Answers are grounded in this paper and cite their sources.
Zinc-oxide thin-film transducers are used in a variety of microwave acoustic device applications for the generation and detection of bulk and surfaceacoustic waves. High coupling factor-low acoustic loss films are characterized by their dense, fine-grain, well-ordered crystallite structure, optical clarity and smooth surface texture. Sputtering the films using a compound ZnO target at moderate rates, with low reactive gas pressures on heated substrates, has produced films whose piezoelectric and acoustic properties approach those of single crystal zinc oxide. Several diagnostic techniques such as XRD, RED, SEM, TEM, optical, chemical and electrical havebeen used to characterize acoustic quality. This paper will discuss process conditions that lead to high quality film growth and diagnostic measures which best predict transducer performance.
No takes yet. Share an insight, caveat, or question.
F.S. Hickernell (1980) studied this question.