Sputtered C-axis inclined piezoelectric films and shear-wave resonators

Conference · Sat Jan 01 00:00:00 EST 1983

OSTI ID:5858845

Wang, J S; Lakin, K M; Landin, A R

Sputtered piezoelectric films are being studied for potential application to VHF through microwave frequency acoustic wave devices. This paper reports on the growth and characterization of C-axis inclined ZnO and AlN films for shear wave resonators. Orientation relationships for shear wave excitation were calculated for these films which suggest a nearly pure shear wave could be excited with films having C-axis orientation approximately 45/sup 0/ from the surface normal. At other angles, quasi-shear and quasi-longitudinal waves are excited. The well oriented ZnO or AlN films with C-axis inclined from the film normal were grown in a reactive dc planar magnetron sputtering system having an auxiliary anode structure. These films were evaluated by scanning electron microscopy (SEM) and BAW device measurements. The columnar structure of the C-axis crystallites, inclined from the Si substrate normal, was clearly visible in SEM. Films having C-axis inclination angles up to 45/sup 0/ and thicknesses up to 10 microns have been obtained. Composite resonators were fabricated by sputtering ZnO or AlN films onto the p/sup +/ Si membrane. Typically, these resonators exhibited Q s of about 5000 in 200 MHz to 500 MHz fundamental resonance range. Of particular interest is the temperature compensation of resonant frequency. Resonators having an absolute temperature coefficient of series resonant frequency of less than 1 ppM/C/sup 0/ around room temperature have been made for both ZnO/Si and AlN/Si composite structures. The temperature coefficient of the ZnO and AlN plate resonators was also measured to be -36.2 ppM/C/sup 0/ and -25 ppM/C/sup 0/ which suggested the temperature coefficient of the p/sup +/ Si membrane to be about +9 ppM/C/sup 0/ in the shear mode.

• Research Organization: Ames Lab., IA (USA)
• DOE Contract Number: W-7405-ENG-82
• OSTI ID: 5858845
• Report Number(s): IS-M-428; CONF-8306120-1; ON: DE83017253
• Resource Relation: Conference: 37. frequency control symposium, Philadelphia, PA, USA, 1 Jun 1983; Other Information: Portions are illegible in microfiche products. Original copy available until stock is exhausted
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
PIEZOELECTRICITY
SPUTTERING
RESONATORS
FABRICATION
ZINC OXIDES
MAGNETRONS
SILICON
TEMPERATURE DEPENDENCE
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTRICITY
ELECTRON TUBES
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
MICROWAVE EQUIPMENT
MICROWAVE TUBES
NITRIDES
NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SEMIMETALS
ZINC COMPOUNDS
420800* - Engineering- Electronic Circuits & Devices- (-1989)
360601 - Other Materials- Preparation & Manufacture