Langmuir probe diagnostics of a radio frequency magnetron discharge for deposition of high T_c YBCO films

Abstract

Determination of the key internal discharge parameters such as charge particle concentration, plasma potential, and electron temperature has been made for sputter deposition of superconducting YBCO films in Ar and Ar+O₂ plasma using a tuned Langmuir probe technique. The plasma parameters measured from probe characteristics have been used to qualitatively explain the effect of deposition conditions on film property. The behavior of dc self-bias at the target is discussed in the light of the combined effect of O^̅₂ ion emission and Ba⁺ ion interaction with the target.