| Title |
Optical Device,Display ; Influence of Substrate Temperature and Oxygen/argon Flow Ratio on the Electrical and Optical Properties of GZO Thin Films Prepared by Rf Magnetron Sputtering |
| Authors |
김숙주(Sook Joo Kim); 전진호(Jin Ho Jeon); 이종무(Chong Mu Lee) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Ga-doped ZnO; resistivity; Transmittance; Gas flow ratio; Substrate temperature |
| Abstract |
Effects of substrate temperature and atmosphere on the electrical and optical properties of Ga-doped ZnO thin films deposited by rf magnetron sputtering were investigated. The electrical resistivity of Ga-doped ZnO (GZO) films decrease as the substrate temperature increases from room temperature to 300℃. A minimum resistivity of 3.3 × 10(-4) Ωcm is obtained at 300℃ and then the resistivity increases with a further increase in the substrate temperature to 400℃. This change in resistivity with the substrate temperature is related to the crystallinity of the GZO film. The resistivity nearly does not change with the O2/(O2 + Ar) flow ratio, R for R < 0.33 but increases rapidly with R for R>0.33. This change in resistivity with R is also related to crystallinity. The crystallinity is enhanced as R increases, but if the oxygen partial pressure is higher than a certain level (R = 0.33 ± 0.10) gallium oxides precipitate at grain boundaries, which decrease both carrier concentration and mobility. Optical transmittance increases as R increases for R < 0.67. This change in transmittance with R is related to changes in oxygen vacancy concentration and surface roughness with R. |