The time and cost needed to produce microchips could be drastically reduced thanks to a simple low-cost a new process invented by Princeton engineers in which a thin polymer film is sandwiched between two flat plates that are then pulled apart creating ultra small grooves over large areas as if by "magic".
The new method, published in the journal Nature Nanotechnology, results in the formation in the self-formation of periodic gratings separated by as few as 60 nanometers that have many significant applications in electronic, optical, magnetic, chemical and biological devices and materials.
“It’s like magic,” said electrical engineer Stephen Chou, the Joseph C. Elgin Professor of Engineering. “This is a fundamentally different way of making nanopatterns.”
The process, called fracture-induced structuring, starts by painting a thin polymer film onto a rigid plate, such as a silicon wafer
Then, a second plate is placed on top, creating a polymer sandwich that is heated to ensure adhesion.
Finally, the two plates are pried apart, and as the film fractures, it automatically breaks into two complementary sets of nanoscale gratings, one on each plate, with the distance between the lines, called the period, being four times the film thickness.
The ease of creating these lines is in marked contrast to traditional fabrication methods, which typically use a beam of electrons, ions, or a mechanical tip to “draw” the lines into a surface, which are serial processes which are extremely slow and therefore only suitable for areas one square millimeter or smaller.
According to the researchers, other techniques suitable for larger areas have difficulties achieving small grating periods or producing a high yield, or they require complex and expensive processes.
Fracture-induced structuring is not only simple and fast, but it enables patterning over a much larger area, the scientists claim.
The researchers have already demonstrated the ability of the technique to create gratings over several square centimeters, and the patterning of much large areas should be possible with further optimization of the technique.
"Many of us have broken an ordinary water glass and seen the irregular paths taken by the cracks that grow through the material," Ben Freund from Brown University commented. "Materials normally fracture in this way, which is why the observation of cracks that follow a regular path through a polymeric material — as reported by Stephen Chou, William Russel and colleagues at Princeton University on the Nature Nanotechnology website today — is particularly striking."
"The availability of periodic substrates with surface wavelengths in the submicrometre range holds promise for applications in many fields, including the study of cell adhesion and other biomolecular phenomena," Freund added. "Up until now, the task of preparing such substrates has been daunting, but fracture-induced structuring offers an appealing alternative to existing technologies for fabricating patterned surfaces."
Post new comment