Breakdown study of dc silicon micro-discharge devices

Abstract

Abstract. The influence of geometrical and operating parameters on the electrical characteristics of dc micro-cavity discharges provides insight into their controlling physics. We present here results of such a study on silicon based micro-cavity discharge devices carried out in helium at pressure ranging from 100 to 1000 Torr. Different micro-reactor configurations were measured. The differences include: isolated single cavities versus arrays of closely spaced cavities, various cavity geometries (un-etched as well as isotropically and anisotropically etched), various dimensions (100 or 150 µm cavity diameter and 0 to 150 µm depth). The electrode gap was kept constant in all cases at approximately 6 µm. The applied electric field reaches 5·10 7 V·m −1 which results in current and power densities up to 2 A·cm −2 and 200 kW·cm −3 respectively. The number of micro-cavities and the micro-cavity depth are shown to be the most important geometrical parameters for predicting breakdown and operation of microcavity devices. The probability of initiatory electron generation which is volume dependent and the electric field strength which is depth dependent are respectively considered to be responsible. The cavity shape (isotropic/anisotropic) and diameter had no significant influence. The number of micro-discharges that could be ignited depends on the rate of voltage rise and pressure. Larger numbers ignite at lower frequency and pressure. In addition, the voltage polarity has the largest influence on the electrical characteristics of the micro-discharge of all parameters, which is due to both the asymmetric role of electrodes as electron emitter and the non-uniformity of the electric field resulting in different ionization efficiencies. The qualitative shape of all breakdown voltage versus pressure curves can be explained in terms of the distance over which the discharge breakdown effectively occurs as long as one understand that this distance can depend on pressure.

Electrical Properties of Microdischarge in Porous Zeolites

“…It is known that the electrode material shape and structure affect the U B . The SEE, γ , of the material, which provides information on the efficiency of electron emission from the cathode due to ion bombardment, can have a large impact on the U B . In addition, the nanoporous structure of zeolite might also influence on the electron emission and consequently on the U B .…”

“…Finally, the interaction of the discharge with a dielectric surface requires the study of secondary processes at the dielectric surface. It should be noted that the secondary emission coefficient (SEE), γ , of the material, can have a large impact on the U B . In most studies of surface DBDs, SEE due to ion bombardment are considered.…”

“…It should be noted that the secondary emission coefficient (SEE), g, of the material, can have a large impact on the U B . [20,21] In most studies of surface DBDs, SEE due to ion bombardment are considered. However, electrons may also be emitted from other processes such as field emission or SEE of electrons by impact of metastable molecules.…”

Theoretical and Experimental Exploration of Breakdown Phenomena in an Argon-Filled GaP Device

“…The energy conversion from the cathode for an incident ion can be evaluated by studying f esc . [18][19][20] Indeed, an external field can also occur and propagate in the gas volume. Thus, the electrons lead to a certain spatiotemporal distribution below the breakdown voltage.…”

“…21,22 SEE attracts attention because of the important applications of such microdevices, including microelectromechanical systems, semiconductor devices, excimer sources, plasma display panels, lasers, electron multipliers, etc. [23][24][25] According to recent studies, the importance of emission processes from a surface and of electron-induced collisional transfer has increased in the framework of SEE; For instance, Ref. 21 showed that SEE levels for various gas media change with E/N, where E and N are the electrical field and gas density, respectively.…”