Determining pressure of working gas in plasmas, measures plasma current or emission line intensity under two different states defined by voltage and pressure

摘要

Plasma is ignited in at least two different working states. These are defined by different values of plasma voltage Uj(j=1-n) and/or of gas pressure Pj(j=1-n). For each state, measurements are taken of plasma current i1-in, or the intensity I j(j=1-n) of one or more emission lines of the working gas. The calibration formula is then used to determine the associated p-values. Taking into account the pj-values and the ij values or the Ij values, the heat dissipation constant ki or KI at the sputtering plane is calculated. Finally, gas pressure pB at the sputter plane is calculated in the operating state, taking into account the thermal dissipation constants ki or KI.