Thin film volume acoustic wave harmonic oscillator structure and manufacturing method thereof

Abstract

The invention discloses a thin film volume acoustic wave harmonic oscillator structure and a manufacturing method thereof. The method comprises the steps that a polyimide liquid coating is evenly coated on the surface of an integrated circuit chip directly in a spin mode, then a polyimide layer is formed between the high temperature of 170 DEG C and 250 DEG C in a solidifying mode, a piezoelectric stack structure is deposited on the surface of the polyimide layer, the polyimide layer is used as an acoustic reflecting layer, then interconnected through holes are formed, and the entire thin film volume acoustic wave harmonic oscillator structure and an integrated circuit of the integrated circuit chip are electrically connected through the interconnected through holes. According to the thin film volume acoustic wave harmonic oscillator structure and the manufacturing method thereof, the thin film volume acoustic wave harmonic oscillator structure comprises the integrated circuit chip, the polyimide layer and a piezoelectric stack, the structure is simple and reliable, integrated mechanical firmness is high, sensing is facilitated, and the thin film volume acoustic wave harmonica oscillator structure is applied to radio frequency or sensing systems and is suitable for various complex environments. The manufacturing method of the thin film volume acoustic wave harmonic oscillator structure is simple and quick, the production cycle is shortened, the production cost is lowered, and a good application prospect is achieved.

Description

technical field [0001] The invention relates to the technical field of microelectronics, in particular to a film bulk acoustic wave resonator structure and a preparation method thereof. Background technique [0002] In the field of wireless communication, high communication frequency, high transmission rate, high-intensity multiplexing and high integration have become the development trend, which puts forward higher requirements for the integration of components. At present, the integration of active devices into a chip is quite mature in semiconductor technology, but the research on the integration of passive devices is relatively small and immature, which seriously restricts the development of integration technology. Passive devices are mainly multiplexers, Filters, resonators, and matching LC networks, resonators can form multiplexers, filters, oscillators, etc. A wireless transceiver needs multiple resonators to form multiplexers, oscillators, and filters. Therefore, bas...

AI Technical Summary

Problems solved by technology

In 2008, the patent document WO 2008 / 101646 Al proposed a monolithic integration technology, which is to invert the FBAR, use a metal layer to support the electrical contact of the CMOS circuit, and form an air gap structure. This method can further reduce the chip area, but still Two sets of different processes are required to prepare FBAR and CMOS circuits separately, and this method uses a support structure, the reliability is not high enough, and the yield rate will be relatively low. Therefore, the existing integration technology requires a single silicon wafer area for the manufacture of FBAR. It is made on a silicon wafer, and the general area of ​​FBAR is 1~5*10 4 um 2 , which is too large and expensive for a silicon integrated circuit

In 2009, the patent document CN101630946A (a thin film bulk acoustic resonator and its preparation method) jointly applied by Zhejiang University and Tsinghua University proposed a method for preparing FBAR on the passivation layer, which further reduces the chip area, but requires Deposit a layer of Bragg acoustic wave reflection layer on the first layer and then make thin-film bulk acoustic resonator. Due to the deposition of Bragg emission layer, the thickness of each layer needs to be strictly controlled, and it is easy to fall off, and it is difficult to realize in the process.

Images