Ion Beam Sputtered Indium Antimonide Thin Films and Their Application to Surface Acoustic Wave Amplifiers.

A process combining ion beam sputtering and zone melt refining (ZMR) has been developed to deposit thin InSb films (~500-1000A) on LiNbO _3, Si, and 7059 glass. X-ray diffraction results indicate the InSb film's (111) orientation is along the normal direction of the surface. Auger electron spectroscopy (AES) analysis shows that the atomic ratio between In and Sb is near 1: 1. With Raman scattering technique, not only is InSb clearly identified, but also locally crystallized Antimony due to constitutional supercooling is detected by its A_{1g} and E_{g} Raman modes. Smooth surface and dense InSb films are illustrated by optical and scanning electron microscope photographs. The SAW amplification theory is derived with a much simplified transmission line model. The results are consistent with the normal mode theory and can be used to examine the SiO_{x} /InSb/AlN/LiNbO_3 SAW amplifier. A practical device, which has six of such amplifiers embedded, is built to demonstrate the potential application of the films. It provides 56musec delay at 150MHz.