A surface acoustic wave device based on silicon carbide substrate/zinc oxide or doped zinc oxide thin film and its preparation method

Abstract

The invention discloses a surface acoustic wave device based on a silicon carbide substrate / a zinc oxide or doped zinc oxide film, and a preparation method thereof. The structure of the device comprises the silicon carbide substrate, an intermediate transition layer located on the silicon carbide substrate, a piezoelectric layer on the intermediate transition layer, and an interdigital electrode on the piezoelectric layer; the piezoelectric layer is made of zinc oxide or doped zinc oxide; and the interdigital electrode comprises a metal substrate layer located on the piezoelectric layer and ametal main body layer located on the metal substrate layer. The surface acoustic wave device uses the silicon carbide substrate as the substrate, a thin aluminum gallium nitride intermediate transition layer is introduced between the silicon carbide substrate and the (doped zinc oxide) thin film, and a high-quality smooth epitaxy (doped) zinc oxide film is grown by precisely controlling the growthconditions. The surface acoustic wave device disclosed by the invention has the advantages of simple process steps and low cost, and the manufactured surface acoustic wave device has high center frequency, high power endurance, small temperature coefficient, and has huge application in the field of high frequency, high power and low temperature coefficient.

Description

technical field [0001] The invention belongs to the technical field of information electronic materials, and specifically relates to a surface acoustic wave device based on a silicon carbide single crystal substrate with high sound velocity, high thermal conductivity and low temperature coefficient, high resistance and piezoelectricity (doped) zinc oxide thin film and a preparation method thereof. Background technique [0002] With the rapid growth of the wireless communication market in the past few decades, SAW filters have been greatly developed. At the same time, great advances in semiconductor planar technology, material science, and microelectronics technology have enabled other types of SAW devices, such as various sensors, actuators, and microfluidic devices, to be used in remote control telemetry, aerospace, medical testing, and smart homes. It has also been widely used. [0003] Traditional surface acoustic wave devices are fabricated on lithium tantalate, lithium...

AI Technical Summary

Problems solved by technology

Although the substrate or film has high sound velocity and thermal conductivity, it is expected to produce high-frequency and high-power devices, but the major defects of these substrates or films are relatively large propagation loss and poor consistency compared with single crystal substrates.

These reflect on the device that the Q value is small, the propagation loss is large, and the uniformity of the device is poor.

The reason is that these diamonds or diamond-like carbons are polycrystalline materials, and the high density of crystal defects causes high propagation loss

In addition, these defects also largely deteriorate the quality of the piezoelectric film grown on it, further deteriorating the performance of the device

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