Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Year | Description |
| 2000 | Invention patented by Margarita P. Thompson and Gregory W. Auner on April 6th, 2000. Abstract: Device quality, single crystal film of cubic zinc-blend aluminum nitride (AlN) is deposited on a cubic substrate, such as a silicon (100) wafer by plasma source molecular beam epitaxy (PSMBE). The metastable zinc-blend form of AlN is deposited on the substrate at a low temperature by a low energy plasma beam of high-energy activated aluminum ions and nitrogen ion species produced in a molecular beam epitaxy system by applying a pulsed d.c. power to a hollow cathode source. In this manner, films having a thickness of at least 800 .ANG. were produced. The lattice parameter of as-deposited films was calculated to be approximately 4.373 .ANG. which corresponds closely to the theoretical calculation (4.38 .ANG.) for cubic zinc-blend AlN. An interfacial layer of silicon carbide, specifically the cubic 3C--SiC polytype, interposed between the epitaxial film of zinc-blend AlN and the Si(100) wafer provides a template for growth and a good lattice match. The epitaxial layer of zinc-blend AlN has been characterized for its physical and optical properties. As a result, experimental data confirmed that zinc-blend AlN is an indirect semiconductor and has a bandgap about 5.34 eV. Due to the extraordinary piezoelectric properties of zinc-blend AlN, an illustrative device embodiment is a surface acoustic wave (SAW) device comprising interdigitated electrodes deposited by conventional means on the surface of the epitaxial layer of zinc-blend AlN to convert an electrical signal to a surface acoustic wave and vice versa. |
| Source: selected by the editor from original sources. | |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
