The Effect Of Capacitive-coupling On Discharge Modes And Tuned Substrate Self-bias In A Radio-frequency Inductively Coupled Plasma

The radio-frequency capacitive-coupling is always concurring with inductive-coupling inradio-frequency inductively coupled discharge. One of the effects of capacitive-coupling isinductively coupled discharge mode(H mode) and capacitively coupled discharge mode(Emode) are twinbom in radio-frequency inductively coupled plasma sources. As the workabout effects of impedance matching network in existing experimental investigations aboutproperties of discharge mode transition are infrequent, only including the work of G. Cunge[G. Cunge, B. Crowley, D. Vender and M. M. Turner, Plasma Sources Sci.) Technol. 8,576(1999)] about E-H mode transition on the different matching but which is lacking in theanalysis on the mechanism, the systemic research about physical mechanism of modetransition are needed. The studies on the influencing of the installation conductor ground toproperties of discharge mode transition which is the inevitable road of capacitive-couplingare not found.Using advanced Z-Scan measuring system, current probe and voltage probe, measuringmany parameters including plasma absorbed power, antenna current, antenna voltage, andplasma floating voltage, the effects on the properties of transition between plasma dischargeE-mode and H-mode transition by changing impedance matching network, coupled density ofantenna, area of installation conductor ground and pressure are studied. The concepts ofpositive and negative feedback regions are established basing on the influencing of straycapacitor inΓimpedance matching work to the output power of radio-frequency powersupply. It is found that jump mode transition easily exists and many parameters includingcritical antenna current of jump mode transition, width of hysteresis, critical power of jumpmode transition and gap power of jump mode transition obviously changes as alteringimpedance matching network at the same condition when plasma discharge is in positivefeedback region; in negative feedback region, the process of mode transition tend tocontinuous. As the effect of impedance matching network, the jump critical current ofE-mode to H-mode is not always more than the jump critical current of H-mode to E-mode.The evolutive nonlinear behaviors which is deriving from the driven oscillation ofradio-frequency power supply are also studied in discharge mode transition. In the research ofthe influencing of area of installation conductor ground to discharge mode transition, it is also found that different area of ground combining with matching network and antenna couplingdensity makes multiple mode transition.The investigation on the properties of the tuned substrate self-bias basing oncapacitive-coupling are studies research team in the past. At the foundation of past work, thesecond continuous region of the tuned substrate self-bias, the effect of coupling betweenpositive and negative feedback regions of discharge and positive and negative feedbackregions of tuned substrate self-bias and period-doubling behavior of pulsed self-oscillation arefound.