Origin of Electron Beam Lithography System and what exactly is it –
Electron projection lithography is an imaging technique that is quite similar to that of the optic stepper.
SCALPEL (Scattering with Angular Limitation Projection Electron Beam Lithography,) and
IBM (International Business Machines) were popular for using this lithography technique in the 1990s.
Electron Beam Lithography is a method of forming patterns or writing directly on a surface with the help of a focused beam of electrons by altering the chemical or physical state of the surface by additive or subtractive means. A strong beam of electron is used upon as respective substance, which comprises of materials which can be chemically or physically altered by the beam .
In layman terms, it is a simple method of producing a very high-resolution work.
EBeam Technology is highly used in laboratories, universities for research, and other similar places.
Some of the components of the Electron Beam Lithography system are –
- An electron gun from which the beam is radiated
- A handling module for wafer feeding
- A control system attached to the computer
- A computer system
- Designing columns
Moving on to the Standard steeps in sequential order :
- Dehydration bake
- HMDS prime
- Resist spray
- Soft bake alignment exposure
- Post exposure bake
- Hard bake and descum.
Table of Contents
Here are 5 Amazing Electron Beam Lithography Hacks at your disposal
Enhancing quality of the resolution
The Electron beam lithography system produces a high-resolution result while creating patterns. This is because of the short wavelength employed to create it, which is within the range of 10 KeV ( Kilo electron-volt) to 100 KeV. The size of the aperture can also be adjusted for this purpose.
The quality of Resolution is dependent on the speck size of the beam light
Hence, resolution can be enhanced with the use of a wobulation technique. Wobulation technique works by overlapping pixels and is also used for smoothing edges. It is mainly used for sophisticated microstructures.
Another method to improve the resolution is by using a phase shifting mask which has the capacity to nearly double the resolution.
When it comes to 3d patterns, concentration has to be attributed to both lateral resolution and axial resolution
Cancelling the diffraction effects involved in Electron-beam Lithography system –
Destructive interference between waves from adjacent apertures causes some diffraction effects.
The Fraunhofer diffraction formula.
Diffraction affects the spatial resolution produced during the Electron beam lithography system.
Abbe’s diffraction barrier and the criterion of a two-photon sparrow, both have been overcome by the recent development of the Lithography system.
Choosing between the scanning techniques, the Raster scan and Vector Scan –
In the raster scan, the beam scans the entire surface even in those areas where no features are present on the surface. Regardless of how limited the area to be scanned is it will scale through the entire surface. It I’m generally considered a time-efficient method of scanning.
On the other hand, in the Vector scanning, the electron beam lithography can be adjusted to scan exactly those surfaces which need to be scanned.
This is made possible as the beam can be directed to move in any direction on the surface and hence eliminates the process of unnecessarily scanning irrelevant areas unlike the raster scanning method.
This is a complex yet time efficient method. So if your looking for tricks to save your time the vector scanning is the perfect option for you.
Usage of Higher acceleration voltage to produce precise patterns –
When creating precise pattern is the goal, employing a higher acceleration voltage for the Electron Beam Lithography is the key .
Desktop sized electron microscope has been widely used for writing purposes .
Linewidths, resolution on the scale of minute tens of nanometer and even below are highly in demand for multiple of application usage in nano technology.
Creating low resistivity, and enhancing field emission –
CNT or carbon nanotubes have the properties deemed ideal for field emission such as low resistivity and low field emission voltage due to the strong electron field concentration. The focusing property of the condenser lens can also be diversified.
Conclusion
Now you have a rudimentary idea of the electron beam lithography and some hacks to adjust it and fit it to your desired goal.
ElectRon beam lithography is a very popular method while designing masks. It’s lack of mass necessity makes it advantageous to it’s users. Althits the cost of purchase is very high but very simple compared to other lithography techniques such as photolithography, x ray lithography-ray ion beam lithography.
With all the hacks you can now get a better hold of this device.
Lithography is still widely used as an alternative to digital printing. With an advanced electronic n beam lithography system, the process of, electron lithography has improved significantly.