WO2020238286A1

WO2020238286A1 - Resonant thin film layer, resonator and filter

Info

Publication number: WO2020238286A1
Application number: PCT/CN2020/075501
Authority: WO
Inventors: 林志东; 谢祥政; 罗捷; 朱庆芳; 杨濬哲
Original assignee: 厦门市三安集成电路有限公司
Priority date: 2019-05-31
Filing date: 2020-02-17
Publication date: 2020-12-03
Also published as: CN110190826A; CN110190826B

Abstract

Provided in the present application are a resonant thin film layer, a resonator and a filter; the resonant thin film layer comprises a first electrode layer disposed on a first wafer, a piezoelectric layer disposed on the first electrode layer, a second electrode layer disposed on the piezoelectric layer, an adjustable layer disposed on the second electrode layer, and a counterweight pattern which is implemented on the adjustable layer and disposed on the second electrode layer, and which is used for adjusting different weights of the counterweight pattern so as to adjust different working frequencies of the resonant thin film layer of a resonant thin film. The present application achieves the adjustment of the counterweight pattern of the resonant thin film layer according to needs, which thus enables different resonant thin film layers to have different working frequencies.

Description

Resonant film layer, resonator and filter

Technical field

This application relates to the field of semiconductor technology, and specifically to a resonant film layer, a resonator and a filter.

Background technique

The basic principle of the film bulk acoustic resonator is to use resonance technology to convert electric energy into sound waves through the inverse piezoelectric effect of the piezoelectric film to form resonance. This resonance technology can be used to make advanced components such as film frequency shaping devices. The thin film bulk acoustic wave resonator acoustic wave device has the characteristics of small size, low cost, high quality factor, strong power tolerance, high frequency (up to 1-10GHz) and compatibility with IC technology. The functions of image elimination, parasitic filtering and channel selection are realized in the wireless transceiver, so it is widely used in the field of wireless communication.

The existing thin film bulk acoustic resonator structure generally includes an upper electrode layer, a lower electrode layer, and a piezoelectric layer sandwiched between the upper electrode layer and the lower electrode layer. However, the frequency of the resonator of this structure is relatively single, which cannot meet people's requirements for the diversity of resonator operating frequencies.

Summary of the invention

technical problem

The solution to the problem

Technical solutions

The purpose of the embodiments of the present application is to provide a resonant film layer, a resonator, and a filter, which are used to adjust the weight pattern of the resonant film layer as required, so that different resonant film layers have different operating frequencies.

The first aspect of the embodiments of the present application provides a resonant film layer, including: a first electrode layer, which is arranged on a first wafer; a piezoelectric layer, which is arranged on the first electrode layer; and a second electrode layer, which is arranged On the piezoelectric layer; an adjustable layer, disposed on the second electrode layer, a weight pattern implemented on the adjustable layer, used to adjust different weights of the weight pattern to adjust the Different working frequencies of the resonant film layer.

In one embodiment, the weight pattern does not penetrate the adjustable layer.

In one embodiment, the thickness range of the weight pattern is 20% to 80% of the thickness of the adjustable layer.

In one embodiment, the thickness of the adjustable layer ranges from 200A to 4000A.

In one embodiment, the thickness of the second electrode layer ranges from 1000A to 5000A.

The second aspect of the embodiments of the present application provides a resonant film layer, including: a first electrode layer, which is arranged on a first wafer; a piezoelectric layer, which is arranged on the first electrode layer; and a second electrode layer, which is arranged On the piezoelectric layer; an adjustable layer, disposed on the second electrode layer, a weight pattern implemented on the adjustable layer and the second electrode layer, for adjusting the weight pattern Different weights to adjust different working frequencies of the resonant film layer.

In one embodiment, the weight pattern penetrates the adjustable layer and extends to the second electrode layer.

In one embodiment, the weight pattern extends to a thickness range of the second electrode layer to account for 20% to 80% of the thickness of the second electrode layer.

A third aspect of the embodiments of the present application provides a resonator, including: the resonant film layer described in the first aspect of the embodiments of the present application or the second aspect of the embodiments of the present application, and a first cavity provided on the resonant film Layer below the first electrode layer; a second cavity, arranged on the second electrode layer above the resonant film layer; the first electrode layer, the piezoelectric layer and the second electrode layer connect the first electrode layer One cavity is isolated from the second cavity; the weight of the weight pattern of the resonant film layer in each resonator is different, so that different resonators have different operating frequencies.

A fourth aspect of the embodiments of the present application provides a filter, including: a plurality of resonators as described in the third aspect of the embodiments of the present application, wherein the filter includes: at least one first resonator, a plurality of The first resonator is connected in series with the input end and the output end of the filter; at least one second resonator, each of the second resonators is connected between the node and the common end of the two first resonators The weight of each of the first resonator and the weight pattern of the second resonator is different, so that the filters of different frequencies caused by the process have the same work after adjusting the weight pattern frequency.

The beneficial effects of the invention

Beneficial effect

In the resonant film layer, resonator and filter provided in the present application, the weight pattern can be adjusted by arranging the weight pattern on the second electrode layer of the resonant film layer, and the weight pattern of the resonant film layer can be adjusted as required. The weight allows different resonant film layers to have different operating frequencies. Furthermore, the operating frequency of the resonator with the resonant film layer can be adjusted, the diversity of the resonator can be enriched, and the design method of the filter can be further enriched.

Brief description of the drawings

Description of the drawings

In order to explain the technical solutions of the embodiments of the present application more clearly, the following will briefly introduce the drawings that need to be used in the embodiments of the present application. It should be understood that the following drawings only show some embodiments of the present application. Therefore, It should not be regarded as a limitation of the scope. For those of ordinary skill in the art, other related drawings can be obtained from these drawings without creative work.

FIG. 1A is a schematic diagram of a filter according to an embodiment of the application;

FIG. 1B is a schematic structural diagram of a resonator according to an embodiment of the application;

2A is a schematic structural diagram of a resonator according to an embodiment of the application;

2B is a schematic structural diagram of a resonator according to an embodiment of the application;

3 is a schematic diagram of the structure of a resonator according to an embodiment of the application;

FIG. 4 is a schematic structural diagram of a resonator according to an embodiment of the application;

4A is an enlarged schematic diagram of a weight pattern according to an embodiment of the application;

4B is a schematic plan view of a counterweight pattern according to an embodiment of the application;

4C is an enlarged schematic diagram of another counterweight pattern according to an embodiment of the application;

FIG. 4D is a schematic plan view of a weight pattern according to an embodiment of the application.

Reference signs:

10-filter, 100-resonator, 110-resonant film layer, 111-first electrode layer, 112-piezoelectric layer, 113-second electrode layer, 114-adjustable layer, 115-weight pattern, 115a- The first recessed area, 115b-the second recessed area, 115c-the third recessed area, 115d-the fourth recessed area, 116-the protective layer, 120-the first cavity, 121-the first wafer, 130-the second cavity Body, 131-second wafer, 150-weight interface layer.

Invention embodiment

Embodiments of the invention

The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. In the description of this application, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

Please refer to FIG. 1A, which is a schematic diagram of a filter 10 according to an embodiment of the present application. The filter 10 of this embodiment includes: a plurality of first resonators, and the plurality of first resonators are connected in series at the input end of the filter 10 and The output end, the resonator Y1, the resonator Y2, and the resonator Y3 shown in FIG. 1 are the first resonators.

A plurality of second resonators, each second resonator is connected between the node and the common terminal of the two first resonators. The resonator Y4 and the resonator Y5 shown in FIG. 1A are second resonators, wherein one end of the resonator Y4 is connected to the node of the resonator Y1 and the resonator Y2, and the other end is connected to the common terminal. One end of the resonator Y5 is connected to the node of the resonator Y2 and the resonator Y3, and the other end is connected to the common terminal.

As shown in FIG. 1B, it is a schematic structural diagram of a resonator 100 according to an embodiment of the application, which includes: a resonant film layer 110, a first cavity 120 and a second cavity 130. A first cavity 120 is formed in the first wafer 121 and disposed under the resonant film layer 110. A second cavity 130 is formed in the second wafer 131 and disposed above the resonant film layer 110. The resonant film layer 110 is disposed between the first cavity 120 and the second cavity 130.

The resonant film layer 110 includes a first electrode layer 111, a piezoelectric layer 112 and a second electrode layer 113. The first electrode layer 111 is disposed on the first wafer 121. The piezoelectric layer 112 is provided on the first electrode layer 111. The second electrode layer 113 is provided on the piezoelectric layer 112. The weight pattern 115 is formed on the second electrode layer 113, and the weight pattern 115 and the second electrode layer 113 are integrally formed. In an embodiment, the first electrode layer 111 may be formed into a weight pattern 115 of any pattern through a laser engraving or etching process.

The resonant film layer 110 of this embodiment is provided with a weight pattern 115 on the second electrode layer 113, and the weight pattern 115 can adjust the weight, so that the weight of the weight pattern 115 of the resonant film layer 110 can be adjusted as required to make different The resonant film layer 110 has different operating frequencies. Furthermore, the resonator 100 with the resonant film layer 110 can adjust the operating frequency.

In an embodiment, as shown in FIG. 2A, the resonant film layer 110 may further include: an adjustable layer 114. The adjustable layer 114 is disposed on the second electrode layer 113. In this embodiment, different weight patterns 115 can be formed by the adjustable layer 114 to adjust the operating frequency of the resonant thin film layer 110 by changing the weight ratio. In one embodiment, the weight pattern 115 of the adjustable layer 114 can be formed by etching, laser engraving, or the like.

In an embodiment, the thickness of the second electrode layer 113 may range from 2000A to 4000A.

In one embodiment, the density of the adjustable layer 114 is greater than the density of the piezoelectric layer 112.

As shown in FIG. 2B, it is a schematic structural diagram of another resonator according to an embodiment of the application. The resonant thin film layer 110 may further include a protective layer 116 disposed above the weight pattern 115, and the protective layer 116 is laid on the weight pattern 115 to protect the weight pattern 115. In an embodiment, the material of the protective layer 116 may be the same as the material of the piezoelectric layer 112 or other insulating materials.

In one embodiment, the adjustable layer 114 may be formed by laser engraving or etching to form a weight pattern 115 (as shown in FIG. 2B) with a columnar structure, and is formed on the second electrode layer 113. The weight The thickness of the pattern 115 may range from 20% to 80% of the thickness of the second electrode layer 113. The weight pattern 115 cannot penetrate the second electrode layer 113 to ensure that the resonant thin film layer 110 works normally after being energized. In one embodiment, when the thickness of the weight pattern 115 is in the range of 40% to 60% of the thickness of the second electrode layer 113, the resonant film layer 110 will have a better center frequency.

In an embodiment, as shown in FIG. 3, which is a schematic structural diagram of another resonator 100 according to an embodiment of the application, the weight pattern 115 of the resonant film layer 110 may be formed on the adjustable layer 114. The adjustable layer 114 can be formed by laser engraving or etching to form a weight pattern 115 in the recessed area (as shown in FIG. 3), but the recessed area does not penetrate the adjustable layer 114, and the recessed area is covered by the protective layer 116 , The gap is filled.

In one embodiment, the thickness of the adjustable layer 114 may range from 200A to 1000A.

In an embodiment, the thickness range of the weight pattern 115 may account for 20% to 80% of the thickness of the adjustable layer 114. For example, when the thickness of the weight pattern 115 accounts for 40% to 60% of the thickness of the adjustable layer 114, the resonant film layer 110 will have a better center frequency.

In the resonant thin film layer 110 of this embodiment, the adjustable layer 114 is disposed on the second electrode layer 113, and the weight pattern 115 is formed on the adjustable layer 114, and the thickness of the weight pattern 115 does not penetrate the adjustable layer 114 In this way, the weight pattern 115 is formed on the basis of not damaging the second electrode layer 113, and the weight adjustment of the weight pattern 115 does not pass through the second electrode layer 113. Through the weight adjustment of the weight pattern 115, the resonant film layer 110 working frequency adjustment.

In an embodiment, as shown in FIG. 4, which is a schematic structural diagram of another resonator 100 according to an embodiment of the application, the resonator film layer 110 may further include: penetrating the adjustable layer 114 and extending to the second electrode layer 113 of the counterweight pattern 115.

In one embodiment, different weight patterns 115 can be etched on the adjustable layer 114 and the second electrode layer 113 by means of laser engraving or etching. In one embodiment, different depths can be etched according to actual needs. The recessed area can be adjusted for different weights. After the recessed area is covered by the protective layer 116, the gap is filled.

In order to facilitate the description of the structure of the weight pattern 115, the partial weight interface layer 150 where the weight pattern 115 in FIG. 4 is located is enlarged, and the protective layer 116 is removed to obtain FIG. 4A.

As shown in FIG. 4A, the weight pattern 115 may be recessed regions of different depths and sizes formed by laser etching, and the first recessed regions 115a and the second recesses are formed on the second electrode layer 113 and the adjustable layer 114 The regions 115b are two forms of the weight pattern 115 respectively.

As shown in FIG. 4B, it is a schematic plan view of the first recessed area 115a and the second recessed area 115b. In the same resonator 100, the first recessed region 115a may penetrate the adjustable layer 114, and the second recessed region 115b may not penetrate the adjustable layer 114. The size and depth of the two can be different, which are specifically determined according to actual needs, which is not limited in this embodiment.

In an embodiment, the weight pattern 115 may be a recessed area with different depths and the same size formed by laser engraving or etching. In order to facilitate the description of the composition of the weight pattern 115, the part of the weight pattern 115 in FIG. The weight interface layer 150 is enlarged, and the protective layer 116 is removed to obtain FIG. 4C.

As shown in FIG. 4C, the third recessed area 115c and the fourth recessed area 115d formed on the second electrode layer 113 and the adjustable layer 114 are two forms of the weight pattern 115, respectively.

As shown in FIG. 4D, it is a schematic plan view of the third recessed area 115c and the fourth recessed area 115d. In the same resonator 100, the third recessed area 115c may penetrate the adjustable layer 114 and extend to the second electrode layer 113, and does not penetrate the second electrode layer 113, so as to ensure that the resonant thin film layer 110 works normally after being energized. Similarly, the fourth recessed region 115d may also extend to the second electrode layer 113 but does not penetrate the second electrode layer 113, and its extension depth in the second electrode layer 113 may be the same as or different from the third recessed region 115c. The plane size of the two can be the same, and the depth can be different, which is specifically determined according to actual needs, which is not limited in this embodiment.

The above are only preferred embodiments of this application, and are not used to limit this application. Any modification, equivalent replacement, improvement, etc., made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

A resonant film layer is characterized in that it comprises:

The first electrode layer is arranged on the first wafer;

A piezoelectric layer disposed on the first electrode layer;

The second electrode layer is arranged on the piezoelectric layer;

The adjustable layer is disposed on the second electrode layer, and a weight pattern is implemented on the adjustable layer, and is used to adjust different weights of the weight pattern to adjust different working frequencies of the resonant film layer.
The resonant film layer according to claim 1, wherein:

The weight pattern does not penetrate the adjustable layer.
3. The resonant film layer according to claim 2, wherein the thickness of the weight pattern ranges from 20% to 80% of the thickness of the adjustable layer.
The resonant film layer according to claim 1, wherein:

The thickness of the adjustable layer ranges from 200A to 4000A.
The resonant film layer of claim 1, wherein the thickness of the second electrode layer ranges from 1000A to 5000A.
A resonant film layer is characterized in that it comprises:

The first electrode layer is arranged on the first wafer;

A piezoelectric layer disposed on the first electrode layer;

The second electrode layer is arranged on the piezoelectric layer;

The adjustable layer is disposed on the second electrode layer, and a weight pattern is implemented on the adjustable layer and the second electrode layer, and is used to adjust different weights of the weight pattern to adjust the resonance Different working frequencies of the film layer.
The resonant film layer according to claim 6, wherein:

The weight pattern penetrates the adjustable layer and extends to the second electrode layer.
8. The resonant film layer of claim 7, wherein the weight pattern extends to a thickness range of the second electrode layer, which accounts for 20% to 80% of the thickness of the second electrode layer.
8. The resonant film layer of claim 6, wherein the thickness of the second electrode layer is in the range of 1000A to 5000A.
A resonator, characterized by comprising: the resonant film layer according to any one of claims 1 to 5 or claims 6 to 9, and

The first cavity is arranged under the first electrode layer under the resonant film layer;

The second cavity is arranged on the second electrode layer above the resonant film layer;

The first electrode layer, the piezoelectric layer, and the second electrode layer isolate the first cavity from the second cavity;

The weight of the weight pattern of the resonant film layer in each resonator is different, so that different resonators have different operating frequencies.
A filter, characterized by comprising: a plurality of resonators as claimed in claim 10, wherein the filter comprises:

At least one first resonator, and a plurality of the first resonators are connected in series at the input end and the output end of the filter;

At least one second resonator, each of the second resonators is connected between the node and the common end of the two first resonators;

The weights of the weight patterns of each of the first resonator and the second resonator are different, so that the filters with different frequencies caused by the process have the same operating frequency after adjusting the weight patterns.