共查询到20条相似文献,搜索用时 31 毫秒
1.
Extrinsic p-type doping during molecular-beam epitaxy (MBE) growth represents an essential generic toolbox for advanced heterostructures
based on the HgCdTe material system: PiN diodes, mesa avalanche photodiodes (APD) or third-generation multispectral focal-plane
arrays. Today, arsenic appears to be the best candidate to fulfill this role and our group is actively working on its incorporation
during MBE growth, using an original radio frequency (RF) plasma source for arsenic. Such a cell is supposed to deliver a
monatomic As flux, and as expected we observed high As electrical activation rates after annealing short-wave (SW), mid-wave
(MW), and long-wave (LW) layers. At last, a couple of technological runs have been carried out in the MW range in order to
validate the approach on practical devices. p-on-n focal-plane arrays (FPA) have been fabricated using a mesa delineated technology on an As-on-In doped metallurgical heterojunction
layer grown on a lattice-matched CdZnTe layer (320 × 256, 30 μm pitch, 5 μm cutoff at 77 K). Observed diodes exhibit very interesting electro-optical characteristics: large shunt impedance, high quantum
efficiency, and no noticeable excess noise. The resulting focal-plane arrays were observed to be very uniform, leading to
high operabilities. Noise equivalent temperature difference (NETD) distributions are very similar to those observed with the
As ion-implanted p-on-n technology, fabricated in our laboratory as well. In our opinion, those excellent results demonstrate the feasibility of
our MBE in situ arsenic doping process. Good electrical activation rates and high-quality layers can be obtained. We believe that such an
approach allows precise control of the p-doping profile in the HgCdTe layer, which is necessary for advanced structure designs. 相似文献
2.
A. A. Lebedev A. M. Strel’chuk D. V. Davydov N. S. Savkina A. S. Tregubova A. N. Kuznetsov V. A. Solov’ev N. K. Poletaev 《Semiconductors》2003,37(4):482-484
Sublimation epitaxy in a vacuum has been employed to grow n-and p-type 3C-SiC layers on 6H-SiC substrates. Diodes have been fabricated on the basis of the p-n structure obtained, and their parameters have been studied by measuring their current-voltage and capacitance-voltage characteristics and by applying the DLTS and electroluminescence methods. It is shown that the characteristics of the diodes studied are close to those of diodes based on bulk 3C-SiC. A conclusion is made that sublimation epitaxy can be used to fabricate 3C-SiC p-n structures on substrates of other silicon carbide polytypes. 相似文献
3.
Sh. O. Eminov 《Semiconductors》2016,50(8):1005-1009
The optical absorption coefficient α in p+-InSb layers (with hole concentrations of p ≈ 1 × 1017–1.2 × 1019 cm–3), grown by liquid-phase epitaxy on p-InSb substrates, is measured in the spectral range of 5-12 µm at 90 K, and the impurity photoconductivity is measured (at 60 and 90 K) in p+–p structures. It is found that a in the p+ layers reaches a value of 7000 cm–1 (at p ≈ 2 × 1019 cm–1). It is shown that the measured substrate value of (α ≈1–3 cm–1) is overestimated in comparison with estimates (α ≈ 0.1 cm–1) based on comparing the photoconductivity data. This discrepancy is explained by the fact that the optical transitions of holes responsible for photoconductivity are obscured by the excitation of electrons to the conduction band. The photoionization cross section for these transitions does not exceed 1 × 10–15 cm2. 相似文献
4.
G. A. Il’chuk S. E. Nikitin Yu. A. Nikolaev V. Yu. Rud’ Yu. V. Rud’ E. I. Terukov 《Semiconductors》2005,39(2):218-220
n-ZnO:Al/PbPc/p-Si photosensitive structures are fabricated for the first time. The steady-state current-voltage characteristics and spectral dependences of the relative quantum efficiency of the photoconversion of these structures are studied, and the mechanisms of charge transport and the photosensitivity processes are discussed. It is concluded that they are promising for application as multiband photoconverters of natural light. 相似文献
5.
G. I. Ayzenshtat A. Y. Yushenko S. M. Gushchin D. V. Dmitriev K. S. Zhuravlev A. I. Toropov 《Semiconductors》2010,44(10):1362-1364
It is established that the radiative recombination of charge carriers plays a substantial role in the GaAs-based p-i-n diodes at high densities of the forward current. It is shown experimentally that the diodes operating in microwave integrated
circuits intensely emit light in the IR range with wavelengths from 890 to 910 nm. The obtained results indicate the necessity
of taking into account the features of recombination processes in the GaAs-based microwave p-i-n diodes. 相似文献
6.
N. D. Stoyanov B. E. Zhurtanov A. N. Imenkov A. P. Astakhova M. P. Mikhaĭlova Yu. P. Yakovlev 《Semiconductors》2007,41(7):855-859
A new type of light-emitting diodes (LEDs), a high-efficiency device based on an n-GaSb/p-GaSb/n-GaInAsSb/P-AlGaAsSb thyristor heterostructure, with the maximum emission intensity at wavelength λ = 1.95 μm, has been suggested and its electrical and luminescent characteristics have been studied. It is shown that the effective radiative recombination in the thyristor structure in the n-type GaInAsSb active region is provided by double-sided injection of holes from the neighboring p-type regions. The maximum internal quantum efficiency of 77% was achieved in the structure under study in the pulsed mode. The average optical power was as high as 2.5 mW, and the peak power in the pulsed mode was 71 mW, which exceeded by a factor of 2.9 the power obtained with a standard n-GaSb/n-GaInAsSb/P-AlGaAsSb LED operating in the same spectral range. The approach suggested will make it possible to improve LED parameters in the entire mid-IR spectral range (2–5 μm). 相似文献
7.
M. P. Mikhailova I. A. Andreev G. G. Konovalov L. V. Danilov E. V. Ivanov E. V. Kunitsyna N. D. Il’inskaya R. V. Levin B. V. Pushnyi Yu. P. Yakovlev 《Semiconductors》2018,52(8):1037-1042
Significant photocurrent/photoconductivity amplification is observed at low reverse biases in a type-II n-GaSb/InAs/p-GaSb heterostructure with a single quantum well (QW), grown by metal-organic vapor phase epitaxy. A sharp increase in the photocurrent by more than two orders of magnitude occurs under exposure of the heterostructure to monochromatic light with a wavelength of 1.2–1.6 μm (at 77 K) and the application of a reverse bias in the range 5–200 mV. The optical gain depends on the applied voltage and increases to 2.5 × 102 at a reverse bias of 800 mV. Theoretical analysis demonstrated that the main role in the phenomenon is played by the screening of the external electric field by electrons accumulated in the deep InAs QW and by the mechanism of the tunneling transport of carriers with a small effective mass. It is shown that the effect under study is common to both isotype and anisotype type-II heterojunctions, including structures with QWs and superlattices. 相似文献
8.
R. Wollrab A. Bauer H. Bitterlich M. Bruder S. Hanna H. Lutz K.-M. Mahlein T. Schallenberg J. Ziegler 《Journal of Electronic Materials》2011,40(8):1618-1623
Mainly driven by space applications, mercury cadmium telluride (MCT) focal-plane arrays (FPAs) have been successfully developed
for very long wavelengths (λ
CO > 14 μm at 55 K). For this purpose, the standard n-on-p technology based on MCT grown by liquid-phase epitaxy (LPE) and involving vacancy doping has been modified to extrinsic doping
by a monovalent acceptor. Due to the planar diode geometry obtained by ion implantation, most of the carrier generation volume
is located in the p-type region with a thickness of approximately 8 μm. According to our understanding, the Shockley–Read centers connected with the Hg vacancies are thus significantly reduced.
This situation should lead to longer minority-carrier lifetimes and smaller generation rates under equilibrium conditions,
therefore yielding lower dark current. We indeed observe a reduction by a factor of approximately 15 by using extrinsic doping.
Recent dark current data obtained in the temperature range from 55 K to 85 K on 288 × 384 FPAs with λ
CO(60 K) = 12 μm, either intrinsically or extrinsically doped, corroborate this finding. These data, new results on a 112 × 112 pixel demonstrator
array with λ
CO(55 K) = 14.4 μm, and earlier measurements are compared with Tennant’s Rule 07 established for p-on-n technology. 相似文献
9.
E. V. Kalinina N. B. Strokan A. M. Ivanov A. A. Sitnikova A. V. Sadokhin A. Yu. Azarov V. G. Kossov R. R. Yafaev 《Semiconductors》2008,42(1):86-91
Results obtained in a study of spectrometric characteristics of arrays of four detectors based on 4H-SiC ion-implantation-doped p +-n junctions in the temperature range 25–140 °C are reported for the first time. The junctions were fabricated by ion implantation of aluminum into epitaxial 4H-SiC layers of thickness ≤45 μm, grown by chemical vapor deposition with uncompensated donor concentration N d ? N a = (4–6) × 1014 cm?3. The structural features of the ion-implantation-doped p +-layers were studied by secondary-ion mass spectrometry, transmission electron microscopy, and Rutherford backscattering spectroscopy in the channeling mode. Parameters of the diode arrays were determined by testing in air with natural-decay alpha particles with an energy of 3.76 MeV. The previously obtained data for similar single detectors were experimentally confirmed: the basic characteristics of the detector arrays, the charge collection efficiency and energy resolution, are improved as the working temperature increases. 相似文献
10.
11.
Eric Lebel Ali Assi Mohamad Sawan 《Analog Integrated Circuits and Signal Processing》2008,54(1):21-29
We propose in this paper a programmable band-pass filter based on an array of fully differential transconductance circuits
that controls the filter parameters. The signal path does not contain any switch, and fine-tuning of the filter parameters
is implemented using programmable capacitors. A digital building block is implemented in the proposed band-pass filter to
tune its central frequency as well as its bandwidth. The filter circuit is based on a biquad topology, which is designed and
implemented with CMOS 0.18 μm technology. Experimental results show a programming ability of the center frequency between
5.9 and 58 MHz, and the quality factor can be tuned from 0.36 to 10. These features are obtained for a total power consumption
of less than 10.5 mW from a single 1.8 V power supply. 相似文献
12.
P. A. Ivanov A. S. Potapov T. P. Samsonova O. Korol’kov N. Sleptsuk 《Semiconductors》2011,45(10):1306-1310
Deep-level transient spectroscopy (DLTS) has been used to study p-n junctions fabricated by implantation of boron into epitaxial 4H-SiC films with n-type conductivity and the donor concentration (8–9) × 1014 cm−3. A DLTS signal anomalous in sign is observed; this signal is related to recharging of deep compensating boron-involved centers
in the n-type region near the metallurgical boundary of the p-n junction. 相似文献
13.
O. Yu. Ledyaev A. M. Strel’chuk A. N. Kuznetsov N. V. Seredova A. S. Zubrilov A. A. Volkova A. E. Nikolaev A. A. Lebedev 《Semiconductors》2005,39(12):1403-1405
Epitaxial GaN layers were grown by hydride vapor phase epitaxy (HVPE) on commercial (CREE Inc., USA) p+-6H-SiC substrates (Na ? Nd ≈ 7.8 × 1017 cms?3) and n+-6H-SiC Lely substrates with a predeposited p+-6H-SiC layer. A study of the electrical properties of the n-GaN/p-SiC heterostructures obtained confirmed their fairly good quality and demonstrated that the given combination of growth techniques is promising for fabrication of bipolar and FET transistors based on the n-GaN/p-SiC heterojunctions. 相似文献
14.
E. V. Bogdanova A. A. Volkova A. E. Cherenkov A. A. Lebedev R. D. Kakanakov L. P. Kolaklieva G. A. Sarov T. M. Cholakova A. V. Kirillov L. P. Romanov 《Semiconductors》2005,39(6):730-733
The possibility of fabricating heavily doped (N a ?N d ≥ 1 × 1019 cm?3) p+-4H-SiC layers on CVD-grown lightly doped n-4H-SiC layers by sublimation epitaxy has been demonstrated. It is shown that a Au/Pd/Ti/Pd contact, which combines a low specific contact resistance (~2 × 10?5 Ω cm2) with high thermal stability (up to 700°C), is the optimal contact to p-4H-SiC. The p-n structures obtained are used to fabricate packaged diodes with a breakdown voltage of up to 1400 V. 相似文献
15.
A. A. Lebedev P. L. Abramov E. V. Bogdanova A. S. Zubrilov S. P. Lebedev D. K. Nelson N. V. Seredova A. N. Smirnov A. S. Tregubova 《Semiconductors》2009,43(6):756-759
The 3C-SiC layers grown on the 15R-SiC substrates by sublimation epitaxy in vacuum are studied. Using X-ray topography and Raman spectroscopy, it is shown that the obtained layers are of a rather high structural quality. By the data of the Raman spectroscopy and capacitance-voltage measurements, it is established that the electron concentration in the 3C-SiC layer is (4–6) × 1018 cm?3. 相似文献
16.
A. E. Brown N. Baril D. Zuo L. A. Almeida J. Arias S. Bandara 《Journal of Electronic Materials》2017,46(9):5367-5373
The influence of dopant concentration on both in-plane mobility and minority carrier lifetime in long-wave infrared InAs/InAsSb superlattices (SLs) was investigated. Unintentially doped (n-type) and various concentrations of Be-doped (p-type) SLs were characterized using variable-field Hall and photoconductive decay techniques. Minority carrier lifetimes in p-type InAs/InAsSb SLs are observed to decrease with increasing carrier concentration, with the longest lifetime at 77 K determined to be 437 ns, corresponding to a measured carrier concentration of p 0 = 4.1 × 1015 cm?3. Variable-field Hall technique enabled the extraction of in-plane hole, electron, and surface electron transport properties as a function of temperature. In-plane hole mobility is not observed to change with doping level and increases with reducing temperature, reaching a maximum at the lowest temperature measured of 30 K. An activation energy of the Be-dopant is determined to be 3.5 meV from Arrhenius analysis of hole concentration. Minority carrier electrons populations are suppressed at the highest Be-doping levels, but mobility and concentration values are resolved in lower-doped samples. An average surface electron conductivity of 3.54 × 10?4 S at 30 K is determined from the analysis of p-type samples. Effects of passivation treatments on surface conductivity will be presented. 相似文献
17.
Tae-Hong Kim Chan-Oh Jang Han-Kyu Seong Heon-Jin Choi Sang-Kwon Lee 《Journal of Electronic Materials》2009,38(4):505-510
We demonstrated that manganese (Mn)-doped GaN nanowires (NWs) exhibit p-type characteristics using current–voltage (I–V) characteristics in both heterojunction p–n structures (GaN:Mn NWs/n-Si substrate) and p–p structures (GaN:Mn NWs/p-Si). The heterojunction p–n diodes were formed by the coupling of the Mn-doped GaN NWs with an n-Si substrate by means of an alternating current (AC) dielectrophoresis-assisted assembly deposition technique. The GaN:Mn
NWs/n-Si diode showed a clear current-rectifying behavior with a forward voltage drop of 2.4 V to 2.8 V, an ideality factor of
30 to 37, and a parasitic resistance in the range of 93 kΩ to 130 kΩ. On the other hand, we observed that other heterojunction
structures (GaN:Mn NWs/p-Si) showed no rectifying behaviors as seen in p–p junction structures. 相似文献
18.
Results of X-ray diffraction and spectral-optical studies of n-ZnO and p-CuO films deposited by gas-discharge sputtering with subsequent annealing are presented. It is shown that, despite the difference in the crystal systems, the polycrystallinity of n-ZnO and p-CuO films enables fabrication of a heterojunction from this pair of materials. 相似文献
19.
Evandro Daniel Calderaro Cotrim Luís Henrique de Carvalho Ferreira 《Analog Integrated Circuits and Signal Processing》2012,71(2):275-282
In this paper an ultra-low-power CMOS symmetrical operational transconductance amplifier (OTA) for low-frequency G
m
-C applications in weak inversion is presented. Its common mode input range and its linear input range can be made large using
DC shifting and bulk-driven differential pair configuration (without using complex approaches). The symmetrical OTA was successfully
verified in a standard CMOS 0.35-μm process. The measurements show an open loop gain of 61 dB and a unit gain frequency of
195 Hz with only 800 mV of power supply voltage and just 40 nW of power consumption. The transconductance is 66 nS, which
is suitable for low-frequency G
m
-C applications. 相似文献
20.
Siham Benkouda Mounir Amir Tarek Fortaki Abdelmadjid Benghalia 《Journal of Infrared, Millimeter and Terahertz Waves》2011,32(11):1350-1366
The dual-frequency behavior of stacked high T
c
superconducting rectangular microstrip patches fabricated on a two-layered substrate is investigated using a full-wave spectral
analysis in conjunction with the complex resistive boundary condition. Using a matrix representation of each layer, the dyadic
Green’s functions of the problem are efficiently determined in the vector Fourier transform domain. The stationary phase method
is used for computing the radiation electric field of the antenna. The proposed approach is validated by comparison of the
computed results with previously published data. Variations of the lower and upper resonant frequencies, bandwidth and quality
factor with the operating temperature are given. Results showing the effects of the bottom patch thickness as well as the
top patch thickness on the dual-frequency behavior of the stacked configuration are also presented and discussed. Finally,
for a better comprehension of the dual-frequency operation, a comparison between the characteristics of the lower and upper
resonances is given. 相似文献