Study of optical and electrical properties of sputtered indium oxide films

The indium oxide films were deposited by dc reactive magnetron sputtering from In target on unheated Si substrate with oxygen flow in the ranging from 40 to 80 sccm. The deposited films were annealed in a conventional tube at T=400°C for 1 hour in N
₂
atmosphere. Measured absorption coefficients of all indium oxide films were in the range the values of 2.6÷12.5×10
⁶
m
^-1
. It was found that calculated values of the direct band gap and indirect band gap depend on oxygen content in the sputtering gas mixture. Electrical resistivity increased from 6.8×10
³
to 28.5×10
³
Ωcm with increasing oxygen flow 40 - 80 sccm. Finally, the correlation between optical properties and surface roughness of examined samples was identified.