зоны не только после облучения при комнатной температуре, но и после облучения при Ti=175oС. Ключевые слова: карбид кремния, диоды Шоттки, электронное облучение, вольт-амперные характеристики, DLTS-спектры.

Effect of irradiation with 0.9 MeV electrons on the parameters of 4H-SiC Schottky diodes with a limiting blocking voltage Ub = 600 and 1700 V was studied for the first time in the range of operating temperatures Ti (23 and 175°C). The range of fluences Φ was 1 × 1016–2 × 1016 cm–2 for devices with Ub = 600 V and 5 × 1015–1.5 × 1016 cm–2 for devices with Ub = 1700 V. Irradiation at room temperature increases significantly the differential resistance of the base of the diodes. Irradiation with the same doses at Ti = 175°C—i.e. at limiting operating temperature of devices, does not affect practically the parameters of current–voltage characteristics. Nevertheless, the DLTS spectra demonstrate a significant increase in the concentration of deep levels in the upper half of the band gap not only after irradiation at room temperature, but also after irradiation at Ti = 175°C.

Impact of high temperature electron irradiation on the characteristics of power silicon carbide-based semiconductor devices was studied for the first time. Commercial 4H-SiC integrated Schottky diodes (JBS) with blocking voltage of 1700 V were irradiated with 0.9 MeV electrons at temperatures from 23 to 5000C in the fluence range phi from 1 x 1016 cm-2 to 1.3 x 1017 cm-2. It was shown that ruggedness of the diodes during high temperature ("hot") irradiation significantly exceeds the ruggedness of diodes at room temperature ("cold") irradiation. With an increase in the irradiation temperature from 23 to 500 degrees C, the change in the base resistance at a fluence of 1.3 x 1017 cm-2 decreases by 6 orders of magnitude. In the entire investigated range of irradiation temperatures and fluences, irradiation does not change the height of the metal-semiconductor barrier even at the maximum fluence phi.

We report the results of a study into the impact of irradiation with 0.9 MeV electrons on the main properties of 4H-SiC MOSFETs of 1.2 kV class at irradiation doses Phi within the range from 0.125 to 3 MGy (fluence F from 75 x 10(14) to 1.2 x 10(16) cm(-2)). The effects of irradiation on the threshold voltage, leakage current, output characteristics, and channel electron mobility have been studied. The results obtained are compared with the known data on the irradiation of high-voltage 4H-SiC MOSFETs with 4.5 MeV electrons and gamma-photons from a(60)Co source. It is shown that the parameter variations of the MOSFETs under influence of irradiation depends on both the dose and the electron energy. A high radiation hardness of the structures under study has been demonstrated.

For the first time, the effect of irradiation at high temperature (“hot irradiation”) by protons on the capacitance – voltage and current – ​​voltage characteristics of silicon carbide based semiconductor devices was studied. We investigated commercial high-voltage (blocking voltage of 1700 V) integrated 4H-SiC Schottky diodes. Irradiation was carried out by protons with an energy of 15 MeV at temperatures of 20-400 ° C. It has been established that the most sensitive to radiation parameter determining the radiation resistance of devices is the ohmic resistance of the base, which increases monotonically with increasing radiation dose D. It is shown that during “hot” irradiation, the radiation resistance of diodes significantly exceeds the resistance of diodes in low-temperature (“cold”) irradiation . It was concluded that, with increasing irradiation temperature, the rate of formation of deep centers in the upper half of the band gap of silicon carbide decreases.