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1.
A. I. D’Souza M. G. Stapelbroek P. S. Wijewarnasuriya R. E. Dewames G. M. Williams 《Journal of Electronic Materials》2002,31(7):699-704
This paper investigates 1/f noise performance of very-long-wavelength infrared (VLWIR) Hg1−xCdxTe (cutoff wavelengths λc=15 μm and λc=16 μm) photodiodes at 78 K, where detector current is varied by changing detector area, detector bias, and illumination conditions.
Holding detector bias and temperature constant, the 1/f noise current is proportional to the detector current. Significant
nonuniformity is observed in the noise data for each detector area because of the varying detector quality. Defects are presumed
resident in the detectors to produce greater nonuniformity in 1/f noise as compared to dark current at 100-mV reverse bias.
For λc=16 μm, 4-μ-radius, diffusion-limited diodes at 78 K and 100-mV reverse bias, the average dark current is Id=9.76±1.59×10−8 A, while the average noise current measured at 1 Hz is in=1.01±0.63×10−12 A/Hz1/2. For all detector areas measured, the average ratio in 1-Hz bandwidth is α
D
=in/Id=1.39±1.09×10−5. The 1/f noise was also measured on one diode as a function of detector-dark current as the applied bias is varied. In the
diffusion-limited portion of this detector’s current-voltage (I-V) curve, to about 130 mV, the 1/f noise was independent of
bias. For this diode, the ratio αD=in/Id=1.51±0.12×10−5. The 1/f noise associated with tunneling currents is a factor of 3 greater than the 1/f noise associated with diffusion currents,
αT=in/IT=5.21±0.83×10−5. In addition, 1/f noise was measured on detectors held at −100 mV and 78K under dark and illuminated conditions. The measured
ratios αP ∼αD ∼1.5×10−5 were about the same for the dark and photon-induced diffusion currents. Therefore, the diffusion current appears to have
a unique value of α as compared to the tunneling current. This may be indicative of unique noise-generation mechanisms associated
with each current. 相似文献
2.
A. I. D’Souza L. C. Dawson C. Staller P. S. Wijewarnasuriya R. E. Dewames W. V. Mclevige J. M. Arias D. Edwall G. Hildebrandt 《Journal of Electronic Materials》2000,29(6):630-635
Very long wavelength infrared (VLWIR; 15 to 17 μm) detectors are required for remote sensing sounding applications. Infrared
sounders provide temperature, pressure and moisture profiles of the atmosphere used in weather prediction models that track
storms, predict levels of precipitation etc. Traditionally, photoconductive VLWIR (λc >15 μm) detectors have been used for sounding applications. However, photoconductive detectors suffer from performance issues,
such as non-linearity that is 10X – 100X that of photovoltaic detectors. Radiometric calibration for remote sensing interferometry
requires detectors with low non-linearity. Photoconductive detectors also suffer from non-uniform spatial optical response.
Advances in molecular beam epitaxy (MBE) growth of mercury cadmium telluride (HgCdTe) and detector architectures have resulted
in high performance detectors fabricated in the 15 μm to 17 μmm spectral range. Recently, VLWIR (λc ∼ 17 μm at 78 K) photovoltaic large (1000 μm diameter) detectors have been fabricated and measured at flux values targeting
remote sensing interferometry applications. The operating temperature is near 78 K, permitting the use of passive radiators
in spacecraft to cool the detectors. Detector non-AR coated quantum efficiency >60% was measured in these large detectors.
A linear response was measured, while varying the spot size incident on the 1000 μm detectors. This excellent response uniformity,
measured as a function of spot size, implies that low frequency spatial response variations are absent. The 1000 μm diameter,
λc ∼ 17 μm at 78 K detectors have dark currents ∼160 μA at a −100 mV bias and at 78 K. Interfacing with the low (comparable
to the contact and series resistance) junction impedance detectors is not feasible. Therefore a custom pre-amplifier was designed
to interface with the large VLWIR detectors operating in reverse bias. A breadboard was fabricated incorporating the custom
designed preamplifier interfacing with the 1000 μm diameter VLWIR detectors. Response versus flux measurements were made on
the large VLWIR detectors and non-linearity <0.15% was measured at high flux values in the 2.5×1017 to 3.5×1017 ph-cm−2sec−1 range. This non-linearity is an order of magnitude better than for photoconductive detectors. 相似文献
3.
A. I. D’Souza J. Bajaj R. E. De Wames D. D. Edwall P. S. Wijewarnasuriya N. Nayar 《Journal of Electronic Materials》1998,27(6):727-732
Mid wavelength infrared p-on-n double layer planar heterostructure (DLPH) photodiodes have been fabricated in HgCdTe double
layers grown in situ by liquid phase epitaxy (LPE), on CdZnTe and for the first time on CdTe/sapphire (PACE-1). Characterization of these devices
shed light on the nature of the material limits on device performance for devices performing near theoretical limits. LPE
double layers on CdZnTe and on PACE-1 substrates were grown in a horizontal slider furnace. All the photodiodes are p-on-n
heterostructures with indium as the n-type dopant and arsenic the p-type dopant. Incorporation of arsenic is via implantation
followed by an annealing step that was the same for all the devices fabricated. The devices are passivated with MBE CdTe.
Photodiodes have been characterized as a function of temperature. R0Aimp values obtained between 300 and 78K are comparable for the two substrates and are approximately a factor of five below theoretical
values calculated from measured material parameters. The data, for the PACE-1 substrate, indicates diffusion limited performance
down to 110K. Area dependence gives further indications as to the origin of diffusion currents. Comparable R0Aimp for various diode sizes indicates a p-side origin. R0A and optical characteristics for the photodiodes grown on lattice-matched CdZnTe substrates and lattice mismatched PACE-1
are comparable. Howover, differences were observed in the noise characteristics of the photodiodes. Noise was measured on
50 × 50 μm devices held under a 100 mV reverse bias. At 110K, noise spectrum for devices from the two substrates is in the
low 10−15 A/Hz1/2 range. This value reflects the Johnson noise of the room temperature 1010 Ω feedback resistor in the current amplifier that limits the minimum measurable noise. Noise at 1 Hz, −100 mV and 120K for
the 4.95 μm PACE-1 devices is in the 1–2 × 10−14 A/Hz1/2, a factor of 5–10 lower than previously grown typical PACE-1 n+-on-p layers. Noise at 120K for the 4.60 μm PACE-1 and LPE on CdZnTe was again below the measurement technique limit. Greatest
distinction in the noise characteristics for the different substrates was observed at 163K. No excess low frequency noise
was observed for devices fabricated on layers grown by LPE on lattice-matched CdZnTe substrates. Photodiode noise measured
at 1Hz, −100 mV and 163K in the 4.60 μm PACE-1 layer is in the 1–2×10−13 A/Hz1/2, again a factor of 5–10 lower than previously grown PACE-1 n+-on-p layers. More variation in noise (4×10−13−2×10−12 A/Hz1/2) was observed for devices in the 4.95 μm PACE-1 layer. DLPH devices fabricated in HgCdTe layers grown by LPE on lattice-matched
CdZnTe and on lattice-mismatched PACE-1 have comparable R0A and quantum efficiency values. The distinguishing feature is that the noise is greater for devices fabricated in the layer
grown on lattice mismatched substrates, suggesting dislocations inherent in lattice mismatched material affects excess low
frequency noise but not zero bias impedance. 相似文献
4.
Correlation between visual defects and increased dark current in large-area Hg1−xCdxTe photodiodes 总被引:1,自引:0,他引:1
A. I. D’Souza M. G. Stapelbroek R. Willis S. Masterjohn P. Dolan M. Alderete E. Bryan J. C. Ehlert J. E. Andrews P. S. Wijewarnasuriya E. Boehmer S. Bhargava 《Journal of Electronic Materials》2005,34(6):933-938
The Cross-Track Infrared Sounder (CrIS) program [an instrument on the National Polar-Orbiting Operational Environmental Satellite
System (NPOESS)] requires photodiodes with spectral cutoffs denoted by short-wavelength infrared [γc(98 K) ∼5.1 μm], midwavelength infrared [γc(98 K) ∼9.1 μm], and long-wavelength infrared (LWIR) [γc(81 K) ∼15.5 μm]. The CrIS instrument also requires large-area (850-μm-diameter) photodiodes with state-of-art performance.
Molecular beam epitaxy (MBE) is used to grow n-type short-wavelength infrared, midwavelength infrared, or LWIR Hg1−xCdxTe on latticematched CdZnTe. Detectors with p-type implants 7 μm in diameter are used to constitute the 850-μm-diameter lateral
collection diodes (LCDs). The photodiode architecture is the double-layer planar heterostructure architecture.
Quantum efficiency, I-V, Rd-V, and 1/f noise in photovoltaic Hg1−xCdxTe detectors are critical parameters that limit the sensitivity of infrared sounders. These are some of the parameters used
to select photodiodes that will be part of the CrIS focal plane module (FPM). During fabrication of the FPM, the photodiodes
are subject to a significant amount of handling while transitioning from part of newly processed Hg1–xCdxTe wafers to individual photodiodes mounted in a CrIS FPM ready to be flown on NPOESS. Quantum efficiency, I-V, noise, and
visual inspections are performed at several steps in the detector’s journey. Initial I-V and visual inspections are conducted
at the wafer level followed by I-V, noise, and quantum efficiency after dicing and mounting the photodiodes in leadless chip
carriers (LCCs). A visual inspection is performed following removal of the detectors from the LCCs. Finally, the individual
photodiodes are precision mounted on an FPM base, and I-V, noise, quantum efficiency, and visual inspections are performed
again. Each step in the FPM fabrication process requires handling and environmental conditioning that can result in detector
dark current and noise increase. Some photodiodes on the first flightlike FPMs fabricated exhibited an increase in dark current
and noise characteristics at the FPM level as compared to the measurements performed when the photodiodes were in LCCs prior
to integration into the FPM. The degradation observed resulted in an investigation to discern the cause of the performance
degradation (baking at elevated temperatures, mechanical handling, electrical stress, etc.). This paper outlines the results
of the study and the corrective actions that led to the successful manufacture of LWIR large detectors from material growth
to insertion into flight FPMs for the CrIS program. 相似文献
5.
The photoconductivity degradation rates γ (σ
ph∼t
−γ
) of nondoped, amorphous, hydrated silicon films deposited at T
s
=300–400 °C and subjected to illumination for 5 h at 300 K (light source 100 mW/cm2, λ<0.9 μm) were investigated. It was shown that the degradation rate γ depends on the preillumination position of the Fermi level ɛ
c
−ɛ
F
and often is not directly related to the hydrogen content in the film. It was found that there are correlations between the
value of γ and the bonds in the silicon-hydrogen subsystem [isolated SiH and SiH2 complexes, clusters (SiH)n, and chains (SiH2)n].
Fiz. Tekh. Poluprovodn. 32, 484–489 (April 1998) 相似文献
6.
H. Yoon M. S. Goorsky B. A. Brunett J. M. Van Scyoc J. C. Lund R. B. James 《Journal of Electronic Materials》1999,28(6):838-842
We investigated the resistivity variation of semi-insulating Cd1−xZnxTe used as room temperature nuclear radiation detectors, in relationship to the alloy composition. The resistivity and the
zinc composition were determined using leakage current measurements and triple axis x-ray diffraction lattice parameter measurements,
respectively. While the zinc content of the nominally xZn∼0.1 ingot varied monotonically according to the normal freezing behavior with an effective segregation coefficient of keff=1.15, the resistivity was found to vary non-systematically throughout the ingot. Furthermore, the “expected” relationship
of higher zinc content with higher resistivity was not always observed. For example, wafer regions of xZn∼0.12 and xZn∼0.08 exhibited resistivity values of ∼1010 and ∼1011 Ω·cm, respectively. In general, the experimental resistivity values can be explained by calculated values which take into
account a compensating deep level defect and various electron and hole mobility values. The relative influence of the parameters
that govern the resistivity (n,p, μe, and μh) are quantitatively investigated. 相似文献
7.
L. O. Bubulac W. E. Tennant J. G. Pasko L. J. Kozlowski M. Zandian M. E. Motamedi R. E. De Wames J. Bajaj N. Nayar W. V. McLevige N. S. Gluck R. Melendes D. E. Cooper D. D. Edwall J. M. Arias R. Hall A. I. D’souza 《Journal of Electronic Materials》1997,26(6):649-655
Short wave infrared (SWIR) devices have been fabricated using Rockwell’s double layer planar heterostructure (DLPH) architecture
with arsenic-ion implanted junctions. Molecular beam epitaxially grown HgCdTe/CdZnTe multilayer structures allowed the thin,
tailored device geometries (typical active layer thickness was ∼3.5 μm and cap layer thickness was ∼0.4 μm) to be grown. A
planar-mesa geometry that preserved the passivation advantages of the DLPH structure with enhanced optical collection improved
the performance. Test detectors showed Band 7 detectors performing near the radiative limit (∼3-5X below theory). Band 5 detector
performance was ∼4-50X lower than radiative limited performance, apparently due to Shockley-Hall-Read recombination. We have
fabricated SWIR HgCdTe 256 × 12 × 2 arrays of 45 um × 45 μm detector on 45 μm × 60 μm centers and with cutoff wavelength which
allows coverage of the Landsat Band 5 (1.5−1.75 μm) and Landsat Band 7 (2.08−2.35 μm) spectral regions. The hybridizable arrays
have four subarrays, each having a different detector architecture. One of the Band 7 hybrids has demonstrated performance
approaching the radiative theoretical limit for temperatures from 250 to 295K, consistent with test results. D* performance
at 250K of the best subarray was high, with an operability of ∼99% at 1012 cm Hz1/2/W at a few mV bias. We have observed 1/f noise below 8E-17 AHz 1/2 at 1 Hz. Also for Band 7 test structures, Ge thin film diffractive microlenses fabricated directly on the back side of the
CdZnTe substrate showed the ability to increase the effective collection area of small (nominally <20 μm μm) planar-mesa diodes
to the microlens size of 48 urn. Using microlenses allows array performance to exceed 1-D theory up to a factor of 5. 相似文献
8.
E. M. Verbitskaya V. K. Eremin A. M. Ivanov N. B. Strokan V. I. Vasil'ev V. N. Gavrin E. P. Veretenkin Yu. P. Kozlova V. B. Kulikov A. V. Markov A. Ya. Polyakov 《Semiconductors》2004,38(4):472-479
The characteristics of detectors based on bulk semi-insulating GaAs (SI-GaAs) have been studied by α particle detection and spectrometry. A distinctive feature of these detectors is the dependence
of the width of the space charge region W on reverse bias voltage U. The rate of increase in W(U) is ∼1 μm/V, which permits formation of a sensitive region a few millimeters thick. The main obstacle to applying kilovolt-range
bias voltages U is the reverse current noise. The characteristics of diode structures in which a rectifying barrier to SI-GaAs was formed by metal deposition (Schottky diodes) and by growing heterostructures with heavily doped AlGaAs or GaAsSb
epitaxial layers were compared. Nonequilibrium carrier transport in epitaxial structures capable of sustaining bias voltages
above 1 kV was investigated in both weak (below 1 kV/cm) and strong (10–30 kV/cm) electric fields. In both cases, the carrier
lifetimes were found to be about a few nanoseconds. Such low values are due to the high concentration of trapping centers
(EL2-type native defects), which limits the carrier transport. An analysis of the spectral line shape revealed that the lifetime
is almost constant throughout the detector volume. The charge introduced by a particle was found to be enhanced in fields
of ∼30 kV/cm. This effect can be qualitatively explained by focusing the electric field lines at the vertex of the α-particle
track, which leads to an increase in the local field strength to ∼10−5 V/cm and impact ionization by nonequilibrium electrons.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 38, No. 4, 2004, pp. 490–497.
Original Russian Text Copyright ? 2004 by Verbitskaya, Eremin, Ivanov, Strokan, Vasil'ev, Gavrin, Veretenkin, Kozlova, Kulikov,
Markov, Polyakov. 相似文献
9.
Transformation of luminescence centers in CVD ZnS films subjected to a high hydrostatic pressure 总被引:8,自引:0,他引:8
N. K. Morozova I. A. Karetnikov V. G. Plotnichenko E. M. Gavrishchuk É. V. Yashina V. B. Ikonnikov 《Semiconductors》2004,38(1):36-41
The cathodoluminescence and optical-transmission spectra of ZnS were analyzed to study the effect of a high hydrostatic gas
pressure (1500 atm at 1000°C) on the equilibrium between intrinsic point defects in zinc sulfide grown by chemical vapor deposition
(CVD) with an excess of zinc. The cathodoluminescence spectra were measured at 80–300 K and excitation levels of 1022 and 1026 cm−3 s−1; the optical-transmission spectra were measured at 300 K in the wavelength range 4–12 μm. It is found that exposure to a
high hydrostatic gas pressure transforms the self-activated emission in the cathodoluminescence spectrum: (i) a new short-wave-length
band appears at 415 nm with its intensity increasing by one to three orders of magnitude; and (ii) the long-wavelength band
that peaks at 445 nm and is observed in as-grown crystals becomes quenched. Simultaneously, the cathodoluminescence band peaked
at 850 nm and related to vacancies V
S is no longer observed after high-pressure treatment. These effects are attributed to a partial escape of excess zinc (Zni) from crystals and additional incorporation of oxygen into lattice sites (OS). A doublet band I
1, which peaked at ∼331–332 nm at 80 K and at ∼342–343 nm at 300 K and is related to excitons bound to acceptor levels of oxygen
centers, was observed. This band is found to be dominant in the cathodoluminescence spectrum at an excitation level of 1026 cm−3 s−1. Traces of the ZnO phase are apparent after the high-pressure treatment in both the cathodolumi-nescence spectra (the bands
at 730 and 370 nm) and the transmission spectra (narrow bands in the region of 6–7 μm).
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 38, No. 1, 2004, pp. 39–43.
Original Russian Text Copyright ? 2004 by Morozova, Karetnikov, Plotnichenko, Gavrishchuk, Yashina, Ikonnikov. 相似文献
10.
G. N. Violina E. V. Kalinina G. F. Kholujanov V. G. Kossov R. R. Yafaev A. Hallén A. O. Konstantinov 《Semiconductors》2002,36(6):710-713
The results of studying 4H-SiC p
+-n junctions ion-implanted with aluminum as detectors of high-energy particles are reported. The junctions were formed in SiC
epitaxial films grown by chemical vapor deposition. The concentration of uncompensated donors was (3–5)×1015 cm−3, and the charge-carrier diffusion length was L
p=2.5 μm. The detectors were irradiated with 4.8–5.5-MeV alpha particles at 20°C. The efficiency of collection of the induced
charge was as high as 0.35. The possibilities of operating SiC detectors at elevated temperatures (∼500°C) are analyzed.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 36, No. 6, 2002, pp. 750–753.
Original Russian Text Copyright ? 2002 by Violina, Kalinina, Kholujanov, Kossov, Yafaev, Hallén, Konstantinov. 相似文献
11.
The method of spin-dependent recombination was used to record electron spin resonance (ESR) spectra of recombination centers
in a thin (∼1 μm) surface layer of p-type silicon grown by the Czochralski method and irradiated by protons with energies of ∼100 keV. Spectra of excited triplet
states of the oxygen + vacancy complex (A-centers) were observed along with complexes consisting of two carbon atoms and an interstitial silicon atom (CS-SiI-CS complexes). The intensity of the ESR spectra of these radiation-induced defects was found to be largest at irradiation doses
of ∼1013 cm−2, and decreased with increasing dose, which is probably attributable to passivation of the radiation-induced defects by hydrogen.
Fiz. Tekh. Poluprovodn. 33, 1164–1167 (October 1999) 相似文献
12.
Majid Zandian J. D. Garnett R. E. Dewames M. Carmody J. G. Pasko M. Farris C. A. Cabelli D. E. Cooper G. Hildebrandt J. Chow J. M. Arias K. Vural Donald N. B. Hall 《Journal of Electronic Materials》2003,32(7):803-809
We report on Hg1−xCdxTe mid-wavelength infrared (MWIR) detectors grown by molecular-beam epitaxy (MBE) on CdZnTe substrates. Current-voltage (I-V)
characteristics of HgCdTe-MWIR devices and temperature dependence of focal-plane array (FPA) dark current have been investigated
and compared with the most recent InSb published data. These MWIR p-on-n Hg1−xCdxTe/CdZnTe heterostructure detectors give outstanding performance, and at 68 K, they are limited by diffusion currents. For
temperatures lower than 68 K, in the near small-bias region, another current is dominant. This current has lower sensitivity
to temperature and most likely is of tunneling origin. High-performance MWIR devices and arrays were fabricated with median
RoA values of 3.96 × 1010 Ω-cm2 at 78 K and 1.27 × 1012 Ω-cm2 at 60 K; the quantum efficiency (QE) without an antireflection (AR) coating was 73% for a cutoff wavelength of 5.3 μm at
78 K. The QE measurement was performed with a narrow pass filter centered at 3.5 μm. Many large-format MWIR 1024 × 1024 FPAs
were fabricated and tested as a function of temperature to confirm the ultra-low dark currents observed in individual devices.
For these MWIR FPAs, dark current as low as 0.01 e−/pixel/sec at 58 K for 18 × 18 μm pixels was measured. The 1024 × 1024 array operability and AR-coated QE at 78 K were 99.48%
and 88.3%, respectively. A comparison of these results with the state-of-the-art InSb-detector data suggests MWIR-HgCdTe devices
have significantly higher performance in the 30–120 K temperature range. The InSb detectors are dominated by generation-recombination
(G-R) currents in the 60–120 K temperature range because of a defect center in the energy gap, whereas MWIR-HgCdTe detectors
do not exhibit G-R-type currents in this temperature range and are limited by diffusion currents. 相似文献
13.
M. Aidaraliev N. V. Zotova S. A. Karandashev B. A. Matveev M. A. Remennyi N. M. Stus’ G. N. Talalakin 《Semiconductors》1999,33(6):700-703
We report on a study characterizing internal losses and the gain in InGaAsSb/InAsSbP diode-heterostructure lasers emitting
in the mid-infrared (3–4 μm). Numerical simulations of the current dependence of the intensity of spontaneous emission above
the laser threshold and of the differential quantum efficiency allowed us to determine the intraband absorption k
0 ≈5.6×10−16 cm2. The cavity-length dependence of the threshold current is used to estimate the internal losses at zero injection current
α
0≈5 cm−1. Calculations of the internal losses at laser threshold showed that they increase more than fourfold when the cavity length
is decreased from 500 μm to 100 μm. The temperature dependence of the differential quantum efficiency is explained on the
assumption that intraband absorption with hole transitions into a split-off band occurs. It is shown that the maximum operating
temperature of “short-cavity” lasers is determined by the intraband absorption rather than by Auger recombination. The internal
losses are shown to have a linear current dependence. The separation of the quasi-Fermi levels as a function of current demonstrates
an absence of voltage saturation of the p-n junction above threshold.
Fiz. Tekh. Poluprovodn. 33, 759–763 (June 1999) 相似文献
14.
P. S. Wijewarnasuriya M. Zandian J. Phillips D. Edwall R. E. Dewames G. Hildebrandt J. Bajaj J. M. Arias A. I. D’Souza F. Moore 《Journal of Electronic Materials》2002,31(7):726-731
State-of-the-art large-area photovoltaic (PV) detectors fabricated in HgCdTe grown by molecular beam epitaxy (MBE) have been
demonstrated for the Crosstrack Infrared Sounder (CrIS) instrument. Large-area devices (1 mm in diameter) yielded excellent
electrical and optical performance operating at 81 K for λc ∼ 15 μm, at 98 K for λc ∼ 9 μm, and λc ∼ 5-μm spectral cutoffs. Fabricated detectors have near-theoretical electrical performance, and Anti Reflection coated quantum
efficiency (QE) is greater than 0.70. Measured average R0A at 98 K is 2.0E7 Ωcm2, and near-theoretical QEs greater than 0.90 were obtained on detectors with λc ∼ 5-μm spectral cutoffs. These state-of-the-art large-area PV detector results reflect high-quality HgCdTe grown by MBE on
CdZnTe substrates in all three spectral bands of interest. 相似文献
15.
The results of a photoreflectance spectroscopy study of Ga2Se3/n-GaAs samples prepared by long-term annealing of GaAs wafers (n≈1017 cm−3) in a Se-vapor atmosphere are presented. It was established that no photovoltage appears in the interface region of these
structures under illumination. Photogeneration of the charge carriers in the substrate does not lead to a change in the Fermi
level position at the interface, with only the depth of the space-charge region being modulated. The quantitative analysis
of the spectra also indicates that the growth of a thick (∼ 1 μm) Ga2Se3 layer does not result in the expected shift of the Fermi level position in comparison to the natural oxide-covered surface.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 36, No. 7, 2002, pp. 838–842.
Original Russian Text Copyright ? 2002 by Kuz’menko, Domashevskaya. 相似文献
16.
Our earlier reports concerning the fabrication by liquid-phase epitaxy and investigation of InAsSbP/InAsSb/InAsSbP double
heterostructure lasers emitting at 3–4 μm are reviewed. The dependences of spectral characteristics and the spatial distribution
of the laser emission on temperature and current are discussed. Lasing modes are shifted by 0.5–1.0 cm−1 to longer wavelengths with increasing temperature. The tuning of the lasing modes by means of current is very fast (10−8–10−12 s). With increasing current, the modes are shifted to shorter wavelengths by 50–60 ? at 77 K. The maximum mode shift of 104
? (10 cm−1) is observed at 62 K. The spectral line width of the laser is as narrow as 10 MHz. Abnormally narrow directional patterns
in the p-n junction plane are observed in some cases in the spatial distribution of laser emission. The current tuning of lasers, due
to nonlinear optical effects, has been modeled mathematically in good agreement with the experiment. Transmittance spectra
of OCS, NH3, H2O, CH3Cl, and N2O gases were recorded using current-tuned lasers.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 35, No. 12, 2001, pp. 1466–1480.
Original Russian Text Copyright ? 2001 by Danilova, Imenkov, Kolchanova, Yakovlev.
See [1]. 相似文献
17.
Piyas Samanta 《半导体学报》2017,38(10):104001-6
The conduction mechanism of gate leakage current through thermally grown silicon dioxide (SiO2) films on (100) p-type silicon has been investigated in detail under negative bias on the degenerately doped n-type polysilicon (n+-polySi) gate. The analysis utilizes the measured gate current density JG at high oxide fields Eox in 5.4 to 12 nm thick SiO2 films between 25 and 300℃. The leakage current measured up to 300℃ was due to Fowler–Nordheim (FN) tunneling of electrons from the accumulated n+-polySi gate in conjunction with Poole Frenkel (PF) emission of trapped-electrons from the electron traps located at energy levels ranging from 0.6 to 1.12 eV (depending on the oxide thickness) below the SiO2 conduction band (CB). It was observed that PF emission current IPF dominates FN electron tunneling current IFN at oxide electric fields Eox between 6 and 10 MV/cm and throughout the temperature range studied here. Understanding of the mechanism of leakage current conduction through SiO2 films plays a crucial role in simulation of time-dependent dielectric breakdown (TDDB) of metaloxide–semiconductor (MOS) devices and to precisely predict the normal operating field or applied gate voltage for lifetime projection of the MOS integrated circuits. 相似文献
18.
The leakage current I
p
over the surface of CdxHg1−x
Te-based photodiodes that have a cutoff wavelength of the photosensitivity spectrum of λ=9.8–11.6 μm and are fabricated by
implanting Zn++ ions into the p-type solid solution is investigated. The surface character of the I
p
current is indicated by a coordinate shift of the peak in the sensitivity profile of n
+-p junctions, which is measured in a scanning mode by the beam of a CO2 laser with a wavelength of 10.6 μm, with an increase in voltage U across the photodiode and the shift of spectral characteristics to shorter wavelengths with increasing U.
__________
Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 38, No. 7, 2004, pp. 890–895.
Original Russian Text Copyright ? 2004 by Biryulin, Turinov, Yakimov. 相似文献
19.
P. Mitra F. C. Case M. B. Reine T. Parodos S. P. Tobin P. W. Norton 《Journal of Electronic Materials》1999,28(6):589-595
New results are reported on the growth of high performance medium wavelength infrared (3–5 μm) (MWIR) HgCdTe photodiodes in
the three-layer P-n-N configuration. The detector structures were grown in situ by metalorganic vapor phase epitaxy (MOVPE) on (211)B oriented CdZnTe substrates. The mobilities of the single n-type layers
with x-values of ∼0.30 are in the range of (3–4.5)×104 cm2/V-s at 80K. The lifetimes on unpassivated films range from 1–5 and 4–10 μs at 80 and 180K, respectively, which are within
a factor of two or less of the lifetimes calculated for Auger-1 and radiative recombination. The P-n-N films were processed
into variable-area backside-illuminated diagnostic arrays and tested for quantum efficiency, spectral response, RDA, I–V curves and 1/f noise in the 120–180K range. The internal one-dimensional quantum efficiencies are in the range of 85–100%.
The optical collection lengths are typically ∼25 μm. I–V curves showed that diffusion current is the dominant junction current
mechanism for temperatures ≥100K. R0A values are at the one-dimensional limit for n-side diffusion currents over the 100–180K range. 1/f noise was measured to
be very low at 120K and is the same as that measured in similarly processed arrays from recent LPE grown P-on-N heterojunctions.
The results demonstrate that MOVPE growth can be used for large area, high performance MWIR HgCdTe detector arrays operating
in the 120–180K temperature range. 相似文献
20.
C. T. Elliott N. T. Gordon R. S. Hall T. J. Phillips C. L. Jones A. Best 《Journal of Electronic Materials》1997,26(6):643-648
We have studied the 1/f noise current in narrow gap semiconductor heterostructure diodes fabricated in mercury cadmium telluride
(HgCdTe) and designed to operate in a non-equilibrium mode at room temperature. HgCdTe heterostructure diodes exhibit Auger
suppression giving current-voltage characteristics with high peak-to-valley ratios (up to 35), and low extracted saturation
current densities (e.g., 20 Acnr−2 at 10 pm at 295K) but high 1/f knee frequencies (e.g., 100 MHz at 10 μm at 295K). A comparison is made with the noise levels
found in room temperature non-equilibrium mode heterostructure InAlSb/InSb diodes. The devices are being used at high frequencies
for CO2 laser heterodyne detector demonstrators. For the devices to be useful in low frame-rate imaging arrays, the 1/f noise level
must be sufficiently low that the signal is not swamped. Ideally, the knee frequency should be below the frame rate. The relationship
between the noise current and reverse bias voltage, current density, and temperature will be examined in order to attempt
to identify the principal 1/f generation mechanisms. 相似文献