WO2021227941A1

WO2021227941A1 - Bulk acoustic wave resonance assembly and manufacturing method, filter and electronic device

Info

Publication number: WO2021227941A1
Application number: PCT/CN2021/092061
Authority: WO
Inventors: 庞慰; 闫德海; 边子鹏; 杨清瑞
Original assignee: 诺思(天津)微系统有限责任公司
Priority date: 2020-05-09
Filing date: 2021-05-07
Publication date: 2021-11-18
Also published as: CN112054777A

Abstract

The present disclosure relates to a bulk acoustic wave resonance assembly, comprising two bulk acoustic wave resonators, including a first resonator and a second resonator, wherein the first resonator is a temperature compensation resonator in which an electrode comprises a temperature compensation layer, and the second resonator is a non-temperature-compensation resonator without a temperature compensation layer; and the temperature drift coefficient of the first resonator is zero, and the difference of the electromechanical coupling coefficient between the second resonator and the first resonator accounts for 30% or above of the value of the electromechanical coupling coefficient of the second resonator. The thickness of a piezoelectric layer of the first resonator may be less than and at least 50% of the thickness of a piezoelectric layer of the second resonator. The present disclosure further discloses a filter having the bulk acoustic wave resonance assembly, and an electronic device having the filter or the bulk acoustic wave resonance assembly.

Description

Bulk acoustic wave resonator assembly and manufacturing method, filter and electronic equipment

Technical field

The present disclosure relates to the field of semiconductors, and in particular to a bulk acoustic wave resonator component and a manufacturing method, a filter, and an electronic device having the resonator component or the filter.

Background technique

With the development of wireless communication applications, people have higher and higher requirements for data transmission rates. Corresponding to the data transmission rate is the high utilization of spectrum resources and the complexity of the spectrum. The complexity of the communication protocol puts forward strict requirements on the various performance of the radio frequency system. In the radio frequency front-end module, the radio frequency filter plays a vital role. It can filter out the out-of-band interference and noise to meet the requirements of the radio frequency system and The requirements of the communication protocol for the signal-to-noise ratio.

Radio frequency filters are mainly used in wireless communication systems, such as radio frequency front-ends of base stations, mobile phones, computers, satellite communications, radars, electronic countermeasures systems, and so on. The main performance indicators of radio frequency filters are insertion loss, out-of-band suppression, power capacity, linearity, device size and temperature drift characteristics. Good filter performance can improve the data transmission rate, life and reliability of the communication system to a certain extent. Therefore, the design of high-performance and simplified filters for wireless communication systems is very important. At present, the small-size filter devices that can meet the use of communication terminals are mainly piezoelectric acoustic wave filters. The resonators that constitute this type of acoustic wave filter mainly include: FBAR (Film Bulk Acoustic Resonator), SMR (Solidly Mounted Resonator, solid-state assembly resonator) and SAW (Surface Acoustic Wave, surface acoustic wave resonator). Among them, the filters manufactured based on the principle of bulk acoustic wave FBAR and SMR (collectively referred to as BAW, bulk acoustic wave resonator) have the advantages of lower insertion loss and faster roll-off characteristics compared to filters manufactured based on the principle of surface acoustic wave SAW. .

Because the piezoelectric materials and metal materials constituting the acoustic wave resonator both have the characteristics of negative temperature drift coefficient, that is, when the temperature increases, the resonant frequency of the resonator will move in a certain proportion to the low frequency direction (temperature drift). In general, the temperature coefficient of SAW (Temperature Coefficient of Frequency, TCF), referred to as the temperature coefficient of drift is -35ppm/℃～-50ppm/℃, and the coefficient of temperature drift of BAW is -25ppm/℃～-30ppm/℃. Although BAW has obvious performance advantages in terms of temperature drift compared to SAW, in some special application scenarios, such a temperature drift coefficient will still have an adverse effect on the performance of the RF transceiver system with filters, such as a filter The filter defines the frequency variable range from the edge of the passband to the out-of-band suppression, so the existence of the temperature drift coefficient makes this variable range smaller after taking into account the frequency drift caused by temperature changes, thereby greatly increasing the filter The difficulty of design. The external environment and the heating of the bulk wave resonator itself will cause the temperature of the resonator to change, which will cause the resonant frequency of the resonator to drift, which will cause the performance of the resonator or various electronic devices composed of the resonator. Negative Effects.

In order to solve the common temperature drift problem of the filter, a common solution is to add a material that can realize the temperature compensation effect in the resonator. For acoustic wave resonators, this temperature compensation material is usually silicon dioxide, because silicon dioxide has a positive temperature drift coefficient, and can be made through a general process. At the same time, it has a low price and is suitable for mass production applications; The material of the temperature compensation layer can also be a positive temperature drift coefficient material such as polysilicon, borophosphate glass (BSG), chromium (Cr) or tellurium oxide (TeO(x)); the thickness of the temperature compensation layer is generally in the range of

(Angstrom) to

between. This type of temperature-compensated material resonator is also called temperature-drift coefficient temperature-compensated resonator, hereinafter referred to as TCF resonator or temperature-compensated resonator, which means that it has a low or even zero frequency temperature drift coefficient The resonator is a component unit of the temperature compensation filter.

However, after the above-mentioned temperature compensation layer is introduced into the resonator, the performance of the resonator deteriorates, which is mainly reflected in the increase of the loss of the resonator and the decrease of the ^{electromechanical coupling coefficient (Kt 2 ).} The loss of the resonator directly affects the passband insertion loss characteristics of the filter, thereby increasing the loss in the RF link and deteriorating the transceiver performance of the RF front-end. The electromechanical coupling coefficient becomes smaller. Under certain frequency conditions, the frequency difference between the series resonance frequency and the parallel resonance frequency of the resonator is reduced. The roll-off characteristics of the filter may be improved, but at the same time the bandwidth of the filter will also be narrowed. In most communication systems, the bandwidth of the filter is proposed according to the system requirements, and the bandwidth cannot be narrowed indefinitely.

FIG. 1 is a circuit diagram of a filter in the prior art, where T1 is the input terminal of the filter 100, T2 is the output terminal of the filter, and the input terminal T1 and the output terminal T2 are ports connected to the external signal of the filter . Between the input terminal T1 and the output terminal T2, there are a series of series resonators S11, S12, S13, and S14 at the position of the series path connected to each other in series. Between the input terminal T1 and the series resonator S11, a series inductor L1 is connected in series; between the input terminal T2 and the series resonator S14, a series inductor L2 is connected in series. One end of the parallel resonator P11 is connected to the node between the series resonators S11 and S12, one end of the parallel resonator P12 is connected to the node between the series resonators S12 and S13, and the other ends of the parallel resonators P11 and P12 are connected to each other. One end of the parallel inductor L3 is connected, and the other end of the parallel inductor L3 is grounded; one end of the parallel resonator P13 is connected to the node between the series resonators S13 and S14, and one end of the parallel resonator P14 is connected to the series resonator S14 and the series inductor L2 The nodes between are connected, the other ends of the parallel resonators P13 and P14 are connected to each other and connected to one end of the shunt inductor L4, and the other end of the shunt inductor L4 is grounded.

The series resonant frequencies of the series resonators S11, S12, S13 and S14 are fss1, fss2, fss3 and fss4 respectively, and the parallel resonant frequencies are fsp1, fsp2, fsp3 and fsp4; the series resonant frequencies of the parallel resonators P11, P12, P13 and P14 They are fps1, fps2, fps3, and fps4, respectively, and the parallel resonance frequencies are fpp1, fpp2, fpp3, and fpp4. The series resonator and the parallel resonator realize that the series resonant frequency is different from each other through different designs of the mass load (adjusting the area and thickness of the mass load, etc.).

Fig. 2 is a comparative example, that is, a curve diagram of the insertion loss characteristic of the filter in the prior art and the impedance characteristic of the resonator. The series resonator and the parallel resonator work together to form the passband characteristic of the filter. By setting the series resonant frequencies of the series resonators to be different from each other and ^{the change of Kt 2} of the series resonators, the roll-off characteristics on the right side of the passband of the filter can be effectively improved. Filters using small Kt ² resonators are easy to achieve good roll-off characteristics, but once the design indicators (bandwidth, insertion loss, out-of-band rejection, etc.) are determined, the Kt ^{2 of the} resonator is basically determined, so the filter bandwidth and filtering The good roll-off characteristics of the filter are mutually contradictory. It is difficult to achieve good roll-off characteristics in the design of a wide bandwidth filter under the conventional architecture, and under the condition that the resonator stack in the ordinary filter has been determined, the resonator structure ^{The Kt 2} change of the 50 Ohm resonator is only about ±0.5%, and the improvement of the filter roll-off characteristics is limited.

Summary of the invention

In order to further improve the roll-off characteristics and temperature drift characteristics of the filter, the present disclosure is proposed.

According to an aspect of the embodiments of the present disclosure, a bulk acoustic wave resonant component and a manufacturing method thereof are provided. The resonator assembly includes two bulk acoustic wave resonators, namely a first resonator and a second resonator, wherein:

The first resonator is a temperature-compensated resonator whose electrode includes a temperature-compensated layer, and the second resonator is a non-temperature-compensated resonator whose electrode does not include a temperature-compensated layer;

The temperature drift coefficient of the first resonator is zero, and the difference in the electromechanical coupling coefficient between the second resonator and the first resonator accounts for 30% or more of the value of the electromechanical coupling coefficient of the second resonator.

Optionally, the thickness of the piezoelectric layer of the first resonator is smaller than the thickness of the piezoelectric layer of the second resonator and is at least 50% of the thickness of the piezoelectric layer of the second resonator. Furthermore, the difference in the electromechanical coupling coefficient between the second resonator and the first resonator accounts for 40% or more of the value of the electromechanical coupling coefficient of the second resonator.

The embodiment of the present disclosure also relates to a filter, including the above-mentioned bulk acoustic wave resonator assembly, the filter includes a plurality of series resonators and a plurality of parallel resonators, wherein: part of the series resonator and/or part of the parallel resonator The device is the first resonator.

The embodiment of the present disclosure also relates to an electronic device including the above-mentioned filter or the above-mentioned resonator component.

Description of the drawings

The following description and the accompanying drawings can better help understand these and other features and advantages in the various embodiments disclosed in the present disclosure. The same reference numerals in the figures always denote the same components, in which:

Figure 1 is a circuit diagram of a filter in the prior art;

Fig. 2 is a comparative example, that is, a curve diagram of the insertion loss characteristic of the filter in the prior art and the impedance characteristic of the resonator;

Fig. 3 is a comparative example, that is, the corresponding insertion loss characteristic curve diagram of the filter in the prior art under different temperature environments;

FIG. 4 is a circuit diagram of the filter of the first embodiment in the embodiments of the disclosure;

FIG. 5 is a schematic diagram of an FBAR resonator with a temperature compensation layer added in an embodiment of the disclosure;

Figure 6 is a comparison diagram of the impedance characteristic curves of the resonator before and after heating the compensation layer;

FIG. 7 is a graph of the insertion loss characteristic of the filter and the impedance characteristic of the resonator according to the first embodiment of the disclosure;

8 is a comparison diagram of the insertion loss characteristics of the filters of the first embodiment of the disclosure and the comparative example under normal temperature conditions;

Fig. 9 is a comparison diagram of the corresponding three-temperature characteristic curve diagram of the TCF resonator under the condition of zero temperature drift in the first embodiment of the disclosure and the three-temperature characteristic curve of the comparative example;

Fig. 10 is an enlarged view of the circled area in Fig. 9;

11 is a comparison diagram of the insertion loss characteristics of the TCF resonator in the first embodiment of the disclosure under the condition of zero temperature drift and the comparative example under the conditions of normal temperature and high temperature;

12 is a comparison diagram of the insertion loss characteristics of the TCF resonator in the first embodiment of the disclosure with a positive 1MHz temperature drift and a comparative example under normal temperature and high temperature conditions;

FIG. 13 is a circuit diagram of the filter of the second embodiment of the disclosure;

14 is a graph of the insertion loss characteristic of the filter and the impedance characteristic of the resonator according to the second embodiment of the disclosure;

15 is a comparison diagram of the insertion loss characteristics of the second embodiment of the disclosure and the comparative example under normal temperature conditions;

FIG. 16 is a circuit diagram corresponding to the third embodiment of the disclosure;

FIG. 17 is a graph of the insertion loss characteristic of the filter and the impedance characteristic of the resonator according to the third embodiment of the disclosure;

18 is a comparison diagram of the insertion loss characteristics of the third embodiment of the disclosure and the comparative example under normal temperature conditions;

19 is a comparison diagram of the insertion loss characteristics of the comparative example and the embodiment 1, the embodiment 2, and the embodiment 3 of the present disclosure under normal temperature conditions;

FIG. 20 is a circuit diagram of the filter of the fourth embodiment in the embodiments of the disclosure; FIG.

FIG. 21 is a circuit diagram of the filter of the fifth embodiment in the implementation of the disclosure;

FIG. 22 is a circuit diagram of the filter of the sixth embodiment in the embodiments of the disclosure; FIG.

FIG. 23 is a circuit diagram of the filter of the seventh embodiment in the embodiments of the disclosure;

FIG. 24 is a circuit diagram of the filter of the eighth example in the embodiments of the disclosure.

25A and 25B are structural schematic diagrams of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present disclosure;

26A-26K exemplarily show the manufacturing process of the component shown in FIG. 25;

Fig. 27A is a schematic structural diagram of a bulk acoustic wave resonator assembly according to another exemplary embodiment of the present disclosure;

Fig. 27B exemplarily shows the different steps of processing the assembly shown in Fig. 27A and the assembly shown in 25A;

28A and 28B exemplarily show graphs of the relationship between the thickness of the temperature compensation layer and the resonance frequency of the temperature compensation resonator, the electromechanical coupling coefficient Kt ² and the TCF value of the temperature compensation resonator.

29A and 29B exemplarily show graphs of the relationship between the thickness of the piezoelectric layer and the resonance frequency of the temperature-compensated resonator, the electromechanical coupling coefficient Kt ² and the TCF value of the temperature-compensated resonator.

FIG. 30 exemplarily shows a graph of the relationship between the thickness of the first electrode layer and the electromechanical coupling coefficient Kt ² of the temperature-compensated resonator and the TCF value of the temperature-compensated resonator.

FIG. 31 is a schematic structural diagram of a bulk acoustic wave resonator assembly according to another exemplary embodiment of the present disclosure.

Detailed ways

In the following, the technical solutions of the present disclosure will be further described in detail through the embodiments and in conjunction with the drawings. The following description of the embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the general disclosure concept of the present disclosure, and should not be construed as a limitation to the present disclosure.

In the following, the technical solutions of the present disclosure will be further described in detail through the embodiments and in conjunction with the drawings. In the specification, the same or similar reference numerals indicate the same or similar components. The following description of the embodiments of the present disclosure with reference to the accompanying drawings is intended to explain the general disclosure concept of the present disclosure, and should not be construed as a limitation to the present disclosure.

Fig. 3 is a comparative example, that is, the corresponding insertion loss characteristic curve diagram of the filter in the prior art under different temperature environments, where the curve with a triangle label is the insertion loss characteristic curve under an environment of 95 degrees Celsius, and the curve with a square label It is the insertion loss characteristic curve under a normal temperature of 25 degrees Celsius, and the curve with a circular label is the insertion loss characteristic curve under a -45 degrees Celsius environment. Since the piezoelectric dielectric material and electrode material of the filter are materials with negative temperature drift coefficient, and the heat loss of the filter electrode increases under high temperature conditions, the insertion loss characteristic curve under high temperature conditions moves to the low frequency direction relative to the normal temperature characteristic curve. At the same time, the insertion loss will also drop; compared with the normal temperature curve, the amplitude-frequency curve of the filter moves to the high-frequency direction at low temperature, and the insertion loss becomes better. In general, most of the energy of the passband signal passes through the series when the filter is working. The resonator is transmitted from the input port T1 to the output port T2. The temperature of the series resonator will be higher than the temperature of the parallel resonator. Therefore, in the same external environment, the frequency drift on the right side of the passband is greater than the frequency drift on the left side of the passband.

FIG. 4 is a circuit diagram of the filter of the first embodiment of the disclosed embodiments. Compared with the existing filter, a series resonator in the filter 600 of this embodiment is replaced with a TCF resonance with a temperature compensation layer Resonator (temperature-compensated resonator); in this embodiment, the existing series resonator S12 is replaced with TCF. Through the different design of the thickness of the temperature compensation layer, the different temperature drift characteristics of the TCF resonator are realized.

5 is a schematic diagram of an FBAR resonator with a temperature compensation layer added in an embodiment of the disclosure. In FIG. 5, 51 is a base or semiconductor substrate material, 56 is an air cavity obtained by etching, and the bottom of the film bulk acoustic wave resonator The electrode 53 is deposited on the

semiconductor substrate

51, 52 is a piezoelectric film material, 54 is a top electrode, and 55 is a temperature compensation layer. The area selected by the dashed line is the overlapping area of the air cavity 56, the top electrode 34, the bottom electrode 33, the temperature compensation layer 55, and the piezoelectric layer 32 as the effective resonance area. The material of the temperature compensation layer can be polysilicon, borophosphate glass (BSG), silicon dioxide (SiO ₂ ), chromium (Cr) or tellurium oxide (TeO(x)) and other materials. Among them, the bottom electrode pattern that was originally made once is made twice. Between the two bottom electrode patterns, a layer of temperature compensation layer is made. The material of the temperature compensation layer is generally silicon dioxide, and its pattern is smaller than the bottom electrode pattern. . In this way, when the bottom electrode pattern is completely fabricated, the temperature compensation layer is completely wrapped in the bottom electrode material. This manufacturing method can make the temperature compensation layer completely wrapped by the bottom electrode, thereby effectively protecting it from other manufacturing processes. In addition, because the electrode materials above and below the temperature compensation layer are connected together at the edge, it is avoided that the performance (loss characteristics) of the resonator is greatly deteriorated due to the parasitic capacitance composed of the three. The description based on FIG. 5 also applies to the temperature-compensated resonator in the resonator assembly shown in FIG. 25.

Fig. 6 is a comparison diagram of impedance characteristic curves of the resonator before and after heating the compensation layer. After adding the temperature compensation layer, the series impedance Rs increased from 0.8 ohms to 1.6 ohms, while the parallel impedance Rp decreased from 2800 ohms to 1500 ohms, and Kt ² decreased from 6.0% to 3.0%. It is as small as half of the original, which is less than 70% ^{of the Kt 2 of the original resonator.}

Fig. 7 is a graph of the filter insertion loss characteristics and resonator impedance characteristics of the first embodiment of the disclosure. The series resonant frequency and parallel resonant frequency of the TCF resonator are fss_tcf and fsp_tcf, respectively, and the series resonant frequency and parallel resonant frequency of the S11 resonator The resonant frequencies are fss_11, fsp_11, the series resonant frequency and parallel resonant frequency of the S13 resonator are fss_13, fsp_13, and the series resonant frequency and parallel resonant frequency of the S14 resonator are fss_14 and fsp_14. Under normal temperature conditions, the TCF resonator’s The parallel resonance frequency fsp_tcf has the following relationship with the parallel resonance frequencies fsp_11, fsp_13 and fsp_14 of ordinary resonators S11, S13 and S14:

Min(fsp_11, fsp_13, fsp_14)-fsp_tcf≥delta_FR

Among them, delta_FR is the frequency change of the corresponding frequency at -20dB on the right side of the passband of the filter of the first embodiment under high and normal temperature conditions. The relationship among fss_tcf, fss_11, fss_13, and fss_14 is not limited.

8 is a comparison diagram of the insertion loss characteristics of the filters of the first embodiment of the disclosure and the comparative example under normal temperature conditions. A series resonator in the first embodiment is a TCF resonator with a temperature compensation layer added. The thickness of the temperature compensation layer satisfies the following conditions: the positive temperature drift effect produced by the temperature compensation layer can fully or partially cancel the negative temperature drift effect of all other layers, so that the TCF resonator has a temperature drift coefficient greater than that of an ordinary resonator. The temperature-compensated resonator equal to 0ppm/℃, or the positive temperature-drift effect produced by the temperature-compensated layer is greater than the negative temperature-drift effect of all other layers, so that the TCF resonator becomes a temperature-compensated resonator with a positive temperature drift coefficient; In one embodiment, a TCF resonator is added, and the TCF resonator has a small Kt ² characteristic. In the first embodiment, the roll-off characteristic on the right side of the passband can be greatly improved without affecting the bandwidth of the filter.

FIG. 9 is a comparison diagram of the corresponding three-temperature characteristic curve and the three-temperature characteristic curve of the comparative example under the condition of zero temperature drift of the TCF resonator in the first embodiment of the disclosure (that is, the frequency does not change with temperature changes), as shown in FIG. 9, The corresponding three-temperature characteristic curve (low temperature: -45 degrees Celsius, normal temperature: 25 degrees Celsius, high temperature: 95 degrees Celsius) of the TCF resonator under the condition of zero temperature drift is a solid line, and the three-temperature characteristic curve of the comparative example is a dotted line. The temperature drift characteristics of the right side of the pass band of an embodiment are greatly improved. Figure 10 is an enlarged view of the circled area in Figure 9. The temperature drift on the right side of the passband of the first embodiment is 0.5MHz under high temperature conditions, which is greatly improved compared to the 2MHz temperature drift of the comparative example. At the same time, the temperature drift is at 2150MHz under high temperature conditions. Compared with the comparative example, the insertion loss of the first embodiment is increased by about 3dB.

FIG. 11 is a comparison diagram of the insertion loss characteristics of the TCF resonator in the first embodiment of the disclosure under the condition of zero temperature drift and the comparative example under the conditions of normal temperature and high temperature. FIG. 12 shows that the TCF resonator in the first embodiment of the present disclosure has a positive temperature drift coefficient. Specifically, when the temperature rises from 25°C to 95°C, the frequency of the TCF resonator rises by 1 MHz, which is compared with the comparative example under normal temperature and high temperature conditions. Insertion loss characteristics comparison chart below. It can be seen from the figure that the first embodiment achieves the zero temperature drift characteristic on the right side of the filter passband. That is, the reasonable design of the thickness of the temperature compensation layer of the TCF resonator realizes the zero temperature drift characteristic of the filter.

13 is a circuit diagram of the filter of the second embodiment of the disclosure. Compared with the existing filter, one of the series resonators in the filter 700 in the second embodiment is replaced with a TCF resonator with a temperature compensation layer (Temperature Compensated Resonator): In this embodiment, the existing series resonator S13 is replaced with TCF. Through the different design of the thickness of the temperature compensation layer, the different temperature drift characteristics of the TCF resonator are realized.

14 is a graph of the filter insertion loss characteristic and the resonator impedance characteristic of the second embodiment of the disclosure. The series resonance frequency and parallel resonance frequency of the TCF resonator are fss_tcf and fsp_tcf, respectively, and the series resonance frequency and parallel resonance frequency of the S11 resonator are The resonant frequencies are fss_11, fsp_11, the series resonant frequency and parallel resonant frequency of the S12 resonator are fss_12, fsp_12, and the series resonant frequency and parallel resonant frequency of the S14 resonator are fss_14 and fsp_14, respectively. Under normal temperature conditions, the TCF resonator's The parallel resonance frequency fsp_tcf has the following relationship with the parallel resonance frequencies fsp_11, fsp_12 and fsp_14 of ordinary resonators S11, S12 and S14:

Min(fsp_11, fsp_12, fsp_14)-fsp_tcf≥delta_FR

Among them, delta_FR is the frequency change of the corresponding frequency at -20dB on the right side of the passband of the filter of the second embodiment under high and normal temperature conditions. The relationship among fss_tcf, fss_11, fss_13, and fss_14 is not limited.

FIG. 15 is a comparison diagram of the insertion loss characteristics of the second embodiment of the disclosure and the comparative example under normal temperature conditions. As shown in FIG. 15, the same as the first embodiment, because the TCF resonator is added in the second embodiment, the TCF resonates The filter has a small Kt ² characteristic, and the second embodiment can achieve a greater improvement in the roll-off characteristic on the right side of the passband without affecting the bandwidth of the filter.

16 is a circuit diagram corresponding to the third embodiment of the disclosure. Compared with the existing filter, the two series resonators in the filter 800 of the third embodiment are replaced by TCF resonators with a temperature compensation layer. Compensation resonator), respectively TCF1 and TCF2; in this embodiment, the TCF1 resonator and TCF2 resonator are replaced with the series resonators S12 and S13 in the comparative example, and the TCF1 resonator and TCF2 resonance are realized through different designs of the temperature compensation layer thickness. Change of temperature drift characteristics of the device.

FIG. 17 is a graph of the filter insertion loss characteristic and the resonator impedance characteristic of the third embodiment of the disclosure. As shown in FIG. 17, the series resonance frequency and parallel resonance frequency of the TCF1 resonator are fss_tcf1, fsp_tcf1, and TCF2 resonators, respectively The series resonant frequency and parallel resonant frequency are fss_tcf2, fsp_tcf2, the series resonant frequency and parallel resonant frequency of S11 resonator are fss_11, fsp_11, and the series resonant frequency and parallel resonant frequency of S14 resonator are fss_14 and fsp_14, respectively. Normal temperature conditions Below, the parallel resonance frequencies fsp_tcf1 and fsp_tcf2 of TCF1 and TCF2 resonators have the following relationship with the parallel resonance frequencies fsp_11 and fsp_14 of ordinary series resonators S11 and S14:

Min(fsp_11, fsp_14)-Max(fsp_tcf1, fsp_tcf2)≥delta_FR

Among them, delta_FR is the frequency change of the corresponding frequency at -20dB on the right side of the passband of the filter of the third embodiment under high and normal temperature conditions. The relationship between fss_tcf1, fss_tcf2, fss_11, and fss_14 is not limited.

Figure 18 is a comparison diagram of the insertion loss characteristics of the third embodiment of the disclosure and the comparative example under normal temperature conditions. The TCF resonator and the TCF resonator have a small Kt ² characteristic. Therefore, the third embodiment can achieve a greater improvement in the roll-off characteristic on the right side of the passband without affecting the bandwidth of the filter.

19 is a comparison diagram of the insertion loss characteristics of the comparative example and the first embodiment, the second embodiment, and the third embodiment of the present disclosure under normal temperature conditions. There is no TCF resonator in the comparative example, the first embodiment and the second embodiment One of the series resonators is a TCF resonator, and two of the series resonators in the third embodiment are TCF resonators. As mentioned earlier, the Kt ^{2 of the} TCF resonator is reduced compared with the ordinary resonator, Rs is about twice that of the ordinary resonator, and Rp is reduced to about half of the ordinary resonator. The loss of the resonator The increase leads to a decrease in the Q value, so the more TCF resonators included in the filter, the worse the passband insertion loss characteristics, but the better the temperature drift characteristics and roll-off characteristics, so the design process should be based on the design indicators It is required to balance the temperature drift characteristics, roll-off characteristics and passband insertion loss characteristics.

FIG. 20 is a circuit diagram of the filter of the fourth embodiment in the embodiments of the disclosure. Compared with the existing filter, the one-stage series circuit of the filter 900 of this embodiment includes two resonators, which are the existing ones. The series resonator S12 and the temperature-compensated resonator TCF. In this embodiment, one of the two resonators in the series circuit of the same stage is set as an ordinary series resonator, and the other is set as a temperature-compensated resonator. The structure is not limited to this. It is also possible to set the two resonators as temperature-compensated resonators; by setting the temperature-compensated resonator, and by designing the thickness of the temperature-compensating layer, different temperature drift characteristics of the TCF resonator can be realized.

21 is a circuit diagram of the filter of the fifth embodiment of the disclosed embodiments. Compared with the existing filter, one of the parallel resonators in the filter 110 of this embodiment is replaced with a temperature-compensated resonator TCF; The temperature compensation resonator, and through the different design of the temperature compensation layer thickness, realizes the different temperature drift characteristics of the TCF resonator.

The series resonant frequency and parallel resonant frequency of P11 resonator are fps_11 and fpp_11, respectively. The series resonant frequency and parallel resonant frequency of P13 resonator are fps_13 and fpp_13 respectively. The series resonant frequency and parallel resonant frequency of P14 resonator are fps_14 and fpp_14, respectively. The series resonance frequency and parallel resonance frequency of the TCF resonator are fps_tcf and fpp_tcf respectively. Under normal temperature conditions, the parallel resonance frequency fpp_tcf of the TCF resonator and the parallel resonance frequencies fpp_11, fpp_13 and fpp_14 of the ordinary resonators P11, P13 and P14 exist as follows relation:

Min(fpp_11, fpp_12, fpp_14)-fpp_tcf≥delta_FL

Among them, delta_FL is the frequency change of the corresponding frequency at -20dB on the left side of the filter passband of the fifth embodiment under high and normal temperature conditions, and the relationship between fps_11, fps_12, fps_tcf, and fps_14 is not limited.

FIG. 22 is a circuit diagram of the filter of the sixth embodiment of the embodiments of the disclosure. Compared with the existing filter, the two parallel resonators in the filter 120 of this embodiment are replaced with temperature-compensated resonators, which are respectively TCF1 and TCF2; By setting the temperature compensation resonator, and through the different design of the temperature compensation layer thickness, the different temperature drift characteristics of the TCF resonator are realized.

The series resonance frequency and parallel resonance frequency of the P11 resonator are fps_11 and fpp_11, respectively, the series resonance frequency and parallel resonance frequency of the P14 resonator are fps_14, fpp_14, respectively, and the series resonance frequency and parallel resonance frequency of the TCF1 resonator are fps_tcf1, fpp_tcf1, respectively The series resonance frequency and parallel resonance frequency of the TCF2 resonator are fps_tcf2 and fpp_tcf2, respectively. Under normal temperature conditions, the parallel resonance frequencies fpp_tcf1 and fpp_tcf2 of the TCF resonators have the following relationship with the parallel resonance frequencies fpp_11 and fpp_14 of the ordinary resonators P11 and P14:

Min(fpp_11, fpp_14)-Max(fpp_tcf1, fpp_tcf2)≥delta_FL

Among them, delta_FL is the frequency change of the corresponding frequency at the left -20dB of the filter passband of the sixth embodiment under high and normal temperature conditions, and the relationship between fps_11, fps_tcf1, fps_tcf2, and fps_14 is not limited.

FIG. 23 is a circuit diagram of the filter of the seventh embodiment in the embodiments of the present disclosure. Compared with the existing filter, the one-stage parallel circuit of the filter 900 of this embodiment includes two resonators, which are temperature compensated. The resonator TCF and the parallel resonator P12. In this embodiment, one of the two resonators in the parallel circuit of the same level is set as an ordinary parallel resonator, and the other is set as a temperature-compensated resonator. The structure is not limited to this, but can also The two resonators are both set as temperature-compensated resonators; by setting the temperature-compensated resonator, and through different designs of the thickness of the temperature-compensated layer, different temperature drift characteristics of the TCF resonator are realized.

FIG. 24 is a circuit diagram of the filter of the eighth embodiment in the embodiments of the present disclosure. Compared with the existing filter, in the filter 140 of this embodiment, a temperature-compensated resonator TCF1 is provided in the series branch, which is connected in parallel A temperature-compensated resonator TCF2 is set in the branch, that is, a temperature-compensated resonator is set in both the series branch and the parallel branch; in this embodiment, the temperature-compensated resonator is set, and the thickness of the temperature-compensated layer is designed differently. , To achieve different temperature drift characteristics of the TCF resonator.

By adopting the technical solution of the present disclosure, whether it is a filter that is all ordinary FBAR resonators or a filter that is all temperature-compensated resonators, it has obvious advantages in performance, and takes into account the filter bandwidth and both sides of the passband. Roll-off and passband insertion loss characteristics.

In order to ensure that the use of temperature-compensated resonators can improve the roll-off characteristics of the filter, in this disclosure, the temperature-compensated resonator is set as a zero-temperature-drift resonator or a resonator with a zero temperature-drift coefficient, and non-temperature-compensated resonance is selected The difference in the electromechanical coupling coefficient between the temperature-compensated resonator and the temperature-compensated resonator accounts for 30% or more of the value of the electromechanical coupling coefficient of the non-temperature-compensated resonator, that is, the electro-mechanical coupling coefficient of the temperature-compensated resonator is a non-temperature-compensated resonator. The electromechanical coupling coefficient is less than 70%. In order to further improve the roll-off characteristics of the filter, in this disclosure, the difference in the electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator is selected to account for the value of the electromechanical coupling coefficient of the non-temperature-compensated resonator 40% and above.

In the present disclosure, a temperature drift coefficient of zero means that the temperature drift coefficient of the resonator is within the range of ±5 ppm/°C.

FIG. 25A is a schematic structural diagram of a bulk acoustic wave resonator assembly according to an exemplary embodiment of the present disclosure. The assembly includes a temperature-compensated resonator and a non-temperature-compensated resonator. Fig. 25B is a detailed enlarged view of the temperature-compensated resonator on the left side of Fig. 25A. Among them, the bottom electrode thickness (the sum of the thickness of the first electrode layer and the second electrode layer) of the temperature-compensated resonator (the left resonator in FIG. 25A) and the bottom of the non-TCF resonator (the right resonator in FIG. 25A) The thickness of the electrode is the same, and the thickness of the top electrode of the two is the same, only the thickness of the piezoelectric layer is different.

FIG. 27A is a schematic structural diagram of a bulk acoustic wave resonator assembly according to another exemplary embodiment of the present disclosure. The assembly includes a temperature-compensated resonator and a non-temperature-compensated resonator. The difference from FIG. 25A lies in the thickness of the bottom electrode (the sum of the thickness of the first electrode layer and the second electrode layer) of the temperature-compensated resonator (the left resonator in FIG. 27A). In the present disclosure, the thickness of the temperature-compensated layer When the electrode is divided into a first electrode layer and a second electrode layer, the thickness of the electrode is the sum of the thickness of the first electrode layer and the thickness of the second electrode layer), the thickness of the piezoelectric layer, and the thickness of the top electrode are all less than The thickness of the corresponding layer of the non-temperature-compensated resonator (the right resonator in Figure 27A).

It is understandable that the two resonators in FIG. 25A and FIG. 27A may be the temperature-compensated resonator and the S11 resonator in the filter shown in FIG. 4, respectively, or they may be in the filter shown in FIG. 13 respectively. The temperature-compensated resonator and S12 resonator, or other corresponding temperature-compensated resonators and non-temperature-compensated resonators in the filter structure described in this disclosure.

The reference numerals in FIG. 25A, FIG. 25B, FIGS. 26A-26K, FIG. 27A, FIG. 27B, and FIG. 31 are exemplarily described as follows:

1: Substrate, optional materials are monocrystalline silicon, gallium arsenide, sapphire, quartz, etc.

2: The sacrificial layer can be made of silicon dioxide, doped silicon dioxide, silicon oxide and other materials.

3: The first seed layer can be made of aluminum nitride, zinc oxide, PZT and other materials and contains rare earth element doped materials with a certain atomic ratio of the above materials.

4: Bottom electrode or second electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, platinum, iridium, osmium, chromium or a combination of the above metals or their alloys.

5: The second seed layer, which can be selected from materials such as aluminum nitride, zinc oxide, PZT, and contains rare earth element doped materials with a certain atomic ratio of the above materials.

6: Temperature compensation layer, its material can be silicon dioxide (SiO ₂ ), doped silicon dioxide (such as F doping), polysilicon, borophosphate glass (BSG), chromium (Cr) or tellurium oxide (TeO) (x)) Materials with a positive temperature drift coefficient. In FIG. 25, the thickness of the temperature compensation layer is D.

7: The third seed layer, which can be selected from materials such as aluminum nitride, zinc oxide, PZT, and contains rare earth element doped materials with a certain atomic ratio of the above materials.

8: Sandwich electrode or first electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, platinum, iridium, osmium, chromium or a combination of the above metals or their alloys. In FIG. 25, the thickness of the first electrode layer of the temperature-compensated resonator on the left is C.

9: Piezoelectric film layer or piezoelectric layer, the material can be single crystal/polycrystalline aluminum nitride (AlN), zinc oxide (ZnO), lead zirconate titanate (PZT), lithium niobate (LiNbO ₃ ), quartz ( Materials such as Quartz), potassium niobate (KNbO ₃ ), or lithium tantalate (LiTaO ₃ ) may also contain rare earth element doped materials with a certain atomic ratio of the above materials. In FIGS. 25A and 31, the thickness of the piezoelectric layer of the temperature-compensated resonator on the left is A, and the thickness of the piezoelectric layer of the non-temperature-compensated resonator on the right is B.

10: A hard mask layer, which can be selected from materials such as silicon nitride, aluminum nitride, zinc oxide, and PZT, and contains rare earth element doped materials with a certain atomic ratio of the above materials.

11: The first top electrode or the first electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, platinum, iridium, osmium, chromium or a combination of the above metals or their alloys.

12: The second top electrode or the second electrode layer, the material can be molybdenum, ruthenium, gold, aluminum, magnesium, tungsten, copper, titanium, platinum, iridium, osmium, chromium or a combination of the above metals or their alloys.

13: Acoustic mirror, which can be a cavity, or Bragg reflector and other equivalent forms. In the examples shown in this disclosure, a cavity is used.

14: The bottom electrode additional layer, the material is the same as that of the bottom electrode.

15: The top electrode additional layer, the material is the same as that of the top electrode.

As shown in FIG. 25B, the lateral size of the third seed layer 7 is greater than the size of the temperature compensation layer 6. In other words, the third seed layer 7 plus the second seed layer 5 completely envelop the temperature compensation layer 6, and the third seed layer also has Extending the extension part of the temperature compensation layer 6 laterally, the size of the extension part may be in the range of 0.5 μm-5 μm.

In addition, in FIG. 25B, the upper side of the end of the temperature compensation layer 6 is a slope so that the end of the temperature compensation layer is a wedge-shaped end surface. The angle between the slope and the bottom surface of the temperature compensation layer may be less than 60°, and further less than 20°. °, furthermore, in the range of 8°-12°.

In addition, only the third seed layer 7 can be provided without the second seed layer 5; the second seed layer 5 can also extend to the outside of the warm compensation layer 6, so that the extension of the third seed layer 7 can be at least partially connected to the second seed layer 5. The end of the seed layer 5 is covered and laminated.

The following describes how to determine the thickness of each layer of the temperature-compensated resonator with reference to FIGS. 28A, 28B, 29A, 29B, and 30. 28A and 28B exemplarily show the relationship between the thickness D of the temperature compensation layer and the resonator frequency, the electromechanical coupling coefficient Kt ² and the TCF value of the temperature compensation resonator. 29A and 29B exemplarily show the relationship between the thickness A of the piezoelectric layer and the resonator frequency, the electromechanical coupling coefficient Kt ² and the TCF value of the temperature-compensated resonator. FIG. 30 exemplarily shows the relationship between the thickness C of the first electrode layer and the electromechanical coupling coefficient Kt ² and TCF value of the temperature compensated resonator.

The data of Figures 28A and 28B are obtained when the thickness of the remaining electrode layers and piezoelectric layer is unchanged, and only the temperature compensation layer of different thickness is added to the determined position of the bottom electrode (that is, the thickness of the first electrode layer and the second electrode layer are constant) curve.

It can be seen that as the thickness D increases, the value of TCF gradually increases, and ^{the value of Kt 2} gradually decreases. At the same time, due to the mass loading effect, its resonance frequency also decreases. However, the filter technology described in this disclosure requires the use of temperature-compensated resonators with equivalent frequencies to replace series or parallel resonators at specific positions in the original design. Therefore, after adding a temperature-compensated layer to the original resonator stack, it is necessary Further adjust the thickness of each layer so that the frequency rises again to near the original resonance frequency.

Generally, the electromechanical coupling coefficient and TCF value of a resonator are related to the thickness ratio of each layer of the resonator. Therefore, one method is to add a temperature compensation layer at a specific bottom electrode position, select a suitable thickness of the temperature compensation layer, so that the electromechanical coupling coefficient and TCF value meet the design requirements, and then calculate the resonance frequency and the temperature compensation resonator at this time The ratio of the resonant frequency of the original resonator, the ratio is a number less than 1, the thickness of each layer is multiplied by this ratio to reduce, thereby adjusting the frequency of the temperature-compensated resonator to the original resonator frequency. At this time, the thickness of the bottom electrode (the sum of the thickness of the first electrode layer and the second electrode layer), the thickness of the piezoelectric layer, and the thickness of the top electrode of the temperature compensated resonator will all be smaller than the thickness of each layer of the original resonator, as shown in FIG. 27A. In processing, on the one hand, it is necessary to thin the piezoelectric layer of the temperature-compensated resonator, and on the other hand, it is necessary to deposit additional metal layers under the bottom and top electrodes of the non-temperature-compensated resonator to realize the corresponding structure, which adds more processes. Steps will result in a decrease in manufacturing cost and yield. The specific processing steps will be described later.

Another method is to keep the bottom electrode (the sum of the thickness of the first electrode layer and the second electrode layer) of the temperature compensated resonator and the bottom electrode of the non-temperature compensated resonator equal in thickness. At this time, you can choose to thin the top electrode or the thickness of the piezoelectric layer to achieve frequency compensation for the temperature-compensated resonator. However, the present disclosure requires that the electromechanical coupling coefficient of the temperature-compensated resonator is less than 70% of the original resonator in order to have a better effect. The electrode cannot adjust its frequency back to the original resonance frequency, and thinning the top electrode will increase the electromechanical coupling coefficient and increase the electrical loss. Therefore, it is not possible to choose to adjust the thickness of the top electrode alone to achieve the goal, but to thin the piezoelectric layer. Thickness to achieve the goal. In a further solution, the thickness of the top electrodes of the two resonators is also equal, that is, the frequency compensation of the temperature-compensated resonator is realized only by reducing the thickness of the piezoelectric layer. As shown in Figure 29A and 29B, the thickness of the piezoelectric layer obtained when only the thickness of the piezoelectric layer A is adjusted and the resonator frequency, the electromechanical coupling coefficient Kt ² and the TCF value of the temperature compensated resonator are obtained under the condition that the thickness of the other layers remains unchanged. relation. It can be seen from the figure that the smaller the thickness of the piezoelectric layer, the higher the resonance frequency, the Kt ² value gradually decreases, and the TCF value gradually increases. Therefore, when selecting the initial temperature compensation layer thickness, it is necessary to select ^{a temperature compensation layer thickness D that is lower than the target TCF value and higher than the target Kt 2} value. On this basis, the piezoelectric layer thickness A is reduced to make the temperature compensation layer thickness D. The frequency of the resonator rises to the original resonance frequency. At this time, if the obtained TCF value is greater than the target value, it is necessary to reselect a temperature compensation layer thinner than the initial temperature compensation layer and repeat the above process. If the obtained TCF value is less than For the target value, it is necessary to re-select a temperature compensation layer thicker than the initial temperature compensation layer and repeat the above process. In the end, even if the TCF value can reach the target value, Kt ² may still not meet the requirements at this time. At this time, another ^{parameter that affects TCF and Kt 2} needs to be considered, that is, the longitudinal position of the temperature compensation layer in the bottom electrode. As shown in Figure 30, if the thickness ratio of the first electrode layer and the second electrode layer is adjusted (to ensure that the sum of the two remains unchanged), that is, the position of the temperature compensation layer in the bottom electrode is adjusted, the As the thickness increases, the resonance frequency will not fluctuate too much, but the Kt ² value will increase and the TCF value will decrease. Therefore, in the above adjustment process, the thickness C of the first electrode layer can be adjusted comprehensively, so as to realize that the resonant frequency is basically unchanged by adjusting the thickness of the piezoelectric layer, but the Kt ² and TCF reach the target setting value of the temperature-compensated resonator, As shown in Figure 25A. Compared with the structure shown in 27A, the machining process only needs to adjust the thickness of the piezoelectric layer A, and does not need to adjust the electrode thickness of the non-temperature compensated resonator, which can simplify the process and reduce the processing cost. The specific processing steps are later illustrate.

In a further embodiment, as in the manufacturing process of the resonator assembly mentioned later, due to the hard mask process and the limitation of the height and angle of the piezoelectric layer slope, the thickness A of the piezoelectric layer of the temperature-compensated resonator is not less than The piezoelectric layer thickness B of the temperature-compensated resonator is 50%.

The manufacturing process of the assembly shown in FIG. 25A is exemplified below with reference to FIGS. 26A-26K.

Step 1: As shown in FIG. 26A, the sacrificial layer 2 is filled after the cavity is etched on the substrate 1.

Step 2: As shown in FIG. 26B, on the basis of Step 1, the first seed layer 3 and the bottom electrode material layer or the second electrode material layer (corresponding to the second electrode 4) are sequentially deposited.

Step 3: As shown in FIG. 26C, in the region corresponding to the temperature-compensated resonator, the structure of step 2 is sequentially deposited and patterned to form the second seed layer 5 and the temperature-compensated layer 6.

Step 4: As shown in FIG. 26D, a third seed layer 7 is deposited and etched on the structure of FIG. 26C.

Step 5: As shown in FIG. 26E, on the basis of the structure in FIG. 26D, deposit an interlayer electrode material layer or a first electrode material (corresponding to the first electrode 8).

Step 6: Etch the top electrical material electrode, the piezoelectric layer 4 and the first seed layer 3 to form a structure as shown in FIG. 26F.

Step 7: As shown in FIG. 26G, the piezoelectric layer 9 is deposited on the structure shown in FIG. 26F with a thickness of B (see FIG. 26K).

Step 8: As shown in Fig. 26H, on the structure shown in Fig. 26G, deposit and pattern the hard mask layer 10 as a barrier layer in the region of the non-temperature compensated resonator. In the present disclosure, other materials can also be used as the barrier layer of the piezoelectric layer, as long as the barrier layer can, for example, be used for thinning the piezoelectric layer of the temperature compensated resonator in the trimming process in the following step 9, without affecting the non-influence. The thickness of the piezoelectric layer in other parts of the temperature-compensated resonator may be sufficient. For example, the barrier layer may be left at the end of trimming. The barrier layer can be further selected so that there is no excessive piezoelectric layer loss when the barrier layer is removed.

Step 9: As shown in FIG. 26I, the piezoelectric layer 9 and the hard mask layer 10 are simultaneously thinned by a trimming process (trim) using particle beam bombardment. The thinning speed of the trimming process to the piezoelectric layer is greater than the thinning speed of the hard mask layer. In the present disclosure, the trimming here uses a particle beam to physically bombard the target surface, for example, bombarding the target surface with argon gas. The bombardment does not have any chemical reaction, and the control accuracy is relatively high, and the accuracy of the thickness can be controlled within 3%, for example, the target needs to be trimmed.

(

It is a range suitable for the use of trimming methods. Beyond this range, the process time will be too long. At this time, a combination of partial etching and trimming can be used to achieve), the actual situation is probably

This kind of control precision is incomparable to etching. The thickness of the bombarded material layer can be controlled very accurately by trimming, the process is simple, and the precision is high.

Step 10: As shown in Figure 26J, after the thickness of the piezoelectric layer corresponding to the temperature-compensated resonator reaches a predetermined value (its thickness is A, see Figure 26K), stop the trimming process, and then remove the pressure in the non-temperature-compensated resonator The remaining hard mask layer 10 on the electrical layer. The hard mask layer can be removed by a process such as dry or wet etching. Both dry and wet methods need to fully consider the impact on the piezoelectric layer when the hard mask layer is removed.

Step 11: As shown in FIG. 26K, on the basis of the structure shown in FIG. 26J, deposit and pattern the top electrode material to form the top electrode 11.

Step 12: Release the sacrificial layer 2 to form a cavity 13 as an acoustic mirror, thereby forming the resonator assembly structure shown in FIG. 25A.

Compared with the processing process of FIG. 25A, the assembly shown in FIG. 27A requires two additional layers of processing steps. Between the steps shown in FIGS. 26A and 26B, it is necessary to deposit and pattern the bottom electrode additional layer 14 after depositing the first seed layer 3, and then deposit the second electrode material layer (corresponding to the second electrode 4) to form As shown in the structure shown in FIG. 27B, note that at this time, the edge contour of the bottom electrode additional layer 14 is larger than that of the final bottom electrode. Between the steps shown in Figs. 26J and 26K, the top electrode additional layer 15 needs to be deposited and patterned.

In the present disclosure, in addition to being provided in the bottom electrode of the resonator, as shown in FIG. 31, the temperature compensation layer can also be provided in the top electrode of the resonator. In FIG. 31, the top electrode includes a first electrode layer 11 and a second electrode layer 12, and the temperature compensation layer 6 is disposed between the first electrode layer and the second electrode layer.

In the present disclosure, when a temperature-compensated resonator replaces the original resonator, the resonant frequencies of the two are only equivalent, not strictly equal. For example, according to the filter design requirements, the difference between the two frequencies is within ±2% of the original resonator frequency That is, in the embodiment shown in FIG. 25A, the thickness of the top electrode of the temperature-compensated resonator can be further fine-tuned, so as to achieve fine-tuning of the frequency. In addition, in the claims of the present disclosure, the same resonant frequency of the temperature-compensated resonator and the non-temperature-compensated resonator includes both the frequency equivalent (for example, the frequency difference is within ±2%), and the strictly equal situation. In addition, it should be noted that the non-temperature-compensated resonator is another resonator in the filter that is different from the original resonator replaced by the temperature-compensated resonator. It can be either a parallel resonator or a series resonator. In an optional embodiment, the original resonator replaced by the temperature-compensated resonator and the non-temperature-compensated resonator in the resonator assembly have at least the same bottom electrode and piezoelectric layer thickness, and both may have the same top electrode thickness , Can also have different top electrode thicknesses. In an alternative embodiment, the non-temperature-compensated resonator may also have a mass load structure to achieve the specific frequency required by the specific resonator in the filter design.

Based on the above embodiments and drawings, the present disclosure proposes the following technical solutions:

1. A bulk acoustic wave resonator component, comprising two bulk acoustic wave resonators, a first resonator and a second resonator, wherein:

The temperature drift coefficient of the temperature-compensated resonator is zero, and the difference in the electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for the difference in the electromechanical coupling coefficient of the non-temperature-compensated resonator 30% of the value and above.

2. The assembly according to 1, wherein:

The thickness of the bottom electrode of the first resonator is the same as the thickness of the bottom electrode of the second resonator;

At least the thickness of the temperature compensation layer is set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.

3. The assembly according to 2, wherein:

The electrode provided with the temperature compensation layer of the first resonator includes a first electrode layer and a second electrode layer provided on both sides of the temperature compensation layer in the thickness direction of the electrode, wherein the first electrode layer is attached to the first resonator Piezoelectric layer setting; and

At least the thickness of the first electrode layer and the thickness of the temperature compensation layer are set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.

4. The assembly according to 3, wherein:

The thickness of the first electrode layer, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer of the first resonator are set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.

5. The assembly according to 4, wherein:

The temperature compensation layer is arranged in the bottom electrode of the first resonator; and

The thickness of the top electrode of the first resonator is the same as the thickness of the top electrode of the second resonator.

6. The assembly according to 1, wherein:

The thickness of the bottom electrode, the piezoelectric layer and the top electrode of the first resonator are respectively m% of the thickness of the bottom electrode, the piezoelectric layer and the top electrode of the second resonator, where m is less than 100.

7. The assembly according to 1, wherein:

The first resonator is connected to the bottom electrode or the top electrode of the second resonator.

8. The assembly according to any one of 1-7, wherein:

The resonant frequency of the first resonator is the same as the resonant frequency of the second resonator.

9. The assembly according to any one of 1-7, wherein:

The thickness of the piezoelectric layer of the first resonator is smaller than the thickness of the piezoelectric layer of the second resonator and is at least 50% of the thickness of the piezoelectric layer of the second resonator.

10. The resonator assembly according to 9, wherein:

The difference in electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for 40% or more of the value of the electro-mechanical coupling coefficient of the non-temperature-compensated resonator.

11. A method for manufacturing a bulk acoustic wave resonator assembly, the assembly comprising two bulk acoustic wave resonators, respectively a first resonator and a second resonator arranged on the same side of the same substrate spaced apart in the lateral direction, so The method includes the steps:

The first resonator and the second resonator are respectively formed on the same side of the same substrate, wherein the top electrode or the bottom electrode of the first resonator is provided with a temperature compensation layer to be a temperature compensation resonator, and the second resonator is not provided The temperature-compensated layer is a non-temperature-compensated resonator, so that the temperature drift coefficient of the temperature-compensated resonator is zero, and the difference in electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator It accounts for 30% or more of the value of the electromechanical coupling coefficient of the non-temperature-compensated resonator.

12. The method according to 11, wherein:

In the process of forming the first resonator, the method includes the step of setting at least the thickness of the temperature compensation layer to a thickness such that the temperature drift coefficient of the first resonator is zero.

13. The method according to 12, wherein:

The electrode provided with the temperature compensation layer of the first resonator includes a first electrode layer and a second electrode layer provided on both sides of the temperature compensation layer in the thickness direction of the electrode, wherein the first electrode layer is attached to the first resonator Piezoelectric layer setting;

In the process of forming the first resonator, the method includes the step of selecting at least the thickness of the first electrode layer and the thickness of the temperature compensation layer of the first resonator so that the temperature drift coefficient of the first resonator is zero.

14. The method according to 13, wherein:

In the process of forming the first resonator, the method includes the steps of selecting the thickness of the first electrode layer, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer of the first resonator to make the temperature drift coefficient of the first resonator Is zero.

15. The method according to 11, comprising the steps:

After the respective bottom electrodes of the first resonator and the second resonator are formed, a piezoelectric layer is covered on the bottom electrode;

Depositing and patterning a hard mask on the upper surface of the piezoelectric layer in the area where the second resonator is located;

At the same time, the thickness of the hard mask and the thickness of the piezoelectric layer in the area where the first resonator is located are reduced until the thickness of the piezoelectric layer of the first resonator reaches a predetermined thickness and the hard mask with reduced thickness is located at the pressure of the second resonator. On the electrical layer, the predetermined thickness is less than the thickness of the second resonator and at least 50% of the thickness of the second resonator;

Removing the remaining hard mask on the piezoelectric layer of the second resonator; and

The top electrodes of the first resonator and the second resonator are deposited and patterned on the finally formed piezoelectric layer.

16. The method according to 15, wherein:

The predetermined thickness is selected such that the difference in the electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for 40% or more of the value of the electro-mechanical coupling coefficient of the non-temperature-compensated resonator .

17. The method according to any one of 11-16, comprising the steps:

At least the thickness of the first electrode layer of the first resonator, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer are selected so that the resonant frequency of the first resonator is the same as the resonant frequency of the second resonator.

18. A filter comprising the resonator assembly according to any one of 1-10, the filter comprising a plurality of series resonators and a plurality of parallel resonators, wherein: part of the series resonator and/or part The parallel resonator is the first resonator.

19. The filter according to 18, wherein:

The number of temperature-compensated resonators in the series branch of the filter is 1, and the relationship between its frequency and the frequencies of other series resonators is as follows: Min(fsp_11, fsp_12, fsp_13...fsp_1n)-fsp_tcf≥delta_FR, where fsp_11 is the series resonator S11 Fsp_12 is the parallel resonant frequency of series resonator S12, fsp_13 is the parallel resonant frequency of series resonator S13...fsp_1n is the parallel resonant frequency of series resonator S1n, fsp_tcf is the parallel resonant frequency of temperature-compensated resonator TCF ; Delta_FR is the frequency change of the corresponding frequency at -20dB on the right side of the filter passband under high and normal temperature conditions;

or

The number of temperature-compensated resonators in the series branch of the filter is greater than or equal to 2. At room temperature, the relationship between its frequency and the frequencies of other series resonators is as follows: Min(fsp_11, fsp_12, fsp_13...fsp_1n)-Max(fsp_tcf1, fsp_tcf2... fsp_tcfn)≥delta_FR, where fsp_11 is the parallel resonance frequency of series resonator S11, fsp_12 is the parallel resonance frequency of series resonator S12, fsp_13 is the parallel resonance frequency of series resonator S13...fsp_1n is the parallel resonance of series resonator S1n Frequency; fsp_tcf1 is the parallel resonant frequency of the temperature-compensated resonator TCF1, fsp_tcf2 is the parallel resonant frequency of the temperature-compensated resonator TCF2...fsp_tcfn is the parallel resonant frequency of the temperature-compensated resonator TCFn; delta_FR is the right side of the filter passband- The frequency change of the corresponding frequency at 20dB under high and normal temperature conditions;

or

In the parallel branch of the filter, the number of temperature-compensated resonators is 1. Under normal temperature, the relationship between its frequency and the parallel resonant frequency is as follows: Min(fpp_11, fpp_12, fpp_13...fpp_1n)-fpp_tcf≥delta_FL, where fpp_11 is The parallel resonant frequency of the parallel resonator P11, fpp_12 is the parallel resonant frequency of the parallel resonator P12; fpp_13 is the parallel resonant frequency of the parallel resonator P13...fpp_1n is the parallel resonant frequency of the parallel resonator P1n, fpp_tcf is the temperature-compensated resonator TCF The parallel resonant frequency of the filter; delta_FL is the frequency change of the corresponding frequency at -20dB on the left side of the filter passband under high and normal temperature conditions;

or

The number of temperature-compensated resonators in the parallel branch of the filter is greater than or equal to 2. Under normal temperature, the relationship between its frequency and the parallel resonance frequency is as follows: Min(fpp_11, fpp_12, fpp_13……fpp_1n)-Max(fpp_tcf1, fpp_tcf2……fpp_tcfn)≥ delta_FL, where fpp_11 is the parallel resonant frequency of parallel resonator P11, fpp_12 is the parallel resonant frequency of parallel resonator S12, fpp_13 is the parallel resonant frequency of parallel resonator P13...fpp_1n is the parallel resonant frequency of parallel resonator P1n; fpp_tcf1 Is the parallel resonant frequency of the temperature-compensated resonator TCF1, fpp_tcf2 is the parallel resonant frequency of the temperature-compensated resonator TCF2...fpp_tcfn is the parallel resonant frequency of the temperature-compensated resonator TCFn; delta_FL is the -20dB corresponding to the left side of the filter passband Frequency The amount of frequency change under high and normal temperature conditions.

20. An electronic device comprising the resonator assembly according to any one of 1-10 or the filter according to 18 or 19.

It should be pointed out that the electronic equipment here includes, but is not limited to, intermediate products such as radio frequency front-ends, filter amplification modules, and terminal products such as mobile phones, WIFI, and drones.

Although the embodiments of the present disclosure have been shown and described, for those of ordinary skill in the art, it will be understood that changes can be made to these embodiments without departing from the principle and spirit of the present disclosure, and the scope of the present disclosure is determined by Attached and its equivalents are limited.

Claims

A bulk acoustic wave resonator component includes two bulk acoustic wave resonators, namely a first resonator and a second resonator, wherein:

The first resonator is a temperature-compensated resonator whose electrode includes a temperature-compensated layer, and the second resonator is a non-temperature-compensated resonator whose electrode does not include a temperature-compensated layer;

The temperature drift coefficient of the temperature-compensated resonator is zero, and the difference in the electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for the difference in the electromechanical coupling coefficient of the non-temperature-compensated resonator 30% of the value and above.
The assembly of claim 1, wherein:

The thickness of the bottom electrode of the first resonator is the same as the thickness of the bottom electrode of the second resonator;

At least the thickness of the temperature compensation layer is set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.
The assembly of claim 2, wherein:

The electrode provided with the temperature compensation layer of the first resonator includes a first electrode layer and a second electrode layer provided on both sides of the temperature compensation layer in the thickness direction of the electrode, wherein the first electrode layer is attached to the first resonator Piezoelectric layer setting; and

At least the thickness of the first electrode layer and the thickness of the temperature compensation layer are set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.
The assembly of claim 3, wherein:

The thickness of the first electrode layer, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer of the first resonator are set to a thickness such that the temperature drift coefficient of the first resonator becomes zero.
The assembly of claim 4, wherein:

The temperature compensation layer is arranged in the bottom electrode of the first resonator; and

The thickness of the top electrode of the first resonator is the same as the thickness of the top electrode of the second resonator.
The assembly of claim 1, wherein:

The thickness of the bottom electrode, the piezoelectric layer and the top electrode of the first resonator are respectively m% of the thickness of the bottom electrode, the piezoelectric layer and the top electrode of the second resonator, where m is less than 100.
The assembly of claim 1, wherein:

The first resonator is connected to the bottom electrode or the top electrode of the second resonator.
The assembly according to any one of claims 1-7, wherein:

The resonant frequency of the first resonator is the same as the resonant frequency of the second resonator.
The assembly according to any one of claims 1-7, wherein:

The thickness of the piezoelectric layer of the first resonator is smaller than the thickness of the piezoelectric layer of the second resonator and is at least 50% of the thickness of the piezoelectric layer of the second resonator.
The resonator assembly of claim 9, wherein:

The difference in electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for 40% or more of the value of the electro-mechanical coupling coefficient of the non-temperature-compensated resonator.
A method for manufacturing a bulk acoustic wave resonator assembly, the assembly comprising two bulk acoustic wave resonators, respectively a first resonator and a second resonator arranged on the same side of the same substrate and spaced apart in a lateral direction, the method Including steps:

The first resonator and the second resonator are respectively formed on the same side of the same substrate, wherein the top electrode or the bottom electrode of the first resonator is provided with a temperature compensation layer to be a temperature compensation resonator, and the second resonator is not provided The temperature-compensated layer is a non-temperature-compensated resonator, so that the temperature drift coefficient of the temperature-compensated resonator is zero, and the difference in electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator It accounts for 30% or more of the value of the electromechanical coupling coefficient of the non-temperature-compensated resonator.
The method of claim 11, wherein:

The thickness of the bottom electrode of the first resonator is the same as the thickness of the bottom electrode of the second resonator;

In the process of forming the first resonator, the method includes the step of setting at least the thickness of the temperature compensation layer to a thickness such that the temperature drift coefficient of the first resonator is zero.
The method of claim 12, wherein:

The electrode provided with the temperature compensation layer of the first resonator includes a first electrode layer and a second electrode layer provided on both sides of the temperature compensation layer in the thickness direction of the electrode, wherein the first electrode layer is attached to the first resonator Piezoelectric layer setting;

In the process of forming the first resonator, the method includes the step of selecting at least the thickness of the first electrode layer and the thickness of the temperature compensation layer of the first resonator so that the temperature drift coefficient of the first resonator is zero.
The method of claim 13, wherein:

In the process of forming the first resonator, the method includes the steps of selecting the thickness of the first electrode layer of the first resonator, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer to make the temperature drift coefficient of the first resonator Is zero.
The method according to claim 11, comprising the steps:

After the respective bottom electrodes of the first resonator and the second resonator are formed, a piezoelectric layer is covered on the bottom electrode;

Depositing and patterning a hard mask on the upper surface of the piezoelectric layer in the area where the second resonator is located;

At the same time, the thickness of the hard mask and the thickness of the piezoelectric layer in the area where the first resonator is located are reduced until the thickness of the piezoelectric layer of the first resonator reaches a predetermined thickness and the hard mask with reduced thickness is located at the pressure of the second resonator. On the electrical layer, the predetermined thickness is less than the thickness of the second resonator and at least 50% of the thickness of the second resonator;

Removing the remaining hard mask on the piezoelectric layer of the second resonator; and

The respective top electrodes of the first resonator and the second resonator are deposited and patterned on the finally formed piezoelectric layer.
The method of claim 15, wherein:

The predetermined thickness is selected such that the difference in the electromechanical coupling coefficient between the non-temperature-compensated resonator and the temperature-compensated resonator accounts for 40% or more of the value of the electro-mechanical coupling coefficient of the non-temperature-compensated resonator .
The method according to any one of claims 11-16, comprising the steps:

At least the thickness of the first electrode layer of the first resonator, the thickness of the temperature compensation layer, and the thickness of the piezoelectric layer are selected so that the resonant frequency of the first resonator is the same as the resonant frequency of the second resonator.
A filter comprising the resonator assembly according to any one of claims 1-10, the filter comprising a plurality of series resonators and a plurality of parallel resonators, wherein: part of the series resonator and/or part of the series resonator The parallel resonator is the first resonator.
The filter according to claim 18, wherein:

The number of temperature-compensated resonators in the series branch of the filter is 1, and the relationship between its frequency and the frequencies of other series resonators is as follows: Min(fsp_11, fsp_12, fsp_13...fsp_1n)-fsp_tcf≥ delta_FR, where fsp_11 is the series resonator S11 Fsp_12 is the parallel resonant frequency of series resonator S12, fsp_13 is the parallel resonant frequency of series resonator S13...fsp_1n is the parallel resonant frequency of series resonator S1n, fsp_tcf is the parallel resonant frequency of temperature-compensated resonator TCF ; Delta_FR is the frequency change of the corresponding frequency at -20dB on the right side of the filter passband under high and normal temperature conditions;

or

The number of temperature-compensated resonators in the series branch of the filter is greater than or equal to 2. At room temperature, the relationship between its frequency and the frequencies of other series resonators is as follows: Min(fsp_11, fsp_12, fsp_13...fsp_1n)-Max(fsp_tcf1, fsp_tcf2... fsp_tcfn)≥delta_FR, where fsp_11 is the parallel resonance frequency of series resonator S11, fsp_12 is the parallel resonance frequency of series resonator S12, fsp_13 is the parallel resonance frequency of series resonator S13...fsp_1n is the parallel resonance of series resonator S1n Frequency; fsp_tcf1 is the parallel resonant frequency of the temperature-compensated resonator TCF1, fsp_tcf2 is the parallel resonant frequency of the temperature-compensated resonator TCF2...fsp_tcfn is the parallel resonant frequency of the temperature-compensated resonator TCFn; delta_FR is the right side of the filter passband- The frequency change of the corresponding frequency at 20dB under high and normal temperature conditions;

or

In the parallel branch of the filter, the number of temperature-compensated resonators is 1. Under normal temperature, the relationship between its frequency and the parallel resonant frequency is as follows: Min(fpp_11, fpp_12, fpp_13...fpp_1n)-fpp_tcf≥delta_FL, where fpp_11 is The parallel resonant frequency of the parallel resonator P11, fpp_12 is the parallel resonant frequency of the parallel resonator P12; fpp_13 is the parallel resonant frequency of the parallel resonator P13...fpp_1n is the parallel resonant frequency of the parallel resonator P1n, fpp_tcf is the temperature-compensated resonator TCF The parallel resonant frequency of the filter; delta_FL is the frequency change of the corresponding frequency at -20dB on the left side of the passband of the filter under high and normal temperature conditions;

or

The number of temperature-compensated resonators in the parallel branch of the filter is greater than or equal to 2. Under normal temperature, the relationship between its frequency and the parallel resonance frequency is as follows: Min(fpp_11, fpp_12, fpp_13……fpp_1n)-Max(fpp_tcf1, fpp_tcf2……fpp_tcfn)≥ delta_FL, where fpp_11 is the parallel resonant frequency of parallel resonator P11, fpp_12 is the parallel resonant frequency of parallel resonator S12, fpp_13 is the parallel resonant frequency of parallel resonator P13...fpp_1n is the parallel resonant frequency of parallel resonator P1n; fpp_tcf1 Is the parallel resonant frequency of the temperature-compensated resonator TCF1, fpp_tcf2 is the parallel resonant frequency of the temperature-compensated resonator TCF2...fpp_tcfn is the parallel resonant frequency of the temperature-compensated resonator TCFn; delta_FL is the -20dB corresponding to the left side of the filter passband Frequency The amount of frequency change under high and normal temperature conditions.
An electronic device comprising the resonator component according to any one of claims 1-10 or the filter according to claim 18 or 19.