Substrate temperature dependent bolometric properties of TiO2 x films for infrared image sensor applications
Abstract In this study, we investigated the substrate temperature (T S dependent bolometric properties on TiO 2 x films for infrared image sensor applications. The film crystallinity was changed from amorphous to rutile phase with increasing the T S The decrement of resistivity with temperature in TiO 2 x test devices confirms the typical semiconducting property. All the test pattern devices have linear I V characteristic performance which infers that the ohmic contact was well formed at the interface between the TiO 2 x and the Ti electrode. The resistivity, activation energy (E a and the temperature coefficient of resistance (TCR) values of the device samples were decreased up to 200 degC of T S The sample deposited at 200 degC had a significantly low 1/f noise parameter and a high universal bolometric parameter (b) However, at the substrate temperature of 250 degC, the E a TCR and the 1/f noise values were increased due to increase of the resistivity. The TCR and the 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 deposited at 200 degC is a viable bolometric material for uncooled IR image sensors.