Duplexer filter having film bulk acoustic resonator and semiconductor package thereof

Abstract

Disclosed are a film bulk acoustic resonator, a duplexer filter having the same, and a semiconductor package thereof. The film bulk acoustic resonator comprising: a semiconductor substrate; a lower electrode more than two layers formed at an upper surface of the semiconductor substrate; a piezoelectric layer deposited on an upper surface of the lower electrode with a certain thickness; and an upper electrode more than two layers formed at an upper surface of the piezoelectric layer, has an excellent bonding characteristic. The duplexer filter can microminiaturize a size thereof by integrating a film bulk acoustic filter formed by connecting the plurality of film bulk acoustic resonators serially and in parallel and peripheral passive elements of the film bulk acoustic filter into one semiconductor chip. Also, the semiconductor package is suitable for the duplexer filter.

Description

Technical field [0001] The present invention relates to a duplex filter, and more particularly, to a duplex filter with a thin film cavity acoustic resonator and a semiconductor package thereof. Background technique [0002] Generally, a thin film cavity acoustic resonator (FBAR) is a bulk acoustic wave filter using a piezoelectric layer. The size of an ordinary frequency filter is proportional to the wavelength of the electromagnetic wave in the frequency band used. Therefore, the size of a common frequency filter using electromagnetic waves is relatively large. For example, when the frequency of the electromagnetic wave is 1 GHz, the size of the ordinary frequency filter is about 30 cm, and when the frequency of the electromagnetic wave is 300 GHz, the size of the ordinary frequency filter is about 1 mm. However, if the piezoelectric layered bulk acoustic wave is used, the wavelength of the bulk acoustic wave becomes smaller to one ten thousandth of the wavelength of the electr...

AI Technical Summary

Problems solved by technology

[0011] However, in the conventional thin-film cavity acoustic resonators 10, 20, and 30, the lower electrode 14 formed on the semiconductor base layers 11, 21, and 31 forms a single layer, thereby reducing the contact between the lower electrode 14 and the semiconductor base layers 11, 21. Adhesive properties between and 31

In addition, it is difficult to expand the underlying electrode 14 and the piezoelectric layer 15 with C-axis positioning due to the influence of the semiconductor bottom layer 11, 21 and 31.

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