Technological aspects of potentiometric BSC-type microsensor fabrication

The reported back-side contact sensor were fabricated using a standard IC technology. The silver/silver chloride layers were deposited using electrochemical technique. The sensor chips were passivated with silicon nitride layer deposited by LPCVD, which ensure the stability of measurements. Preliminary examination of prepared sensor included the evaluation of their electrical properties and potentiometric response toward chloride. It was found that 19 sensors among 20 exhibited fast and reversible response toward chloride. Near theoretical slopes were obtained over the 10-4- 10-1 M chloride concentration range. The response time was shorter than 10S. The statistical evaluation, the calibration curves and the dynamic response of 20 sensors tested at the same time indicates that the proposed technology ensures preparation of sensor chips in a very reproducible way.