共查询到20条相似文献,搜索用时 15 毫秒
1.
A. P. Gnana Prakash T. M. Pradeep Vinayakprasanna N. Hegde N. Pushpa P. K. Bajpai S. P. Patel 《辐射效应与固体损伤》2017,172(11-12):952-963
NPN transistors and N-channel depletion metal oxide semiconductor field effect transistors (MOSFETs) were irradiated with 5?MeV protons and 60Co gamma radiation in the dose ranging from 1?Mrad(Si) to 100?Mrad(Si). The different electrical characteristics of the NPN transistor such as Gummel characteristics, excess base current (ΔIB), dc current gain (hFE), transconductance (gm), displacement damage factor (K) and output characteristics were studied as a function of total dose. The different electrical characteristics of N-channel MOSFETs such as threshold voltage (Vth), density of interface trapped charges (ΔNit), density of oxide trapped charges (ΔNot), transconductance (gm), mobility (µ) and drain saturation current (IDSat) were studied systematically before and after irradiation in the same dose ranges. A considerable increase in the base current (IB) and decrease in the hFE, gm and collector saturation current (ICSat) were observed after irradiation in the case of the NPN transistor. In the N-channel MOSFETs, the ΔNit and ΔNot were found to increase and Vth, gm, µ and IDSat were found to decrease with increase in the radiation dose. The 5?MeV proton irradiation results of both the NPN transistor and N-channel MOSFETs were compared with 60Co gamma-irradiated devices in the same dose ranges. It was observed that the degradation in 5?MeV proton-irradiated devices is more when compared with the 60Co gamma-irradiated devices at higher total doses. 相似文献
2.
T. M. Pradeep Vinayakaprasanna N. Hegde N. Pushpa Ambuj Tripathi K. Asokan 《辐射效应与固体损伤》2013,168(9-10):859-872
ABSTRACTThe pre- and post-irradiation effects on the DC electrical characteristics of 100?MeV Phosphorous (P7+) and 80?MeV Nitrogen (N6+) ion-irradiated NPN transistors were studied in the dose range from 600?krad (Si) to 100?Mrad (Si). The different electrical characteristics, such as Gummel characteristics, excess base current (ΔIB?=?IB-Post?–?IB-Pre), current gain (hFE), damage constant (K) and output characteristics, were measured in situ after ion irradiation. The considerable increase in the base current (IB) at lower VBE and slight decrease in the collector current (IC) at higher VBE were observed after ion irradiation. The C–V measurements revealed that the doping concentration (Nd) was found decreased, while the built-in potential (Vbi) increased after irradiation. The ion-irradiated results are compared with 60Co gamma-irradiated results in the same dose range. The SRIM simulation was performed to understand the range of ions and energy loss in the transistor structure. The SRIM simulation showed that 100?MeV P7+ and 80?MeV N6+ ions can easily pass through the active region of transistors by creating ionization and displacement damages in the device structure. The irradiation results showed that ions induce more degradation in the electrical characteristics when compared to 60Co gamma radiation at the same dose range. 相似文献
3.
利用高能离子研究了110 keV 的He+注入Al2O3单晶及随后230 MeV的208Pb27+辐照并在不同温度条件下退火样品的光致发光的特性. 从测试结果可以清楚地看到在375 nm,390 nm,413 nm 和450 nm 出现了强烈的发光峰. 经过600 K退火2 h后测试结果显示,390 nm发光峰增强剧烈,而别的发光峰显示不明显. 在900 K退火条件下,390 nm的发光峰开始减弱相反在510 nm出现了较强的发光峰,到1100 K退火完毕后390 nm的发光峰完全消失,而510 nm的发光峰相对增强. 从辐照样品的FTIR谱中看到,波数在460—510 cm-1间的吸收是振动模式,经过离子辐照后,吸收带展宽,随着辐照量的增大,Al2O3振动吸收峰消失,说明Al2O3振动模式被完全破坏. 1000—1300 cm-1之间为Al-O-Al桥氧的伸缩振动模式,辐照后吸收带向高波数方向移动. 退火后的FTIR谱变化不大. 相似文献
4.
Silicon carbide (SiC) single crystals with the 6H polytype structure were irradiated with 4.0-MeV Au ions at room temperature (RT) for increasing fluences ranging from 1?×?1012 to 2?×?1015 cm?2, corresponding to irradiation doses from ~0.03 to 5.3 displacements per atom (dpa). The damage build-up was studied by micro-Raman spectroscopy that shows a progressive amorphization by the decrease and broadening of 6H-SiC lattice phonon peaks and the related growth of bands assigned to Si–Si and C–C homonuclear bonds. A saturation of the lattice damage fraction deduced from Raman spectra is found for ~0.8?dpa (i.e. ion fluence of 3?×?1014 cm?2). This process is accompanied by an increase and saturation of the out-of-plane expansion (also for ~0.8?dpa), deduced from the step height at the sample surface, as measured by phase-shift interferometry. Isochronal thermal annealing experiments were then performed on partially amorphous (from 30 to 90%) and fully amorphous samples for temperatures from 200 °C up to 1500 °C under vacuum. Damage recovery and densification take place at the same annealing stage with an onset temperature of ~200 °C. Almost complete 6H polytype regrowth is found for partially amorphous samples (for doses lower than 0.8 dpa) at 1000 °C, whereas a residual damage and swelling remain for larger doses. In the latter case, these unrelaxed internal stresses give rise to an exfoliation process for higher annealing temperatures. 相似文献
5.
R. Bevilacqua S. Pomp V.D. Simutkin U. Tippawan P. Andersson J. Blomgren M. ?sterlund M. Hayashi S. Hirayama Y. Naito Y. Watanabe M. Tesinsky F.-R. LeColley N. Marie A. Hjalmarsson A.V. Prokofiev A. Kolozhvari 《Radiation measurements》2010,45(10):1145-1150
We have measured light-ion (p, d, t, 3He and α) production in the interaction of 175 MeV neutrons with iron and bismuth with low-energy thresholds and for a wide angular range (from 20° to 160°, in steps of 20°). Measurements have been performed with the Medley setup, semi-permanently installed at the The Svedberg Laboratory, Uppsala (Sweden), where a quasi-monoenergetic neutron beam is available and well characterized. Medley is a conventional spectrometer system and consists of eight telescopes, each of them composed of two silicon surface barrier detectors, to perform particle identification, and a CsI(Tl) scintillator to fully measure the kinetic energy of the produced light-ions. We report preliminary double-differential cross sections for production of protons, deuterons and tritons in comparison with model calculations using TALYS-1.0 code. These show better agreement for the production of protons, while the theoretical calculations seem to overestimate the experimental production of deuterons and tritons. 相似文献
6.
P. Andersson C. Gustavsson R. Bevilacqua J. Blomgren A. Hjalmarsson A. Kolozhvari F.-R. LeColley N. Marie M. ?sterlund S. Pomp A. Prokofiev V. Simutkin M. Tesinsky U. Tippawan 《Radiation measurements》2010,45(10):1142-1144
The experimental setup SCANDAL, used for measurements of the differential cross section for elastic and inelastic neutron scattering, has recently been upgraded with larger CsI scintillating detectors to enable measurements at energies up to 175 MeV. Measurements on Fe, Bi and Si have been carried out using the quasi mono-energetic neutron beam at the The Svedberg Laboratory, and data is under analysis. The experimental setup can be used for measurements on a wide range of target nuclei, including C and O, which are important for dosimetry applications. SCANDAL can also run in proton mode, for measurements of the (n,p) reaction. This paper describes the new experimental setup, and reports on its properties, such as energy resolution. 相似文献
7.
In this work, we present the temperature and 1 MeV irradiation proton effects on the light emission in bulk silicon emitter-base junctions for direct and reverse polarizations. Our samples were exposed at room temperature to 5.3 × 108, 5.3 × 1010, 5 × 1011, 5 × 1012 and 5 × 1013 p cm−2. The spectral range for which electroluminescence spectrums were recorded for forward and reverse polarizations is 0.6–2 eV. For forward bias, EL maximum intensity occurs at 1.0923 ± 0.0001 eV (structure (a)) which decreases as function of irradiation fluencies. For reverse bias, the spectra contain two structures (b) and (c). The first structure (c) occurred at 1.6243 ± 0.0013 eV is independent of irradiation while the second structure (b) decreases as function of fluencies irradiation. The Gaussian deconvolution of (b) shows two sub-structures (b1) and (b2) which are located, respectively, at 0.8064 ± 0.0004 eV and 0.9917 ± 0.0016 eV. We studied temperature dependence of full width at half-maximum (FWHM) and we found that the phonons involved in (a), (b1) and (b2) on the one hand and (c) on the other hand are not the same. Moreover, we obtained from the study of EL intensity temperature dependence that the activation energies of (a), (b1) and (b2) are identical and differ from that of (c). These effects enable us to conclude that visible light emission does not have the same origin as that in infra-red. From these observations, we can attribute the structures (a) and (b) to indirect inter-bands transitions and (c) to a direct intra-band transitions. 相似文献
8.
Wei-Qi Huang Rong-Tao Zhang Feng Jin Shui-Jie Qin Shi-Rong Liu 《Optics Communications》2008,281(20):5229-5233
Stimulated emission has been observed from oxide structure of silicon when optically excited by 514 nm laser. The photoluminescence (PL) pulse has a Lorentzian shape with a full width at half maximum (FWHM) of 0.5-0.6 nm. The twin peaks at 694 nm and 692 nm are dominated by stimulated emission which can be demonstrated by its threshold behavior and transition from sub-threshold to linear evolution in light emission. The gain coefficient from the evolution of the peak-emission intensity as a function of the optically pumped sample length has been measured. The oxide structure was fabricated by laser irradiation and annealing treatment on silicon. A model for explaining the stimulated emission has been proposed in which the trap states of the interface between oxide of silicon and porous nanocrystal play an important role. 相似文献
9.
V. Suresh Kumar J. KumarP. Puviarasu S. Munawar BashaD. Kanjilal K. Asokan 《Physica B: Condensed Matter》2011,406(22):4210-4213
Metal-organic chemical vapor deposition (MOCVD) grown n-type Gallium nitride (GaN) has been irradiated with 100 MeV Ni9+ ions at room temperature. Atomic force microscopy (AFM) images show the nano-clusters' formation upon irradiation and the irradiated GaN surface roughness increases with the increasing ion fluences. High-resolution X-ray diffraction (HR-XRD) analysis reveals the formation of Ga2O3 due to the interface mixing of GaN/Al2O3 upon irradiation. FWHM values of GaN (0 0 0 2) increases due to the lattice disorder. Photoluminescence studies show reduced band edge emission and yellow luminescence (YL) intensity with the increasing ion fluences. Change in the band gap energy between 3.38 and 3.04 eV was measured by UV-visible optical absorption spectrum on increasing the ion fluences. 相似文献
10.
PbS quantum dots of average size 10 nm are encapsulated in a matrix (polyvinyl alcohol (PVA)) following chemical route. They are irradiated with 160 MeV Ni12+ ion beam with fluences 1012-1013 ions/cm2. Red shift in the absorption response in the optical absorption spectra reveal size enhancement of the quantum dots after irradiation and was confirmed by transmission electron microscopy (TEM). Photoluminescence (PL) study was carried out with excitation wavelength 325 nm on both unirradiated and irradiated samples at different fluences and fluence-dependent surface states and excitonic emission is observed in the PL study. The Huang-Rhys coupling constant decreases significantly after swift heavy ion (SHI) irradiation and shows a decreasing trend with increase in ion fluence. 相似文献
11.
Kawaljeet Singh Samra 《Journal of luminescence》2011,131(4):686-694
Photoluminescent, structural and thermal changes induced in polyvinylidenechloride (PVDC) films by irradiation with energetic silicon and oxygen ions have been determined using different techniques viz PL, FTIR, UV-vis, XRD, TGA and AFM. Noticeable photoluminescence was observed in PVDC after irradiation with 84 MeV oxygen ions at fluence 3.2×1011 ions cm−2, which is attributed to the small carbon cluster formed in the polymer due to irradiation. Quenching and shifting in the position of the PL band towards the longer wavelength side of the spectrum was observed with the increase in ion fluence. UV-vis and FTIR analysis have strongly corroborated the results of PL spectroscopy. X-ray diffractograms and TGA curves show decrease in crystallinity and weight loss, respectively, of PVDC films after irradiation. The strong correlation between the behaviors of different properties were analyzed and discussed in the present paper. 相似文献
12.
V. A. Skuratov V. A. Altynov A. Yu. Didyk S. M. Abu Alazm 《Radiation measurements》1995,25(1-4):167-168
Luminescence spectra from pure LiF generated with high-energy heavy ions were studied in dependence on exciting density and irradiation temperature. 相似文献
13.
E. F. Krimmel A. G. K. Lutsch R. Swanepoel J. Brink 《Applied Physics A: Materials Science & Processing》1985,38(2):109-115
Surfaces of single-crystal silicon wafers are amorphized by high-dose phosphorous ion implantation. These surfaces of the wafers, immersed in concentrated KOH, are laser-chemically etched by pulse irradiation of a ruby laser. Simultaneously, the remaining parts of the amorphous layer are annealed. The time dependence of the etching process enhanced during pulse irradiation is recorded and analysed. Reasons for the etching rates which differ between amorphous and single-crystal silicon are given on the basis of experimental and numerical results. 相似文献
14.
N. Pushpa A. P. Gnana Prakash K. C. Praveen John D. Cressler D. Revannasiddaiah 《辐射效应与固体损伤》2013,168(10):592-603
Abstract The effects of 8 MeV electrons and 60 and 95 MeV oxygen ions on the electrical properties of Si npn RF power transistors have been investigated as a function of fluence. The dc current gain (h FE), displacement damage factor, excess base current (Δ I B=I Bpost?I Bpre), excess collector current (Δ I C=I Cpost?I Cpre), collector saturation current (I CS) and deep level transient spectroscopy trap signatures of the irradiated transistors were systematically evaluated. 相似文献
15.
Comparison of total dose effects on SiGe heterojunction bipolar transistors induced by different swift heavy ion irradiation
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The degradations in NPN silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) were fully studied in this work, by means of 25-MeV Si, 10-MeV C1, 20-MeV Br, and 10-MeV Br ion irradiation, respectively. Electrical parameters such as the base current (IB), current gain (β), neutral base recombination (NBR), and Early voltage (VA) were investigated and used to evaluate the tolerance to heavy ion irradiation. Experimental results demonstrate that device degradations are indeed radiation-source-dependent, and the larger the ion nuclear energy loss is, the more the displacement damages are, and thereby the more serious the performance degradation is. The maximum degradation was observed in the transistors irradiated by 10-MeV Br. For 20-MeV and 10-MeV Br ion irradiation, an unexpected degradation in Ic was observed and Early voltage decreased with increasing ion fluence, and NBR appeared to slow down at high ion fluence. The degradations in SiGe HBTs were mainly attributed to the displacement damages created by heavy ion irradiation in the transistors. The underlying physical mechanisms are analyzed and investigated in detail. 相似文献
16.
Radíatíon annealing due to a 1.0 MeV election beam of intensity 25 μA/cm2 was studied in silicon samples implanted with phosphorus and boron ions and annealed at 350–500°C. A significant annealing enhancement as compared to thermal annealing has been observed in phosphorus-implanted samples. In boron-implanted samples, a fast initial rise of electrical activity is followed by a continuous decrease of carrier concentration. The results are interpreted in terms of two competing processes: electron irradiation induced removal of post-implantation defects and introduction of simple electrically active defects. 相似文献
17.
Polypropylene films were irradiated with C5+ (70 MeV) and Ni11+ (150 MeV) ions of varying fluence. The ion induced optical, chemical and structural changes were investigated using UV-Vis and Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffractometry (XRD). UV-Vis data showed an increase of optical absorbance and a shift of the absorption edge towards the red end of the spectrum when the ion fluence was increased. This shift may be attributed to the greater degree of conjugation. FTIR analysis revealed the formation of alcoholic and ketonic groups. Significant loss of crystallinity occurred with increasing ion fluence. 相似文献
18.
GaAs solar cells hold the record for the highest single band-gap cell efficiency. Successful application of these cells in
advanced space-borne systems demand characterization of cell properties like dark current under different ambient conditions
and the stability of the cells against particle irradiation in space. In this paper, the results of the studies carried out
on the effect of 8 MeV electron irradiation on the electrical properties of GaAs solar cells are presented. The I–V (current-voltage) characteristics of the cells under dark and AM1.5 illumination condition are studied and 8 MeV electron
irradiation was carried out on the cells where they were exposed to graded doses of electrons from 1 to 100 kGy. The devices
were also characterized using capacitance measurements at various frequencies before and after irradiation. The effect of
electron irradiation on the solar cell parameters was studied. It is found that only small changes were observed in the GaAs
solar cell parameters up to an electron dose of 100 kGy, exhibiting good tolerance for electrons of 8 MeV energy. 相似文献
19.
V. S. Chernysh A. S. Patrakeev E. S. Soldatov D. V. Petrov S. V. Alyshev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2007,1(6):717-721
The surface topography of silicon and germanium single crystals formed under 10-keV Ar+ and Ne+ irradiation was studied experimentally. A relief with typical nanometer-scale dimensions is detected using atomic-force microscopy. It is established that the average height of the nanorelief formed depends on the silicon doping levels. It is also shown that the average height is determined by the parameters of ion irradiation. 相似文献
20.
Microstructure evolution of zircaloy-4 during Ne ion irradiation and annealing: An in situ TEM investigation
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The microstructural evolution of zircaloy-4 was studied, including the amorphization and recrystallization of Zr(Fe, Cr)2 precipitates, and the density of dislocations under in situ Ne ion irradiation and post annealing. The results show that irradiation at a relatively high temperature and dose induces the formation of nanocrystals in pre-amorphized Zr(Fe, Cr)2 precipitates. The recrystallized nanocrystals also have the structure of hcp-Zr(Fe, Cr)2. The formation of the nanocrystals is thought to be the consequence of competition between atomistic disordering and the recrystallization of precipitates under ion irradiation. The free energy of the nanocrystal is lower than that of the amorphous state, which is another reason for the recrystallization of the precipitates. With increased annealing temperature, the density of the nanocrystals is increased. The dislocation density sharply decreases with the increase in the annealing temperature, and its size increases. 相似文献