Method for preparing thin film bulk acoustic wave device by using thin film transfer technology

Abstract

The invention provides a method for preparing a thin-film bulk acoustic wave device using thin-film transfer technology, including: 1) providing an oxide single crystal substrate; Form the lower electrode on the implanted surface; or form the lower electrode on the implanted surface, and then carry out ion implantation into the oxide single crystal substrate from the implanted surface; 3) Provide a supporting substrate, and bond the structure obtained in step 2) to the supporting substrate; 4 ) peel off part of the oxide single crystal substrate along the defect layer to obtain the oxide single crystal film, and transfer the oxide single crystal film and the lower electrode to the supporting substrate; 5) corrode the supporting substrate to form a cavity; 6) in the oxidation The upper electrode is formed on the surface of the single crystal thin film. The invention provides a new method for preparing the core structure of a metal electrode-single crystal oxide-metal electrode film bulk acoustic wave filter, which effectively solves the problem that single crystal oxide cannot be prepared between metal electrodes.

Description

technical field [0001] The invention belongs to the technical field of semiconductor preparation, and in particular relates to a method for preparing a thin-film bulk acoustic wave device by using thin-film transfer technology. Background technique [0002] With the development of science and technology, thin film bulk acoustic wave devices have been widely used in more and more areas. In the prior art, the fabrication method of thin-film bulk acoustic wave devices is generally to deposit an oxide dielectric thin film on the metal bottom electrode, and then prepare a metal top electrode on the oxide thin film to form a metal-oxide-metal sandwich structure. The key technology is the preparation of oxide dielectric thin films. The common preparation methods of oxide dielectric thin films include pulsed laser deposition, magnetron sputtering, atomic layer deposition, and thermal evaporation. However, there are many problems in these traditional thin film preparation methods. F...

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Problems solved by technology

However, there are many problems in these traditional thin film preparation methods, for example, it is generally necessary to grow oxide thin films at relatively high temperatures, and it is difficult to be compatible with existing CMOS processes

In addition, due to factors such as lattice mismatch, thermal mismatch, and interface defects, these traditional thin film preparation methods cannot grow high-quality single crystal oxide thin films on polycrystalline metal bottom electrodes.

However, the problems of amorphous or polycrystalline thin films prepared by traditional thin film preparation methods include: on the one hand, there are many different defects in both amorphous and polycrystalline thin films; The distribution in the thin film is random, which is a bottleneck that is difficult to break through for reducing the size of the device, stabilizing and optimizing the device parameters, and reliability research.

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