Programmable Nanoscale Crack Lithography for Multiscale PMMA Patterns

Crack
lithography is important for preparing microstructured
materials.
This strategic use of cracking breaks with the traditional idea that
cracks are unwanted and has great potential for high-resolution and
high-throughput production. However, the ability to control nanoscale
crack patterning is still insufficient. Here, we present a nanoscale,
programmable angle-dependent technique to control crack generation
that relies on standard electron-beam lithography. Multiscale patterns
of poly(methyl methacrylate) of arbitrary shape, geometric size, and
large area were obtained, greatly expanding the processing capacity
of electron-beam lithography. In addition, we observed the interaction
between adjacent structures and cracks, which resulted in crack suppression
or second-order cracks. We also demonstrated that angle-dependent
nanoscale cracks can be used in physical unclonable functions and
have great application prospects in the field of information security.
We believe that our strategy for programmable nanoscale crack patterning
provides new opportunities and perspectives for nanofabrication.