Controlled oxidation state of silver oxide thin films deposited by an integrated anode layer ion source ion beam sputter module

An integrated ion beam sputter deposition module utilizing an anode layer ion source has been designed and fabricated. Silver oxide is deposited utilizing this ion beam sputter module. Experimental results show that Ag is fully oxidized only with oxygen partial flow rate equal to and higher than 0.8. With an anode voltage of 700 V, silver oxide with (1 1 1) preferred orientation was obtained. Increasing anode voltage to 1500 V results in (2 0 0) orientated silver oxide thin films. Two band gaps can be identified that increase from 1.0/2.6 eV to 2.0/2.8 eV as anode voltage increases from 700 to 1500 V, respectively. As anode voltage increases, XPS analysis shows that Ag 3d5/2 core level peak position shifts from 367.3 to 367.7 eV. This confirms that increased kinetic energy of sputtered atoms results in partial reduction of AgO to Ag2O. Fully oxidized silver oxide samples are likely to be p-type while the resistivity is in the range of 0.7-2.0 × 104 Ω·cm.