Reducing the Proximity Effect in Electron Lithography

1980 ◽  
Vol 38 ◽  
pp. 310-311
Author(s):  
M.R. Soqard
Keyword(s):  
Electron Beam ◽  
Multiple Scattering ◽  
Proximity Effect ◽  
Energy Deposition ◽  
Incident Beam ◽  
Stopping Power ◽  
Local Energy ◽  
Non Local ◽  
The Mean ◽  
Electron Lithography

When an electron beam is used to expose a resist, neighboring regions of the resist are also partially exposed. This arises from multiple scattering of the electrons in the resist and by backscattering of the electrons in both the resist and (mainly) in the substrate beneath the resist. From various studies1,2 this non-local energy deposition can be characterized by a number of regions, There is a very intense energy deposition, which is typically quite narrow and is produced by the direct incident beam broadened by multiple scattering in the resist. This is surrounded by an approximate plateau of intensity of about 1-2 orders of magnitude weaker, which is produced almost entirely by electrons backscattering from the substrate. The plateau arises from two conflicting effects: the backscattering yield drops as we move away from the central beam, but the mean electron energy also decreases. Therefore the stopping power increases, thus tending to offset the first effect. Finally this plateau cuts off fairly sharply at a distance approximately equal to the Bethe range of electrons in the substrate.

Micropatterning of Permalloy Films by Electron Lithography

1976 ◽  
Vol 34 ◽  
pp. 448-449
Author(s):  
J. K. Maurin
Keyword(s):  
Electron Beam ◽  
Subsequent Development ◽  
Electron Optical System ◽  
Microelectronic Device ◽  
Magnetic Bubble ◽  
Control Beam ◽  
Photosensitive Material ◽  
Direct Exposure ◽  
Electron Lithography ◽  
Scanning Electron

Conductor, resistor, and dielectric patterns of microelectronic device are usually defined by exposure of a photosensitive material through a mask onto the device with subsequent development of the photoresist and chemical removal of the undesired materials. Standard optical techniques are limited and electron lithography provides several important advantages, including the ability to expose features as small as 1,000 Å, and direct exposure on the wafer with no intermediate mask. This presentation is intended to report how electron lithography was used to define the permalloy patterns which are used to manipulate domains in magnetic bubble memory devices.The electron optical system used in our experiment as shown in Fig. 1 consisted of a high resolution scanning electron microscope, a computer, and a high precision motorized specimen stage. The computer is appropriately interfaced to address the electron beam, control beam exposure, and move the specimen stage.

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

scholarly journals Proximity Effect Aware Detailed Placement in Electron Beam Lithography

2018 ◽  
Vol 232 ◽  
pp. 04046
Author(s):  
Yuhang Chen ◽  
Zhipeng Huang ◽  
Xiongfeng Chen ◽  
Jianli Chen ◽  
Wenxing Zhu
Keyword(s):  
Electron Beam ◽  
Objective Function ◽  
Proximity Effect ◽  
Electron Beam Lithography ◽  
State Of The Art ◽  
Experimental Result ◽  
Accurate Evaluation ◽  
Evaluation Scheme ◽  
Gauss Transform ◽  
Detailed Placement

Proximity effect is one of the most tremendous consequences that produces unacceptable exposures during electron beam lithography (EBL), and thus distorting the layout pattern. In this paper, we propose the first work which considers the proximity effect during layout stage. We first give an accurate evaluation scheme to estimate the proximity effect by fast Gauss transform. Then, we devote a proximity effect aware detailed placement objective function to simultaneously consider wirelength, density and proximity effect. Furthermore, cell swapping and cell matching based methods are used to optimize the objective function such that there is no overlap among cells. Compared with a state-of-the-art work, experimental result shows that our algorithm can efficiently reduce the proximity variations and maintain high wirelength quality at a reasonable runtime.

PATH INTEGRAL APPROACH TO A SINGLE POLYMER CHAIN WITH RANDOM MEDIA

2004 ◽  
Vol 18 (10n11) ◽  
pp. 1465-1478 ◽  
Author(s):  
CH. KUNSOMBAT ◽  
V. SA-YAKANIT
Keyword(s):  
Polymer Chain ◽  
Path Integral ◽  
Random Media ◽  
Feynman Path Integral ◽  
Feynman Path ◽  
Short Range Correlation ◽  
Range Correlation ◽  
End Distance ◽  
Non Local ◽  
The Mean

In this paper we consider the problem of a polymer chain in random media with finite correlation. We show that the mean square end-to-end distance of a polymer chain can be obtained using the Feynman path integral developed by Feynman for treating the polaron problem and successfuly applied to the theory of heavily doped semiconductor. We show that for short-range correlation or the white Gaussian model we derive the results obtained by Edwards and Muthukumar using the replica method and for long-range correlation we obtain the result of Yohannes Shiferaw and Yadin Y. Goldschimidt. The main idea of this paper is to generalize the model proposed by Edwards and Muthukumar for short-range correlation to finite correlation. Instead of using a replica method, we employ the Feynman path integral by modeling the polymer Hamiltonian as a model of non-local quadratic trial Hamiltonian. This non-local trial Hamiltonian is essential as it will reflect the translation invariant of the original Hamiltonian. The calculation is proceeded by considering the differences between the polymer propagator and the trial propagator as the first cumulant approximation. The variational principle is used to find the optimal values of the variational parameters and the mean square end-to-end distance is obtained. Several asymptotic limits are considered and a comparison between this approaches and replica approach will be discussed.

scholarly journals Non-local energy transport in tunneling and plasmonic structures

2011 ◽  
Vol 19 (16) ◽  
pp. 15281 ◽  
Author(s):  
Winston Frias ◽  
Andrei Smolyakov ◽  
Akira Hirose
Keyword(s):  
Energy Transport ◽  
Local Energy ◽  
Plasmonic Structures ◽  
Non Local

Estimation of Nanometer-Sized EB Patterning Using Energy Deposition Distribution in Monte Carlo Simulation

2011 ◽  
Vol 497 ◽  
pp. 127-132 ◽  
Author(s):  
Hui Zhang ◽  
Takuro Tamura ◽  
You Yin ◽  
Sumio Hosaka
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Electron Beam ◽  
Energy Distribution ◽  
Electron Energy ◽  
Electron Beam Lithography ◽  
Energy Deposition ◽  
Si Substrate ◽  
Positive Resist

We have studied on theoretical electron energy deposition in thin resist layer on Si substrate for electron beam lithography. We made Monte Carlo simulation to calculate the energy distribution and to consider formation of nanometer sized pattern regarding electron energy, resist thickness and resist type. The energy distribution in 100 nm-thick resist on Si substrate were calculated for small pattern. The calculations show that 4 nm-wide pattern will be formed when resist thickness is less than 30 nm. Furthermore, a negative resist is more suitable than positive resist by the estimation of a shape of the energy distribution.

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