Influence of deposition temperature on TiO_(2-x) films for infrared image sensor applications: TiO_(2-x) films: Infrared image sensor applications

摘要

The present study explores the improved sensor device properties of sputtered TiO_(2-x) films at different deposition temperatures (T_d=25-250°C) by means of test pattern device. All the T_d test pattern samples show linear I-V characteristic performance which implies that ohmic contact was well formed at the interface between the TiO_(2-x) and the Ti electrode. The resistivity, activation energy (Ea) and the temperature coefficient of resistance (TCR) values of the device samples were decreased up to 200°C of T_d. The dependence of the 1/f noise and the TCR on resistivity in TiO_(2-x) has been measured. The sample deposited at 200°C had a significantly low 1/f noise parameter and a high universal bolometric parameter (β). However, at T_d of 250°C the Ea, TCR and the 1/f noise values were increased due to increase of the resistivity. The TCR and 1/f noise values are proportional to the resistivity of TiO_(2-x) films. As a result, the low resistivity of TiO_(2-x) sample sputtered at 200°C is a viable bolometric material for uncooled IR image sensors.