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5 Apr 1993

Volume 62, Issue 14, pp. 1579-1701

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Growth and saturation of stimulated beam modulation in a two‐stream relativistic klystron amplifier

C. Chen, P. Catravas, and G. Bekefi

Appl. Phys. Lett. 62, 1579 (1993); http://dx.doi.org/10.1063/1.108644 (3 pages) | Cited 14 times

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A two‐stream relativistic klystron amplifier (RKA) is proposed in which the amplification of stimulated beam modulation is achieved via the unstable two‐stream interaction rather than the use of passive cavities. After a calculation of the limiting current, the amplification and saturation of the stimulated beam modulation are analyzed using a cold‐fluid model and particle‐in‐cell simulation. Good agreement is found between theory and simulation in the linear regime. Fully modulated intense relativistic electron beams are obtained at saturation. In the proposed scheme, substantial beam energy difference is required to achieve large instability growth.
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41.60.Cr Free-electron lasers
41.75.Ht Relativistic electron and positron beams
52.59.Px Hard X-ray sources
52.27.Jt Nonneutral plasmas

Photoluminescence of plasma polymerized methyl methacrylate films

Guifang Li, Jeffrey A. Tobin, and Denice D. Denton

Appl. Phys. Lett. 62, 1582 (1993); http://dx.doi.org/10.1063/1.108645 (3 pages) | Cited 8 times

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The photoluminescence properties of plasma polymerized methyl methacrylate films are investigated. The photoluminescence is a fluorescence rather than a phosphorescence process with a lifetime on the order of a few nanoseconds. The photoluminescence is a one‐photon volume effect. The wavelength span of the photoluminescence using suitable UV excitation can reach over 300 nm with a FWHM exceeding 200 nm. These photoluminescent films may find potential applications in wavelength transformers for solar cells or as a gain medium for tunable solid‐state dye lasers.
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78.55.Kz Solid organic materials
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.35.-x Polymers: properties; reactions; polymerization
78.66.Qn Polymers; organic compounds

Low resistance wavelength‐reproducible p‐type (Al,Ga)As distributed Bragg reflectors grown by molecular beam epitaxy

S. A. Chalmers, K. L. Lear, and K. P. Killeen

Appl. Phys. Lett. 62, 1585 (1993); http://dx.doi.org/10.1063/1.109608 (3 pages) | Cited 13 times

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We report the reproducible molecular beam epitaxial growth of Be‐doped piecewise linearly graded (Al,Ga)As distributed Bragg reflectors that have vertical series resistivities near bulk values. For mirrors with three linear segments per interface, the center wavelength reproducibility is 0.1% and the series resistivity is as low as 1.8×10−5 Ω cm2 for hole concentrations of 5×1018 cm−3. Measured reflectivities of 6.0% per interface are comparable to conventional single‐linear‐grade mirrors. Vertical‐cavity surface‐emitting lasers incorporating these mirrors exhibit record‐low voltage thresholds of less than 1.5 V.
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78.66.Fd III-V semiconductors
42.55.Px Semiconductor lasers; laser diodes
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Ultralow timing jitter in electrically gain‐switched vertical cavity surface emitting lasers

P. Pepeljugoski, J. Lin, J. Gamelin, M. Hong, and K. Y. Lau

Appl. Phys. Lett. 62, 1588 (1993); http://dx.doi.org/10.1063/1.108646 (3 pages) | Cited 8 times

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We report that contrary to common belief, it is possible to achieve very low timing jitters of less than (≊100 fs) in gain‐switched semiconductor lasers, which is comparable to actively mode‐locked semiconductor lasers. A vertical cavity surface emitting laser was used to achieve these results, with a gain‐switched pulse width of 12 ps.
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42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers

Direct measurement of linewidth enhancement factors in quantum well lasers of different quantum well barrier heights

B. Zhao, T. R. Chen, S. Wu, Y. H. Zhuang, Y. Yamada, and A. Yariv

Appl. Phys. Lett. 62, 1591 (1993); http://dx.doi.org/10.1063/1.108647 (3 pages) | Cited 16 times

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The wavelength dependence of the linewidth enhancement factor (amplitude‐phase coupling factor) α in quantum well lasers of different quantum well barrier heights have been determined from the spontaneous emission spectra and the Fabry–Perot mode wavelength shifts. It is found that the α parameter at lasing wavelength in GaAs/Al0.15Ga0.85As lasers is about twice as large as that in GaAs/Al0.30Ga0.70As lasers. The observation is consistent with the previously observed spectral linewidth behavior in these lasers, which were attributed to the different state filling effects.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation

Monte Carlo hydrodynamic simulation of neutral radical transport in low pressure remote plasma activated chemical vapor deposition

Michael J. Hartig and Mark J. Kushner

Appl. Phys. Lett. 62, 1594 (1993); http://dx.doi.org/10.1063/1.108648 (3 pages) | Cited 10 times

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In electron cyclotron resonance plasma sources for semiconductor processing (1–10 s mTorr), the mean free paths of neutral radical species are commensurate with the dimensions of the reactor. To address these conditions, a hybrid hydrodynamic Monte Carlo simulation has been developed to model the transport of neutral excited state and radical species. The continuity and momentum equations are solved to obtain an average advective flow field. Monte Carlo techniques are then employed to model the trajectories of the neutral particles, while allowing for momentum transfer collisions with the background gas, and chemical reactions. Results are presented for Ar/SiH4 plasmas where the uniformity of the radical flux and hot atom effects are investigated.
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52.65.-y Plasma simulation
52.25.Fi Transport properties
52.50.Gj Plasma heating by particle beams
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Enhancement of diffusion‐induced grain boundary migration by ion irradiation

Dale E. Alexander, L. E. Rehn, P. M. Baldo, and Y. Gao

Appl. Phys. Lett. 62, 1597 (1993); http://dx.doi.org/10.1063/1.108597 (3 pages) | Cited 3 times

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Diffusion‐induced grain boundary migration (DIGM) was observed in Au/Cu bilayers irradiated with 1.5 MeV Kr at T≥400 K. Rutherford backscattering spectrometry (RBS) showed nearly uniform distributions of Cu present throughout polycrystalline Au films after irradiation and after annealing treatments. Irradiation increased the amount of Cu relative to annealed‐only areas. Cross‐section transmission electron microscopy combined with x‐ray energy dispersive spectroscopy (XEDS) identified alloyed zones (14–20 at. % Cu), confirming DIGM in the Au film of an ion bombarded bilayer. A description of DIGM is presented relating RBS measurements of the film‐averaged Cu composition with treatment time, average grain size, and film thickness. Application of this model to the experimental results in combination with XEDS work indicates that irradiation enhances DIGM by increasing the grain boundary velocity.
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61.80.Jh Ion radiation effects
66.30.Ny Chemical interdiffusion; diffusion barriers
66.30.Lw Diffusion of other defects
61.72.Mm Grain and twin boundaries

Observation of solid phase epitaxy processes of Ar ion bombarded Si(001) surfaces by scanning tunneling microscopy

Katsuhiro Uesugi, Takafumi Yao, Tomoshige Sato, Takashi Sueyoshi, and Masashi Iwatsuki

Appl. Phys. Lett. 62, 1600 (1993); http://dx.doi.org/10.1063/1.108598 (3 pages) | Cited 7 times

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Scanning tunneling microscopy (STM) is used to investigate the surface morphology of Ar+‐ion bombarded Si(001) surfaces and to elucidate the very beginning stages of solid phase epitaxy (SPE) processes of the Ar+‐ion bombarded Si surfaces. The Ar+‐ion bombarded Si surface consists of hillocks of 1–2 nm in diameter and 0.35–0.75 nm in height. The onset of SPE initiates at around 590 °C, at which a temperature (2×2) structure surrounded by amorphous regions is partially observed on terraces of the surface. During annealing at 590–620 °C, the areas of the (2×2) and c(4×4) reconstruction surrounded by amorphous regions develop. New defect models for the (2×2) and c(4×4) structures are proposed where alternating arrangements of the buckled dimers together with missing dimer defects are considered.
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81.15.Np Solid phase epitaxy; growth from solid phases
61.50.Ks Crystallographic aspects of phase transformations; pressure effects
61.80.Jh Ion radiation effects

Aligned and twinned growth of α‐Fe thin films on atomically cleaned (111)Si at room temperature

M. H. Wang and L. J. Chen

Appl. Phys. Lett. 62, 1603 (1993); http://dx.doi.org/10.1063/1.108599 (3 pages) | Cited 8 times

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Epitaxial α‐Fe thin films have been grown on atomically cleaned (111)Si at room temperature under ultrahigh vacuum condition. The α‐Fe epitaxy on (111)Si was analyzed by transmission electron microscopy (TEM) to be predominantly of twinned epitaxy with a small fraction of epitaxy being aligned with respect to the substrate. High resolution TEM showed that the interface between the epitaxial iron thin film and Si substrate is atomically flat with the presence of a low density of atomic steps. Interfacial dislocations were found to be of edge type with 1/2<110≳ Burgers vectors. The average spacing of interfacial dislocations was found to be close to the theoretically predicted value.
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68.55.-a Thin film structure and morphology
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Existence of extinction temperature in WSix film growth from WF6 and SiH4: An indication of the role played by radical chain reactions

T. Saito, Y. Shimogaki, Y. Egashira, H. Komiyama, Y. Yuyama, K. Sugawara, S. Nagata, K. Takahiro, and S. Yamaguchi

Appl. Phys. Lett. 62, 1606 (1993); http://dx.doi.org/10.1063/1.108600 (3 pages) | Cited 3 times

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Low pressure chemical vapor deposition (LPCVD) was carried out to deposit tungsten silicide films (WSix) from WF6 and SiH4 in a low temperature range from 80 to 390 °C, using a tubular reactor system. Drastic decrease of the deposition rate occurred at an extinction temperature Tex. Increase of the reactor size in the range from 4 to 22 mmϕ decreased Tex from 140 to 80 °C. Above Tex, the sticking probability of the film forming species (η) and the film composition, x of WSix , did not depend on the reactor diameter. Dependence of Tex on the reactor diameter and independence of η and x above Tex from the reactor diameter indicates that a radical chain process dominates CVD‐WSix process to form film forming species.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces

Investigation of ballistic elastic scattering length and specularity in multiterminal GaAs/AlGaAs by magnetic electron focusing effect

K. Tsukagoshi, S. Takaoka, K. Murase, K. Gamo, and S. Namba

Appl. Phys. Lett. 62, 1609 (1993); http://dx.doi.org/10.1063/1.108601 (3 pages) | Cited 8 times

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Magnetic electron focusing effect has been investigated by paying attention to its electron density (ns) dependence in a GaAs/AlGaAs device with multiparallel terminal. With increasing ns, a ballistic elastic scattering length increases, but a specularity at boundary decreases. In a configuration in which the electrons could enter into the extra probe between injector and collector probes, still the focusing effect is clearly observed.
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73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.20.My Galvanomagnetic and other magnetotransport effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Solubility of hydrogen in silicon at 1300 °C

S. A. McQuaid, M. J. Binns, R. C. Newman, E. C. Lightowlers, and J. B. Clegg

Appl. Phys. Lett. 62, 1612 (1993); http://dx.doi.org/10.1063/1.108602 (3 pages) | Cited 11 times

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The incorporation of hydrogen in boron doped Czochralski silicon heated to 1300 °C in H2 gas has been studied. The anneal was terminated by a rapid quench to room temperature giving rise to an unknown hydrogen‐related defect as well as H‐B close pairs. All the hydrogen in the crystal can be driven into such pairs by a low temperature (200 °C) anneal, after which the values of [H‐B] [D‐B] are in agreement with the total deuterium concentration, measured by secondary ion mass spectrometry. The estimated solubility of 1.5×1016 cm−3 is not affected by the isotopic mass of the hydrogen nor by the presence of boron or oxygen impurities.
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61.72.uf Ge and Si
64.75.-g Phase equilibria

Influence of ion‐implanted titanium on the performance of edge‐defined, film‐fed grown silicon solar cells

J. T. Borenstein, J. I. Hanoka, B. R. Bathey, J. P. Kalejs, and S. Mil’shtein

Appl. Phys. Lett. 62, 1615 (1993); http://dx.doi.org/10.1063/1.108603 (2 pages) | Cited 2 times

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The electrical properties of edge‐defined, film‐fed grown and Czochralski silicon solar cells ion implanted with titanium have been investigated using deep level transient spectroscopy. In both types of solar cell materials, the observed degradation in cell performance is associated with the Ti deep level reported in earlier studies. During the cell fabrication sequence, Ti in‐diffuses into the bulk of the sample, creating a low‐lifetime zone extending beneath the junction. Solar cell modeling, based on the extent of the titanium‐diffused layer and the properties of the Ti center, is in excellent agreement with observed cell performance.
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84.60.Jt Photoelectric conversion
71.55.Cn Elemental semiconductors
61.72.uf Ge and Si

Study on the photoconductivity characteristics of porous Si

C. C. Yeh, Klaus Y. J. Hsu, L. K. Samanta, P. C. Chen, and H. L. Hwang

Appl. Phys. Lett. 62, 1617 (1993); http://dx.doi.org/10.1063/1.108604 (3 pages) | Cited 5 times

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We utilized the conventional planar fabrication technique and the electrochemical etching method to prepare porous Si layers in the p‐type region of a p‐n junction, which makes the study on the transverse transport property of this material possible. The junctions were fabricated by low energy ion implantation, with porous Si formed perpendicular to the junction and between two metal contacts. This structure confines currents to the direction parallel to the surface. Distinct photoconductivity and photovoltaic effects have been clearly revealed from the I‐V curves.
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72.20.-i Conductivity phenomena in semiconductors and insulators
72.40.+w Photoconduction and photovoltaic effects
72.80.Cw Elemental semiconductors

Amphoteric behavior of germanium in In0.5Ga0.5P grown by liquid phase epitaxy

Jong Boong Lee, In Kim, Ho Ki Kwon, and Byung‐Doo Choe

Appl. Phys. Lett. 62, 1620 (1993); http://dx.doi.org/10.1063/1.108605 (3 pages) | Cited 6 times

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Properties of Ge‐doped In0.5Ga0.5P grown by liquid phase epitaxy were investigated by Hall effect, capacitance‐voltage, photoluminescence, and electroluminescence measurements. The Ge dopant in InGaP shows amphoteric behavior with a compensation ratio (Na/Nd) of about 0.4. The activation energies of donor and acceptor were measured to be 47 and 58 meV, respectively. The deep acceptor transition related to Ge complex is also observed by luminescence measurements.
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72.80.Ey III-V and II-VI semiconductors
78.66.Fd III-V semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

X‐ray diffraction reciprocal space mapping of a GaAs surface grating

M. Gailhanou, T. Baumbach, U. Marti, P. C. Silva, F. K. Reinhart, and M. Ilegems

Appl. Phys. Lett. 62, 1623 (1993); http://dx.doi.org/10.1063/1.108606 (3 pages) | Cited 44 times

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A GaAs surface grating (period 574 nm) is analyzed by four crystal‐six reflection x‐ray diffraction. Two‐dimensional measurements in the vicinity of the 004 GaAs reciprocal lattice point show satellites in the transverse direction related to the periodicity of the grating. A cross pattern, centered on the 004 GaAs reciprocal lattice point, is formed by these satellites. An explanation is given by a model which includes the influence of transmission through the surface pattern on the substrate diffraction.
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61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.
68.35.B- Structure of clean surfaces (and surface reconstruction)

Ellipsometric study of Si0.5Ge0.5/Si strained‐layer superlattices

R. M. Sieg, S. A. Alterovitz, E. T. Croke, and M. J. Harrell

Appl. Phys. Lett. 62, 1626 (1993); http://dx.doi.org/10.1063/1.108607 (3 pages) | Cited 6 times

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We present an ellipsometric study of two Si0.5Ge0.5/Si strained‐layer superlattices grown by MBE at low temperature (500 °C), and compare our results with x‐ray diffraction (XRD) estimates. Excellent agreement is obtained between target values, XRD, and ellipsometry when one of two available SixGe1−x databases is used. We show that ellipsometry can be used to nondestructively determine the number of superlattice periods, layer thicknesses, SixGe1−x composition, and oxide thickness without resorting to additional sources of information. We also note that we do not observe any strain effect on the E1 critical point.
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68.55.-a Thin film structure and morphology
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
78.66.Li Other semiconductors

Nanometer scale patterning of a monolayer Langmuir–Blodgett film with a scanning tunneling microscope in air

H. C. Day, D. R. Allee, R. George, and V. A. Burrows

Appl. Phys. Lett. 62, 1629 (1993); http://dx.doi.org/10.1063/1.108608 (3 pages) | Cited 12 times

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Nanometer scale patterns have been fabricated on a Langmuir–Blodgett deposited monolayer film of stearic acid using a scanning tunneling microscope in air. Carbon deposits build up underneath the tip for tip voltages with absolute value greater than 4 V. Using an atomic force microscope for image, lines 25 nm wide on a 60 nm period have been written. As confirmed with Auger electron spectroscopy, the unexposed film can be removed with a chloroform soak without affecting the existing carbon patterns, and no additional patterns could then be written because of the removal of the monolayer film.
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81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices
85.40.Hp Lithography, masks and pattern transfer

High‐resolution transmission electron microscopy of vicinal AlAs/GaAs interfacial structure

Nobuyuki Ikarashi, Toshio Baba, and Koichi Ishida

Appl. Phys. Lett. 62, 1632 (1993); http://dx.doi.org/10.1063/1.108609 (3 pages) | Cited 7 times

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AlAs‐on‐GaAs vicinal interfaces grown by molecular beam epitaxy were investigated by high‐resolution transmission electron microscopy in the 〈110〉 cross section, and the interfacial step structures were clearly observed. For the first time, distinctly different step interval distributions are found for interfaces tilted 2° from (001) towards (111)A and towards (111)B. Step bunching is observed for A steps, while a regular array of steps is observed for B steps. The edges of A steps are also straighter than those of B steps.
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68.55.-a Thin film structure and morphology
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices
68.35.B- Structure of clean surfaces (and surface reconstruction)

Time‐dependent Hall effect analysis method used for investigation of the DX center in AlGaAs:Si

G. Brunthaler, G. Stöger, A. Aumayr, and K. Köhler

Appl. Phys. Lett. 62, 1635 (1993); http://dx.doi.org/10.1063/1.108610 (3 pages) | Cited 3 times

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A new time‐dependent Hall effect analysis method is demonstrated on the DX center in AlGaAs:Si. Due to the time dependence of the carrier concentration and the mobility in the metastable temperature region of the DX center, errors are usually made in a standard estimation of the Hall effect values. By using an interpolation method for the individual measured voltages, we are able to omit these errors and also to explain them by a linear error approximation. We present mobility data and show that correlation effects between DX centers are important.
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71.55.Eq III-V semiconductors
72.80.Ey III-V and II-VI semiconductors
72.20.My Galvanomagnetic and other magnetotransport effects

Formation of P precipitates during annealing of InP grown by gas source molecular beam epitaxy at low temperature

A. Claverie, J. Crestou, and J. C. Garcia

Appl. Phys. Lett. 62, 1638 (1993); http://dx.doi.org/10.1063/1.108611 (3 pages) | Cited 4 times

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We have studied by transmission electron microscopy the structural changes that take place in monocrystalline InP grown by gas source molecular beam epitaxy at low temperature upon annealing at about 600 °C. It is shown that the partial relaxation of the crystal which is observed by x rays is due to the formation of small precipitates (3–7 nm). Electron diffraction experiments show that the structure of these precipitates is cubic with a simple cube‐to‐cube orientation relationship with the substrate. Most probably, these precipitates are of alpha‐white cubic P which is known to be insulating.
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68.55.-a Thin film structure and morphology
72.80.Ey III-V and II-VI semiconductors
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization

Masked growth of InGaAsP‐based quantum wells for optoelectronic device applications

Y. Chen, T. H. Chiu, J. E. Zucker, and S. N. G. Chu

Appl. Phys. Lett. 62, 1641 (1993); http://dx.doi.org/10.1063/1.108612 (3 pages) | Cited 5 times

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We investigate selective area growth of lattice‐matched InGaAsP/InP, and strained InGaAs/InP and InAsP/InP multiple quantum wells on SiO2‐masked InP substrate by chemical beam epitaxy. This method can be used to produce quantum well p‐i‐n waveguide modulators with a single growth step. Photoluminescence measurements performed on waveguide stripes ranging from 1–50 μm in width reveal a red shift of the band edge with decreasing stripe width in InGaAsP/InP and InGaAs/InP quantum well systems, but no shift in InAsP/InP quantum wells for stripe widths larger than 1 μm. In addition, we find that this band‐gap tunability is stripe orientation dependent.
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68.55.-a Thin film structure and morphology
78.55.Cr III-V semiconductors
42.79.Hp Optical processors, correlators, and modulators

Strain‐compensated InGaAs/GaAsP/GaInAsP/GaInP quantum well lasers (λ∼0.98 μm) grown by gas‐source molecular beam epitaxy

G. Zhang and A. Ovtchinnikov

Appl. Phys. Lett. 62, 1644 (1993); http://dx.doi.org/10.1063/1.108613 (3 pages) | Cited 17 times

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We report on the first strain‐compensated InGaAs/GaAsP/GaInAsP/GaInP separate‐confinement‐heterostructure quantum well lasers emitting at about 0.98 μm. The laser structure was grown by gas‐source molecular beam epitaxy. The lasers exhibited low threshold current densities and high characteristic temperatures. It was found that the structural and optical quality of a strain‐compensated InGaAs/GaAsP multiple‐quantum well (MQW) was superior to that of an InGaAs/GaAs MQW when the number of quantum wells was large. This was due to the presence of tensile strain in GaAsP which balanced compressive strain in InGaAs so that the InGaAs lattice does not relax. As a result, much fewer defects were formed in InGaAs/GaAsP than in InGaAs/GaAs. Thus strain‐compensated InGaAs/GaAsP MQW structures are desirable for device applications which require many quantum wells.
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42.55.Px Semiconductor lasers; laser diodes
42.60.-v Laser optical systems: design and operation
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Perfectly selective Si epitaxial growth due to synchrotron radiation irradiation during disilane molecular beam epitaxy

Yuichi Utsumi, Housei Akazawa, Masao Nagase, Tsuneo Urisu, and Izumi Kawashima

Appl. Phys. Lett. 62, 1647 (1993); http://dx.doi.org/10.1063/1.108614 (3 pages) | Cited 7 times

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Perfect selectivity in Si epitaxial growth has been achieved by irradiating SR during molecular beam epitaxy (MBE) using disilane. No Si nucleation occurs on SiO2 irrespective of growth time, in contrast to conventional selective growth by MBE using disilane. At a given disilane pressure, higher temperatures are preferable for SR‐induced selective growth, whereas lower temperatures are preferable for conventional selective growth. It is proposed that perfect selectivity results from SR‐stimulated SiO2 evaporation which expels Si atoms with dangling bonds, i.e., Si nucleation sites, from the SiO2 surface.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
61.80.Cb X-ray effects
82.50.-m Photochemistry

Millimeter‐wave monolithic barrier n‐n+ diode grid frequency doubler

Xiaohui Qin, C. Domier, N. C. Luhmann, H‐X L. Liu, E. Chung, L. Sjogren, and Wenhsing Wu

Appl. Phys. Lett. 62, 1650 (1993); http://dx.doi.org/10.1063/1.108615 (3 pages) | Cited 1 time

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A monolithic quasioptical frequency multiplier array, comprised of approximately 1760 Ga0.5Al0.5As/GaAs barrier n‐n+ (BNN) diodes, has been successfully fabricated. The BNN diode, first fabricated in these studies, possesses strongly nonlinear capacitance‐voltage (C‐V) characteristics, thereby offering the potential for a highly efficient device for millimeter‐wave frequency multiplication applications. A frequency doubled power of 2.1 W at 66 GHz has been observed with a conversion efficiency of 7.5%.
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85.30.De Semiconductor-device characterization, design, and modeling
85.30.Kk Junction diodes
73.40.Cg Contact resistance, contact potential
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
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