High permittivity dielectrics are studied intensively in the view of their use in the integrated circuits. However, the real emergence of tantalum oxide (Ta2O5) as a dielectric material happened due to its high-dielectric constant, chemical and thermal stability with the promise of compatibility in microelectronic processing. This book covenants with the optimized deposition conditions of Ta2O5 films formed on quartz and p-type Si substrates using dc and rf reactive magnetron sputtering method for structural and optical studies. Further, aluminum metal deposited as a top electrode on Ta2O5 and Si stack to prepare metal oxide semiconductor device for investigating electrical and dielectric properties. The possible ways for depositing good quality Ta2O5 layers on Si, to obtain high dielectric constant explained in this book are quite useful to prepare high quality metal oxide semiconductor device for capacitor applications.