Study of plasma characteristic and properties of flexible ultra-thin ITO films prepared by large area 3-D confined and planar magnetron sputtering

Abstract

This work presents the plasma characteristics in a conventional planar magnetron source (PMS) and a large 3-D confined magnetron source (3DMS). We utilize different plasma diagnostic methods to study the plasma characteristics and the favorable plasma condition for the deposition of ultra-thin indium tin oxide (ITO) film near room temperature. Measurements of plasma parameters by Langmuir probe (LP) and energy flux by Calorimetric probe (CP) respectively showed a very high-density plasma and deposited energy flux (EF) on the substrate when operated by the 3DMS. Plasma diagnostic reveals that the plasma density measured in the 3DMS process is nearly one order higher compared to that of the PMS process. We consider the experimental condition of high-density plasma and deposition EF as the favorable process condition for the deposition. In this condition, flexible ultra-thin ITO (UT-ITO) films were deposited by changing the O2 flow rate. The role of negative oxygen ions (NOIs) on the film properties is studied at different O2 flow rates. The condition with the lowest NOI flux produced a UT-ITO film with the lowest resistivity ∼5.0 × 10−4 Ωcm and visible transmittance ∼82% with crystalline microstructure and smooth morphology using 3DMS at low-temperature.