Pulsed Laser-Assisted Helium Ion Nanomachining of Monolayer Graphene—Direct-Write Kirigami Patterns

摘要： A helium gas ?eld ion source has been demonstrated to be capable of realizing higher milling resolution relative to liquid gallium ion sources. One drawback, however, is that the helium ion mass is prohibitively low for reasonable sputtering rates of bulk materials, requiring a dosage that may lead to signi?cant subsurface damage. Manipulation of suspended graphene is, milling. We demonstrate that competitive ion beam-induced therefore, a logical application for He deposition from residual carbonaceous contamination can be thermally mitigated via a pulsed laser-assisted He milling. By optimizing pulsed laser power density, frequency, and pulse width, we reduce the carbonaceous byproducts and mill graphene gaps down to sub 10 nm in highly complex kiragami patterns.