共查询到20条相似文献,搜索用时 31 毫秒
1.
Schwarz T. Springholz G. Seyringer H. Krenn H. Lanzerstorfer S. Heiss W. 《Quantum Electronics, IEEE Journal of》1999,35(12):1753-1758
High-quality lead-salt-based Bragg mirror stacks were fabricated on BaF2(111) substrates by molecular beam epitaxy. The mirrors consisted of Pb1-xEuxTe quarter-wavelength layer pairs with 1% and 6% Eu content and were designed for use in mid-infrared (MIR) vertical emitting devices with a PbTe active zone. From theoretical simulations, we obtained the internal reflectivity with incidence from an active resonator medium and the reflectivity spectra of Bragg/metal mirror combinations. For a 32-layer pair mirror, we measured a record stopband reflectivity for the MIR of over 99% at 5.7 μm, in excellent agreement with our calculations 相似文献
2.
The design, fabrication, and testing of distributed Bragg reflector (DBR), distributed feedback (DFB), and grating coupled emission (GCE) Pb1-xSnxSe/Pb1-x-yEuySn xSe double heterostructure stripe geometry molecular-beam-epitaxy (MBE) grown diode lasers are discussed. The DBR and DFB lasers are the first Pb-salt corrugated lasers to operate in CW (continuous) mode at temperatures above that of liquid nitrogen. For the GCE lasers, a narrow far field distribution of ~5° was obtained for the first time 相似文献
3.
Xiao X. Sturm J.C. Parihar S.R. Lyon S.A. Meyerhofer D. Palfrey S. Shallcross F.V. 《Electron Device Letters, IEEE》1993,14(4):199-201
By employing a thin silicon sacrificial cap layer for silicide formation, the authors successfully demonstrated Pd2Si/strained Si1-xGex Schottky-barrier infrared detectors with extended cutoff wavelengths. The sacrificial silicon eliminates the segregation effects and Fermi level pinning which occur if the metal reacts directly with Si1-x Gex alloy. The Schottky barrier height of the silicide/strained Si1-xGex detector decreases with increasing Ge fraction, allowing for tuning of the detector's cutoff wavelength. The cutoff wavelength was extended beyond 8 μm in PtSi/Si 0.85Ge0.15 detectors. It is shown that high quantum efficiency and near-ideal dark current can be obtained from these detectors 相似文献
4.
Heterojunction GexSi1-x/Si internal photoemission infrared detectors exhibiting nearly ideal thermionic-emission dark-current characteristics have been fabricated with cutoff wavelengths out to 16 μm. High-quality imaging without uniformity correction has been demonstrated in the long-wavelength infrared (LWIR) spectral band for 400×400-element focal plane arrays consisting of Ge0.44Si0.56 detectors with a cutoff wavelength of 9.3 μm and monolithic charged-coupled-device readout circuitry. The Ge0.44Si0.56 composition was chosen in order to obtain a barrier height low enough to yield a cutoff length within the LWIR band, but high enough to permit low dark-current operation at about 50 K 相似文献
5.
Lin T.L. Park J.S. Gunapala S.D. Jones E.W. Del Castillo H.M. 《Electron Device Letters, IEEE》1994,15(3):103-105
A photoresponse model has been developed for the Si1-xGex/Si heterojunction internal photoemission (HIP) infrared detector at wavelengths corresponding to photon energies less than the Fermi energy. A Si0.7Ge0.3/Si HIP detector with a cutoff wavelength of 23 μm and an emission coefficient of 0.4 eV-1 has been demonstrated. The model agrees with the measured detector response at λ>8 μm. The potential barrier determined by the model is in close agreement (difference ~4 meV) with the potential barrier determined by the Richardson plot, compared to the discrepancies of 20-50 meV usually observed for PtSi Schottky detectors 相似文献
6.
Coupling coefficient calculations of the type originally published for gallium arsenide distributed feedback (DFB) lasers are here extended to the lead-tin telluride based family of devices. Specific calculations of the coupling coefficient as a function of active region and grating dimensions are presented for PbTe/Pb1-x Snx Te/PbTe devices,x = 0.13 andx = 0.18 , at 8 K and 77 K, and the implications of the results for device design and fabrication are discussed. 相似文献
7.
Distributed-feedback Pb1-xSnxSe double heterostructure stripe geometry diode lasers fabricated using molecular-beam epitaxy are discussed. These lasers operate in the CW mode up to 90 K and in the pulse mode up to 100 K. They are unique in their low tuning rate with injection current 4 cm-1/A, and in that they withstand high CW injection currents without damage. These features are probably the result of the metal cladding layer located on top of the gratings 相似文献
8.
Bean J.C. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1992,80(4):571-587
The use of strained layer epitaxy to grow high-quality Gex Si1-x/Si heterostructures and their application to a wide range of heterostructure devices are addressed. The author reviews the mechanisms of strained layer growth, the bandstructure of the resulting material, and its use in test devices, including superlattice avalanche photodiodes for fiber optic communication, intrasubband optical detectors and arrays operating in the 10-15 μm wavelength range, mobility enhanced modulation-doped transistors, heterojunction bipolar transistors with cutoff frequencies of 75 GHz, and negative resistance devices based on resonant tunneling and real-space carrier transfer 相似文献
9.
Linga K.R. Olsen G.H. Ban V.S. Joshi A.N. Kosonocky W.F. 《Lightwave Technology, Journal of》1992,10(8):1050-1055
The dark current properties of InxGa1-xAs photodiodes, where x is varied from 0.53 to 0.82 for extending the long wavelength cutoff from 1.7 to 2.6 μm, are described. Detailed analyses of optoelectrical parameters of In0.82Ga 0.1As photodiodes are presented. Dark current, which is a critical parameter and limits the operation of the photodiode, is analyzed and compared with the experimental values. Typical characteristics of photodiodes with cutoff wavelengths of 1.7 μm (x =0.53), 2.2 μm (x =0.72), and 2.6 μm (x =0.82) are presented. The typical and best values of the dark currents obtained are presented 相似文献
10.
We report a deep submicron vertical PMOS transistor using strained Si1-xGex channel formed by Ge ion implantation and solid phase epitaxy. These vertical structure Si1-xGex /Si transistors can be fabricated with channel lengths below 0.2 μm without using any sophisticated lithographic techniques and with a regular MOS process. The enhancement of hole mobility in a direction normal to the growth plane of strained Si1-xGex over that of bulk Si has been experimentally demonstrated for the first time using this vertical MOSFET. The drain current of these vertical MOS devices has been found to be enhanced by as much as 100% over control Si devices. The presence of the built-in electric field due to a graded SiGe channel has also been found to be effective in further enhancement of the drive current in implanted-channel MOSFET's 相似文献
11.
Hsiang-Jen Huang Kun-Ming Chen Chun-Yen Chang Liang-Po Chen Guo-Wei Huang Tiao-Yuan Huang 《Electron Device Letters, IEEE》2000,21(9):448-450
P-channel MOS transistors with raised Si1-xGex and Si source/drain (S/D) structure selectively grown by ultra high vacuum chemical vapor deposition (UHVCVD) were fabricated for the first time. The impact of Si1-xGex and Si epitaxial S/D layers on S/D series resistance and drain current of p-channel transistors were studied. Our results show that devices with the raised Si1-xGex S/D layer display only half the value of the specific contact resistivity and S/D series resistance (RSD), compared with those with a Si raised S/D layer. The improvement is even more dramatic when comparing with conventional devices without any raised S/D layer, i.e., RSD of devices with Si1-xGex raised S/D is only about one fourth that of conventional devices. Moreover, the raised SiGe S/D structure produces a 29% improvement in transconductance (gm) at an effective channel length of 0.16 μm. These performance improvements, together with several inherent advantages, such as self-aligned selective epitaxial growth (SEG) and the resultant T-shaped gate structure, make the new device with raised Si1-xGex S/D structure very attractive for future sub-0.1 μm p-channel MOS transistors 相似文献
12.
Koester S.J. Hammond R. Chu J.O. Mooney P.M. Ott J.A. Perraud L. Jenkins K.A. Webster C.S. Lagnado I. de la Houssaye P.R. 《Electron Device Letters, IEEE》2001,22(2):92-94
The dc and microwave results of Si0.2Ge0.8/Si0.7Ge0.3 pMODFETs grown on silicon-on-sapphire (SOS) substrates by ultrahigh vacuum chemical vapor deposition are reported. Devices with Lg=0.1 μm displayed high transconductance (377 mS/mm), low output conductance (25 mS/mm), and high gate-to-drain breakdown voltage (4 V). The dc current-voltage (I-V) characteristics were also nearly identical to those of control devices grown on bulk Si substrates. Microwave characterization of 0.1×50 μm2 devices yielded unity current gain (fT) and unilateral power gain (f max) cutoff frequencies as high as 50 GHz and 116 GHz, respectively. Noise parameter characterization of 0.1×90 μm2 devices revealed minimum noise figure (Fmin) of 0.6 dB at 3 GHz and 2.5 dB at 20 GHz 相似文献
13.
Wang G.W. Feng M. Kaliski R. Liaw Y.P. Lau C. Ito C. 《Electron Device Letters, IEEE》1989,10(10):449-451
The authors present the fabrication and characterization of ion-implanted graded InxGa1-xAs/GaAs MESFETs. The InxGa1-xAs layers are grown on GaAs substrates by MOCVD (metal-organic chemical vapor deposition) with InAs concentration graded from 15% at the substrate to 0% at the surface. 0.5-μm gate MESFETs are fabricated on these wafers using silicon ion implantation. In addition to improved Schottky contact, the graded InxGa 1-xAs MESFET achieves maximum extrinsic transconductance of 460 mS/mm and a current-gain cutoff frequency f t of 61 GHz, which is the highest ever reported for a 0.5-μm gate MESFET. In comparison, In0.1Ga0.9As MESFETs fabricated with the same processing technique show an f t of 55 GHz 相似文献
14.
King C.A. Hoyt J.L. Noble D.B. Gronet C.M. Gibbons J.F. Scott M.P. Kamins T.I. Laderman S.S. 《Electron Device Letters, IEEE》1989,10(4):159-161
Si1-xGex/Si p-N heterojunctions prepared by a chemical vapor deposition technique, limited reaction processing (LRP) were characterized using DC electrical measurements, transmission electron microscopy (TEM), and X-ray topography. Heterojunctions with Si 1-xGex layer thickness ranging from 52 to 295 nm and a constant Ge fraction of 23% were fabricated to study the effect of increasing the number of misfit dislocations on the device characteristics. Devices with the thinnest layers (⩽120 nm) display forward characteristics with ideality factors of 1.01 and reverse leakage current densities of less than 4 nA/cm for a 5-V reverse bias. These thin-layer devices have dislocation spacings greater than 10 μm. Devices utilizing Si1-xGex layers thicker than 200 nm have forward characteristics which clearly display the presence of recombination currents, and reverse leakage current densities greater than 290 nA/cm2 at -5 V. The dislocation spacing in these devices is less than 1 μm. Ideal characteristics were found at room temperature in devices known to contain dislocations 相似文献
15.
Electroabsorption in quantum wells under biaxial tension is investigated theoretically. It is found that enhanced electroabsorption due to a field-induced merging of the light and heavy hole absorption edges can be achieved in these structures at moderate operating fields. Calculations showing this merging and electroabsorption enhancement for InxGa1-xAs-InP and GaAsxP1-x-Al0.35Ga0.65As quantum well structures are described. Trade-offs involving the advantages of merged absorption edges are identified through comparisons of tensile strained modulators utilizing the merging effect of analogous lattice matched structures. Optimal structures for operation at 1.55 μm in InxGa1-xAs-InP and 0.77 μm in GaAsxP1-x-Al0.35Ga0.65As are identified, and the sensitivities of their electroabsorption characteristics to material and structural parameters are examined 相似文献
16.
We have applied the (Pb1-xLax)(ZryTiz)1-x/4 O3 (PLZT) electro-optic ceramic material to produce variable and rotatable waveplates for polarization controls. This plate has a 90 μm×90 μm window between four sides. Each of the four sides is coated with a material that acts as an electrode. The plate is inserted in a trench across an array of parallel optical waveguides. A single PLZT waveplate of this type was capable of continuous and complete conversion. This requires the control of only two parameters, the direction and strength of the applied voltage. The device is fast with a response time of only 1 μs 相似文献
17.
Stutius W. Gavrilovic P. Williams J.E. Meehan K. Zarrabi J.H. 《Electronics letters》1988,24(24):1493-1494
Separate confinement single-quantum-well lasers with 100-120 Å-thick strained Ga1-xInxAs/GaAs active layers have been grown on (100) GaAs substrates by metalorganic chemical vapour deposition. Ten-stripe proton-implanted arrays with 90 μm-wide aperture and 250 μm cavity length emit 200 mW CW optical power at wavelengths 0.87⩽λ⩽0.95 μm. Lifetest data on an uncoated device emitting 90 mW/facet at 50°C and λ=0.95 μm suggest a mean-time-to-failure in excess of 2500 h at room temperature. The performance of lasers with strained Ga1-xInxAs quantum wells is comparable to that of unstrained AlxGa1-xAs/GaAs quantum-well lasers without facet coating 相似文献
18.
Bethea C.G. Levine B.F. Shen V.O. Abbott R.R. Hseih S.J. 《Electron Devices, IEEE Transactions on》1991,38(5):1118-1123
A long-wavelength infrared imaging camera that uses a GaAs/AlxGa1-xAs quantum-well infrared photodetector (QWIP) array is demonstrated. Excellent noise equivalent temperature difference sensitivity (NE ΔT <0.1°C) has been achieved. The long-wavelength cutoff for the QWIP used in this camera is at λ c=10.7 μm with the peak response being at λp =9.8 μm. A peak detectivity of 2×1010 cm√Hz/W has been achieved at 77 K as well as an excellent pixel-to-pixel uniformity of 2%. Since GaAs has a more mature growth and processing technology as well as higher uniformity than HgCdTe, it shows great promise for the fabrication of large two-dimensional arrays 相似文献
19.
Agahi F. Yang J.-X. Lau K.M. Yngvesson K.S. 《Electron Devices, IEEE Transactions on》1993,40(3):502-506
A combination of high mobility and high sheet carrier density in AlxGa1-xAs/GaAs two-dimensional electron gas (2DEG) elements was obtained by low-pressure organometallic vapor phase epitaxy (OMVPE). The sheet charge densities (n s) and mobilities (μ) at 77 K are 1.2×1012/cm2 and 90000 cm2/V-s for single-channel, and 2.0× 1012/cm2 and 64500 cm2/V-s for double-channel elements, respectively. Strong correlations between the photoluminescence spectrum of the AlxGa1-xAs layers and the 2DEG mobility were found. The 2DEG elements were used as mixers and detectors at millimeter wavelengths. Mixing at 94 GHz with a 1.7-GHz IF bandwidth and detection of signals as high as 238 GHz under a magnetic field were achieved with these devices 相似文献
20.
Hong Wang Geok Ing Ng Haiqun Zheng Hong Yang Yongzhong Xiong Subratra Halder Kaihua Yuan Chee Leong Tan Rahdakrishnan K. Soon Fatt Yoon 《Electron Devices, IEEE Transactions on》2001,48(12):2671-2676
High-performance InP/In0.53Ga0.47As metamorphic heterojunction bipolar transistors (MHBTs) on GaAs substrate have been fabricated using InxGa1-xP strain relief buffer layer grown by solid-source molecular beam epitaxy (SSMBE). The MHBTs exhibited a dc current gain over 100, a unity current gain cutoff frequency (fT) of 48 GHz and a maximum oscillation frequency (fMAX) of 42 GHz with low junction leakage current and high breakdown voltages. It has also been shown that the MHBTs have achieved a minimum noise figure of 2 dB at 2 GHz (devices with 5×5 μm 2 emitter) and a maximum output power of 18 dBm at 2.5 GHz (devices with 5×20 μm2 emitter), which are comparable to the values reported on the lattice-matched HBTs (LHBTs). The dc and microwave characteristics show the great potential of the InP/InGaAs MHBTs on GaAs substrate for high-frequency and high-speed applications 相似文献