Structuring technologies at the nano scale based on Electron Beam Lithography and related techniques
  - developing and refining nano-structuring technologies based on Electron Beam Lithography patterning;
  - design and fabrication of  nanostructures by EBID and EBIE;
  EBID technique has been used in order to obtain Pt, W and  SiO2 nanostructures  

SiO2  nanodots (70 nm diameter)
deposited by EBID on Si

Tungsten  lines (width <30 nm) on Si,
obtained by EBID

a) 45º tilted view

b) top view

SEM images of tungsten nanodots deposited by EBID

  Structures with  various geometries have been fabricated through  Electron beam assisted local etching (EBID) in PMMA  and SiO2, using water and fluorine vapors as precursors.

“Chessy-like” structure, composed of 1 micron squares (30 nm corner radius)
etched by EBIE process  in PMMA using water vapor precursor

Right: Etched structure in SiO2 substrate by EBIE using fluorine precursor        Left: detail

- National basic funding Project MINASIST +, 2006-2008
- FP7 project Carbon nAnotube Technology for High-speed nExt-geneRation nano-InterconNEcts – CATHERINE (FP7/STREP, 2008-2010)

  - high aspect ratio structures at nm scale fabricated through EBL-based techniques

By proper tuning various EBL process parameters, we managed to obtain nanostructures with high aspect ratio (> 5:1) both in PMMA and SU8 electronresists.

SEM micrographs of high aspect ratio (12:1) PMMA cross-lines , 125 nm pitch
a) top view;  b) (450 tilt angle)

SEM images (45 degree tilting)at different magnifications  of PMMA nano-pillars (300 nm height, 45 nm average diameter, 7:1 aspect ratio

a) 45º tilted view

b) top view

SEM micrographs of 2 μm height, high aspect ratio  SU8 structures.
a) lines with 1/3 fill factor (aspect ratio 20:1) ; b)  pillars (aspect ratio 6:1)

  - aditive methods for fabrication of nano-interconections on various substrates: lift-off for metals and dielectrics by using special methods for exposure and treatment of electronresist, lithography with double layer etc.

Additive methods - lift-off si EBID - have been used for transferring on different substrates nanometer configurations of dots and lines – basic elements of vertical and horizontal interconnects. The ultimate goal was to produce areas of metallic nanodots used as catalysts for vertical growth  of carbon nanotubes and lines with less than 100 nm widths, intended as test structures for interconnection of two vertical beams of CNTs.

SEM micrographs of 18 nm diameter (left) and  79 nm diameter (right) holes in PMMA, fabricated  by EBL



SEM micrographs of Ni dots (average diameter 80 nm) and lines
(100 nm medium width), fabricated using EBL and lift-off.

  - fabrication of 2D and 3D nanostructures intended to be used as calibration gratings for  optical microscopy,  AFM and  STM with better than 100 nm accuracy

Calibration structure for optical microscopy fabricated using EBL. Linewidths: 1 μm to 80 μm

calibration grid with periodic1 µm pitch squares, fabricated by EBL
 - SEM (a) and AFM (b) images (c) Power spectrum of the Fourier transform of the image in b)

Project:  National basic funding Project CONVERT +, PN II - (2009-2011)
Contact person: Dr. Adrian Dinescu


Suspended PMMA structures for photonic applications

3D patterning of PMMA 35K

Calibration structure for high frequency measurements on CNts

Carbon nanotube fixed in place using EBID (Electron Beam Induced Deposition)


Nanolithography with sub 20 nm resolution;
• Three-dimensional nanostructures;
• CNT based interconnections for next-generation integrated circuits
• CNT based nanodevices
• SAW devices with nanometer interdigitated electrodes;
• Optical devices, holograms, micro lenses, gratings
• Development of Nanodevices using E-beam induced deposition and etching
• Development of circuits for communications based on photonic crystals

Contact person: Dr. Adrian Dinescu



top of page

Last update: March, 2012