An invention by scientists at IISc is all set to make inroads into the billion-dollar nanoelectronics industry.
This is disruptive because the technology can drastically reduce the cost of the existing state-of-the-art e-beam lithography and optical lithography. This invention is a new way to etch thin lines on a substrate using electrodes, termed electrolithography.
This will come in very useful in inscribing, for instance, nanometer-scale circuits which make up IC chips, minute transistors among others.
The process of lithography is straightforward. You take a transparent glass plate, coat it with a layer of a suitable polymer. On top of this, add a layer of chromium, then you dig a trench of the desired pattern on the chromium layer so that parts of the polymer layer are exposed. Using acetone, dissolve the exposed polymer and remove those parts of it. This caused a gap to be formed in the polymer-chromium sandwich.
This whole assemblage functions like the negative of a developed photo film. Now, if the metal of choice is “sputtered” on to this sandwich, it will go and occupy the gap that’s been created and directly fall on the glass plate. In this way, the desired pattern using a metal of choice can be formed.
The crucial difference between existing processes and this one is in the manner of digging the trench. Here, the researchers use electrodes that are widely separated from each other. The very thin cathode, when it moves like a nib over the chromium layer, causes the metal to heat up, dissolve and flow out. This makes a trench whose width is nearly that of the electrode tip.
Other techniques, the e-beam lithography which is very popular, or the optical lithography using ultraviolet light, involve machines that cost a few crores of rupees whereas this set up could be assembled at a cost price of some Rs 20 lakhs.