Aqueous base development and acid diffusion length optimization in negative epoxy resist for electron beam lithography

Author(s):  
N. Glezos ◽  
P. Argitis ◽  
D. Velessiotis ◽  
I. Raptis ◽  
M. Hatzakis ◽  
...  
2000 ◽  
Vol 53 (1-4) ◽  
pp. 453-456 ◽  
Author(s):  
P. Argitis ◽  
N. Glezos ◽  
M. Vasilopoulou ◽  
I. Raptis ◽  
M. Hatzakis ◽  
...  

1993 ◽  
Vol 328 ◽  
Author(s):  
Wu-Song Huang

ABSTRACTIn electron beam lithography, charging on photoresist usually causes image distortion and placement error. To dissipate the charge, a conductive polymeric layer can be introduced either over or under the photoresist coating. In this paper, we will discuss the approach of using toluene and xylene soluble polyalkylthiophcne in combination with photoacid generator as a discharge underlayer or interlayer beneath photoresist to dissipate the accumulated charge during li-bcam exposure. We will also discuss the use of water soluble acid or ammonium salt form of poly 3- (cthanesulfonate) thiophene as discharge. toplayer. During the resist image developing process, the toplayer will be removed by aqueous base. Therefore, it is advantageous to use discharge toplayer due to its simplicity. In this study, the salt and acid form of poly 3- (ethanesulfonate) thiophene was synthesized through chemical polymerization of the corresponding methanesulfonate ester. It exhibits the same properties as that of electrochemically synthesized polymer reported in the literature.


Author(s):  
L. D. Jackel

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.


Author(s):  
D.P. Malta ◽  
M.L. Timmons

Measurement of the minority carrier diffusion length (L) can be performed by measurement of the rate of decay of excess minority carriers with the distance (x) of an electron beam excitation source from a p-n junction or Schottky barrier junction perpendicular to the surface in an SEM. In an ideal case, the decay is exponential according to the equation, I = Ioexp(−x/L), where I is the current measured at x and Io is the maximum current measured at x=0. L can be obtained from the slope of the straight line when plotted on a semi-logarithmic scale. In reality, carriers recombine not only in the bulk but at the surface as well. The result is a non-exponential decay or a sublinear semi-logarithmic plot. The effective diffusion length (Leff) measured is shorter than the actual value. Some improvement in accuracy can be obtained by increasing the beam-energy, thereby increasing the penetration depth and reducing the percentage of carriers reaching the surface. For materials known to have a high surface recombination velocity s (cm/sec) such as GaAs and its alloys, increasing the beam energy is insufficient. Furthermore, one may find an upper limit on beam energy as the diameter of the signal generation volume approaches the device dimensions.


2020 ◽  
Vol 59 (12) ◽  
pp. 126502
Author(s):  
Moataz Eissa ◽  
Takuya Mitarai ◽  
Tomohiro Amemiya ◽  
Yasuyuki Miyamoto ◽  
Nobuhiko Nishiyama

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

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Goncharsky ◽  
Anton Goncharsky ◽  
Dmitry Melnik ◽  
Svyatoslav Durlevich

AbstractThis paper focuses on the development of flat diffractive optical elements (DOEs) for protecting banknotes, documents, plastic cards, and securities against counterfeiting. A DOE is a flat diffractive element whose microrelief, when illuminated by white light, forms a visual image consisting of several symbols (digits or letters), which move across the optical element when tilted. The images formed by these elements are asymmetric with respect to the zero order. To form these images, the microrelief of a DOE must itself be asymmetric. The microrelief has a depth of ~ 0.3 microns and is shaped with an accuracy of ~ 10–15 nm using electron-beam lithography. The DOEs developed in this work are securely protected against counterfeiting and can be replicated hundreds of millions of times using standard equipment meant for the mass production of relief holograms.


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