Lithography
Electron Beam Lithography (EBL)
Electron Beam Lithography (EBL)
Introduction
Electron Beam Lithography (EBL) is the tool of choice for patterns with extremely high resolution. It makes use of a highly energetic, tightly focused electron beam, which is scanned onto a sample coated by an electron-sensitive polymer according to a geometry that has been previously defined on a CAD file. Subsequent development into an appropriate solvent reveals the structures defined into the polymer, which acts as a mould for subsequent pattern transfer techniques such as dry etching or metal liftoff.
Applications
Due to the extreme flexibility of the technique, EBL has a vast range of applications: nano-electronics, to photonics, plasmonics, nano-fluidics, Nano Electro Mechanical Systems, x-ray and neutron optics.
Projects
Characterisation of gold nanoparticle surface assemblies
Fabrication of sub 50nm biosensors
Scanning electron microscope images of nanostructures fabricated with high accuracy
Controlled plasmonic 3D nano-architechtures
Nanofabricating nano-particulate building blocks
Vertical arrays of gold nanorods on patterned substrates
Equipment
MCN installed a top tier EBL tool, a Vistec EBPG5000plusES, which is the only one of its kind in Australia. The tool is capable of writing up to six inch masks and wafers, with a maximum resolution of less than 10 nm. Some of the key specifications are outlined in the following:
- 100 kV acceleration voltage
- 1 mm main field size
- 50 MHz pattern generator
- automated operation
- <20nm overlay accuracy
Contacts
For more details about the EBL at MCN or enquiries about access please contact:
Dr Matteo Altissimo – matteo.altissimo@monash.edu
This equipment can be booked through ACLS after receiving the appropriate inductions.
Focused Ion Beam (FIB)
Introduction
Dual-beam Focused Ion Beam-Scanning Electron Microscopy (FIB-SEM) is a very powerful technique combining the imaging capability of an electron microscope with the ability to remove material from a sample surface using a beam of energetic ions. The ion beam can be used to create nano/micro-scale patterns on a sample surface or to cut a cross-section of the sample surface for imaging/analysis of thin film heterostructures beneath the sample surface.
Applications
FIB-SEM is a very versatile technique with a wide range of applications including advanced materials development/characterization, electronics, mining and forensics.
Projects
Industry looks to partner with MCN in R&D
Photonic circuitry from the noble metals: nanocrystal coupling
FIB cross-section & viewing of carbon nanotube yarns
Focused ion beam milling of biological cells
Nanoplasmonic optical circuits – building blocks for optical metamaterials
Equipment
MCN has a FEI Helios NanoLab 600 DualBeam FIB-SEM that features ultrahigh resolution imaging with resolution down to 3 nm, FIB milling resolution down to 20 nm, rapid, automated 3D profiling and150 mm diameter stage movement.
Documentation
For an introduction to the concepts of FIB-SEM, please refer to the document entitled “Introduction to EM booklet July 10” from FEI Company.
Contact
For more details regarding the FIB-SEM at MCN or enquiries about training/access, please contact:
Manoj Sridhar – manoj.sridhar@monash.edu
Telephone: (03) 9902 9656
Hot Embossing
Applications
Hot embossing addresses a wide range of applications, from polymer-based lab-on-chip systems, where imprinting is done on thick polymers substrates to the fabrication of sub 50 nm features for bio-sensing or data recording applications, where imprinting is required. The field where hot embossing is relevant includes microfluidics, MEMS, optoelectronics, packaging and SOI production.
Equipment
The semi-automated Hot Embossing System is designed for embossing and nanoimprinting applications. This production-proven system
from EVG accepts substrates up to 200 mm and is compatible with standard semiconductor manufacturing technologies.
The hot embossing system is configured with a universal embossing chamber (size up to 8” diameter), high-vacuum (10e-5mbar), high temperature (550°C) and high-contact force (up to 40kN) capabilities and manages the whole range of polymers suitable for hot embossing. Together with high-aspect ratio embossing and multiple de-embossing options many processes for high quality pattern transfer and nm resolution are offered. The system is also capable of performing bonding operations which includes anodic, fusion and thermal compression bonding with Si to Glass, Si to Si and polymer to polymer.
Documentation
For more information on hot embossing, please refer to the link provided below: http://www.evgroup.com/en/products/lithography/nil_systems/evg520he/
Contacts
For more details about hot embossing at MCN or enquiries about access please contact:
Sasikaran Kandasamy – sasikaran.kandasamy@monash.edu
Projects
Scanning electron microscope (SEM) images of carbon nanoTube (CNT) webs
Intelligent Micropatterning
Photolithography
Introduction
Photolithography is a process used to transfer a pattern from a mask to a substrate. This is achieved by spinning
on a photosensitive resist layer and exposing it to UV light via a patterned mask which causes the resist to cross link or breakdown depending on the resist tone.
The photoresist is then developed in a solution to remove the unwanted material. The substrate can then move onto the next process e.g. metal deposition, etching etc.
Multiple layers can be built up on a single device by using the alignment capabilities of the EVG620 and appropriate alignment markers in the mask design.
The minimum feature size that can be defined with photolithography depends on a number of factors:
- Wavelength of exposure
- Photoresist used
- Photoresist thickness
- Subsequent processing considerations
The minimum feature sized acheived at MCN using photolithography is 800nm with a subsequent metal lift-off process. For smaller dimensions the user should consider using Electron Beam Lithography.
MCN supplies a number of photoresists some of which are:
- AZ4562 positive tone, general purpose
- AZ9260 positive tone, high aspect ratio
- AZ1512HS positive tone, high resolution
- AZ5214E image reversal resist
- AZMIR701 positive tone, high resolution
- AZnLOF2070 negative tone, for lift of process
In addition to the mask aligner MCN hosts the following lithography equipment:
Applications
Photolithography is central to most micro and nanofabrication applications including microfluidics, cantilever fabrication etc.
Projects
Protecting the nations' water supply
Liquitab seeks the expertise of MCN Tech Fellow James Friend
Rapid point of care sensor for infectious disease discrimination
DNA - Plasmonics, materials and devices
Equipment
- EVG620 mask aligner and exposure system
- Suss Delta80 RC photoresist spinner with hotplate
- Laurell photoresist spinners
- UV Flood light source from ABM
- Ovens for resist baking
- Fume hoods for cleaning and developing
Contacts
For information and training on these tools and related processes, please contact:
Douglas Mair - douglas.mair@monash.edu
Patterned AZ2070nLOF resist on silicon substrate