A high-Q diaphragm-structure film bulk acoustic resonator （FBAR） with a flat support diaphragm, made of Si3 N4/SiOz/Si3 N4 composite films ,is proposed. The N/O/N composite diaphragm overcomes the wrinkling in the r...A high-Q diaphragm-structure film bulk acoustic resonator （FBAR） with a flat support diaphragm, made of Si3 N4/SiOz/Si3 N4 composite films ,is proposed. The N/O/N composite diaphragm overcomes the wrinkling in the released support diaphragm caused by the residual stress of a single Si3N4 or SiO2 diaphragm. ZnO piezoelectric film deposited employing a DC reactive magnetron sputtering method is used as the piezoelectric material for the FBAR device. The XRD 0- 20 scan indicates that the ZnO film has the preferred c-axis orientation growth,implying good piezoelectric properties. The S parameter measurement shows that there＇ are three primary resonances in the frequency range from 0.4 to 2.6GHz. The series resonant frequency,parallel resonant frequency, Kett^2, and quality factors of the three resonances are calculated. The third one,with a frequency of about 2.4GHz,has the highest quality factor about 500. Thus,it is expected to be a candidate to form a 2.4GHz low-phase-noise oscillator.展开更多
基金the National Natural Science Foundation of China(No.90607012)~~
文摘A high-Q diaphragm-structure film bulk acoustic resonator （FBAR） with a flat support diaphragm, made of Si3 N4/SiOz/Si3 N4 composite films ,is proposed. The N/O/N composite diaphragm overcomes the wrinkling in the released support diaphragm caused by the residual stress of a single Si3N4 or SiO2 diaphragm. ZnO piezoelectric film deposited employing a DC reactive magnetron sputtering method is used as the piezoelectric material for the FBAR device. The XRD 0- 20 scan indicates that the ZnO film has the preferred c-axis orientation growth,implying good piezoelectric properties. The S parameter measurement shows that there＇ are three primary resonances in the frequency range from 0.4 to 2.6GHz. The series resonant frequency,parallel resonant frequency, Kett^2, and quality factors of the three resonances are calculated. The third one,with a frequency of about 2.4GHz,has the highest quality factor about 500. Thus,it is expected to be a candidate to form a 2.4GHz low-phase-noise oscillator.
