Showing papers on "Proximity effect (electron beam lithography) published in 2013"
TL;DR: In this article, a homogeneous, electrically conductive, and transparent graphene layer is used as a discharge layer for EBL processes on insulating substrates, and dense arrays of holes with diameters of 50nm and gratings with line/space of 50/30nm are obtained on quartz substrate.
Abstract: Charging of insulating substrates is a common problem during Electron Beam lithography (EBL), which deflects the beam and distorts the pattern. A homogeneous, electrically conductive, and transparent graphene layer is used as a discharge layer for EBL processes on insulating substrates. The EBL resolution is improved compared with the metal discharge layer. Dense arrays of holes with diameters of 50 nm and gratings with line/space of 50/30 nm are obtained on quartz substrate. The pattern placement errors and proximity effect are suppressed over a large area and high quality complex nanostructures are fabricated using graphene as a conductive layer.
7 citations
TL;DR: In this article, a line-and-space (LS) pattern was used to fabricate a large-scale NIL mold with elastic ultraviolet (UV)-curable resin.
5 citations
01 Jan 2013
TL;DR: In this article, the radial density of absorbed energy is calculated for PMMA resist with various settings of resist thickness and substrate material, and coefficients of proximity effect function were calculated for beam energy of 15 keV, 50 keV and 100 keV which is desirable for proximity effect correction.
Abstract: E-beam lithography is the most used pattern generation technique for academic and research prototyping. During this patterning by e-beam into resist layer, several effects occur which change the resolution of intended patterns [1]. Proximity effect is the dominant one which causes that patterning areas adjacent to the beam incidence point are exposed due to electron scattering effects in solid state [2]. This contribution deals with Monte Carlo simulation of proximity effect for various accelerating beam voltage (15 kV, 50 kV, 100 kV), typically used in e-beam writers. Proximity effect simulation were carried out in free software Casino and commercial software MCS Control Center, where each of electron trajectory can be simulated (modeled). The radial density of absorbed energy is calculated for PMMA resist with various settings of resist thickness and substrate material. At the end, coefficients of proximity effect function were calculated for beam energy of 15 keV, 50 keV and 100 keV which is desirable for proximity effect correction.
5 citations
Patent•
14 Nov 2013
TL;DR: In this paper, a drawing device for performing drawing on a substrate with charged particle rays includes: a correction part which corrects drawing data for controlling the drawing; and a drawing part for performing the drawing with the charged particle ray based on data corrected by the correction part.
Abstract: PROBLEM TO BE SOLVED: To provide a technique which is advantageous for performing proximity effect correct.SOLUTION: A drawing device for performing drawing on a substrate with charged particle rays includes: a correction part which corrects drawing data for controlling the drawing; and a drawing part for performing the drawing with the charged particle rays based on data corrected by the correction part. After performing geometric correction for overlapping a drawing area with a target area on the substrate, to the drawing data, the correction part performs the proximity effect correction to the corrected drawing data.
4 citations
Patent•
14 Nov 2013
TL;DR: In this paper, a charged particle beam writing apparatus is described, which includes a calculation unit to calculate a dose density that corrects a dimensional variation caused by at least one of a proximity effect, a fogging effect, and a loading effect, where the dose density has been modulated based on a dose modulation amount input from outside.
Abstract: A charged particle beam writing apparatus according to one aspect of the present invention includes a calculation unit to calculate a dose density that corrects a dimensional variation caused by at least one of a proximity effect, a fogging effect, and a loading effect, and indicates a dose per unit area of a charged particle beam, where the dose density has been modulated based on a dose modulation amount input from outside, a determination unit to determine whether the dose density exceeds an acceptable value, and a writing unit to write a pattern on a target object with the charged particle beam.
4 citations
TSMC1
TL;DR: In this paper, the model accuracy of electron scattering in terms of multiple Gaussian kernels with an in-house proximity error correction with much better accuracy and more self-consistency than the double Gaussian kernel on the 100-keV electron energies.
Abstract: Electron beam lithography is a promising technology for next generation lithography. Compared to optical
lithography, it has better pattern fidelity and larger process window. However, the proximity effect caused by the
electron forward scattering and backscattering in the resist and the underlying substrate materials has a severe influence
on the pattern fidelity when the required critical dimensions (CD) are comparable to the electron beam blur size.
Therefore, an accurate electron scattering model and a proper proximity correction play a vital role in electron beam
lithography. In this paper, we describe the model accuracy of electron scattering in terms of multiple Gaussian kernels
with an in-house proximity error correction to reduce proximity error with much better accuracy and more
self-consistency than the double Gaussian kernel on the 100-keV electron energies. The impact of various Gaussian
kernels used in the proximity correction on the lineation of typical patterns is also addressed.
2 citations
01 Jan 2013
TL;DR: In this article, a comparison of two different e-beam writer systems with different electron energies of 50 keV and 100 keV was made. And the achievable resolution was tested on patterns consisting of single lines, single dots and small areas of periodic gratings, which were measured and evaluated using of atomic force microscope and scanning electron microscope.
Abstract: This contribution deals with the comparison of two different e-beam writer systems. E-beam writer with rectangular shaped beam BS600 is the first system. This system works with electron energy of 15 keV. Vistec EBPG5000+ HR is the second system. That system uses the Gaussian beam for pattern generation and it can work with two different electrons energies of values 50 keV and 100 keV. The ultimate resolution of both systems is the main aspect of comparison. The achievable resolution was tested on patterns consisted of single lines, single dots (rectangles for e-beam writer with shaped beam) and small areas of periodic gratings. Silicon wafer was used as a substrate for resist deposition. Testing was carried out with two resists, PMMA as a standard resist for electron beam lithography, and HSQ resist as a material for ultimate resolution achievement. Process of pattern generation (exposition) is affected by the same undesirable effect (backscattering and forward scattering of electrons, proximity effect etc.). However, these effects contribute to final pattern (resolution) by various dispositions. These variations caused the different results for similar conditions (the same resist, dose, chemical developer etc.). Created patterns were measured and evaluated by using of atomic force microscope and scanning electron microscope.
2 citations
TL;DR: In this paper, the authors analyzed the image contrast of line-cut and contact hole features patterned using complementary E-Beam Lithography (CEBL) at advanced technology nodes and determined that the influence of back scattered electrons was not a significant factor in CEBL applications when feature pattern density is less than 11%.
Abstract: Image contrast of line-cut and contact hole features patterned using Complementary E-Beam Lithography (CEBL) at
advanced technology nodes are analyzed. The study assumes one beam in each column is used to pattern features less
than 20 nm (Full Width Half Maximum, FWHM), consistent with Multibeam’s multi-column vector-scan approach for
CEBL patterning. When the feature size approaches the resolution of the e-beam column design, the dose intensity
profile follows a Gaussian model. Using Gaussian profiles, the image contrast of line cut or contact hole features can be
studied as a function of beam FWHM size, spacing between features, and proximity effect. As expected, the image
contrast was dominated by contact hole stepping distance (i.e., spacing between neighboring contact holes) and
proximity effect. The plot of image contrast versus contact position becomes very useful in studying the impact of
contact spacing, proximity effect and process window in writing line-cut or contact features in CEBL applications. Based
on a given design rule of contact hole size and spacing, we can determine the appropriate e-beam size and resist contrast
to achieve good image contrast. The relationship between resist contrast and image contrast is discussed to estimate the
process window in CEBL applications. Finally, the impact of electron forward scattering in resist is analyzed, including
the effects of resist thickness and beam voltage selections. We determined that the influence of back scattered electrons
is not a significant factor in CEBL applications when feature pattern density is less than 11%.
1 citations
Patent•
25 Oct 2013
TL;DR: In this paper, a method for improving the uniformity of a grating was proposed, where trapezoid compensatory figures were arranged around the grating structure by utilizing a layout design tool.
Abstract: The invention discloses a method for improving the uniformity of a grating, and particularly relates to an electron beam exposure method for improving the uniformity of a grating structure. The method comprises the steps that electron beam glue coats a wafer, and the wafer coated with the electron beam glue is placed in a baking oven to be prebaked; trapezoid compensatory figures are arranged around the grating structure by utilizing a layout design tool; electron beam exposure and development are carried out on the wafer to finish the grating structure containing the trapezoid compensatory figures. By utilizing the compensatory figures, the method weakens the influence of the proximity effect in the electron beam exposure, and the uniformity of nanometer-scale grating exposure is increased. Instead of weakening the proximity effect by changing the exposure dose and size of a figure, the proximity effect is weakened by increasing the compensatory figures around the figure in order to improve the grating exposure uniformity.
Patent•
23 May 2013
TL;DR: In this article, the authors determined the optimal irradiation amount for correcting the proximity effect caused by mid-range backscattering and short-range frontscattering, respectively, and calculated the total optimal irradiance amount to correct the proximity effects caused by both mid and short range backscatterings.
Abstract: A first optimal irradiation amount for correcting the proximity effect caused by mid-range backscattering and a second optimal irradiation amount for correcting the proximity effect caused by short-range backscattering are determined separately The total optimal irradiation amount is calculated to correct the proximity effects caused by both mid-range backscattering and short-range backscattering The second optimal irradiation amount for correcting the proximity effects caused by short-range backscattering is determined to correspond to the first optimal irradiation amount for correcting the proximity effect caused by mid-range backscattering Thus, when a beam is irradiated to draw the desired pattern on a sample, the optimal irradiation amount of the beam can be determined to reduce the dimension changes of the drawn pattern (circuit pattern) caused by the proximity effect due to the plurality of backscattering in different operating ranges
01 Aug 2013
TL;DR: In this paper, the complex scattering process of the high-energy electron beams in resist is simulated by Monte Carlo method, and three-dimensional (3-D) development profiles are obtained with the developing threshold model.
Abstract: The complex scattering process of the high-energy electron beams in resist is simulated by Monte Carlo method. The energy deposition distributions are presented under different exposure conditions. The three-dimensional (3-D) development profiles are obtained with the developing threshold model. It is found that, in the high energy range, higher electron beam energy, thinner resist, appropriate dose and lower substrate's atom number will cause lower proximity effect. Based on the simulations, we can explain the proximity effect and the dose control on proximity effect correction via the three-dimensional development profiles. The results will be useful to optimize the exposure conditions in electron beam lithography, and to provide more accurate data for proximity effect correction.