Measurement of high temperature sensitivity of Al/(Zn:Cd:Ni:TiO2)/p-Si structure based on capacitance/conductance-voltage (C/G-V)

In this work, a cryogenic metal oxide diode temperature sensor has been fabricated using ZnCdNi:TiO2 metal oxide semiconductor on p-type silicon substrate for thermal sensor applications. The temperature sensing performance and fundamental electrical properties of Al/(ZnCdNi:TiO2)/p-Si were investigated using temperature dependent impedance measurements. There are two linear areas for low and high temperatures in the temperature sensibility (S) for the fixed capacitance driver mode. The highest S value of 8.3 mV/K at 0.10 nF was obtained at high temperatures. The capacitance/conductance values were demonstrated to be considerably affected by voltage and temperature, particularly at accumulation and depletion regimes. The reverse bias 1/C2-V characteristic was used to compute certain basic electrical parameters, including barrier height (B), diffusion potential (VD), and density of acceptor atoms (NA) for each temperature. The resistance (Ri) values were calculated using the Nicollian-Brews method. Additionally, c2 values were used to derive density of surface states (NSS) values. Al/(ZnCdNi:TiO2)/p-Si's excellent quality and performance are further demonstrated by its low RS values and suitable NSS size. Furthermore, low Arrhenius plot activation energy values (Ea) suggest that the trapped electron either hops between traps or that the conduction band predominates. Al/(Zn:Cd:Ni:TiO2)/p-Si's suitability as thermal sensors both in low and high temperature regions is thus supported by the variations in electrical characteristics and high S value.