BiFeO3 ince filmlerin yapısal ve elektriksel özellikleri ve radyasyon sensörü olarak kullanımı

In this thesis, the structural and electrical characterization of BiFeO3 thin films and possible usage of BiFeO3 in MOS based radiation sensors were investigated. BiFeO3 thin films were deposited on (100) p-type silicon wafers with a thickness about 300 nm by magnetron sputtering. The deposited thin films were divided into two groups. First group samples were annealed at 550°C for 30 minutes under atmospheric environment. The second group samples were kept as-deposited. Structural characterizations were studied by using XRD and SEM measurements before and after annealing of samples. The BiFeO3 MOS capacitors were fabricated in both annealed and as-deposited samples by using evaporation technique. High frequency C-V measurements were performed for both type samples, but frequency dependent C-V hysteresis and G/ω-F measurements were carried out for annealed samples exhibited the desired characteristic. To examine their gamma irradiation response of the annealed ones, the devices were irradiated up to 16 Gray by using the GAMMACELL 220 Co-60 radioactive source at a dose rate of 0.0030 Gy/s. C–V measurements were recorded prior to and after irradiation and the effects of radiation were determined from the mid-gap and flat-band voltage shifts. The results show that BiFeO3 can be used as dielectric layer for future dielectric applications such as radiation sensors.