scholarly journals Fabrication of Superconducting Nb–AlN–NbN Tunnel Junctions Using Electron-Beam Lithography

Electronics ◽  
2021 ◽  
Vol 10 (23) ◽  
pp. 2944
Author(s):  
Mikhail Yu. Fominsky ◽  
Lyudmila V. Filippenko ◽  
Artem M. Chekushkin ◽  
Pavel N. Dmitriev ◽  
Valery P. Koshelets
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Tunnel Junctions ◽  
Intrinsic Noise ◽  
Exposure Dose ◽  
Quality Parameters ◽  
Lower Sensitivity ◽  
Input Devices ◽  
Plasma Chemical Etching ◽  
Etching Parameters

Mixers based on superconductor–insulator–superconductor (SIS) tunnel junctions are the best input devices at frequencies from 0.1 to 1.2 THz. This is explained by both the extremely high nonlinearity of such elements and their extremely low intrinsic noise. Submicron tunnel junctions are necessary to realize the ultimate parameters of SIS receivers, which are used as standard devices on both ground and space radio telescopes around the world. The technology for manufacturing submicron Nb–AlN–NbN tunnel junctions using electron-beam lithography was developed and optimized. This article presents the results on the selection of the exposure dose, development time, and plasma chemical etching parameters to obtain high-quality junctions (the ratio of the resistances below and above the gap Rj/Rn). The use of a negative-resist ma-N 2400 with lower sensitivity and better contrast in comparison with a negative-resist UVN 2300-0.5 improved the reproducibility of the structure fabrication process. Submicron (area from 2.0 to 0.2 µm2) Nb–AlN–NbN tunnel junctions with high current densities and quality parameters Rj/Rn > 15 were fabricated. The spread of parameters of submicron tunnel structures across the substrate and the reproducibility of the cycle-to-cycle process of tunnel structure fabrication were measured.

scholarly journals Изготовление сверхпроводниковых туннельных структур с использованием электронно-лучевой литографии

2021 ◽  
Vol 63 (9) ◽  
pp. 1228
Author(s):  
М.Ю. Фоминский ◽  
Л.В. Филиппенко ◽  
А.М. Чекушкин ◽  
В.П. Кошелец
Keyword(s):  
Tunnel Junctions ◽  
High Current Density ◽  
Exposure Dose ◽  
Quality Parameter ◽  
Lower Sensitivity ◽  
High Current ◽  
Plasma Chemical ◽  
Plasma Chemical Etching ◽  
Etching Parameters

The technology for manufacturing submicron Nb - AlN - NbN tunnel junctions using electron beam lithography has been developed and optimized. Investigations have been carried out to select the exposure dose, development time, and plasma-chemical etching parameters to obtain the high quality of junctions (the ratio of the resistances below and above the gap Rj/Rn). The use of a negative resist ma-N 2400 with lower sensitivity and better contrast in comparison with a negative resist UVN 2300-0.5 has improved the reproducibility of the structure fabrication process. The submicron (area from 2.0 to 0.2 µm2) tunnel junctions Nb - AlN - NbN with high current density and quality parameter Rj / Rn> 15 were fabricated. The spread of parameters of submicron tunnel structures across the substrate and the reproducibility of the cycle-to-cycle process of fabrication of tunnel structures has been experimentally measured.

Electron Beam Dose and PMMA Thickness Dependent Circularity and Diameter Analysis of Au Nanodots

2019 ◽  
Vol >15 (5) ◽  
pp. 486-491 ◽  
Author(s):  
Furkan Kuruoğlu ◽  
Özgür Yavuzçetin ◽  
Ayşe Erol
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Electron Beam ◽  
Electron Beam Lithography ◽  
Thermal Evaporation ◽  
Exposure Dose ◽  
Homogeneous Distribution ◽  
Electrical And Optical Properties ◽  
Beam Dose ◽  
Au Nanodots

Background: The electrical and optical properties of nanoparticle-based devices depend on the shape, dimension and uniformity of these particles. Methods: In this work, we fabricated ordered Au nanodots using electron beam lithography and thermal evaporation. Au nanodot diameter and circularity varied with a changed exposure dose and resist thickness. Electron beam dose ranged from 5 fC to 200 fC for single dot patterns. Commonly used PMMA thin films of thicknesses 60 nm and 100 nm coated samples were used for investigating the resist thickness dependency with varying dose exposure. Results: The analyses of patterns show that the diameter and circularity of the Au nanodots ranged from smaller to larger diameters and from lower to higher circularities with increasing dose and resist thickness. Conclusion: The distributions of the nanodot diameter began to show Gaussian behavior at larger electron doses. Besides, single circularity value became dominant up to the medium doses and then a homogeneous distribution was observed with the increasing dose.

scholarly journals Accurate Coulomb blockade thermometry up to 60 kelvin

2016 ◽  
Vol 374 (2064) ◽  
pp. 20150052 ◽  
Author(s):  
M. Meschke ◽  
A. Kemppinen ◽  
J. P. Pekola
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Coulomb Blockade ◽  
Tunnel Junctions ◽  
Nano Fabrication ◽  
Temperature Reading

We demonstrate experimentally a precise realization of Coulomb blockade thermometry working at temperatures up to 60 K. Advances in nano-fabrication methods using electron beam lithography allow us to fabricate uniform arrays of sufficiently small tunnel junctions to guarantee an overall temperature reading precision of about 1%.

Magnetic tunnel junctions fabricated at tenth-micron dimensions by electron beam lithography

1997 ◽  
Vol 35 (1-4) ◽  
pp. 249-252 ◽  
Author(s):  
S.A. Rishton ◽  
Y. Lu ◽  
R.A. Altman ◽  
A.C. Marley ◽  
X.P. Bian ◽  
...  
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions

Fabrication of ultrasmall tunnel junctions by electron‐beam lithography

1992 ◽  
Vol 63 (3) ◽  
pp. 1918-1921 ◽  
Author(s):  
S. J. Koester ◽  
G. Bazán ◽  
G. H. Bernstein ◽  
W. Porod
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Tunnel Junctions

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.

Fabrication of Si photonic waveguides by electron beam lithography using improved proximity effect correction

2020 ◽  
Vol 59 (12) ◽  
pp. 126502
Author(s):  
Moataz Eissa ◽  
Takuya Mitarai ◽  
Tomohiro Amemiya ◽  
Yasuyuki Miyamoto ◽  
Nobuhiko Nishiyama
Keyword(s):  
Electron Beam ◽  
Proximity Effect ◽  
Electron Beam Lithography ◽  
Photonic Waveguides ◽  
Proximity Effect Correction

Salicidation process for submicrometre gate MOSFET fabrication using a resistless electron beam lithography process

1999 ◽  
Vol 35 (15) ◽  
pp. 1283 ◽  
Author(s):  
S. Michel ◽  
E. Lavallée ◽  
J. Beauvais ◽  
J. Mouine
Keyword(s):  
Electron Beam ◽  
Electron Beam Lithography ◽  
Lithography Process
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