Bulk acoustic wave resonator with electrical isolation layer, manufacturing method thereof, filter and electronic device

Abstract

The invention discloses a bulk acoustic wave resonator. The bulk acoustic wave resonator comprises a substrate; a bottom electrode; a top electrode; a piezoelectric layer arranged between the bottom electrode and the top electrode as well as an acoustic mirror. The resonator also comprises an electrode connecting part, an electrical isolation layer and an electrode pin, the electrode connecting part covers the electrical isolation layer, one end of the electrode connecting part is electrically connected with the top electrode, and the other end of the electrode connecting part is suitable forbeing electrically connected with the electrode pin; one part of the electrical isolation layer forms electrical isolation between the electrode connecting part of the resonator and the bottom electrode; and at least one part of the electrical isolation layer covers at least one part of the end surface of the piezoelectric layer and the end surface of the bottom electrode so as to form electricalisolation between the electrode connecting part and the bottom electrode, and the resonator is also provided with a temperature compensation layer. The invention further discloses a manufacturing method of the bulk acoustic wave resonator, a filter with the resonator and electronic equipment with the filter or the resonator.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular to a bulk acoustic wave resonator, a filter, an electronic device with the resonator or the filter, and a manufacturing method of the bulk acoustic wave resonator. Background technique [0002] As the basic elements of electronic equipment, electronic devices have been widely used, including mobile phones, automobiles, home appliances, etc. In addition, technologies such as artificial intelligence, the Internet of Things, and 5G communications that will change the world in the future still need to rely on electronic devices as the basis. [0003] Film Bulk Acoustic Resonator (FBAR, also known as Bulk Acoustic Resonator, also known as BAW), as an important member of piezoelectric devices, is playing an important role in the field of communication, especially FBAR filters in radio frequency filters The field market share is increasing. FBAR has excellent characteristics such as small si...

AI Technical Summary

Problems solved by technology

[0004] In traditional bulk acoustic wave resonators, the bottom-up processing method is often used. The key step is to pattern the bottom electrode after sputtering the bottom electrode and then continue to grow the piezoelectric layer, resulting in the piezoelectric layer on the electrode. The edge is prone to breakage or crystal orientation changes, resulting in a decrease in the electromechanical coupling coefficient

[0005] In addition, in single crystal acoustic resonators, since single crystal growth has extremely high requirements on interface materials, interface crystallinity, interface cleanliness, roughness, and flatness, it is not possible to grow single crystal materials directly on the patterned bottom electrode. , the method of back etching is often used to deposit the bottom electrode, which increases the difficulty of the process and the complexity of wafer-level device packaging (both sides of the front and back are required)

[0006] Moreover, in the traditional temperature compensation technology, the temperature compensation layer is usually formed on the patterned metal electrode or piezoelectric layer by physical sputtering or chemical vapor deposition. One of the problems of this manufacturing method is: due to the process compatibility properties, such as thermal compatibility, the manufacturing process and parameter selection of the deposition temperature compensation layer such as silicon dioxide are limited, and the thermal compensation layer film thus produced has a large acoustic loss (such as insufficient compactness, more impurities, and more defects)

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