Fabrication of a Slotted SiO₂Film/Embedded Grating Electrodes/128° YX-LiNbO₃Structure

Abstract

In this paper, we describe the fabrication of Al grating electrodes embedded in a slotted SiO 2 film on a 128 YX-LiNbO 3 substrate in order to control both reflection characteristics and the temperature coefficient of frequency (TCF) of surface acoustic wave (SAW) devices. First, the fabrication process is discussed. It is shown that the combined usage of ion milling and reactive ion etching enables independent control of the thicknesses of the slotted SiO 2 film and grating electrodes to be embedded in the slots. Next, the process is applied to the fabrication of an SAW transversal filter, showing the possibility of controlling the reflection characteristics and TCF independently.