A New Experimental Approach to Evaluate Plasma-induced Damage in Microcantilever

Plasma  etching,  during  micro-fabrication  processing  is  indispensable  for  fabricating  MEMS  structures.  During  the plasma  processes,  two  major matters,  charged  ions  and  vacuum–ultraviolet  (VUV)  irradiation  damage,  take  charge  of reliability  degradation.  The  charged  ions  induce  unwanted  sidewall  etching,  generally  called  as  “notching”,  which causes  degradation  in  brittle  strength.  Furthermore,  the  VUV  irradiation  gives  rise  to  crystal  defects  on  the  etching surface.  To  overcome  the  problem,  neutral  beam  etching  (NBE),  which  use  neutral  particles  without  the  VUV irradiation,  has  been  developed.  In  order  to  evaluate  the  effect  of  the  NBE  quantitatively,  we  measured  the  resonance property of a micro-cantilever before and after NBE treatment. The thickness of damage layer (δ) times the imaginary part  of  the  complex  Young's  modulus  (Eds)  were  then  compared,  which  is  a  parameter  of  surface  damage.  Although plasma processes  make the initial surface of cantilevers damaged during their fabrication, the removal of that damage by NBE was confirmed as the reduction in δEds. NBE will realize a damage-free surface for microstructures

Simulations of electromagnetic effects in high frequency capacitively coupled discharges using the Darwin approximation

The Darwin approximation is investigated for its possible use in simulation of electromagnetic effects in large size, high frequency capacitively coupled discharges. The approximation is utilized within the framework of two different fluid models which are applied to typical cases showing pronounced standing wave and skin effects. With the first model it is demonstrated that Darwin approximation is valid for treatment of such effects in the range of parameters under consideration. The second approach, a reduced nonlinear Darwin approximation-based model, shows that the electromagnetic phenomena persist in a more realistic setting. The Darwin approximation offers a simple and efficient way of carrying out electromagnetic simulations as it removes the Courant condition plaguing explicit electromagnetic algorithms and can be implemented as a straightforward modification of electrostatic algorithms. The algorithm described here avoids iterative schemes needed for the divergence cleaning and represents a fast and efficient solver, which can be used in fluid and kinetic models for self-consistent description of technical plasmas exhibiting certain electromagnetic activity

Electron scattering from molecules and molecular aggregates of biological relevance

In this Topical Review we survey the current state of the art in the study of low energy electron collisions with biologically relevant molecules and molecular clusters. We briefly describe the methods and techniques used in the investigation of these processes and summarise the results obtained so far for DNA constituents and their model compounds, amino acids, peptides and other biomolecules. The applications of the data obtained is briefly described as well as future required developments

The 2017 Plasma Roadmap: Low temperature plasma science and technology

Journal of Physics D: Applied Physics published the first Plasma Roadmap in 2012 consisting of the individual perspectives of 16 leading experts in the various sub-fields of low temperature plasma science and technology. The 2017 Plasma Roadmap is the first update of a planned series of periodic updates of the Plasma Roadmap. The continuously growing interdisciplinary nature of the low temperature plasma field and its equally broad range of applications are making it increasingly difficult to identify major challenges that encompass all of the many sub-fields and applications. This intellectual diversity is ultimately a strength of the field. The current state of the art for the 19 sub-fields addressed in this roadmap demonstrates the enviable track record of the low temperature plasma field in the development of plasmas as an enabling technology for a vast range of technologies that underpin our modern society. At the same time, the many important scientific and technological challenges shared in this roadmap show that the path forward is not only scientifically rich but has the potential to make wide and far reaching contributions to many societal challenges.I Adamovich et al 2017 J. Phys. D: Appl. Phys. 50 32300