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1. |
Reflection high energy electron diffraction intensity behavior during homoepitaxial molecular beam epitaxy growth of GaAs and implications for growth kinetics and mechanisms |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1317-1322
B. F. Lewis,
F. J. Grunthaner,
A. Madhukar,
T. C. Lee,
R. Fernandez,
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摘要:
The dynamic behavior of GaAs surfaces during and after growth by MBE has been probed by detailed measurements of the specular beam intensity in RHEED patterns from the surfaces. The damping of the intensity oscillations observed after growth has commenced is shown to be a strong function of arsenic pressure with high pressure causing strong damping and rough growth fronts. The specular beam intensity after steady‐state growth has been interrupted shows first an initial fast increase with the largest increase occurring at low arsenic pressure, and then a slow recovery to its equilibrium no‐growth intensity at a rate that increases with arsenic pressure. Measurements of the intensity recovery after short growths on an equilibrated no‐growth surface provide new information about the growth front behavior during the first few monolayers of growth. The surface recovers in the shortest time after deposition of either a small fraction of a monolayer or slightly more than an integer number of monolayers. Recovery is slow after deposition of half a monolayer due to the resulting high step density. Surprisingly, recovery is slowest after deposition of 1.0 monolayer, indicating that such surfaces are very different from the equilibrium no‐growth surface.
ISSN:1071-1023
DOI:10.1116/1.582986
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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2. |
Molecular beam epitaxy growth of high performance GaAs power field effect transistors |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1323-1326
J. K. Abrokwah,
J. Geddes,
M. Longerbone,
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摘要:
GaAs power field effect transistors (FET’s) with the highest power output per unit gate width (0.46 W/mm) reported to data at Ka‐band frequency were fabricated using molecular beam epitaxy material with active layer doping of 3.6×1017cm3. Power output of 110 mW and conversion efficiency of 11% were achieved with half‐micron gate GaAs FET’s in a 30 GHz amplifier with an associated gain of 3.4 dB. This report describes the molecular beam epitaxy (MBE) growth conditions and results of characterization of the power FET.
ISSN:1071-1023
DOI:10.1116/1.582987
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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3. |
Silicide formation of thin vanadium layers in ultrahigh vacuum studied by ion scattering, Auger electron spectroscopy, low energy electron diffraction, and secondary ion mass spectrometry |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1327-1331
C. Achete,
H. Niehus,
W. Losch,
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摘要:
Vanadium silicide formation has been monitored by low energy noble gas ion scattering (IS), Auger electron spectroscopy (AES), and secondary ion mass spectrometry (SIMS). Vanadium deposited at 300 K shows no silicide formation. The topmost layer is composed of V atoms only. Annealing leads to a chemical reaction of vanadium and silicon to a vanadium silicide. Upon annealing atT=830 K the top layer consists of a Si layer. The silicide formation could be monitored by the VSi+2SIMS line. At 830 K a complete reaction of a 5000‐Å‐thick V film into a VSi2silicide occurs.
ISSN:1071-1023
DOI:10.1116/1.582988
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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4. |
High‐current and thermal‐shock testing of TaSi2–polycide/Al‐alloy composites |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1332-1339
T. J. Faith,
R. S. Irven,
E. P. Bertin,
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摘要:
High‐current failure levels of TaSi2–polycide/Al‐alloy bilevel‐conductor composites were measured using 10 min increment step‐stress tests. Al‐alloy metallizations were Al and Al–1%Si; polycide and metal linewidths ranged from 2.5 to 3.0 μm; and interlevel‐contact sizes ranged from 1.5 to 2.0 μm2. In all cases, the weak links in the bilevel composite were the interlevel contacts. In units with contact resistances less than 1 Ω, failures occurred at the positive contact at polycide‐line current densities ≥1.4×107A/cm2, which resulted in Joule heating of the polycide line to ≥400 °C. Polycide line damage and Al, which had migrated in the direction of the electric field, often extended to distances>100 μm from the failed contact. Early failures, highly localized at the negative contact, were consistently experienced by units with initial contact resistances above approximately 1 Ω. The failure levels decreased (to current densities as low as 5×106A/cm2) with increasing initial contact resistance. Thirty cycles of thermal shock (−70 to +100 °C) resulted in no reduction in the current level at which high‐current failure occurred in units with good contacts.
ISSN:1071-1023
DOI:10.1116/1.582989
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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5. |
Preparation of low‐reflectivity Al–Si film using dc magnetron sputtering and its application to multilevel metallization |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1340-1345
K. Kamoshida,
T. Makino,
H. Nakamura,
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摘要:
A low‐reflectivity aluminum–silicon (LR Al–Si) film is prepared using a dc magnetron sputtering system under high Ar pressures. At a wavelength 4360 Å, the Al–2% Si film deposited at 3.99 Pa shows a specular reflectivity of 0.15 and a diffuse reflectivity of 0.10. The low‐reflectivity is ascribable to the formation of columnar structures of several hundred angstroms with open boundaries. The formation is caused by thermalization of sputtered Al(Si) atoms and the suppression of surface migration by Si atoms. Microvoids formed between columnar crystallites are thought to absorb incident light. This film is applied to multilevel metallization, and the results obtained include improvement of patternability in photolithography, reduction of hillock formation, and thermal stability of contact characteristics. This film is thus attractive because it is simply prepared and processing procedures for multilevel metallization do not require any major modification of conventional processes.
ISSN:1071-1023
DOI:10.1116/1.582990
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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6. |
Block copolymers as bilevel resists |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1346-1351
M. A. Hartney,
A. E. Novembre,
F. S. Bates,
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摘要:
A bilayer resist system is demonstrated using chlorinated polymethylstyrene‐polydimethylsiloxane (CPMS/DMS) block copolymers. The copolymers are prepared using anionic polymerization techniques and are subsequently sensitized to electron beam, and 250–300 nm radiation by preferential chlorination of the polymethylstyrene block. The electron lithographic performance of a block copolymer containing 15.5 wt. % silicon, 0.58 chlorines per methylstyrene unit (totalM̄w=8.7×104) and polydispersity=1.3 was determined to exhibit a sensitivity (D0.5g)=0.9 μC/cm2, and contrast=1.3. The etch ratio compared to the HPR‐204 planarizing layer was 13.5 : 1 with an observed resolution range of 0.75 to 1.0 μm. These results derive from the intrinsic behavior of block copolymers, which provides for the synergistic combination of inherently distinct polymer species while avoiding macroscopic phase separation prevalent in homopolymer blends. The concept of utilizing block copolymers as resists is general and may be extended to positive tone resists as well.
ISSN:1071-1023
DOI:10.1116/1.582991
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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7. |
O2plasma‐converted spin‐on‐glass for planarization |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1352-1356
A. D. Butherus,
T. W. Hou,
C. J. Mogab,
H. Schonhorn,
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摘要:
So‐called ‘‘spin‐on‐Glass’’ materials (herein abbreviated as SOG) have generated a considerable amount of interest in the field of microelectronic materials and processing. The materials have been used for some time as doping sources, and have recently been investigated for use as dielectric layers, planarizing layers, RIE etch stops in multilevel lithography processes, and as final passivation layers. We report here the use of a commercially available SOG, Owens‐Illinois GR‐650 as a planarizing layer. Additionally we report a process by which this material can be converted from the as‐deposited organic polysiloxane material to an inorganic SiO2. This conversion is effected at low (≤100 °C) temperatures by an rf‐generated oxygen plasma. This process is particularly attractive for fabricating devices when the higher temperatures of plasma deposited SiO2(>250 °C) or thermally converted SOG (≊500 °C) cannot be tolerated.
ISSN:1071-1023
DOI:10.1116/1.582992
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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8. |
Resist patterning and x‐ray mask fabrication employing focused ion beam exposure and subsequent dry etching |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1357-1361
Hiroki Kuwano,
Hedetoshi Takaoka,
Akira Ozawa,
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摘要:
A lithographic method using focused ion beam exposure and subsequent dry etching is examined. The lithographic mechanism is also investigated. Employing resist patterns formed by this method, an x‐ray mask is prepared. It is shown that Ga ion exposed regions of polymer resists act as aninsitumask during the O2reactive ion etching dry development of unexposed regions. Gallium distribution and its chemical shift in a resist after exposure or development are measured by XPS. The surface gallium atoms of resist exposed to oxygen plasma are changed to Ga2O3, which covers the resist surface and acts asinsitumasks against the oxygen plasma. The feasibility of the lithographic method is demonstrated by a preparation of submicron pattern x‐ray masks.
ISSN:1071-1023
DOI:10.1116/1.582993
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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9. |
Near surface damage induced in polyimides by ion beam etching |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1362-1364
William E. Vanderlinde,
Peter J. Mills,
Edward J. Kramer,
Arthur L. Ruoff,
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摘要:
Polyimide layers approximately 10 μm thick on Si wafers were ion beam etched (IBE) by Ar. Ion energies up to 1000 eV and beam current densities as high as 0.3 mA/cm2were used to a total dose of 54 mC/cm2. After etching, the samples were exposed to iodine vapor for fixed periods of time. The diffusion of iodine into the samples was used to probe for ion induced changes in the polyimide structure. The concentration of the diffused iodine was measured as a function of depth by Rutherford backscattering spectrometry. For the IBE samples the surface concentration of iodine was markedly decreased. The iodine diffusivity in the near surface region of thickness 0.2 μm was reduced by two orders of magnitude. These results indicate that etching appears to cause modification of the polyimide film at depths far greater than the range of the incident ions or their secondary electrons in polyimide.
ISSN:1071-1023
DOI:10.1116/1.582994
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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10. |
Summary Abstract: Ion‐enhanced processes in etching of silicon |
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Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena,
Volume 3,
Issue 5,
1985,
Page 1373-1375
T. M. Mayer,
M. S. Ameen,
E. L. Barish,
T. Mizutani,
D. J. Vitkavage,
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ISSN:1071-1023
DOI:10.1116/1.582995
出版商:American Vacuum Society
年代:1985
数据来源: AIP
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