Image Gallery

Gallery of structures and devices created using electron beam lithography (EBL) or focused ion beam (FIB) milling with the nanonic eLitho system.

Tuesday, 30 November -0001

Micro-Traps for Bacteria

Traps for bacteria patterned with EBL into PMMA. This simple structure demonstrates an intersting usage of EBL for biological appplications. The magnetotactical bacteria have been colorized for better identification.

Fabrication: W. Cebulla, AG Prof. Dr. Weiss, Physik, Univ. Regensburg

The World of EBL

World map written into a thin layer of PMMA (coverd with 5 nm Cr): The eLitho package allows to write complex polygons with many edges and arbitrary scan-direction.

Fabrication: L. Heitzer, Mikrosystemtechnik, FH Regensburg

Semiconductor Mircotube

Semiconductor microtube cut into slices of different thickness by means of a direct focused ion beam milling process. The tube itself was fabricated using the self-rolling mechanism of a thin strained semiconductor bilayer and wet chemical etching-processes.

Fabrication: D. Stickler, T. Kipp, S. Mendach, W. Hansen, D. Heitmann and H.P. Oepen, Physik, Universität Hamburg.

Spiral

This spiral line of less than 20 nm width was written using a PMMA resist layer of about 100 nm thickness. The resist was coated with 5 nm Cr after development in MIBK.

Radio Tower of Hamburg

This three-dimensional pattern of the Hamburg radio tower was milled directly into a Permalloy-film of 20 nm thickness. The original image was translated into a greyscale image which served as a height encoded master for the focused-ion-beam etching process.

Fabrication: D. Stickler, R. Frömter and H.P. Oepen, Physik, Universität Hamburg.

GaMnAs Ring

This GaMnAs ring-structure is written as a sequence of line-elements employing PMMA as negativ resist, followed by reactive ion etching. The line-width of the structure remains within 30 nm and its height amounts to more than 300 nm.

Fabrication: K. Wagner, AG Prof. Dr. D. Weiss, Univ. Regensburg

Honeycomb Array

Honeycomb pattern, defined by electron beam lithography and etched into the ferromagnetic semiconductor GaMnAs with 6 nm wide semiconductor bars, shows the ultimate potential of top down patterning techniques. Such ultra small structures are used to probe interference phenomena of charge carriers in ferromagnetic semiconductors. Preparation: Lst. Weiss, Universität Regensburg

High Resolution Honeycomb Structure

Topography of Europe - Software

Gray level image import for the 3D preparation of e-beam resist.

Topography of Europe

Optical micrograph of a 3-dimensional map of europe. This PMMA pattern was prepared using an imported gray-scale height map of europe. As the depth of the developed PMMA is not proportional to the dose, the eLitho software package provides a module for mapping non-linear dose functions.

Fabrication: T. Riepel, Mikrosystemtechnik, FH Regensburg

Shadow Mask

This shadow-mask is fabricated from Germanium, whereas the sacrificial layer consists of temperature insensitive synthetic material.

Fabrication: A. Bauer, AG Prof. Dr. C. Strunk, Univ. Regensburg

Football pitch 2006

K.Wagner, Universität Regensburg wrote this football pitch on the occasion of the world championship 2006. It measures only 1000x700 nm. Although the result of the here shown fictive final is written very small, it seems to be a great desire of the creator of this structure.

Point Contact

Ni Point Contact (dark area) was structured applying a lift-off process on a Si3N4 membrane substrate: Using a membrane prevents a pronounced proximity effect, that can be noticed with many bulk material substrates. The narrow part of 24 nm of the contact was written as a rectangular area-element.
Fabrication: T. Haug, AG Prof. Dr. C. Back, Univ. Regensburg

Logo of the University of Hamburg

Focused-ion-beam micropattern of the logo of the University of Hamburg. The structure was milled into a 70 nm Co/Pt-film deposited on a Si-substrate employing the bitmap import feature of eDraw.

Fabrication: D. Stickler, R. Frömter and H.P. Oepen, Physik, Universität Hamburg.

Aharonov-Bohm Ring

Hybrid-structure of an etched semiconductor AB-ring and a ferromagnetic ring on top of it: This example demonstrates the high alignment accuracy of the semi-automatic structure alignment for multi-step lithography processes.

Proximity Correction

Line-grid

Another example for the high precision of our EBL-System: The line-array with a period of 500 nm was written as single-pixel-lines. Again the PMMA-structure is covered with 5 nm of Cr in order to suppress the charging of the resist during image capture.

High Resolution Dot Array

Dot array of 75 nm period written into PMMA of 130 nm thickness on a GaAs substrate: The whole structure is covered with 5 nm of Cr. Note the regularity of the diameter and the position of the dots.

Cone

This cone was milled using an Ga-FIB into a Silicon sample featuring the circular milling mode.

Mach-Zehnder Interferometer

Mach-Zehnder interferometer structured on a GaAs/AlGaAs substrate containing a shallow two-dimentional electron gas (2DEG).

Fabrication: L. Litvin, AG Prof. Dr. C. Strunk, Physik, Univ. Regensburg

(Ga,Mn)As Disk Array

This colourful light microscope image shows an section (1.6 mm x 1.2 mm) of an array of (Ga,Mn)As-disks prepared using electron beam lithography. The orange colour origins from the interference effect as the period of the patterns matches the corresponding wavelength of the light. The gray-scale inset shows an even much smaller section of the array captured with a SEM. The diameter of the disks as well as their period is 1 µm. In total more than 3 million disks have been prepared in this array. Fabrication: F. Götz, D. Neumaier, chair Prof. Dr. Weiss, Univ. Regensburg

Air-Bridge

Air-bridge structured by means of a three-layer resist and evaporation of 25 nm Ti and 300 nm Au. The bridge spans 3 um and features a height of 400 nm.

Fabrication: L. Litvin, AG Prof. Dr. C. Strunk, Univ. Regensburg

Carbon Nanotube

Coloured SEM image of a multi-wall carbon nanotube contacted by a Palladium (3nm) and Niob (45nm) dual layer sputtered on top of the tube. The artefacts seen at the edges of the patterns origin from the here used lift-off process. The (yellow) contact wires made from gold. Fabrication: E. Pallecchi, M. Gaass, F. Otto., Chair Prof. Dr. Weiss, Univ. Regensburg

Spin Injection Device

The current path of this device is 50 µm in width and its length is 350 µm with two large non magnetic contacts at both ends. The four contacts in the middle of the current path are designed as ferromagnetic Esaki diodes. They can be used as injectors for spins into the current path or as detectors for the spin accumulation. The whole device was created using electron beam lithography in different process steps. On the large bonding pads the bond wires can be seen which are connecting this device to the outside world. Fabrication: A. Einwanger, Chair Prof. Dr. Weiss, Univ. Regensburg