Single Crystal Thin Films of Semiconductor and Piezoelectric Materials on Refractory Substrates.
Abstract
Composites of single-crystal thin film piezoelectric ans semiconductor materials heteroepitaxially grown on insulating substrates were investigated for application to the generation, processing, and guiding of acoustic surface waves. Emphasis was on AlN as the piezoelectric material, Si as the semiconductor, and single-crystal sapphire (alpha-Al2O3) as the substrate; the multistrip-coupler acoustic amplifier was the device structure utilized, fabricated with films of AlN and Si deposited side-by-side on Al2O3 surfaces. AlN film growth was accomplished by the metalorganic-hydride CVD process using trimethylaluminum and ammonia; both close-space vapor transport of AlN and the AlCl3-NH3 reaction were also investigated for AlN deposition, but they did not produce results comparable with those of the metalorganic CVD process. Impedance and transmission measurements using interdigital transducers (IDT's) on composite samples of AlN/Al2O3 both with and without adjoining layers of Si were used for evaluation of film acoustic properties; other film evaluations were carried out by X-ray and electron diffraction and replica electron microscopy techniques.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1974
- Accession Number
- AD0917408
Entities
People
- Frank A. Pizzarello
- Harold M. Manasevit
- J. Edward Coker
- Ralph P. Ruth