Interdigital electrode structure, manufacturing method thereof, and surface acoustic wave device having the structure

Abstract

An interdigital electrode structure is disclosed. The interdigital electrode structure is disposed on a substrate, wherein the ends of the interdigital electrodes in the interdigital electrode structure are implanted with ions to form a doped part. Also disclosed is a surface acoustic wave device, which includes the above interdigitated electrode structure, and the surface acoustic wave device is a filter or a resonator. In addition, a method for manufacturing an interdigital electrode structure is also disclosed, including preparing a substrate with a piezoelectric layer; fabricating an interdigital electrode on the substrate; and performing ion implantation on the interdigital electrode to form a The end forms a doped portion. The doped part is formed by ion implantation at the end of the interdigitated electrode, which improves the electric field gradient at the end of the electrode without changing the weight of the agent and does not adjust the thickness of the interdigitated electrode, suppresses parasitic oscillations, and ultimately improves the performance of the surface acoustic wave device. .

Description

technical field [0001] The embodiments of the present application relate to the field of communication devices, and in particular to an interdigital electrode structure, a manufacturing method thereof, and a surface acoustic wave device having the structure. Background technique [0002] In recent years, the rapid development of mobile communication and the increasing demand for SAW devices, SAW devices are wireless, purely passive devices, with low insertion loss, high out-of-band suppression, high image attenuation, high carrying power, and low cost And advantages like miniaturization or miniaturization. With the continuous improvement of semiconductor technology, the operating frequency of SAW devices extends from 10MHz to 3GHz. This makes SAW widely used in vehicle traffic management, biomedicine, industrial automation, smart grid, inventory of dangerous weapons, and environmental testing. [0003] The SAW device adopts the process of semiconductor integrated circuit. ...

AI Technical Summary

Problems solved by technology

[0004] If the interdigital electrode structure in the prior art is not optimized, it is difficult to solve the parasitic oscillation caused by the gradient change of the electric field; the interdigital electrode structure with floating electrodes is designed to improve the insertion loss; or the apodization weighting adjusts the interdigital voltage The excitation intensity of the electric substrate to the acoustic wave is accurately weighted to the interdigitation according to the weighting function to improve the performance of the device (such as high Q value, frequency response performance, flat passband, high out-of-band rejection, low insertion loss, etc.); or further adopt more For the complex apodized weighted interdigital structure, use Cu, Pt and Au and other high-density metals as a part of the electrode to change the sound wave transmission mode to reduce unwanted resonance; or use interdigitated electrodes with a piston structure The structure, the piston at the end of the electrode can also suppress the parasitic oscillation of the saw, the material is generally metal or PI, the protruding piston will relatively affect the thickness of the electrode, and have a certain impact on the center frequency and bandwidth of the device, so as to reduce false resonance and improve Resonator performance; some use high-quality density (such as Au and Ag, etc.) Al or AlCu alloy), improve the design freedom of Saw devices, improve process compatibility (weaken the obvious change in frequency caused by the change of interdigital electrode width in the process), and improve the reflectance of the reflective layer (suppress the leakage of SAW energy or convert it into Longitudinal waves can also be designed to reduce the number of reflective layers and reduce the size of the device), in order to achieve the purpose of improving the performance of the resonator

Images