Ga doped ZnO thin films prepared by RF plasma assisted DC magnetron sputtering under reductive atmosphere without heating substrates

Ga doped ZnO (GZO) transparent conductive thin films have been prepared by RF plasma assisted DC magnetron sputtering under a reductive atmosphere without intentionally heating substrate. The resistivity of the GZO film facing the erosion area in the source target falls to about a 1/1000 value by providing the RF plasma, resulting in a uniform distribution of the sheet resistance. Currently obtained values of resistivity, Hall mobility, and carrier concentration are 1 × 10^-2 Ω-cm, 4 cm²/Vs, and 3 × 10²⁰ cm^-3, respectively. It has been also found that the crystallization of GZO films is also enhanced by the RF plasma. After the accelerated aging test (60 °C - 95%RH) for 250 hrs, the sheet resistance maintains almost the same as the initial value for the GZO film prepared with RF plasma, though that increases by 15 times for the film prepared without RF plasma.