Ge dot organization on Si substrates patterned by focused ion beam

ABSTRACTThe pressure filling of anodic alumina templates with molten bismuth has been used to synthesize single crystalline bismuth nanowires with diameters ranging from 7 to 200nm and lengths of 50μm. The nanowires are separated by dissolving the template, and electrodes are affixed to single Bi nanowires on Si substrates. A focused ion beam (FIB) technique is used first to sputter off the oxide from the nanowires with a Ga ion beam and then to deposit Pt without breaking vacuum. The resistivity of a 200nm diameter Bi nanowire is found to be only slightly greater than the bulk value, while preliminary measurements indicate that the resistivity of a 100nm diameter nanowire is significantly larger than bulk. The temperature dependence of the resistivity of a 100nm nanowire is modeled by considering the temperature dependent band parameters and the quantized band structure of the nanowires. This theoretical model is consistent with the experimental results.

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Formation of Sub-100 NM GE Wires on Si by E-Beam Evaporation/Lithography

MRS Proceedings ◽

10.1557/proc-380-105 ◽

1995 ◽

Vol 380 ◽

Cited By ~ 1

Author(s):

C. Deng ◽

J. C. Wu ◽

C. J. Barbero ◽

T. W. Sigmon ◽

M. N. Wybourne

Keyword(s):

Cross Section ◽

Focused Ion Beam ◽

Ion Beam ◽

Si Substrates ◽

Novel Technique ◽

Atomic Force ◽

Transmission Electron ◽

First Time ◽

Scanning Electron

ABSTRACTA fabrication process for sub-100 nm Ge wires on Si substrates is reported for the first time. Wires with a cross section of 6 × 57 nm2 are demonstrated. The wire structures are analyzed by atomic force (AFM), scanning electron (SEM), and transmission electron microscopy (TEM). Sample preparation for TEM is performed using a novel technique using both pre and in situ deposition of multiple protection layers using a Focused Ion Beam (FIB) micromachining system.

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Fabricating Two-Dimensional Metal Nanocrystal Arrays Using Pulsed-Laser Deposition and Focused Ion-Beam Technologies

MRS Proceedings ◽

10.1557/proc-636-d5.6.1 ◽

2000 ◽

Vol 636 ◽

Author(s):

Richard F. Haglund ◽

Robert A. Weller ◽

Cynthia E. Heiner ◽

Matthew D. McMahon ◽

Robert H. Magruder ◽

...

Keyword(s):

Pulsed Laser Deposition ◽

Focused Ion Beam ◽

Ion Beam ◽

High Vacuum ◽

Pulsed Laser ◽

Laser Deposition ◽

Silicon Surfaces ◽

Silver Nanoclusters ◽

Laser Evaporation ◽

Si Substrates

AbstractWe describe recent experiments in which we attempted the initial steps for fabricating twodimensional arrays of metal nanocrystals. We use a commercial pulsed-laser deposition system in concert with a focused ion beam to attempt control over both lateral and vertical dimensions at the nanometer length scale. In our experiments, regular arrays of holes typically 80 nm in diameter were drilled in Si substrates using the focused ion beam. Silver atoms were then deposited onto these substrates by pulsed laser evaporation from a metallic target in high vacuum. Under certain conditions of substrate temperature, laser pulse repetition rate, and fluence, small silver nanoclusters form preferentially around the structures previously etched in the silicon surfaces by the focused ion beam.

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Sub-Micron Selective Photoluminescence in Porous Si by Focused Ion Beam Implantation

MRS Proceedings ◽

10.1557/proc-281-519 ◽

1992 ◽

Vol 281 ◽

Author(s):

A. J. Steckl ◽

J. Xu ◽

H. C. Mogul ◽

S. Mogren

Keyword(s):

Incubation Time ◽

Focused Ion Beam ◽

Hole Concentration ◽

Ion Beam ◽

Porous Si ◽

Strong Function ◽

Si Substrates ◽

Si Doping ◽

Broad Beam ◽

First Time

ABSTRACTThe effect of Si doping on the formation of stain-etched porous Si and its photoluminescent properties was studied. Porous Si is obtained by purely chemical etching of crystalline Si in a solution of HF:HNO3:H2O in the ratio of 1:3:5. We have observed that an incubation time (ti) exists between the insertion of Si into the solution and the onset of porous Si production. This incubation time was found to be a strong function of hole concentration in both n- and p-Si. In p-Si, the ti decreased rapidly with increasing conductivity, whereas for n-Si the opposite (but not as pronounced) trend was found to be the case. For example in (B-doped) p-Si, ti, is only ∼0.5 min for 250 (Ω-cm)−1 but increases to ∼ 5 min for 0.2 (Ω-cm)−1. In (P-doped) n-Si substrates ti was ∼ 8 min for 0.2 (Ω-cm)−1 increasing to ∼ 10 min for 7 (Ω-cm)−1. Photoluminescence (PL) measurements of the porous Si obtained on substrates of various conductivity (p and n) show similar spectra, namely a peak at around 1.94 eV with a full width at half-maximum (FWHM) of about 0.5 eV. Based on the ti difference, we have fabricated localized photoemitting porous Si patterns by Ga+ focused ion beam (FIB) implantation doping and B+ broad beam (BB) implantation doping of n-type Si. Using 30 kV FIB Ga+ implantation, sub-micron photoemitting patterns have been obtained for the first time.

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Development of a Refractory Hexagonal Closed Packed High Entropy Alloy Based on Thin Film Screening

MRS Advances ◽

10.1557/adv.2019.114 ◽

2019 ◽

Vol 4 (25-26) ◽

pp. 1435-1440

Author(s):

Azin Akbari ◽

T. John Balk

Keyword(s):

Thin Film ◽

Single Phase ◽

Focused Ion Beam ◽

Ion Beam ◽

High Entropy Alloy ◽

Electron Backscattered Diffraction ◽

X Ray ◽

High Entropy ◽

Si Substrates ◽

Hexagonal Closed Packed

In order to identify candidate high entropy alloys (HEAs) that have the hexagonal closed packed crystal structure, gradient thin films in the OsRuWMoRe system were deposited by sputtering from multiple elemental targets onto Si substrates. In addition to having compositional gradients, the films exhibited regions with different phases, some of which were single-phase and non-equiatomic. Such alloys have the potential to exhibit properties superior to the primarily equiatomic HEAs that have been the focus of most work in this area. To screen the phases that exist across the thin film gradient samples, a range of characterization techniques were employed, including focused ion beam and scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray diffraction and electron backscattered diffraction analysis. The combinatorial method described in this study enabled the identification of a candidate single-phase HEA that was subsequently fabricated as a bulk alloy.

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Si Nanostructure Fabrication by Ga+ FIB Selective Doping and Anisotropic Etching

MRS Proceedings ◽

10.1557/proc-256-123 ◽

1991 ◽

Vol 256 ◽

Author(s):

A. J. Steckl ◽

H. C. Mogul ◽

S. Mogren

Keyword(s):

Etch Rate ◽

Focused Ion Beam ◽

Ion Beam ◽

Anisotropic Etching ◽

Wet Etching ◽

Fabrication Technique ◽

Nanostructure Fabrication ◽

Implantation Energy ◽

Si Substrates ◽

Si Nanostructures

ABSTRACTA novel fabrication technique involving the use of focused ion beam (FIB) selective implantation to fabricate nanostructures on crystalline Si substrates in conjunction with anisotropic etching is described. Using this maskless & resistless approach, Si nanostructures were fabricated by FIB implantation of Ga+ at doses from 1015 to 1016/cm 2. Wet etching in KOH/IPA does not attack the implanted region, while it removes the underlying Si anisotropically, with a very low etch rate on the {111} planes. The result is a cantilever-like structure whose thickness is dependent on the implantation energy and dose. Pre-etching rapid thermal annealing at 600°C for 30 sec does not prevent structure fabrication and post-etching RTA does not affect the shape of the structures.

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High-Selectivity Growth of GaN Nanorod Arrays by Liquid-Target Magnetron Sputter Epitaxy

Coatings ◽

10.3390/coatings10080719 ◽

2020 ◽

Vol 10 (8) ◽

pp. 719

Author(s):

Elena Alexandra Serban ◽

Aditya Prabaswara ◽

Justinas Palisaitis ◽

Per Ola Åke Persson ◽

Lars Hultman ◽

...

Keyword(s):

Growth Rate ◽

Focused Ion Beam ◽

High Selectivity ◽

Ion Beam ◽

Substrate Surface ◽

Growth Control ◽

High Growth ◽

Si Substrates ◽

Surface Diffusivity ◽

Magnetron Sputter

Selective-area grown, catalyst-free GaN nanorod (NR) arrays grown on Si substrates have been realized using liquid-target reactive magnetron sputter epitaxy (MSE). Focused ion beam lithography (FIBL) was applied to pattern Si substrates with TiNx masks. A liquid Ga target was sputtered in a mixture gas of Ar and N2, ranging the N2 partial pressure (PN₂) ratio from 100% to 50%. The growth of NRs shows a strong correlation with PN₂ on the selectivity, coalescence, and growth rate of NRs in both radial and axial directions. The growth rate of NRs formed inside the nanoholes increases monotonically with PN₂. The PN₂ ratio between 80% and 90% was found to render both a high growth rate and high selectivity. When the PN₂ ratio was below 80%, multiple NRs were formed in the nanoholes. For a PN₂ ratio higher than 90%, parasitic NRs were grown on the mask. An observed dependence of growth behavior upon the PN₂ ratio is attributed to a change in the effective Ga/N ratio on the substrate surface, as an effect of impinging reactive species, surface diffusivity, and residence time of adatoms. The mechanism of NR growth control was further investigated by studying the effect of nanoholes array pitch and growth temperature. The surface diffusion and the direct impingement of adatoms were found to be the dominant factors affecting the lateral and axial growth rates of NR, respectively, which were well elucidated by the collection area model.

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The Effect of Film Thickness on Stress and Transformation Behavior in Cobalt Thin Films

MRS Proceedings ◽

10.1557/proc-594-219 ◽

1999 ◽

Vol 594 ◽

Cited By ~ 5

Author(s):

H. Th. Hesemann ◽

P. Müllner ◽

O. Kraft ◽

E. Arzt

Keyword(s):

Thin Films ◽

Martensitic Transformation ◽

Film Thickness ◽

Focused Ion Beam ◽

Ion Beam ◽

Film Stress ◽

Maximum Temperature ◽

Face Centered Cubic ◽

Temperature Cycles ◽

Si Substrates

AbstractPure cobalt shows a martensitic transformation from a face-centered-cubic to an hexagonal-close-packed phase. In this work it is chosen as a model-system to investigate the influence of film thickness, film stress and microstructure on the martensitic transformation in thin films.Co films of 0.2 μm to 3.0 μm thickness were sputter-deposited on Si substrates. This paper presents wafer curvature measurements during temperature cycles of these films and results obtained by focused ion beam microscopy. Upon repeated thermocycling, the martensitic transformation was repeatedly observed in 3 μm thick films, whereas it was not found in 0.2 μm Co films. A stress drop on heating as well as on cooling accompanied the martensitic transformation. It was observed that the stress level at which the transformation occurs can be changed by varying the film thickness or maximum temperature of the temperature cycles. As a result, the martensitic start temperature decreases with increasing stress. It is concluded that the film stress is a critical parameter which strongly affects the martensitic transformation.

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Hillock formation and thermal stresses in thin Au films on Si substrates

MRS Proceedings ◽

10.1557/proc-875-o5.2 ◽

2005 ◽

Vol 875 ◽

Cited By ~ 2

Author(s):

Linda Sauter ◽

T. John Balk ◽

Gerhard Dehm ◽

Julie A. Nucci ◽

Eduard Arzt

Keyword(s):

Electron Microscopy ◽

Focused Ion Beam ◽

Thermal Stresses ◽

Ion Beam ◽

Morphological Development ◽

Wafer Curvature ◽

Fine Grained ◽

Si Substrates ◽

Hillock Formation ◽

Scanning Electron

AbstractThe wafer curvature technique was used to analyze stresses in fine-grained, 50 nm to 2 μm thick Au films on silicon substrates between room temperature and 500°C. The microstructural evolution was analyzed by scanning electron microscopy (SEM), focused ion beam (FIB) microscopy and transmission electron microscopy (TEM). In situ heating experiments inside a scanning electron microscope provided a comparison between the morphological development and the stress-temperature behavior of the film. Hillock formation was observed, but it can only partially account for the stress relaxation measured by the wafer curvature technique.

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