Bulletin of the American Physical Society
70th Annual Gaseous Electronics Conference
Volume 62, Number 10
Monday–Friday, November 6–10, 2017; Pittsburgh, Pennsylvania
Session DT1: Microdischarges I |
Hide Abstracts |
Chair: Katsuhisa Kitano, Osaka University Room: Salon D |
Tuesday, November 7, 2017 8:00AM - 8:30AM |
DT1.00001: Microdischarge integration on silicon based devices. Invited Speaker: Remi Dussart DC Microhollow cathode discharges (MHCD) were first introduced in the mid 90's [1]. Due to their dimensions and their large surface to volume ratio, the produced microplasmas remain cold and can stably operate at atmospheric pressure in the normal regime provided the cathode area is not fully utilized [2]. Silicon processing intensively developed for microelectronic devices offers many opportunities to design new, original and efficient devices to produce high density microplasmas. [3] Our microreactors are made using processes including steps of oxidation, lithography, magnetron deposition and etching. In our device configuration, the dielectric separating the two electrodes is made of thermal SiO$_{\mathrm{2}}$ and is 6~um thick so that a very high electric field is obtained before breakdown. However, in our device configuration, no field effect assisted breakdown was evidenced. With a cathode of silicon, the operation of our microdischarge arrays is very unstable and produces many current spikes that significantly damage the microcavities and lead to device failure. The mechanism responsible for this unstable operation and short lifetime was observed by other groups [4] and were investigated [5]. The different possibilities to enhance the stability of microdischarges made from silicon wafers will be discussed. One of them consists in using a thin metal film on the silicon cathode. The devices were then tested in 3 different gases (He, Ar N$_{\mathrm{2}})$ and in the air. We will show that a very stable operation can be obtained using this new configuration. The lifetime of the microreactors with a confined cathode is significantly enhanced. [1] K.H. Schoenbach et al., Appl. Phys. Lett. 68 (1996) 13--15 [2] T. Dufour et al. , Appl. Phys. Lett. 93 (2008) 71508 [3] J.G. Eden et al., J. Phys. D: Appl. Phys. 36 (2003) 2869--77 [4] C. Sillerud et al. , Physics of Plasmas, 24, 033502 (2017) [5] V. Felix et al., PSST 25 (2016) 025021 [Preview Abstract] |
Tuesday, November 7, 2017 8:30AM - 8:45AM |
DT1.00002: Detection of CN (B $^{\mathrm{2}}\Sigma^{\mathrm{+}})$ in cold atmospheric plasma jet in argon Jayr Amorim, Marco Ridenti CN(B$^{\mathrm{2}}\Sigma^{\mathrm{+}}\to $X$^{\mathrm{2}}\Sigma ^{\mathrm{+}})$ violet system was investigated using optical emission spectroscopy in a non-equilibrium microwave atmospheric-pressure plasma jet in argon expanding in air. From the analysis of the emission spectra of the discharge in the range of 380 nm and 400 nm, the violet system of CN was found to be overlapped with the N$_{\mathrm{2}}^{\mathrm{+}}$ (B$^{\mathrm{2}}\Sigma ^{\mathrm{+}}_{\mathrm{u}}$, v$=$1$\to $X$^{\mathrm{2}}\Sigma ^{\mathrm{+}}_{\mathrm{g}}$, v$=$1) and N$_{\mathrm{2}}$(C$^{\mathrm{3}}\Pi_{\mathrm{u}}\to $B$^{\mathrm{3}}\Pi_{\mathrm{g}})$ bands, sequence $\Delta $v$=$-3. Data fitting procedure was numerically implemented by means of a homemade routine to disentangle the overlapped spectra of the three different band systems. Through this deconvolution technique it was possible to determine the CN (B$^{\mathrm{2}}\Sigma^{\mathrm{+}}\to $X$^{\mathrm{2}}\Sigma^{\mathrm{+}})$ band head intensity as function of discharge powers between 30 W and 150 W and fluxes between 2.5 slm and 10.0 slm. Maximum intensity of violet band head was found for power of 150 W, flux of 2.5 slm, and for 10.0 slm power of 100W, showing that both power and flow rate increase the cyan violet system emission. Small admixture of nitrogen to the flux put in evidence the importance of excited nitrogen states in the formation of the CN (B $^{\mathrm{2}}\Sigma ^{\mathrm{+}})$ state. The rotational temperatures and vibrational temperature were determined for the upper state level CN (B $^{\mathrm{2}}\Sigma^{\mathrm{+}})$. [Preview Abstract] |
Tuesday, November 7, 2017 8:45AM - 9:00AM |
DT1.00003: Generation of energetic electrons in a plasma source at fore-vacuum pressures. Yevgeny Raitses, Sophia Gershman A DC plasma source with a cylindrical anode and planar cathode separated with a mm-scale distance was operated in a vacuum chamber filled with argon and nitrogen gases at 1-10 torr, without the gas flow. Plasma was characterized with electrostatic probes and optical emission spectroscopy. Results of measurements demonstrate that the operation of this source is governed by non-local electron kinetics. Electrons produced by ion-induced secondary electron emission are accelerated in the cathode sheath and generate the plasma inside and other the plasma source. Calculations showed that at the above operating pressure, the energy relaxation length is larger than the distance between the electrodes. We will also report on controlling of electron energy distribution function in the generated plasma outside the source. [Preview Abstract] |
Tuesday, November 7, 2017 9:00AM - 9:15AM |
DT1.00004: High power electromagnetic filtering with plasma generation in rectangular Fabry-Perot type cut-resonators Konstantinos Kourtzanidis, Laxminarayan Raja Microwave breakdown between all-dielectric resonators has been recently proposed as an efficient way of generating small scale plasmas. At resonant frequencies, electromagnetic fields radiate in the gap between two resonators leading to local field enhancement and plasma formation. We study numerically with a high fidelity electromagnetic-plasma solver, the possibility of efficient high power filtering using arrays of all-dielectric cut-resonators. We characterize the transient plasma formation as well as its steady state under various configurations and input parameters. We demonstrate that using rectangular all-dielectric Fabry-Perot type cut-resonators, full transmittance at resonant frequencies is being canceled when the incident wave power leads to local breakdown. The plasma discharge is formed at the antinodes locations of the standing wave pattern radiating between the arrays of resonators and its spatial extend, maximum electron density and localization depends on the gap size, the operating frequency, the input power as well as the background gas pressure. The application of this power filtering concept to a waveguide structure is also studied, showing that the proposed idea can be used in realistic transmission line configurations. [Preview Abstract] |
Tuesday, November 7, 2017 9:15AM - 9:30AM |
DT1.00005: Computational Modeling of Microwave Interactions with Self-consistent Plasma Rochan Upadhyay, Laxminarayan Raja Computational modeling of microwave plasma needs to resolve several observed phenomena occurring in microwave-sustained plasmas. This is a challenging task as while the microwave wavelength is of the order of millimeters or more, several phenomena of microwave plasma interactions occur in the range of micrometers or less. Examples include the skin effect in over-dense plasma, the “epsilon-zero” resonance and subsequent enhanced power deposition at the critical density interface, the structure of SPP (Surface Plasmon Polaritons) in plasma dielectric interfaces, Microwave-(sheath)Voltage Plasma (MVP) etc. We will briefly present several examples of computational simulations, using a self-consistent fluid plasma model coupled with full field electromagnetic simulations for industrial scale plasma reactors for which the above physical mechanisms are the main processes for the creation and sustenance of the plasma for material processing applications. We will focus on two problems, namely discharges sustained by surface wave propagation (SWP) along plasma- dielectric interface (SPP) and by SWP along the plasma-sheath interface (MVP). Computational simulations illustrate the differences between the two types of discharges and the dependence of plasma on external parameters. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700