| This thesis presents research on the selection and development of thin film deposition of materials and initial data on the integration of a pH measuring device suitable for evaluation. This device used two particular tantalum compounds deposited by dc magnetron reactive sputtering as functional layers. Key parameters to film quality, such as resistivity, optical constants, composition, and pH response will be discussed in detail. Results indicated that nitrogen gas flow both controls the resistivity of sputtered tantalum nitride and suppressed the incorporation of oxygen. Variable Angle Spectroscopic Ellipsometer transmission scan on tantalum oxide with various oxygen pressure indicated insulating oxide forms only when the target enters oxide mode at 10+ sccm of oxygen flow. X-ray Photo-electron Spectroscopy surveys on tantalum oxide films showed that stoichiometric tantalum pentoxide was deposited. Preliminary result on pH response of the devices indicated the resistance increased with increasing pH. |
