Preparation method of film bulk acoustic resonator and filter

A thin-film bulk acoustic wave and resonator technology, which is applied in the field of microelectronics, can solve the problems of low power capacity, unsatisfactory compatibility, and high loss, and achieve the effects of high power tolerance, low loss, and high electromechanical coupling coefficient

Active Publication Date: 2019-06-28
ZHEJIANG HUAYUAN MICRO ELECTRONICS TECH CO LTD +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, provide a kind of preparation method of thin film bulk acoustic resonator and filter, to solve the temperature drift that exists in the thin film bulk acoustic resonator and filter that existing preparation method prepares Large, high loss, low power capacity and unsatisfactory compatibility and other technical problems

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  • Preparation method of film bulk acoustic resonator and filter
  • Preparation method of film bulk acoustic resonator and filter
  • Preparation method of film bulk acoustic resonator and filter

Examples

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preparation example Construction

[0021] On the one hand, an embodiment of the present invention provides a method for preparing a thin film bulk acoustic resonator, combining figure 2 and image 3 , the process flow of the preparation method of the thin film bulk acoustic resonator is as follows figure 1 As shown, it includes the following steps:

[0022] S01: Etching is performed on a surface 11 of the substrate 1 to form a groove 12, such as figure 2 As shown in A;

[0023] S02: Form a sacrificial layer 14 in the groove 12, such as figure 2 Shown in B and 2C;

[0024] S03: Form a supporting layer 2 on the surface of the sacrificial layer 14 and the surface 11 of the substrate 1, and the supporting layer 2 covers the sacrificial layer 14 and at least covers all surrounding areas of the sacrificial layer 14 The surface 11 of the substrate 1; as figure 2 as shown in D;

[0025] S04: Along the extending direction of the substrate 1 to the support layer 2, sequentially form the first bottom electrode ...

Embodiment 1

[0073] This embodiment provides a method for preparing a thin film bulk acoustic resonator. combine Figure 2-3 , the preparation method comprises the steps of:

[0074] Step S11: performing etching treatment on a surface 11 of the elemental silicon substrate 1 by dry etching to form a groove 12; wherein, the depth of the groove 12 is less than 3 μm, and the area of ​​the groove 12 is preferably 1123 μm ×1123μm;

[0075] Step S12: growing amorphous SiO in the groove 12 and on the surface 11 by PECVD 2 layer (P on amorphous SiO 2 The percentage of atoms doped in can be controlled to 8%), and makes the grown amorphous SiO 2 The thickness of the layer exceeds the depth of the groove 12 and covers the surface 11 of the substrate 1; then chemical mechanical polishing (CMP) is used to treat the generated amorphous SiO with 100rpm 2 The layer is subjected to grinding treatment to remove the amorphous SiO grown on the surface 11 2 , so that the amorphous SiO filled in the groove...

Embodiment 2

[0081] This embodiment provides a method for preparing a thin film bulk acoustic resonator. combine Figure 2-3 , the preparation method comprises the steps of:

[0082] Step S11: performing etching treatment on a surface 11 of the elemental silicon substrate 1 by dry etching to form a groove 12; wherein, the depth of the groove 12 is less than 3 μm, and the area of ​​the groove 12 is preferably 1123 μm ×1123μm;

[0083] Step S12: refer to step S12 in Embodiment 1;

[0084] Step S13: refer to step S13 in Embodiment 1;

[0085] Step S14: Follow step S14 in Example 1; wherein, the release reagent for releasing the sacrificial layer 14 includes HF and NH with a mass ratio of 1:3.8:2.3 3 F and glycerin.

[0086] The structure of the film bulk acoustic resonator formed by embodiment 2 is as follows image 3 As shown, the structure of the thin film bulk acoustic resonator is: substrate 1 / support layer 2 / first bottom electrode layer 3 / temperature floating layer 4 / second bottom ...

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Abstract

The invention discloses a preparation method of a film bulk acoustic resonator and a filter. The preparation method of the film bulk acoustic resonator comprises the following steps: etching one surface of a substrate to form a groove; forming a sacrificial layer in the groove, and forming a supporting layer on the surface of the sacrificial layer and the surface of the substrate; a first bottom electrode layer, a temperature drift layer, a second bottom electrode layer, a piezoelectric layer and a top electrode layer are sequentially formed on the surface of the supporting layer in the extending direction from the substrate to the supporting layer; and releasing the sacrificial layer for processing to form a closed cavity. The preparation method of the filter comprises the step of preparing the film bulk acoustic resonator according to the preparation method of the film bulk acoustic resonator. According to the preparation method of the film bulk acoustic wave resonator, the preparedfilm bulk acoustic wave resonator is low in loss and temperature drift, small in temperature coefficient, high in power bearing capacity, working frequency and electromechanical coupling coefficient and good in compatibility and has a very good Q value.

Description

technical field [0001] The invention belongs to the technical field of microelectronics, and in particular relates to a method for preparing a film bulk acoustic wave resonator and a filter. Background technique [0002] Today, with the rapid development of radio communication technology, traditional single-band single-standard equipment is far from being able to meet the diverse requirements of communication systems. New smartphones and personal portable computers no longer only provide basic voice communication functions, but also are compatible with a large number of data interfaces such as digital cameras, MP3, GPS, Bluetooth, and WiFi, and are changing to multi-functional communication terminals. At the same time, with the development of 5G technology, the communication system is becoming more and more multi-band, showing the coexistence of WCDMA, GSM, CDMA and other forms, which requires the communication terminal to be able to accept each frequency band to meet differ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H03H3/04H03H9/17
CPCY02D30/70
Inventor 李善斌刘绍侃董谦史晓婷霍俊标张雪奎
Owner ZHEJIANG HUAYUAN MICRO ELECTRONICS TECH CO LTD
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