Pulsed femtosecond-laser Machining and deep reactive ion etching of diamond

Abstract

This paper reports the deep reactive ion etching of femtosecond laser machined highaspect graphitic channels through diamond. To begin, two chemical vapor deposition-grown diamond plates, one single-crystal and the other polycrystalline, are processed using the bulk microstructural modification technique of femtosecond-pulsed laser machining. Multiple laser parameters are varied in processing the polycrystalline sample, including laser pulse frequency, pulse energy, and number of pulses per micron step size between the back and the front of the diamond, whereas a constrained set of parameters is used with the single-crystal sample. Over the range of parameters evaluated for the polycrystalline diamond, Raman analysis exhibits photoluminescence from defects created near the surface through the laser machining process, but little, if any, graphite-like features. However, a Raman signal from graphite-like material is observed on the surface of the graphitic channels for the single-crystal diamond, from which it is determined that greater diamond to graphite-like phase conversion is obtained with a larger number of pulses per translation step and with a higher laser pulse energy. Further, a larger number of pulses per step results in strong luminescence, observed during Raman investigation. Subsequent deep reactive ion etching of the samples reveals that the laser-treated channels etch considerably faster near the surface than the surrounding diamond, and that a high relative etch rate is obtained even when graphite-like features are absent from the Raman spectra. The highest relative etch rate of the single-crystal sample was 1.61 µm/min.

Attenuated Glial Reactivity on Topographically Functionalized Poly(3,4‐Ethylenedioxythiophene):P‐Toluene Sulfonate (PEDOT:PTS) Neuroelectrodes Fabricated by Microimprint Lithography

“…A range of techniques have been explored to create defined microstructures on electrode surfaces, including laser ablation, focused ion beam, sputter etching, reactive ion etching, deep reactive ion etching, hot embossing, and electron beam lithography . Complementary to these techniques, imprint lithography is an especially attractive approach due to its simplicity, nondestructive character, and feasibility of patterning large areas with features down to 10 nm using elevated temperature and/or pressure processes to transfer a pattern into typically thermoplastic materials .…”

Ultrafast Laser Processing of Diamond Materials: A Review

“…The obtained results were reproduced by multiple measurements [63]. Determining of the barrier potential could be a very important factor for the characterization of graphite wires fabricated by emerging methods, such as the use of Bessel beams [64] as well as for the design of wire junctions [65,66] or gaps in the conductive network [67].…”

Barrier potential for laser written graphitic wires in diamond

“…The experimental findings of the barrier potential in this study can hopefully provide additional useful information in understanding the charge transfer properties of laser written graphitic wires in diamond. Evaluation of the barrier potential will be an important factor when characterising new schemes for laser processing wires, such as the use of Bessel beams [25,26]. The barrier potential is also a highly relevant consideration as more complicated device architectures utilising laser written wires in diamond start to emerge, with designs comprising wire junctions [27] and intentional gaps in the conductive network [28].…”