Transport Measurements of Individual Bi Nanowires

1999 ◽  
Vol 582 ◽  
Author(s):  
Stephen B. Cronin ◽  
Yu Ming Lin ◽  
Takaaki Koga ◽  
Jackie Y. Ying ◽  
Mildred S. Dresselhaus
Keyword(s):  
Electron Beam ◽  
Temperature Dependence ◽  
Electron Beam Lithography ◽  
Ohmic Contacts ◽  
Physical Significance ◽  
Alumina Template ◽  
Burn Out ◽  
Bi Nanowire ◽  
Lithography Technique ◽  
Confined System

ABSTRACTTransport properties are reported for Bi nanowires, prepared by the filling of an alumina template with molten Bi. The temperature dependence of the resistance is presented for such arrays of Bi nanowires with diameters in the 40 to 200nm range. The data are understood qualitatively on the basis of a model for a quantum-confined system. Finally, a 4-point measurement is performed on an individual Bi nanowire prepared by using an electron beam lithography technique. Techniques for handling the practical issues of non-ohmic contacts and wire burn-out are given. The physical significance of the final results of the measurements are discussed in light of various scattering mechanisms in the nanowire.

Facile electron-beam lithography technique for irregular and fragile substrates

2014 ◽  
Vol 105 (17) ◽  
pp. 173109 ◽  
Author(s):  
Jiyoung Chang ◽  
Qin Zhou ◽  
Alex Zettl
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Lithography Technique

Submicron Pseudomorphic Hemt’S Using Non-Alloyed Ohmic Contacts with Contrast Enhancement.

1990 ◽  
Vol 181 ◽  
Author(s):  
Ph. Jansen ◽  
W. De Raedt ◽  
M. Van Hove ◽  
R. Jonckheere ◽  
R. Pereira ◽  
...  
Keyword(s):  
Electron Beam ◽  
Contact Resistance ◽  
Electron Beam Lithography ◽  
High Performance ◽  
Ohmic Contacts ◽  
Sintering Temperature ◽  
Enhancement Mode ◽  
First Time ◽  
Lower Contact ◽  
Very High

ABSTRACTWe report for the first time the realization of submicron pseudomorphic Al.15, Ga.85As-In.20Ga.80As HEMT’s with non-alloyed Pd/Ge ohmic coi tacts. Best results of contact resistance were obtained at a sintering temperature of 340°C with values as low as 0.057 Ωmm. Enhanced contrast, needed for accurate alignment of the gate by electron-beam lithography, was obtained by using Pd/Ge/Ti/Pd and Pd/Ge/Ti/Pt metal sequences. These contacts exhibited even lower contact resistances than the standard Pd/Ge contacts. Although Pd/Ge/Ti/Pd exhibits good morphology, reaction is witnessed at the edges, reducing the accuracy of alignment.Processed enhancement mode devices exhibit maximum transconductances in excess of 520 mS/mm and currents of 300 mA/mm for 0.3 micron gatelength. This study shows that the contact resistance is no longer a restriction for obtaining very high transconductances in high performance devices.

Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

1982 ◽  
Vol 40 ◽  
pp. 78-79
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Inelastic Scattering ◽  
Temperature Dependence ◽  
Structural Damage ◽  
Direct Result ◽  
Second Step ◽  
Strong Temperature Dependence ◽  
Electron Dose ◽  
Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

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