共查询到20条相似文献,搜索用时 46 毫秒
1.
A. Chandolu D. Y. Song M. E. Holtz I. Gherasoiu S. A. Nikishin A. Bernussi M. W. Holtz 《Journal of Electronic Materials》2009,38(4):557-562
We report studies of InN grown by plasma-assisted molecular beam epitaxy. GaN templates were first grown on sapphire substrates
followed by InN overgrown at 457°C to 487°C. Atomic force microscopy shows the best layers to exhibit step-flow growth mode
of the InN, with a root-mean-square roughness of 0.7 nm for the 2 μm × 2 μm scan and 1.4 nm for the 5 μm × 5 μm scan.␣Measurements of the terrace edges indicate a step height of 0.28 nm. Hall measurements at room temperature give mobilities
ranging from 1024 cm2/V s to 1904 cm2/V s and the electron concentrations are in the range of 5.9 × 1017 cm−3 to 4.2 × 1018 cm−3. Symmetric and asymmetric reflection x-ray diffraction measurements were performed to obtain lattice constants a␣and c. The corresponding hydrostatic and biaxial stresses are found to range from −0.08 GPa to −0.29 GPa, and −0.05 GPa to −0.32 GPa,
respectively. Low-temperature photoluminescence peak energies range from 0.67 eV to 0.70 eV, depending on residual biaxial
stress, hydrostatic pressure, and electron concentrations. The electron concentration dependence of the estimated Fermi level
is analyzed using Kane’s two-band model and conduction-band renormalization effects. 相似文献
2.
C.L. Canedy W.W. Bewley J.R. Lindle J.A. Nolde D.C. Larrabee C.S. Kim M. Kim I. Vurgaftman J.R. Meyer 《Journal of Electronic Materials》2008,37(12):1780-1785
We report an experimental investigation of four interband cascade lasers with wavelengths spanning the mid-infrared spectral
range, i.e., 2.9 μm to 5.2 μm, near room temperature in pulsed mode. One broad-area device had a pulsed threshold current density of only 3.8 A/cm2 at 78 K (λ = 3.6 μm) and 590 A/cm2 at 300 K (λ = 4.1 μm). The room-temperature threshold for the shortest-wavelength device (λ = 2.6 μm to 2.9 μm) was even lower, 450 A/cm2. A␣cavity-length study of the lasers emitting at 3.6 μm to 4.1 μm yielded an internal loss varying from 7.8 cm−1 at 78 K to 24 cm−1 at 300 K, accompanied by a decrease of the internal efficiency from 77% to 45%. 相似文献
3.
Takeyasu Saito Kyung-ho Park Kazuyuki Hirama Hitoshi Umezawa Mitsuya Satoh Hiroshi Kawarada Zhi-Quan Liu Kazutaka Mitsuishi Kazuo Furuya Hideyo Okushi 《Journal of Electronic Materials》2011,40(3):247-252
A H-terminated surface conductive layer of B-doped diamond on a (111) surface was used to fabricate a metal–oxide–semiconductor
field-effect transistor (MOSFET) using an electron beam evaporated SiO2 or Al2O3 gate insulator and a Cu-metal stacked gate. When the bulk carrier concentration was approximately 1015/cm3 and the B-doped diamond layer was 1.5 μm thick, the surface carrier mobility of the H-terminated surface on the (111) diamond before FET processing was 35 cm2/Vs and the surface carrier concentration was 1.5 × 1013/cm2. For the SiO2 gate (0.76 μm long and 50 μm wide), the maximum measured drain current at a gate voltage of −3.0 V was −75 mA/mm and the maximum transconductance was
24 mS/mm, and for the Al2O3 gate (0.64 μm long and 50 μm wide), these features were −86 mA/mm and 15 mS/mm, respectively. These values are among the highest reported direct-current
(DC) characteristics for a diamond homoepitaxial (111) MOSFET. 相似文献
4.
C. L. Canedy J. R. Lindle W. W. Bewley C. S. Kim M. Kim J. A. Nolde I. Vurgaftman J. R. Meyer 《Journal of Electronic Materials》2009,38(9):1948-1951
We report a detailed experimental investigation of five interband cascade lasers with five active stages each and emitting
at wavelengths between 3.2 μm and 4.2 μm at room temperature. Pulsed threshold current densities as low as 394 A/cm2 and voltage efficiencies as high as 76% are obtained at 300 K. The low pulsed threshold power densities (0.9–1.6 kW/cm2 at 300 K) imply that ambient-temperature cw operation should be possible over the entire spectral band once optimized narrow
ridges can be fabricated. 相似文献
5.
A. Y. Polyakov N. B. Smirnov A. V. Govorkov A. P. Zhang F. Ren S. J. Pearton J. -I. Chyi T. -E. Nee C. -C. Chou C. -M. Lee 《Journal of Electronic Materials》2001,30(3):147-155
GaN p-i-n rectifiers with 4 μm thick i-layers show typical reverse breakdown voltages of 100–600 V. We have studied the temperature
dependence of current-voltage characteristics in these diodes, along with hole diffusion lengths and the deep level defects
present. Generally we find that i-layer background doping varies significantly (from <1014 cm−3 to 2–3×1016), which influences the current conduction mechanisms. The hole diffusion lengths were in the range 0.6–0.8 μm, while deep
level concentrations were ∼1016 cm−3. 相似文献
6.
Dissipation loss of electromagnetic radiation with wavelengths of 20–55 μm was theoretically studied in a three-layer planar
dielectric insulating waveguide combined with a heterolaser. It was shown that the dependence of the loss on the waveguide
layer thickness behaves differently for different wavelengths in the range of 20–55 μm. The lowest loss (several inverse centimeters)
is characteristic of radiation with wavelength λ = 20 μm. The losses increase with the wavelength and reach a value of 150 cm-1 at λ = 40 μm, which is almost independent of the waveguide layer thickness. For electromagnetic radiation with λ = 50 and 55 μm, a sharp (hundreds of times) decrease in the loss with an increase in the waveguide layer thickness is observed. 相似文献
7.
8.
M. Reddy J. M. Peterson S. M. Johnson T. Vang J. A. Franklin E. A. Patten W. A. Radford J. W. Bangs D. D. Lofgreen 《Journal of Electronic Materials》2009,38(8):1764-1770
This paper presents the progress in the molecular beam epitaxy (MBE) growth of HgCdTe on large-area Si and CdZnTe substrates
at Raytheon Vision Systems. We report a very high-quality HgCdTe growth, for the first time, on an 8 cm × 8 cm CdZnTe substrate.
This paper also describes the excellent HgCdTe growth repeatability on multiple 7 cm × 7 cm CdZnTe substrates. In order to
study the percentage wafer area yield and its consistency from run to run, small lots of dual-band long-wave infrared/long-wave
infrared triple-layer heterojunction (TLHJ) layers on 5 cm × 5 cm CdZnTe substrates and single-color double-layer heterojunction
(DLHJ) layers on 6-inch Si substrates were grown and tested for cutoff wavelength uniformity and micro- and macrovoid defect
density and uniformity. The results show that the entire lot of 12 DLHJ-HgCdTe layers on 6-inch Si wafers meet the testing
criterion of cutoff wavelength within the range 4.76 ± 0.1 μm at 130 K and micro- and macrovoid defect density of ≤50 cm−2 and 5 cm−2, respectively. Likewise, five out of six dual-band TLHJ-HgCdTe layers on 5 cm × 5 cm CdZnTe substrates meet the testing criterion
of cutoff wavelength within the range 6.3 ± 0.1 μm at 300 K and micro- and macrovoid defect density of ≤2000 cm−2 and 500 cm−2, respectively, on the entire wafer area. Overall we have found that scaling our HgCdTe MBE process to a 10-inch MBE system
has provided significant benefits in terms of both wafer uniformity and quality. 相似文献
9.
J.R. Lindle W.W. Bewley I. Vurgaftman J.R. Meyer M.L. Thomas W.E. Tennant D.D. Edwall E. Piquette 《Journal of Electronic Materials》2007,36(8):988-992
We used an InSb radiometric thermal imager to characterize the performance of 1″ × 1″ negative luminescent (NL) arrays. The
devices grown on both CdZnTe (two arrays) and silicon (three arrays) as substrates have cut-off wavelengths ranging from 5.3 μm
to 6.0 μm. The reverse-bias saturation current densities range from 0.3 A cm−2 (λ
co = 5.3 μm) to 1 A cm−2 (λ
co = 6.0 μm). The apparent array temperatures decrease by 37.9 K to 42.8 K under reverse bias, which corresponds to external
NL efficiencies of 80–85%. Most of the inefficiency results from the non-ideal AR coating, whose reflectivity is ≈15% when
weighted over the black body and atmospheric transmission spectra. It is highly encouraging that both the electrical and NL
properties are slightly superior for the devices grown on silicon substrates. 相似文献
10.
E. A. Patten P. M. Goetz M. F. Vilela K. Olsson D. D. Lofgreen J. G. Vodicka S. M. Johnson 《Journal of Electronic Materials》2010,39(10):2215-2219
HgCdTe grown on large-area Si substrates allows for larger array formats and potentially reduced focal-plane array (FPA) cost
compared with smaller, more expensive CdZnTe substrates. The goal of this work is to evaluate the use of HgCdTe/Si for mid-wavelength/long-wavelength
infrared (MWIR/LWIR) dual-band FPAs. A series of MWIR/LWIR dual-band HgCdTe triple-layer n-P-n heterojunction (TLHJ) device structures were grown by molecular-beam epitaxy (MBE) on 100-mm (211)Si substrates. The wafers
showed low macrodefect density (<300 cm−2) and was processed into 20-μm-unit-cell 640 × 480 detector arrays which were mated to dual-band readout integrated circuits (ROICs) to produce FPAs. The
measured 80-K cutoff wavelengths were 5.5 μm for MWIR and 9.4 μm for LWIR, respectively. The FPAs exhibited high pixel operabilities in each band, with noise equivalent differential temperature
(NEDT) operabilities of 99.98% for the MWIR band and 99.6% for the LWIR band demonstrated at 84 K. 相似文献
11.
A. A. Andronov Yu. N. Nozdrin A. V. Okomel’kov V. S. Varavin N. N. Mikhailov G. Yu. Sidorov 《Semiconductors》2010,44(4):457-462
The main requirements for optimization of the MCT-based (Cd
x
Hg1 − x
Te-based) structures for an increase in the wavelength of the stimulated radiation from them under optical pumping are discussed.
The emergence of stimulated radiation in MCT range of 2–2.5 μm at room temperature for optimized MCT structures grown on GaAs
substrates using the method of molecular beam epitaxy is shown experimentally. The obtained experimental data are the first
results of observation of stimulated radiation from the MCT structures at these wavelengths at room temperature. The gain
factor in the active medium measured for this case is very large and attains values of 50 cm−1, which allows one to hope that a further advance to a longer wavelengths is possible. 相似文献
12.
C. Navone M. Soulier M. Plissonnier A. L. Seiler 《Journal of Electronic Materials》2010,39(9):1755-1759
In major applications, optimal power will be achieved when thermoelectric films are at least 100 μm thick. In this paper we demonstrate that screen-printing is an ideal method to deposit around 100 μm of (Bi,Sb)2(Te,Se)3-based films on a rigid or flexible substrate with high Seebeck coefficient value (90 μV K−1 to 160 μV K−1) using a low-temperature process. Conductive films have been obtained after laser annealing and led to acceptable thermoelectric
performance with a power factor of 0.06 μW K−2 cm−1. While these initial material properties are not at the level of bulk materials, the complete manufacturing process is cost-effective,
compatible with large surfaces, and affords a mass-production technique. 相似文献
13.
X. Wang Y. Ezzahri Z. Bian M. Zebarjadi A. Shakouri J. Klem G. Patrizi E.W. Young S.D. Mukherjee 《Journal of Electronic Materials》2009,38(7):1309-1314
The experimental characterization of single barrier heterostructure thermionic cooling devices at cryogenic temperatures is
reported. The device studied was a cylindrical InGaAs microrefrigerator, in which the active layer was a 1 μm thick In0.527Al0.218Ga0.255As heterostructure barrier with n-type doping concentration of 6.68 × 1016 cm−3 and an In0.53Ga0.47As emitter/collector of 5 × 1018 cm−3
n-doping. A full field thermoreflectance imaging technique was used to measure the distribution of temperature change on the
device’s top surface when different current excitation values were applied. By reversing the current direction, we studied
the device’s behavior in both cooling and heating regimes. At an ambient temperature of 100 K, a maximum cooling of 0.6 K
was measured. This value was approximately one-third of the measured maximum cooling value at room temperature (1.8 K). The
paper describes the device’s structure and the first reported thermal imaging at cryogenic temperatures using the thermoreflectance
technique. 相似文献
14.
Status of LWIR HgCdTe-on-Silicon FPA Technology 总被引:1,自引:0,他引:1
M. Carmody J.G. Pasko D. Edwall E. Piquette M. Kangas S. Freeman J. Arias R. Jacobs W. Mason A. Stoltz Y. Chen N.K. Dhar 《Journal of Electronic Materials》2008,37(9):1184-1188
The use of silicon as an alternative substrate to bulk CdZnTe for epitaxial growth of HgCdTe for infrared detector applications
is attractive because of potential cost savings as a result of the large available sizes and the relatively low cost of silicon
substrates. However, the potential benefits of silicon as a substrate have been difficult to realize because of the technical
challenges of growing low-defect-density HgCdTe on silicon where the lattice mismatch is ∼19%. This is especially true for
long-wavelength infrared (LWIR) HgCdTe detectors where the performance can be limited by the high (∼5 × 106 cm−2) dislocation density typically found in HgCdTe grown on silicon. The current status of LWIR (9 μm to 11 μm at 78 K) HgCdTe on silicon focal-plane arrays (FPAs) is reviewed. Recent progress is covered including improvements in noise
equivalent differential temperature (NEDT) and array operability. NEDT of <25 mK and NEDT operability >99% are highlighted
for 640 × 480 pixel, 20-μm-pitch FPAs. 相似文献
15.
Fritz Keilmann Sergiu Amarie 《Journal of Infrared, Millimeter and Terahertz Waves》2012,33(5):479-484
We describe a coherent mid-infrared continuum source with 700 cm-1 usable bandwidth, readily tuned within 600–2500 cm-1 (4–17 μm) and thus covering much of the infrared "fingerprint" molecular vibration region. It is based on nonlinear frequency
conversion in GaSe using a compact commercial 100-fs-pulsed Er fiber laser system providing two amplified near-infrared beams,
one of them broadened by a nonlinear optical fiber. The resulting collimated mid-infrared continuum beam of 1 mW quasi-cw
power represents a coherent infrared frequency comb with zero carrier-envelope phase, containing about 500,000 modes that
are exact multiples of the pulse repetition rate of 40 MHz. The beam's diffraction-limited performance enables long-distance
spectroscopic probing as well as maximal focusability for classical and ultraresolving near-field microscopies. Applications
are foreseen also in studies of transient chemical phenomena even at ultrafast pump-probe scale, and in high-resolution gas
spectroscopy for e.g. breath analysis. 相似文献
16.
B. Krishnan S.P. Kotamraju G. Melnychuk H. Das J. N. Merrett Y. Koshka 《Journal of Electronic Materials》2010,39(1):34-38
In this work, heavily aluminum (Al)-doped layers for ohmic contact formation to p-type SiC were produced by utilizing the high efficiency of Al incorporation during the epitaxial growth at low temperature,
previously demonstrated by the authors’ group. The low-temperature halo-carbon epitaxial growth technique with in situ trimethylaluminum (TMA) doping was used. Nearly featureless epilayer morphology with an Al atomic concentration exceeding
3 × 1020 cm−3 was obtained after growth at 1300°C with a growth rate of 1.5 μm/h. Nickel transfer length method (TLM) contacts with a thin adhesion layer of titanium (Ti) were formed. Even prior to contact
annealing, the as-deposited metal contacts were almost completely ohmic, with a specific contact resistance of 2 × 10−2 Ω cm2. The specific contact resistance was reduced to 6 × 10−5 Ω cm2 by employing a conventional rapid thermal anneal (RTA) at 750°C. Resistivity of the epitaxial layers better than 0.01 Ω cm
was measured for an Al atomic concentration of 2.7 × 1020 cm−3. 相似文献
17.
M.B. Reine J.W. Marciniec K.K. Wong T. Parodos J.D. Mullarkey P.A. Lamarre S.P. Tobin R.W. Minich K.A. Gustavsen M. Compton G.M. Williams 《Journal of Electronic Materials》2008,37(9):1376-1386
This article reports new characterization data for large-area (250 μm × 250 μm) back-illuminated planar n-on-p HgCdTe electron-initiated avalanche photodiodes (e-APDs). These e-APDs were fabricated in p-type HgCdTe films grown by liquid-phase epitaxy (LPE) on CdZnTe substrates. We previously reported that these arrays exhibit
gain that increases exponentially with reverse bias voltage, with gain-versus-bias curves that are quite uniform from element
to element, and with a maximum gain of 648 at −11.7 V at 160 K for a cutoff wavelength of 4.06 μm. Here we report new data on these planar e-APDs. Data from a third LPE film with a longer cutoff wavelength (4.29 μm at 160 K) supports the exponential dependence of gain on cutoff wavelength, for the same bias voltage, that we reported
for the first two films (with cutoffs of 3.54 μm and 4.06 μm at 160 K), in agreement with Beck’s empirical model for gain versus voltage and cutoff wavelength in HgCdTe e-APDs. Our
lowest gain-normalized current density at 80 K and zero field-of-view is 0.3 μA/cm2 at −10.0 V for a cutoff of 4.23 μm at 80 K. We report data for the temperature dependence of gain over 80 K to 200 K. We report, for the first time, the dependence
of measured gain on junction area for widely spaced circular diodes with radii of 20 μm to 175 μm. We interpret the variation of measured gain with junction area in terms of an edge-enhanced electric field, and fit the
data with a two-gain model having a lower interior gain and a higher edge gain. We report data for the excess noise factor
F(M) near unity for gains up to 150 at 196 K. We describe the abrupt breakdown phenomenon seen in most of our devices at high
reverse bias. 相似文献
18.
The current response of a TlBr detector to 137Cs γ-ray radiation has been studied in the dose-rate range 0.033–3.84 Gy/min and within the voltage range 1–300 V; the detectors
are based on pure and doped TlBr crystals grown from the melt by the Bridgman-Stockbarger method. The mass fraction of Pb
or Ca introduced into the TlBr crystals was 1–10 ppm for Pb and 150 ppm for Ca. The current response of nominally undoped
TlBr samples was nearly linear over two decades of studied dose rates. Deep hole levels associated with cationic vacancies
V
c
− determine the dependence of the current response on the voltage in the high electric fields. The parameters of the carriers’
transport μτ are determined. The TlBr crystals grown in vacuum and in the bromine vapor exhibit a large mobility-lifetime
product of 4.3 × 10−4 and 6.4 × 10−5 cm2V−1, respectively. The value of μτ is in the range (4–9) × 10−5 cm2V−1 for crystals doped with a divalent cation. 相似文献
19.
Low-Noise Mid-Wavelength Infrared Avalanche Photodiodes 总被引:1,自引:0,他引:1
Siddhartha Ghosh Shubhrangshu Mallick Koushik Banerjee Christoph Grein Silviu Velicu Jun Zhao Don Silversmith Jean Baptist Rodriguez Elena Plis Sanjay Krishna 《Journal of Electronic Materials》2008,37(12):1764-1769
Mid-wavelength infrared (MWIR) p
+–n
−–n
+ avalanche photodiodes (APDs) were fabricated using two materials systems, one with mercury cadmium telluride (HgCdTe) on
a silicon (Si) substrate and the other with an indium arsenide/gallium antimonide (InAs/GaSb) strained layer superlattice
(SLS). Diode characteristics, avalanche characteristics, and excess noise factors were measured for both sets of devices.
Maximum zero-bias resistance times active area (R
0
A) of 3 × 106 Ω cm2 and 1.1 × 106 Ω cm2 and maximum multiplication gains of 1250 at −10 V and 1800 at −20 V were measured for the HgCdTe and the SLS, respectively,
at 77 K. Gains reduce to 200 in either case at 120 K. Excess noise factors were almost constant with increasing gain and were
measured in the range of 1 to 1.2. 相似文献
20.
L. A. Almeida M. Thomas W. Larsen K. Spariosu D. D. Edwall J. D. Benson W. Mason A. J. Stoltz J. H. Dinan 《Journal of Electronic Materials》2002,31(7):669-676
We report the development and fabrication of two-color mid-wavelength infrared (MWIR) and short-wavelength infrared (SWIR)
HgCdTe-based focalplane arrays (FPAs). The HgCdTe multilayers were deposited on bulk CdZnTe (ZnTe mole fraction ∼3%) using
molecular beam epitaxy (MBE). Accurate control of layer composition and growth rate was achieved using in-situ spectroscopic
ellipsometry (SE). Epilayers were evaluated using a variety of techniques to determine suitability for subsequent device processing.
These techniques included Fourier transform infrared (FTIR) spectroscopy, Hall measurement, secondary ion mass spectroscopy
(SIMS), defect-decoration etching, and Nomarski microscopy. The FTIR transmission measurements confirmed SE’s capability to
provide excellent compositional control with run-to-run x-value variations of ∼0.002. Nomarski micrographs of the as-grown
surfaces featured cross-hatch patterns resulting from the substrate/epilayer lattice mismatch as well as various surface defects
(voids and “microvoids”), whose densities ranged from 800–8,000 cm−2. A major source of these surface defects was substrate particulate contamination. Epilayers grown following efforts to reduce
these particulates exhibited significantly lower densities of surface defects from 800–1,700 cm−2. Dislocation densities, as revealed by a standard defect-decoration etch, were 2–20×105 cm−2, depending on substrate temperature during epitaxy. The FPAs (128×128) were fabricated from these epilayers. Preliminary
performance results will be presented. 相似文献