Time Resolved Spectroscopy of RF Plasmas : A Comparison of Hydrogen and Deuterium Plasmas

Abstract
Spatio-temporal resolved emission is a powerful technique for exploring the neutral, ionic and electron characteristics of rf driven plasmas. Here this is illustrated by measurements of emission from capacitively coupled H₂ and D₂ rf driven plasmas. These exhibit two pronounced emission regions, one associated with the normal sheath edge and the other near the driven electrode. Timeresolved electrode and plasma potential measurements show this near-electrode emission is associated with field reversal in the electrode sheath. The close similarity of the emission structure in the two isotopes, and the general lack of such structure in He plasmas indicates that the structure and hence field reversal are not solely due to ion mass effects but may also involve the details of the electron collisionality of the gas.