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14 Mar 1994

Volume 64, Issue 11, pp. 1315-1455

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All‐fiber source of 100‐nJ subpicosecond pulses

M. E. Fermann, A. Galvanauskas, and D. Harter

Appl. Phys. Lett. 64, 1315 (1994); http://dx.doi.org/10.1063/1.111919 (3 pages) | Cited 4 times

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Chirped pulse amplification of a stretched pulse passively mode‐locked erbium fiber laser is demonstrated. The two‐stage all‐fiber amplifier system delivers 800‐fs pulses with pulse energies up to 100 nJ at a repetition rate of 200 kHz.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Wd Fiber lasers

Laser‐induced photochromic damage in potassium titanyl phosphate

R. Blachman, P. F. Bordui, and M. M. Fejer

Appl. Phys. Lett. 64, 1318 (1994); http://dx.doi.org/10.1063/1.111920 (3 pages) | Cited 27 times

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We report studies of photochromic damage induced in KTiOPO4 single crystals by ultraviolet (UV) irradiation with peak intensities from 0.3 to 4.0 MW/cm2. The photochromic damage progressed to asymptotic values which were not linear with respect to UV intensity. Following UV exposure, transparency of damaged crystals recovered completely over tens of hours at room temperature, faster at elevated temperature. UV irradiation at significantly lower peak but higher average power did not produce damage. We also studied photochromic damage occurring during 1.064‐μm second‐harmonic generation. Fundamental infrared intensities ranged from 1.3 to 5.5 times larger than those producing highest nonlinear frequency conversion efficiency. Damage sites produced by the two methods exhibited similar absorption spectra.
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61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

Phase‐matching property optimization using birefringence tuning in solid solutions of KTiOPO4 isomorphs

L. K. Cheng, L. T. Cheng, J. D. Bierlein, and J. Parise

Appl. Phys. Lett. 64, 1321 (1994); http://dx.doi.org/10.1063/1.111921 (3 pages) | Cited 8 times

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We report here the linear and nonlinear optical properties of the solid‐solutions KTiOPxAs1−xO4 and Cs1−xKxTiOAsO4. Single domain crystals of these solid solutions were grown using a high temperature solution growth technique. By varying the compositional parameter x, the optical birefringence of these crystals was tuned to achieve noncritically phase‐matched type II frequency doubling of the 1.064 and 1.32 μm lines of Nd:YAG. Near optimal compositions for these two applications, and their associated phase‐matching angles, temperature bandwidths and angular acceptances are presented. The birefringence of KTiOPxAs1−xO4 exhibits a Vegard dependence on x, and the phase‐matching property optimization amounts to an accurate determination of the partition coefficients for P and As suitable for crystal growth. For the Cs1−xKxTiOAsO4 solid solution, a non‐Vegard dependence of the crystal birefringence and the cell constants was observed. This is believed to be due to the preferential occupation of the larger K(2) site by Cs.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.20.Fm Birefringence
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
77.84.-s Dielectric, piezoelectric, ferroelectric, and antiferroelectric materials

Terahertz optical rectification from 〈110〉 zinc‐blende crystals

A. Rice, Y. Jin, X. F. Ma, X.‐C. Zhang, D. Bliss, J. Larkin, and M. Alexander

Appl. Phys. Lett. 64, 1324 (1994); http://dx.doi.org/10.1063/1.111922 (3 pages) | Cited 131 times

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We report the study of optically induced terahertz (THz) electromagnetic radiation from 〈110〉 oriented zinc‐blende crystals. This work extends our previous studies of 〈100〉 and 〈111〉 GaAs. Excellent agreement between calculated results and experimental data indicates that, under conditions of moderate optical fluence and normal incidence on the unbiased sample, second‐order optical rectification is the major nonlinear process that generates THz radiation.
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42.65.Re Ultrafast processes; optical pulse generation and pulse compression
78.20.Jq Electro-optical effects
78.30.Fs III-V and II-VI semiconductors
72.40.+w Photoconduction and photovoltaic effects

Infrared to visible energy upconversion in Er3+‐doped oxide glass

B. R. Reddy and P. Venkateswarlu

Appl. Phys. Lett. 64, 1327 (1994); http://dx.doi.org/10.1063/1.111923 (3 pages) | Cited 35 times

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Intense green emission was observed at room temperature from the 4S3/2 level of Er3+ doped in a multielement oxide glass when its 4I9/2 level was resonantly excited with a near‐infrared laser beam of 797 nm. Our studies indicate that energy transfer and excited state absorption are responsible for the generation of upconverted green emission from the sample. The upconversion efficiency is found to be 0.14%.
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42.70.Ce Glasses, quartz
42.70.Hj Laser materials
78.55.Hx Other solid inorganic materials
42.55.Rz Doped-insulator lasers and other solid state lasers

Surface plasmon resonance microscopy: Reconstructing a three‐dimensional image

Hywel Morgan and D. Martin Taylor

Appl. Phys. Lett. 64, 1330 (1994); http://dx.doi.org/10.1063/1.111924 (2 pages) | Cited 13 times

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A method for reconstructing three‐dimensional images of thin films from surface plasmon resonance (SPR) microscopy images is described. As an example, monolayers of a lipid were deposited onto a gold substrate using Langmuir–Blodgett technology and an SPR microscope image obtained. Using data from reflectance‐angle (R‐θ) curves obtained in supplementary measurements, the contrast in the microscope image was used to provide thickness information. Converted to a z modulation this was used to produce a three‐dimensional image of the monolayer.  
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68.55.-a Thin film structure and morphology
68.18.-g Langmuir-Blodgett films on liquids
78.66.-w Optical properties of specific thin films

Phase‐matched second‐harmonic generation by periodic poling of fused silica

Raman Kashyap, Gerrit J. Veldhuis, David C. Rogers, and Paul F. Mckee

Appl. Phys. Lett. 64, 1332 (1994); http://dx.doi.org/10.1063/1.111925 (3 pages) | Cited 21 times

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90° phase matching in periodically poled fused silica is achieved over approximately 2 mm at a wavelength of 1064 nm. Electrical poling was done at 5 kV for 120 min using photolithographed periodic electrodes on fused silica glass at 250 °C. A nonlinearity equivalent to d11/200 of quartz is estimated from measurements. Several phase‐matched interactions are reported and the implications for device applications discussed.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.70.Ce Glasses, quartz
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials

Measurement of the 4Pi‐confocal point spread function proves 75 nm axial resolution

S. W. Hell, S. Lindek, C. Cremer, and E. H. K. Stelzer

Appl. Phys. Lett. 64, 1335 (1994); http://dx.doi.org/10.1063/1.111926 (3 pages) | Cited 44 times

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In a 4Pi‐confocal microscope the specimen is illuminated and observed coherently from above and below such that the numerical aperture is increased [S. W. Hell, European Patent Application 91121368.4 (filed 1990, published 1992), S. W. Hell and E. H. K. Stelzer, J. Opt. Soc. Am. A 9, 2159 (1992)]. The point spread functions of 4Pi‐confocal and confocal microscopes were measured. Our measurements prove a three‐ to seven‐fold increase of axial resolution, thus opening the prospect for a powerful three‐dimensional imaging technique with an axial resolution down to 75 nm.  
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07.60.Pb Conventional optical microscopes
42.25.Hz Interference
42.30.-d Imaging and optical processing

In situ acoustic temperature tomography of semiconductor wafers

F. Levent Degertekin, Jun Pei, Butrus T. Khuri‐Yakub, and Krishna C. Saraswat

Appl. Phys. Lett. 64, 1338 (1994); http://dx.doi.org/10.1063/1.111927 (3 pages) | Cited 20 times

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Spatial temperature distribution in semiconductor wafers during rapid thermal processing is obtained by means of acoustic tomography. Ultrasonic Lamb waves are excited in the wafer by acoustic transducers bonded to spring‐loaded quartz support pins located at the wafer periphery. The Lamb wave time of flight in the wafer is used to measure the average wafer temperature with ±0.5 °C accuracy for a S/N ratio exceeding 55 dB. Spatial temperature information is gathered by electronic switching of the transmitter and receiver transducers. Tomographic reconstruction techniques are then used to calculate the temperature distribution from the measurements with different pixel maps. Using eight transducers, the thermal image of a 10 cm, (100) silicon wafer is obtained with 2×2 cm2 pixel resolution. Thermal image rates of 2 images/s are achieved by the system enabling real‐time control of wafer temperature distribution during rapid thermal processing.
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43.35.Sx Acoustooptical effects, optoacoustics, acoustical visualization, acoustical microscopy, and acoustical holography
85.40.-e Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology
07.20.-n Thermal instruments and apparatus

Epitaxial solid‐solution films of immiscible MgO and CaO

E. S. Hellman and E. H. Hartford

Appl. Phys. Lett. 64, 1341 (1994); http://dx.doi.org/10.1063/1.111928 (3 pages) | Cited 11 times

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Metastable solid solutions in the MgO‐CaO system grow readily on MgO at 300 °C by molecular beam epitaxy. The epitaxy displays both the reflection high‐energy electron diffraction oscillations characteristic of layer‐by‐layer growth and the lattice rotations which have been related to island nucleation. Mg1−xCaxO solid solutions grow despite a larger miscibility gap than in any system for which epitaxial solid solutions have been grown. Epitaxial quenching of nonequilibrium solid solutions is possible because of the very low growth temperatures for rock‐salt oxides.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
64.75.-g Phase equilibria
64.60.My Metastable phases

High quality ArF laser ablation of photoincubated polyethylene

P. E. Dyer and D. M. Karnakis

Appl. Phys. Lett. 64, 1344 (1994); http://dx.doi.org/10.1063/1.111929 (3 pages) | Cited 8 times

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The interaction of ArF excimer laser radiation with polyethylene has been investigated using HeNe laser probe beam deflection, energy transmission of thin films, and scanning electron microscopy of the irradiated site. The ‘‘incubation’’ of ultraviolet absorbing chromophores by photoinduced modification appears to play a major role in controlling ablation of this weakly absorbing polymer (∼500 cm−1 at 193 nm). Analytical solution of the photon transport equation including an integrated exposure term to account for incubation provides a good description of the transmission results.
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79.20.Ds Laser-beam impact phenomena
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
81.65.-b Surface treatments

Piezoelectricity and electrostriction of dye‐doped polymer electrets

H.‐J. Winkelhahn, H. H. Winter, and D. Neher

Appl. Phys. Lett. 64, 1347 (1994); http://dx.doi.org/10.1063/1.111930 (3 pages) | Cited 29 times

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An interferometric measurement technique is reported by which the piezoelectric and electro‐ strictive properties of thin films of electrets can be determined. The frozen‐in polarization can be determined from the ratio between piezoelectric and electrostriction constants of the electret film. The method is applied to a poled‐polymer guest‐host system consisting of a polycarbonate host and 4‐dimethylamino‐4′‐nitrostilbene dye. The frozen in polarization measured as a function of poling field agrees well with the predictions for dilute dipolar systems if an affine motion contribution is added to the established theory of the piezoelectric effect of electrets.
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77.65.Bn Piezoelectric and electrostrictive constants
77.84.Jd Polymers; organic compounds
42.70.Jk Polymers and organics

Deposition of metal nanostructures onto Si(111) surfaces by field evaporation in the scanning tunneling microscope

Gregor S. Hsiao, Reginald M. Penner, and Jeff Kingsley

Appl. Phys. Lett. 64, 1350 (1994); http://dx.doi.org/10.1063/1.111931 (3 pages) | Cited 24 times

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Islands of gold or copper having dimensions as small as 200 Å in diameter and 10 Å in height were prepared by field evaporation from a tip of the appropriate metal in a scanning tunneling microscope (STM). The field emission of metal is induced by the application of tip‐negative bias pulses having amplitudes of 6–20 V, and durations of 2 μs to 2 ms. The metallic composition of the protrusions observed by STM are confirmed by ex situ elemental analysis using the field emission scanning Auger microprobe (FE‐SAM). Tip‐positive bias pulses also produce protrusions, however these are unstable either to STM imaging or to exposure to high‐energy electron beams, as in the FE‐SAM instrument. It is therefore probable that nonostructures formed via tip‐positive bias pulses are not metallic. These data provide the first direct experimental evidence for metal transfer between an STM tip and a surface.  
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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
68.37.Ef Scanning tunneling microscopy (including chemistry induced with STM)
68.37.Ps Atomic force microscopy (AFM)
68.37.Rt Magnetic force microscopy (MFM)
68.37.Uv Near-field scanning microscopy and spectroscopy
79.70.+q Field emission, ionization, evaporation, and desorption

Structures and optical properties of organic/inorganic superlattices

Shizuo Tokito, Jiro Sakata, and Yasunori Taga

Appl. Phys. Lett. 64, 1353 (1994); http://dx.doi.org/10.1063/1.111932 (3 pages) | Cited 19 times

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A new class of superlattice materials consisting of alternating layers of organic and inorganic materials has been prepared from 8‐hydroxyquinoline aluminum (Alq) and MgF2 by vacuum deposition. The Alq layer thickness in the superlattices was varied from 10 to 50 Å. Small‐angle x‐ray diffraction measurements indicate that the superlattices have very uniform layered structure throughout the entire stack, and the interfacial roughness is much smaller than 10 Å. From the optical absorption and photoluminescence measurements, it is found that the exciton energy shifts to higher energy with decreasing Alq layer thickness. The changes of the exciton energy could be interpreted as the confinement effects of exciton in the Alq thin layers.
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68.55.-a Thin film structure and morphology
78.66.-w Optical properties of specific thin films

Isolation of fulleride phases by distillation

D. M. Poirier

Appl. Phys. Lett. 64, 1356 (1994); http://dx.doi.org/10.1063/1.111933 (3 pages) | Cited 33 times

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A technique for the synthesis of phase pure alkali‐metal fullerides is demonstrated. The fulleride compounds are distilled from mixed phase samples or from other pure phases by the preferential evaporation of either fullerenes or alkali‐metal atoms. Distillation has been used to form K3C60, K4C60, RbC60, and Rb4C60 which exhibit core level photoemission spectra that are consistent with bulk structure measurements. The KxC70 system, for which structural information has not been reported, was also examined and the compounds KC70, K3C70, and K4C70 were found.
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61.46.-w Structure of nanoscale materials
81.10.-h Methods of crystal growth; physics and chemistry of crystal growth, crystal morphology, and orientation
61.50.Nw Crystal stoichiometry

Preparation of epitaxial AlN films by electron cyclotron resonance plasma‐assisted chemical vapor deposition on Ir‐ and Pt‐coated sapphire substrates

Wei Zhang, Roberto Vargas, Takashi Goto, Yoshihiro Someno, and Toshio Hirai

Appl. Phys. Lett. 64, 1359 (1994); http://dx.doi.org/10.1063/1.111934 (3 pages) | Cited 14 times

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AlN epitaxial films have been fabricated on Ir‐ and Pt‐coated α‐Al2O3 substrates via electron cyclotron resonance plasma‐assisted chemical vapor deposition (ECRPACVD) using an AlBr3‐N2‐H2‐Ar gas system at substrate temperatures ranging from 500 to 700 °C. The epitaxial relationships between AlN films and substrates were determined by x‐ray diffraction, x‐ray pole figure, and reflection high‐energy electron diffraction. The results are useful in practical applications, such as AlN/metal/α‐Al2O3 structure in surface acoustic wave (SAW) devices.
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68.55.-a Thin film structure and morphology
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Photothermoelastic transfer matrix

Zoltán Bozóki, András Miklós, and Dane Bicanic

Appl. Phys. Lett. 64, 1362 (1994); http://dx.doi.org/10.1063/1.111935 (3 pages) | Cited 4 times

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The photothermoelastic transfer matrix method introduced here was demonstrated to be generally applicable for the calculation of the thermoelastic response of multilayered samples exposed to modulated laser heating. The method enables the modelization of photothermal measurements of samples having arbitrary number of layers and values of optical, thermal, and elastic parameters. To demonstrate its feasibility, a general expression for photopyroelectric signals is being presented.  
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65.40.De Thermal expansion; thermomechanical effects
81.70.-q Methods of materials testing and analysis
44.10.+i Heat conduction

Correlation of surface morphology with luminescence of porous Si films by scanning tunneling microscopy

M. Enachescu, E. Hartmann, and F. Koch

Appl. Phys. Lett. 64, 1365 (1994); http://dx.doi.org/10.1063/1.111936 (3 pages) | Cited 13 times

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The evolution of visible photoluminescence is demonstrated by measuring the surface morphology of thin (∼20 nm) electrochemically etched porous silicon (PS) films with scanning tunneling microscopy (STM). Using low current densities, three sorts of samples were prepared under different conditions: In the dark (A), under illumination with ultraviolet (UV) light (B), and in the dark followed by a postphotochemical treatment (C). Upon UV light excitation, type A samples do not emit visible light, while samples of type B and C show weak and efficient photoluminescence in the visible range, respectively. STM imaging of these PS layers reveals a considerable decrease in the lateral dimensions of the surface features from approximately 10 nm (type A) to roughly 2 nm (type C), in accordance with the quantum confinement approach in describing the luminescence properties.
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78.55.Hx Other solid inorganic materials
68.55.-a Thin film structure and morphology
68.35.B- Structure of clean surfaces (and surface reconstruction)
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Lateral p‐n junctions in metal‐organic vapor‐phase epitaxy of AlGaAs lasers on GaAs substrates having [011] etched ridges

T. Y. Wang

Appl. Phys. Lett. 64, 1368 (1994); http://dx.doi.org/10.1063/1.111937 (3 pages) | Cited 2 times

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AlGaAs lasers with a current‐blocking layer have been grown on GaAs substrates having [011] etched ridges using metal‐organic vapor‐phase epitaxy. Conducting channels are formed over the ridges due to the diffusion of Se dopant atoms on the (311)B facets during the nonplanar growth. The formation of lateral p‐n junctions at the substrate interface is evidenced by measuring the electron‐beam‐induced junction current from the front facet of a bonded diode. This result is useful in the single‐step fabrication of laser structures with a novel current‐blocking scheme.
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42.55.Px Semiconductor lasers; laser diodes
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Mg doping of GaInP grown by chemical beam epitaxy using bis‐cyclopentadienyl magnesium

S. Courmont, Ph. Maurel, C. Grattepain, and J. Ch. Garcia

Appl. Phys. Lett. 64, 1371 (1994); http://dx.doi.org/10.1063/1.111938 (3 pages) | Cited 6 times

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We have investigated the p‐type doping of GaInP grown by chemical beam epitaxy using bis‐cyclopentadienyl magnesium (Cp2Mg). Hole concentrations up to the 1018 cm−3 level have been achieved for substrate temperature as high as 550 °C and Mg incorporation was found to grow linearly with the Cp2Mg flow rate in this range. The doping concentration decreases as the substrate temperature increases with an activation energy of 2.15 eV (50 kcal/mol). Two other parameters are the V/III ratio and the growth rate which both enhance the Mg doping when increased.
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68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
73.61.Ey III-V semiconductors

Study of thermal oxidation and nitrogen annealing of luminescent porous silicon

J. Yan, S. Shih, K. H. Jung, D. L. Kwong, M. Kovar, J. M. White, B. E. Gnade, and L. Magel

Appl. Phys. Lett. 64, 1374 (1994); http://dx.doi.org/10.1063/1.111939 (3 pages) | Cited 20 times

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The properties of thermally oxidized porous Si were studied by Fourier‐transform infrared spectroscopy and secondary ion mass spectroscopy. The results show that residual hydrogen exists in the 1000 °C/10 min thermally oxidized porous Si film in the form of SiOH bonds. The removal of these hydrogen atoms by annealing at 1000 °C in N2 reduces the photoluminescence.
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78.55.Hx Other solid inorganic materials
71.55.Cn Elemental semiconductors

Room‐temperature violet stimulated emission from optically pumped AlGaN/GaInN double heterostructure

H. Amano, T. Tanaka, Y. Kunii, K. Kato, S. T. Kim, and I. Akasaki

Appl. Phys. Lett. 64, 1377 (1994); http://dx.doi.org/10.1063/1.111942 (3 pages) | Cited 61 times

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An AlGaN/GaInN heterostructure has been fabricated by metalorganic vapor phase epitaxy. We observed room‐temperature (RT) violet stimulated emission from an optically pumped double heterostructure (DH) using GaInN as an active layer. The peak wavelength of the stimulated emission at RT from Al0.17Ga0.83N/Ga0.91In0.09N DH is 402.5 nm, and the threshold of excitation power density is about 0.13 MW/cm2.
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78.45.+h Stimulated emission
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
42.55.Px Semiconductor lasers; laser diodes

Positron trapping at divacancies in thin polycrystalline CdTe films deposited on glass

L. Liszkay, C. Corbel, L. Baroux, P. Hautojärvi, M. Bayhan, A. W. Brinkman, and S. Tatarenko

Appl. Phys. Lett. 64, 1380 (1994); http://dx.doi.org/10.1063/1.111994 (3 pages) | Cited 56 times

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We have performed positron annihilation experiments on CdTe films grown by vacuum evaporation at 220 °C on both plain glass and indium‐tin‐oxide‐coated glass substrates. By checking the linearity of the valence annihilation parameter S versus the core annihilation parameter W we introduce a method to analyze the data which directly shows that the same vacancy defect can be present in all the films. By comparing the core annihilation parameter at the defect to that at the VCd vacancy we can identify this defect as the divacancy VCd‐VTe. Its concentration in the films decreases from about 1018 to less than 1016 cm−3 after annealing in air at 400 °C for about 30 min. Chlorine doping seems to stabilize the divacancies.
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61.72.J- Point defects and defect clusters
61.72.Cc Kinetics of defect formation and annealing
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
78.70.Bj Positron annihilation

Self‐limiting oxidation for fabricating sub‐5 nm silicon nanowires

H. I. Liu, D. K. Biegelsen, F. A. Ponce, N. M. Johnson, and R. F. W. Pease

Appl. Phys. Lett. 64, 1383 (1994); http://dx.doi.org/10.1063/1.111914 (3 pages) | Cited 119 times

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The ability to control structural dimensions below 5 nm is essential for a systematic study of the optical and electrical properties of Si nanostructures. A combination of electron beam lithography, NF3 reactive ion etching, and dry thermal oxidation has been successfully implemented to yield 2‐nm‐wide Si nanowires with aspect ratio of more than 100 to 1. With a sideview transmission electron microscopy technique, the oxidation progression of Si nanowires was characterized over a range of temperature from 800 to 1200 °C. A previously reported self‐limiting oxidation phenomenon was found to occur only for oxidation temperatures below 950 °C. A preliminary model suggests that increase in the activation energy of oxidant diffusivity in a highly stressed oxide may be the main mechanism for slowing down the oxidation rate in the self‐limiting regime.
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81.65.-b Surface treatments
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
68.37.Hk Scanning electron microscopy (SEM) (including EBIC)
68.37.Lp Transmission electron microscopy (TEM)

2000 V 6H‐SiC p‐n junction diodes grown by chemical vapor deposition

Philip G. Neudeck, David J. Larkin, J. Anthony Powell, Lawrence G. Matus, and Carl S. Salupo

Appl. Phys. Lett. 64, 1386 (1994); http://dx.doi.org/10.1063/1.111915 (3 pages) | Cited 52 times

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In this letter we report on the fabrication and initial electrical characterization of the first silicon carbide diodes to demonstrate rectification to reverse voltages in excess of 2000 V at room temperature. The mesa structured 6H‐SiC p+n junction diodes were fabricated in 6H‐SiC epilayers grown by atmospheric pressure chemical vapor deposition on commercially available 6H‐SiC wafers. The devices were characterized while immersed in FluorinertTM to prevent arcing which occurs when air breaks down under high electric fields. The simple nonoptimized diodes, whose device areas ranged from 7×10−6 to 4×10−4 cm2, exhibited a 2000 V functional device yield in excess of 50%.
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68.55.-a Thin film structure and morphology
85.30.Kk Junction diodes
73.40.Ei Rectification
73.61.Cw Elemental semiconductors
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