Top electrode structure of bulk acoustic wave resonator and manufacturing process

A bulk acoustic wave resonator and manufacturing process technology, applied to electrical components, impedance networks, etc., can solve problems such as adverse effects of shear waves

Pending Publication Date: 2020-05-29
HANGZHOU JWL TECH INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In view of the adverse effects caused by the shear wave in the resonance area of ​​the bulk acoustic wave

Method used

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  • Top electrode structure of bulk acoustic wave resonator and manufacturing process
  • Top electrode structure of bulk acoustic wave resonator and manufacturing process
  • Top electrode structure of bulk acoustic wave resonator and manufacturing process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0056] like Figure 4 As shown, S2 includes the following sub-steps:

[0057] S21, making a mask 8 on the piezoelectric layer 3 in a region where the dielectric isolation layer 5 does not need to be arranged;

[0058] S22, making a dielectric isolation layer 5 through spin coating, exposure and development processes; and

[0059] S23 , removing the mask 8 .

[0060] In a specific example, such as Figures 2e-2g As shown, the mask 8 is made by CVD, photolithography and etching processes, wherein the material of the mask 8 is SiO 2 . The mask 8 is made on the piezoelectric layer 3 in the area where the dielectric isolation layer 5 does not need to be arranged. On this basis, the dielectric isolation layer 5 is fabricated by spin coating, exposure and development processes, and then the dielectric isolation layer 5 is baked to cure the dielectric isolation layer 5 . In a preferred embodiment, the material of the dielectric isolation layer 5 includes PI, and the baking tempe...

Embodiment 2

[0064] After making the dielectric isolation layer 5 and removing the mask 8 in S22 and S23 in Embodiment 1, as Figure 2k As shown, a second mask 10 is formed on the dielectric isolation layer 5 to protect the dielectric isolation layer 5 . The function of the second mask 10 is to ensure the stability of the dielectric isolation layer 5 . In a preferred embodiment, the material of the second mask 10 is SiO 2 , with a thickness of 10-20nm. The specific thickness of the second mask 10 can be adjusted according to device processing conditions and device requirements. In a preferred embodiment, after the dielectric isolation layer 5 is cured, the height of the upper surface of the dielectric isolation layer 5 is lower than the upper surface of the piezoelectric layer 3 . At this time, after the second mask 10 is made on the dielectric isolation layer 5, the upper surface of the second mask 10 is almost at the same level as the upper surface of the piezoelectric layer 3, and th...

Embodiment 3

[0066] like Figure 2m-2q As shown, on the basis of step S1, the manufacturing process of the dielectric isolation layer 5 is changed, and step S2 may specifically include the following sub-steps:

[0067] making a mask 8 on the piezoelectric layer 3;

[0068] Fabricate a dielectric isolation layer 5 on the mask 8 by spin coating, exposure and development processes; and

[0069] The mask 8 is removed from the regions where the dielectric isolation layer 5 is not applied by an etching process.

[0070] In a specific embodiment, a mask 8 is formed on the piezoelectric layer 3 by a CVD process, wherein the material of the mask 8 includes SiO 2 , the thickness of the mask 8 is 10-20nm. The specific thickness of the mask 8 can be adjusted according to device processing conditions and device requirements. At this time, the function of the mask 8 is to protect the material of the piezoelectric layer 3 from being corroded by the developing solution. The dielectric isolation layer...

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Abstract

The invention discloses a top electrode structure of a bulk acoustic wave resonator and a manufacturing process, and the manufacturing process comprises the steps: preparing a substrate with a cavity,and sequentially manufacturing a bottom electrode layer and a piezoelectric layer, which cover the cavity, on the substrate; manufacturing a dielectric isolation layer on the piezoelectric layer, sothat the dielectric isolation layer covers part of the upper surface of the top of the piezoelectric layer; and manufacturing a top electrode layer on the dielectric isolation layer and the piezoelectric layer, the dielectric isolation layer being covered with the top electrode layer, and at least one side of the top electrode layer extending to the edge of the projection area of the cavity on thepiezoelectric layer. The dielectric isolation layer enhances the mechanical reliability and used for buffering when the stress change of the device layer is increased, and parasitic and reflected transverse waves of radio-frequency signals can be reduced. The mass load layer can form abrupt change of acoustic impedance at the edge of the top electrode layer, increase impedance of the parallel resonator, greatly weaken parasitic resonance, reduce pseudo-resonance and achieve the purpose of improving Q value.

Description

technical field [0001] This application relates to the field of communication devices, and mainly relates to a top electrode structure and manufacturing process of a bulk acoustic wave resonator. Background technique [0002] With the increasingly crowded electromagnetic spectrum and the increase of frequency bands and functions of wireless communication equipment, the electromagnetic spectrum used by wireless communication has grown rapidly from 500MHz to above 5GHz, and it is also necessary for the RF front-end module with high performance, low cost, low power consumption and small size. The demand is increasing day by day. The filter is one of the RF front-end modules, which is mainly composed of multiple resonators connected through a topology network structure, which can improve the transmission and reception signals. Fbar (Thin film bulk acoustic resonator) is a bulk acoustic resonator. The filter composed of it has the advantages of small size, strong integration cap...

Claims

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Application Information

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IPC IPC(8): H03H9/17H03H3/02
CPCH03H9/17H03H3/02
Inventor 李林萍盛荆浩江舟
Owner HANGZHOU JWL TECH INC
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