Title :
Surface acoustic wave H2 sensor on silicon substrate
Author :
Caliendo, C. ; D´Amico, A. ; Varadi, P. ; Verona, E.
Author_Institution :
Consiglio Nazionale delle Ricerche, Istituto di Acustica O.M. Corbino, Rome, Italy
Abstract :
A surface acoustic wave (SAW) hydrogen sensor implemented on a silicon substrate is presented. The device is based on the changes produced in the phase velocity of SAWs propagating along a multilayered Pd/ZnO/SiO2/Si structure by H2 absorption and desorption in the selectively sorbent Pd film. Several devices have been made and tested. The time response and the sensitivity of the devices on exposure to different concentration of H2 in N2 are reported for two different values of the thickness of the Pd film. Measurements have shown a high response of the device on exposure to H 2 concentrations in N2 in the range 50-10000 p.p.m. The frequency of operation, the electrical performances of the device, and the fabrication technology involved have been optimized in view of a future integration of the electroacoustic structure and of the electric signal-processing circuitry on the same Si substrate
Keywords :
gas sensors; hydrogen; surface acoustic wave devices; H2 sensor; N2; Pd-ZnO-SiO2Si; SAW; electric signal-processing circuitry; electroacoustic structure; fabrication technology; gas sensors; phase velocity; sensitivity; surface acoustic wave; time response; Absorption; Acoustic propagation; Acoustic sensors; Acoustic waves; Hydrogen; Silicon; Substrates; Surface acoustic wave devices; Surface acoustic waves; Zinc oxide;
Conference_Titel :
Ultrasonics Symposium, 1988. Proceedings., IEEE 1988
Conference_Location :
Chicago, IL
DOI :
10.1109/ULTSYM.1988.49441
