Study on change of electrical properties of ZnO thin films deposited in low temperature facing targets magnetron sputtering (FTS) system with H-2 and O-2 flow rate changes

作者：Kim Hye R^*; Jin Su B; Wen Long; Choi Yoon S; Choi In S; Hori M; Han Jeon G

来源：Journal of Ceramic Processing Research, 2013, 14(2): 188-193.

• ZnO thin film
• Facing targets magnetron sputtering (FTS)
• Low temperature process
• Sheet resistance
• Optical band gap

The optical, structural and electrical properties of ZnO thin film deposited by FTS system with H-2 and O-2 addition at low processing temperature were studied. The sheet resistance of the ZnO thin film increased from similar to 10(-3) to similar to 10(6) Mohm/sq. with the O-2 flow rate and decreased from similar to 10(-1) to similar to 10(-4) Mohm/sq. with the H-2 flow rate increase. The increase of sheet resistance with O-2 flow rates could be explained by oxygen vacancies. The decrease of sheet resistance with H-2 flow rates could be explained by increase of the electrons from interstitial hydrogen atoms. The electrical property showed dramatic change with the small change of the flow rates. Conversely, the optical and structural characteristics did not show large variation. According to H-2 and O-2 flow rate change, transmittance of the deposited ZnO thin film varied in the range of 84 similar to 87% while the optical band gap showed small shift to the range of 3.22 eV similar to 3.26 eV. XRD measurements showed that the deposited ZnO thin film was composed of amorphous and crystalline phase and the grain size varied in the range of 15.37 similar to 17.89 with the flow rate change of H-2 and O-2. The plasma characteristics were analyzed using optical emission spectroscopy (OES) but the overall spectrum did not change with the H-2 and O-2 gas flow rates. Therefore, the dramatic changes in the electrical properties of ZnO thin films could be attributed to change in chemical composition of the thin films rather than the plasma status.

• 出版日期2013-4