Electron-temperature control by varying dc voltage to a mesh grid covered by thin film in plasmas

We discuss theoretically how the resistance of a film deposited on the metal grid affects the efficiency of electron-temperature control by employing a grid-bias method, in which, by using a naked metal grid, the electron temperature decreases from 3.4 to 0.12 eV with a decrease in the grid potential from 40 to - 60 V, being accompanied by an electron-density increase from 0.6 x 109 cm-3 to 6.0 x 109 cm-3 at an argon gas pressure of 5.0 mTorr. The electron temperature can be varied even when the grid is covered with a film with finite resistance, although the range of electron temperature variation is restricted. This method is applicable to reactive plasmas in which grids are often covered by films with finite resistance