Category Archives: Student

IITBNF – A Unique Experience

Those who appreciate the fine precision of a laser-writer, the ultra-low pressure conditions in e-beam evaporators, the ability to detect deposition rates of few angstroms per second in Atomic Layer Deposition (ALD) and Molecular Beam Epitaxy (MBE) systems and the beauty of a lilac hued plasma – they would say “Bingo!” when they get to know IITBNF. For all others, it is just another lab with tremendous expenses. As for me, I have been on both sides!

We usually don’t value the resources at our disposal while we have them. It is only now, when my time here at IIT Bombay is about to end, I realize what an incredible resource this lab has been!

When I started working here at IITBNF, to me, it was just a “chemistry lab with particle control”. But as time passed by, I realized it is so much more than that! One of the many reasons behind this realization was INUP: Indian Nanoelectronics Users Program. This program allows students and faculty from all over India to use the IITBNF facility to execute their fabrication plans & device ideas. To be honest, I was initially really irritated when asked to do a few runs of the dielectric deposition system for INUP members. But then, these users come from various universities and colleges from all over India. So it got me thinking: there must be something unusual about our lab…

The thought hit home when I was performing a metal stack deposition using the e-beam evaporator system. The HMI (Human Machine Interface) was indicating a chamber pressure of 6×10-6 Torr and then it struck me: 1 torr is nearly 1 milli atm pressure. So it implies that the air inside the chamber is nearly a billion times rarer than the air we breathe in!

Some of the devices fabricated here are about a micrometer in size – that is about one tenth of the thickness of a single hair. The fact that electronic devices of such small dimensions can be built here indigenously makes this facility a unique point of interest in India. The word is “neat” when you see how precisely the lithography tools can create a nanometer thick pattern on given semiconductor substrate! An angstrom, as we know, is 10 billionth part of a meter. Imagine the extent of precision that goes into designing machinery that can “detect” a difference of 1 angstrom on a substrate. Incredible, isn’t it? When one closely observes many such details for the first time, one realizes the tremendous potential and value of these equipments and in turn, of the facility! To fathom the importance of this facility in Indian context, here are some statistics: USA and Canada have 88 fabrication labs while Europe has 240. India has just 2 – one being IITBNF!

For me, getting an opportunity to work here has been a rather fortunate and an enlightening experience.

About the author:
“Ashutosh graduated with M.Tech from IITB in July 2015. He worked with Prof. Subhananda Chakrabarti on Quantum Dot Infrared Photodetectors and Intermediate bandgap solar cells – device characterization and fabrication. Post his graduation, he has joined  Applied Micro Circuits Corporation.”