THE GASEOUS ELECTRONICS CONFERENCE RADIOFREQUENCY REFERENCE CELL - A DEFINED PARALLEL-PLATE RADIOFREQUENCY SYSTEM FOR EXPERIMENTAL AND THEORETICAL-STUDIES OF PLASMA-PROCESSING DISCHARGES

A ''reference cell'' for generating radio-frequency (rf) glow discharg es in gases at a frequency of 13.56 MHz is described. The reference ce ll provides an experimental platform for comparing plasma measurements carried out in a common reactor geometry by different experimental gr oups, thereby enhancing the transfer of knowledge and insight gained i n rf discharge studies. The results of performing ostensibly identical measurements on six of these cells in five different laboratories are analyzed and discussed. Measurements were made of plasma voltage and current characteristics for discharges in pure argon at specified valu es of applied voltages, gas pressures, and gas flow rates. Data are pr esented on relevant electrical quantities derived from Fourier analysi s of the voltage and current wave forms. Amplitudes, phase shifts, sel f-bias voltages, and power dissipation were measured. Each of the cell s was characterized in terms of its measured internal reactive compone nts. Comparing results from different cells provides an indication of the degree of precision needed to define the electrical configuration and operating parameters in order to achieve identical performance at various laboratories. The results show, for example, that the external circuit, including the reactive components of the rf power source, ca n significantly influence the discharge. Results obtained in reference cells with identical rf power sources demonstrate that considerable p rogress has been made in developing a phenomenological understanding o f the conditions needed to obtain reproducible discharge conditions in independent reference cells.