WO2020155670A1

WO2020155670A1 - Filter and manufacturing method therefor

Info

Publication number: WO2020155670A1
Application number: PCT/CN2019/111406
Authority: WO
Inventors: 邱文才; 李晋; 梁思文
Original assignee: 广东大普通信技术有限公司
Priority date: 2019-01-30
Filing date: 2019-10-16
Publication date: 2020-08-06
Also published as: CN109616726A

Abstract

Disclosed are a filter and a manufacturing method therefor. The filter comprises at least one silicon cavity resonance unit, wherein the silicon cavity resonance unit comprises a base metal layer, a high-resistance silicon dielectric layer, and a top metal layer that are sequentially arranged; the edge of each silicon cavity resonance unit is provided with a plurality of through structures; the through structures pass through the base metal layer, the high-resistance silicon dielectric layer, and the top metal layer; a metal deposition layer is formed on an inside surface of each of the through structures; and the through structure is at least one of a through hole and a through slot. The filter further comprises at least one trough line type stepped impedance resonator, wherein the trough line type stepped impedance resonator is composed of a plurality of through lines formed in the top metal layer and communicating with each other; and the depth of the trough lines is equal to the thickness of the top metal layer.

Description

Filter and its making method

This application claims the priority of the Chinese patent application filed with the Chinese Patent Office with application number 201910090637.7 on January 30, 2019. The entire content of this application is incorporated into this application by reference.

Technical field

This application relates to the technical field of miniaturized filters, such as a filter and a manufacturing method thereof.

Background technique

The filter plays an important role in frequency selective filtering in radio frequency and microwave systems. The filter can pass electrical signals of a certain frequency, while blocking other frequencies. The main performance indicators of the filter include insertion loss, bandwidth, out-of-band selectivity, and circuit size. Bandwidth broadening and circuit miniaturization have always been key design difficulties for filters.

Traditional filters include cavity filters, LC filters, and planar filters. Cavity filters are formed by cutting metal as a whole. LC filters are composed of a combination of inductors, capacitors and resistors. The planar filters are composed of transmission lines and printed circuits. Printed Circuit Boards (PCBs) are all made of large size and difficult to be interconnected and integrated with multiple chips, which has affected the development of filters in miniaturized chip filters.

Summary of the invention

The embodiments of the present application provide a filter and a manufacturing method thereof, so as to avoid the situation that the filter in the related art is large in size and difficult to achieve multi-chip integration.

In a first aspect, an embodiment of the present application provides a filter, including: at least one silicon cavity resonant unit, the silicon cavity resonant unit includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer sequentially arranged; each The edge of the silicon cavity resonance unit is provided with a plurality of penetrating structures; the penetrating structure penetrates the bottom metal layer, the high resistance silicon dielectric layer, and the top metal layer; the inner surface of the penetrating structure is formed with Metal deposition layer; the penetrating structure is at least one of a through hole and a through groove; further comprising at least one slot-line ladder impedance resonator, the slot-line ladder impedance resonator formed on the top metal layer mutual A plurality of connected groove lines are formed; the depth of the groove lines is equal to the thickness of the top metal layer.

In the second aspect, an embodiment of the present application also provides a method for fabricating a filter, which is applicable to the filter provided in any embodiment of the present application, including: forming an underlying metal layer on the first side of the high-resistance silicon dielectric layer; The second side of the high-resistance silicon dielectric layer forms a top metal layer, the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer form a stacked structure; the stacked structure includes at least one silicon cavity A resonant unit; a plurality of through structures are formed at the edge of each silicon cavity resonant unit; the through structure penetrates the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer; the through structure Is at least one of a through hole and a through groove; a metal deposition layer is formed on the inner surface of the through structure; at least one slot-line ladder impedance resonator is formed on the top metal layer, and each slot-line ladder impedance resonator includes forming A plurality of interconnected groove lines on the top metal layer; the depth of the groove lines is equal to the thickness of the top metal layer.

Description of the drawings

FIG. 1 is a schematic structural diagram of a filter provided by an embodiment of the present application;

Figure 2 is a cross-sectional view along the line a-a' in Figure 1;

FIG. 3 is a schematic structural diagram of another filter provided by an embodiment of the present application;

FIG. 4 is a schematic structural diagram of another filter provided by an embodiment of the present application;

FIG. 5 is a schematic structural diagram of another filter provided by an embodiment of the present application;

6 is a waveform diagram of frequency-signal strength of a filtered signal provided by an embodiment of the present application;

FIG. 7 is a schematic flowchart of a method for manufacturing a filter according to an embodiment of the present application;

FIG. 8 is a schematic structural diagram of a laminated structure in which silicon cavity resonant units are arranged in an array according to an embodiment of the present application.

detailed description

The embodiment of the present application provides a filter including: at least one silicon cavity resonant unit, the silicon cavity resonant unit includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer arranged in sequence; the edge of each silicon cavity resonant unit A plurality of penetrating structures are provided; the penetrating structure penetrates the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer; the inner surface of the penetrating structure is formed with a metal deposition layer; the penetrating structure is at least one of a through hole and a through groove; It also includes at least one slot line type ladder impedance resonator, which is composed of a plurality of interconnected slot lines formed on the top metal layer; the depth of the slot line is equal to the thickness of the top metal layer.

In this implementation, a bottom metal layer and a top metal layer are sequentially formed on the high-resistance silicon dielectric layer, and at least one silicon cavity is formed by using the above-mentioned stacked structure consisting of the bottom metal layer, high-resistance silicon dielectric layer and top metal layer as the matrix Resonance unit. First, the bottom metal layer is formed by sputtering and then electroplating on the first surface of the high resistance silicon dielectric layer, and then the top metal layer is formed on the second surface of the high resistance silicon dielectric layer by sputtering and then electroplating. An etching process is used to form a through structure that penetrates the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer on the edge of the silicon cavity resonance unit. Illustratively, the through structure uses MEMS dry etching technology from the top metal layer to the bottom layer The metal layer is etched to form an etching cavity, and then a metal deposition layer is formed on the inner surface through processes such as sputtering and electroplating. In addition, when forming the slot line ladder impedance resonator on the top metal layer, an etching process is used to etch the slot line with the same depth as the thickness of the top metal layer.

It is worth noting that the through structure can be formed before the formation of the slot-line ladder impedance resonator, or it can be etched after the formation of the slot-line ladder impedance resonator, both of which can form filters with the same parameters. The order of formation of the structure and the slot-line ladder impedance resonator is not limited.

In the present application, the filter includes at least one silicon cavity resonant unit, at least one silicon cavity resonant unit includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer arranged in sequence, and the edge of each silicon cavity resonant unit is provided with multiple A through structure that penetrates the bottom metal layer, the high-resistance silicon dielectric layer and the top metal layer, and a metal deposition layer is formed on the inner surface of the through structure to form a silicon cavity for resonance, and the top metal layer is formed with a slot line type Step impedance resonator, each slot line type ladder impedance resonator is composed of a plurality of interconnected slot lines formed on the top metal layer. The filter of the present application is equipped with a stepped impedance resonator and a silicon cavity resonator unit, so that the number of stages in the filter passband is increased, the filter bandwidth is broadened, and the out-of-band suppression is improved without increasing the circuit size. The embodiment filter is easy to integrate with the semiconductor integrated circuit process. In addition, the high-resistance silicon medium can make the filter small in size and insertion loss, and reduce the electromagnetic wave transmission loss of the filter.

FIG. 1 is a schematic structural diagram of a filter provided by an embodiment of the present application. As shown in FIG. 1, the filter includes at least one silicon cavity resonator unit 11. Referring to FIG. 2, FIG. 2 is along the line a-a in FIG. In the cross-sectional view of', the silicon cavity resonant unit 11 includes a bottom metal layer 21, a high-resistance silicon dielectric layer 22, and a top metal layer 23 sequentially arranged. At least one silicon cavity resonant unit 11 can be formed on the bottom metal layer 21 and the high-resistance silicon dielectric Layer 22 and the top metal layer 23 are formed on the matrix, and the silicon cavity resonance unit 11 is formed by etching the through structure on the matrix. Exemplarily, as shown in FIGS. 1 and 2, the bottom metal layer 21, high On the matrix formed by the resistive silicon dielectric layer 22 and the top metal layer 23, three silicon cavity resonant units 11 are formed. The edge of each silicon cavity resonant unit 11 is provided with a through structure 12. The through structure 12 may be a through hole 122, or Through slot 121. Two adjacent silicon cavity resonance units 11 have adjacent edges, and adjacent edges of two adjacent silicon cavity resonance units 11 may share the through structure 12.

In an embodiment, the top metal layer 21 and the bottom metal layer 23 may be copper or gold, and the resistivity of the high-resistance silicon dielectric layer 22 is greater than or equal to 3000 Ωcm. The thickness of the bottom metal layer 23 and the top metal layer 21 are respectively less than or equal to 10um; the thickness of the high resistance silicon dielectric layer 22 ranges from 200um to 500um. The through structure 12 provided around the silicon cavity resonance unit 11 of this embodiment prevents electromagnetic waves from leaking out of the silicon cavity, and the energy transmission loss is small, that is, the insertion loss of the filter in this embodiment is small.

The filter includes at least one slot line ladder impedance resonator 13, each slot line ladder impedance resonator 13 includes a plurality of interconnected slot lines, the slot line ladder impedance resonator 13 can be in the filter passband of the filter Introduce multiple transmission poles to increase the working bandwidth and out-of-band rejection of the filter without increasing the size of the filter.

The filter in this embodiment can be processed by micro-electromechanical processing technology. Its three-dimensional stacked structure and circuit structure make the filter body small and easy to integrate with semiconductor integrated circuit technology, which is conducive to miniaturizing the filter and expanding the filter. The scope of application of the device. Exemplarily, the entire circuit of the filter in this embodiment may have a length of 5.9 mm, a width of 3 mm, and a height of 0.504 mm. It can be seen that the filter body in this embodiment is actively small, which facilitates integration on a chip.

In one embodiment, referring to FIG. 1, the filter 1 includes a plurality of silicon cavity resonant units 11; the multiple silicon cavity resonant units 11 are arranged in a matrix; two adjacent silicon cavity resonant units 11 in the same row share a slot-line ladder Impedance resonator 13; slot-line ladder impedance resonator 13 includes a first part and a second part, the first part is located in the same row of silicon cavity resonator units 11 in the previous silicon cavity resonator unit 11, the second part is located in the same row of silicon cavity resonator The latter silicon cavity resonant unit 11 in the unit 11.

In one embodiment, as shown in FIG. 1, the filter 1 includes three silicon cavity resonant units 13 arranged in a row, which are a first silicon cavity resonant unit 111, a second silicon cavity resonant unit 112, and a third silicon cavity resonant unit. Cavity resonance unit 113; filter 1 includes two slot-line ladder impedance resonators 13, respectively a first slot-line ladder impedance resonator 134 and a second slot-line ladder impedance resonator 135; the first slot-line ladder The impedance resonator 134 is formed on the top metal layer 21 of the first silicon cavity resonant unit 111 and the second silicon cavity resonant unit 112, and the second slot line ladder impedance resonator 135 is formed on the second silicon cavity resonant unit 112 and the third silicon cavity. The top metal layer of the cavity resonance unit 113. The first slot-line ladder impedance resonator 134 is divided into a first part and a second part. The first part is located in the first silicon cavity resonance unit 111, and the second part is located in the second silicon cavity resonance unit 112; the second slot-line ladder The impedance resonator 135 is divided into two parts, the first part is located in the second silicon cavity resonance unit 112 and the second part is located in the third silicon cavity resonance unit 113.

In one embodiment, the slot-line ladder impedance resonator 13 is symmetrically arranged about the symmetry side; the adjacent edges of two adjacent silicon cavity resonator units 11 that share a slot-line ladder impedance resonator 13 are the symmetry sides. 1, the first slot-line stepped impedance resonator 134 is divided into a first part and a second part. The first part is located in the first silicon cavity resonance unit 111, the second part is located in the second silicon cavity resonance unit 112, and the first When the silicon cavity resonance unit 111 and the second silicon cavity resonance unit 112 share the first slot-line ladder impedance resonator 134, the adjacent edges of the first silicon cavity resonance unit 111 and the second silicon cavity resonance unit 112 are regarded as symmetric And the first slot-line stepped impedance resonator 134 is symmetrically arranged about the symmetry side, and the first part and the second part are symmetrical about the symmetry side, which is beneficial to realize the slot-line stepped impedance resonator 13 and the silicon cavity resonance unit 11 Uniform coupling improves the filtering performance of the filter.

Referring to FIG. 3, FIG. 3 is a schematic structural diagram of another filter provided by an embodiment of the present application. In the case that the filter 1 includes a plurality of silicon cavity resonant units 11, the number of silicon cavity resonant units 11 may be greater than Other integers of 3, such as 6, as shown in FIG. 3, 6 silicon cavity resonator units 11 can form a matrix of 2 rows and 3 columns. In one embodiment, in each row, two adjacent silicon cavity resonator units 11 can share a slot-line ladder impedance resonator 13, and the silicon cavity resonator units 11 in 2 rows and 3 columns can be provided with 4 slot-line resonators. Step impedance resonator 13.

In an embodiment, as shown in FIGS. 1 and 3, the filter 1 may further include: an input feeder trough 14, an output feeder trough 16, a first defective coupling trough 15, and a second defective coupling trough 17; 14 and the first defect coupling groove 15 are formed on the top metal layer of the first silicon cavity resonator unit 11 of any row of silicon cavity resonant units 11; the output feeder groove 16 and the second defect coupling groove 17 are formed on any row of silicon cavity resonator units 11 The top metal layer of the final silicon cavity resonance unit 11; the input feeder slot 14 is connected to the first defect coupling slot 15, and the input feeder slot 14 is configured to input the signal to be filtered into the filter 1; the output feeder slot 16 and the second defect coupling slot 17 is connected, the output feeder trough 16 is set to output the filtered signal formed by the filtering of the signal to be filtered; the input feeder trough 14, the first defect coupling trough 15, the output feeder trough 16, and the second defect coupling trough 17 are respectively the depth of the top metal layer The thickness is equal.

The filter 1 is connected to an input feeder trough 14 and an output feeder trough 16 formed by a coplanar waveguide transmission trough with an external system. The impedance of the input feeder trough 14 and the output feeder trough 16 may be 50Ω. The input feeder slot 14 communicates with the first defect coupling slot 15 located in the same silicon cavity resonant unit 11, and the first defect coupling slot 15 is coupled with the silicon cavity resonant unit 11, thereby realizing the input feeder slot 14 and the silicon cavity resonant unit 11, the signal to be filtered is input to the filter through the input feeder slot 14. Similarly, the output feeder slot 16 is connected to the silicon cavity resonant unit 11 through the second defect coupling slot 17 located in the same silicon cavity resonant unit 11, and the output feeder The slot 16 is set to output the filtered signal after the filtering of the signal to be filtered is completed. The size of the first defect coupling slot 15 and the second defect coupling slot 17 determines the distance between the input feeder slot 14 and the output feeder slot 16 and the silicon cavity resonant unit 11. The coupling strength. The larger the size of the first defect coupling slot 15 and the second defect coupling slot 17 is, the greater the coupling strength between the input feeder slot 14 and the output feeder slot 16 and the silicon cavity resonance unit 11 is. In an embodiment, the slot line width of the input feeder trough 14 and the output feeder trough 16 can be 88um, the gap between the two input feeder troughs 14 can be 70um, the first defect coupling slot 15 and the second defect coupling slot 17 The length can be 1.3mm, and the width can be 0.3mm.

Exemplarily, as shown in FIG. 3, the input feeder groove 14 and the first defect coupling groove 15 may be formed on the top metal layer of the first silicon cavity resonator unit 11 of the first row of silicon cavity resonator units 11; the output feeder groove 16 and The second defect coupling groove 17 is formed on the top metal layer of the silicon cavity resonator unit 11 at the end of the second row of silicon cavity resonator units 11. In another example of this embodiment, referring to FIG. 4, FIG. 4 is a schematic structural diagram of another filter provided by an embodiment of the present application. The input feeder slot 14 and the first defect coupling slot 15 can be formed in the second The top metal layer of the first silicon cavity resonator unit 11 of the row silicon cavity resonator unit 11; the output feeder groove 16 and the second defect coupling groove 17 are formed on the top metal layer of the last silicon cavity resonator unit 11 of the second row silicon cavity resonator unit 11 Floor. In addition, there may be other settings. It is only necessary to ensure that there is a silicon cavity resonator unit 13 in the first column of silicon cavity resonator unit 13 with an input feeder slot 14 and a first defect coupling slot 15, and there is a silicon cavity in the last column of silicon cavity resonator unit 13 The cavity resonance unit 13 only needs to be provided with an output feeder slot 16 and a second defect coupling slot 17.

The filter may also include a silicon cavity resonant unit 11, as shown in FIG. 5, which is a schematic structural diagram of another filter provided by an embodiment of the present application. The filter 1 includes a silicon cavity resonant unit 11; 1 also includes: an input feeder slot 14, an output feeder slot 16, a first defect coupling slot 15, and a second defect coupling slot 17 formed on the top metal layer of the silicon cavity resonant unit 11; the input feeder slot 14 is coupled with the first defect The slot 15 is connected, the input feeder slot 14 is set to input the signal to be filtered into the filter; the output feeder slot 16 is connected to the second defect coupling slot 17, and the output feeder slot 16 is set to output the filtered signal formed by filtering the signal to be filtered; the input feeder slot 14. The depths of the output feeder slot 16, the first defect coupling slot 15, and the second defect coupling slot 17 are respectively equal to the thickness of the top metal layer. In the case that the filter includes only one silicon cavity resonator unit 11, only one slot-line ladder impedance resonator 13 can be provided on the top metal layer of the silicon cavity resonator unit 11, and the silicon cavity resonator unit 11 is provided with an input feeder The slot 14 and the first defect coupling slot 15 are used to input the signal to be filtered to the filter, and the output feeder slot 16 and the second defect coupling slot 17 are provided to output the filtered signal after filtering.

In an embodiment, the filter frequency of the silicon cavity resonator unit 11 can be determined by controlling the shape and size of the silicon cavity resonator unit 11. Illustratively, this embodiment can use a bottom metal layer 21 and a top metal layer with a thickness of 10um. 23. A high-resistance silicon dielectric layer 22 with a thickness of 500um is used. The silicon cavity resonant unit 11 may be rectangular, and the length of the silicon cavity resonant unit 11 may be 3 mm, and the width may be 1.95 mm. In addition, the silicon cavity resonance unit 11 may also be square, circular or other polygonal shapes.

In one embodiment, referring to FIGS. 1 to 5, the slot line type stepped impedance resonator 13 is a half-wavelength stepped impedance resonator, and includes three slot lines connected in sequence: a first slot line 131, a second slot line 132, and The third groove line 133; the width of the second groove line 132 is greater than the width of the first groove line 131, the width of the second groove line 132 is greater than the width of the third groove line 133; the first groove line 131 and the third groove line 133 The widths are equal, and the lengths of the first slot line 131 and the third slot line 133 are equal.

Each resonator has a resonant fundamental frequency. There will also be resonant frequencies at the second and third magnifications of the fundamental frequency, that is, the second harmonic and the third harmonic. In the case of different slot line widths, as shown in Figure 1, when the width of the second slot line 132 is greater than the first slot line 131, the fundamental frequency approaches the second harmonic, but the frequency of the second harmonic does not change , The fundamental and second harmonics close to the second harmonic form transmission poles, and the fundamental frequency and the second harmonic can be included in nearly one pass band, thereby introducing multiple transmission poles in the filter pass band of the filter. When the filter is provided with multiple slot-line ladder impedance resonators 13, there will be transmission poles generated by cross-coupling between the slot-line ladder impedance resonators 13, plus the transmission poles generated by multiple silicon cavity resonators. , The transmission poles in the entire band pass of the filter are sufficient to ensure the bandwidth of the filter and form a wider working bandwidth.

In an embodiment, by adjusting the total length of the slot line type stepped impedance resonator 13 and the average width of the slot line, the frequency of the fundamental frequency and the second harmonic transmission pole of the filter can be adjusted. In this embodiment, you can select The total length of the slot line ladder impedance resonator 13 is 5.6 mm, and the average width of the slot line is 0.09 mm. The step impedance ratio and the high and low order length ratio of the slot line ladder impedance resonator 13 of the top metal layer 21 are jointly determined The closeness of the fundamental frequency to the second harmonic determines the frequency of the fundamental frequency transmission pole. In this embodiment, the step impedance ratio is the ratio of the width of the second slot line 132 to the first slot line 131, and the ratio of the width of the second slot line 132 to the width of the first slot line 131 is 5:1, that is, the slot The step impedance ratio of the line step impedance resonator 13 is 5:1, and the ratio of the length of the second slot line 132 to the length of the first slot line 131 can be selected to be 1.6:1, that is, the slot line step impedance resonator 13 The ratio of high to low order length is 1.6:1.

Exemplarily, referring to FIG. 1, if the filter uses a bottom metal layer 21 and a top metal layer 23 with a thickness of 10um, and a high-resistance silicon dielectric layer 22 with a thickness of 500um, the silicon cavity resonator unit 11 is rectangular and has a length of 3mm, the width is 1.95mm. In addition, the total length of the slot line type stepped impedance resonator 13 is 5.6 mm, the average width of the slot line is 0.09 mm, and the ratio of the width of the second slot line 132 to the width of the first slot line 131 is 5:1; The ratio of the length of the slot line 132 to the length of the first slot line 131 is 1.6:1. As shown in Fig. 1, in the case where the filter includes three slot-line stepped impedance resonators 13 arranged in a row, the signal to be filtered input from the input feeder trough 14 and the filtered signal output from the output feeder trough 16 are shown in Fig. As shown in FIG. 6, FIG. 6 is a frequency-signal intensity waveform diagram of a filtered signal provided by an embodiment of the present application. The frequency-signal intensity waveform curve of the signal to be filtered input by the input feeder trough 14 is the first curve S11, and the frequency-signal intensity waveform curve of the filtered signal output by the output feeder trough 16 is the second curve S21, as can be seen from FIG. 6, After the filtered signal passes through the filtering process of the filter, the working frequency band of the output filtered signal is 18-33GHz, the working bandwidth is relatively large, and the part of the second curve S21 except the 18-33GHz frequency band drops sharply, that is, the working frequency band of the filtered signal is two The signal strength of the side-filtered signal drops sharply. It can be seen that the out-of-band of the filtered signal is steep and the out-of-band suppression is high. The filter of this example is provided with three silicon cavity resonator units 11 and two slot-line ladder impedance resonators 13, which increase the transmission pole, increase the working bandwidth, and improve the out-of-band suppression.

In one embodiment, the first slot line 131, the second slot line 132, and the third slot line 133 are all U-shaped slot lines, which facilitates the realization of the symmetrical arrangement of the slot line type stepped impedance resonator 13, and the U-shaped slot line occupies The area is small, which facilitates the miniaturization of the filter. In addition, the U-shaped slot line is convenient to obtain a larger length of the slot line, and the resonance frequency adjustment range of the slot line type stepped impedance resonator 13 is increased.

Based on the same concept, an embodiment of the present application also provides a method for manufacturing a filter. FIG. 7 is a schematic flowchart of a method for fabricating a filter according to an embodiment of the present application. As shown in FIG. 7, the method of this embodiment includes steps S110 to S140.

In step S110, a bottom metal layer is formed on the first side of the high resistance silicon dielectric layer, a top metal layer is formed on the second side of the high resistance silicon dielectric layer, the bottom metal layer, the high resistance silicon dielectric layer, and the top metal layer The layers form a laminated structure.

In step S120, the laminated structure includes at least one silicon cavity resonant unit; a plurality of through structures are formed at the edge of each silicon cavity resonant unit; the through structures penetrate through the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer; The structure is at least one of a through hole and a through groove.

As shown in FIG. 8, FIG. 8 is a schematic structural diagram of a laminated structure in which silicon cavity resonator units are arranged in an array according to an embodiment of the present application. The formation includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer. After the stacked structure 2 is formed, a plurality of silicon cavity resonant units 11 arranged in an array can be formed on the stacked structure 2, and a through hole penetrating the stacked structure 2 is provided on the peripheral edge of the silicon cavity resonant units 11 arranged in the array. Structure 12, referring to FIG. 8, the above-mentioned through structure may be at least one of a through hole 122 and a through groove 121.

In step S130, a metal deposition layer is formed on the inner surface of the through structure.

After the metal deposition layer is formed inside the penetrating structure 12, at least one silicon cavity resonator unit 11 of the laminated structure 2 is cut along the edge penetrating structure 12 to form the filter provided by the embodiment of the present application, as shown in the example As shown in FIG. 8, two silicon cavity resonant units 11 can be cut from the laminated structure 2 to form a filter, and the filter includes two silicon cavity resonant units 11. It is worth noting that when the through-structure 12 is cut along the edge of the silicon cavity resonance unit 11, the through hole 122 will be cut to form the through groove 121.

In step S140, at least one slot line ladder impedance resonator is formed on the top metal layer, and each slot line ladder impedance resonator includes a plurality of interconnected slot lines formed on the top metal layer; the depth of the slot line and the top layer The thickness of the metal layers is equal.

In this embodiment, in the case that the filter includes two silicon cavity resonant units 11, a slot-line stepped impedance resonator 13 may be provided on the top metal layer on the two silicon cavity resonant units 11. The resonator 13 is arranged symmetrically with respect to the edges of the two silicon cavity resonance units 11.

In this embodiment, the order of arranging the penetrating structure 12 and arranging the slot-line ladder impedance resonator 13 can be interchanged. That is, in this embodiment, the slot-line ladder impedance resonator 13 can also be arranged on the top metal layer of the filter. After that, the through structure 12 at the edge of each silicon cavity resonance unit 11 is set.

In the method for fabricating a filter provided by an embodiment of the application, the filter includes at least one silicon cavity resonant unit, the at least one silicon cavity resonant unit includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer arranged in sequence, and each silicon The edge of the cavity resonator unit is provided with a plurality of penetrating structures penetrating the bottom metal layer, the high-resistance silicon dielectric layer and the top metal layer, and a metal deposition layer is formed on the inner surface of the penetrating structure to form a silicon cavity for resonance, and The top metal layer is formed with a slot line ladder impedance resonator, and each slot line ladder impedance resonator is composed of a plurality of interconnected slot lines formed on the top metal layer. The filter of the present application is equipped with a stepped impedance resonator and a silicon cavity resonator unit, so that the number of stages in the filter passband is increased, the filter bandwidth is broadened, and the out-of-band suppression is improved without increasing the circuit size. The embodiment filter is easy to integrate with the semiconductor integrated circuit process. In addition, the high-resistance silicon medium can make the filter small in size and insertion loss, and reduce the electromagnetic wave transmission loss of the filter.

Claims

A filter including:

At least one silicon cavity resonant unit, the silicon cavity resonant unit includes a bottom metal layer, a high-resistance silicon dielectric layer, and a top metal layer arranged in sequence; the edge of each silicon cavity resonant unit is provided with multiple through structures; A through structure penetrates the bottom metal layer, the high-resistance silicon dielectric layer, and the top metal layer; a metal deposition layer is formed on the inner surface of the through structure; the through structure is at least one of a through hole and a through groove Species

It also includes at least one slot-line ladder impedance resonator, the slot-line ladder impedance resonator is composed of a plurality of interconnected slot lines formed on the top metal layer; the depth of the slot line and the top metal layer The thicknesses of the layers are equal.
The filter according to claim 1, wherein:

The filter includes a plurality of silicon cavity resonant units; the plurality of silicon cavity resonant units are arranged in a matrix; two adjacent silicon cavity resonant units in the same row share one slot-line stepped impedance resonator; The slot-line stepped impedance resonator includes a first part and a second part, the first part is located in the silicon cavity resonator unit in the same row, and the second part is located in the same row. The latter silicon cavity resonant unit in the silicon cavity resonant unit.
The filter according to claim 2, wherein the slot-line stepped impedance resonator is symmetrically arranged about the symmetry side;

The adjacent edges of the two adjacent silicon cavity resonant units sharing one slot line type stepped impedance resonator are symmetrical edges.
The filter according to claim 2, further comprising: an input feeder groove, an output feeder groove, a first defective coupling groove, and a second defective coupling groove; the input feeder groove and the first defective coupling groove are formed in any The top metal layer of the first silicon cavity resonant unit of a row of silicon cavity resonant units; the output feeder groove and the second defect coupling groove are formed on the top metal layer of the last silicon cavity resonant unit of any row of silicon cavity resonant units;

The input feeder trough is connected to the first defective coupling trough, and the input feeder trough is configured to input the signal to be filtered into the filter;

The output feeder trough is connected to the second defective coupling trough, and the output feeder trough is configured to output a filtered signal formed by filtering the signal to be filtered;

The depths of the input feeder groove, the first defective coupling groove, the output feeder groove and the second defective coupling groove are respectively equal to the thickness of the top metal layer.
The filter according to claim 2, wherein the filter comprises three silicon cavity resonant units arranged in a row, namely a first silicon cavity resonant unit, a second silicon cavity resonant unit, and a third silicon cavity resonator Unit; the filter includes two slot-line ladder impedance resonators, respectively a first slot-line ladder impedance resonator and a second slot-line ladder impedance resonator;

The first slot line type ladder impedance resonator is formed on the top metal layer of the first silicon cavity resonator unit and the second silicon cavity resonator unit, and the second slot line ladder impedance resonator is formed on the The top metal layer of the second silicon cavity resonance unit and the third silicon cavity resonance unit.
The filter according to claim 1, wherein:

The slot line type stepped impedance resonator includes a first slot line, a second slot line, and a third slot line connected in sequence; the width of the second slot line is greater than the width of the first slot line, and the first The width of the second groove line is greater than the width of the third groove line; the width of the first groove line and the third groove line are equal, and the length of the first groove line and the third groove line are equal.
The filter according to claim 6, wherein

The first groove line, the second groove line and the third groove line are all U-shaped groove lines.
The filter according to claim 6, wherein

The ratio of the width of the second groove line to the width of the first groove line is 5:1;

The ratio of the length of the second groove line to the length of the first groove line is 1.6:1.
The filter according to claim 1, wherein the filter comprises a silicon cavity resonance unit;

The filter further includes: an input feeder groove, an output feeder groove, a first defect coupling groove, and a second defect coupling groove formed on the top metal layer of the silicon cavity resonance unit;

The input feeder trough is connected to the first defective coupling trough, and the input feeder trough is configured to input the signal to be filtered into the filter; the output feeder trough is connected to the second defective coupling trough, and the output The feeder trough is configured to output a filtered signal formed by filtering the signal to be filtered;

The depths of the input feeder groove, the output feeder groove, the first defective coupling groove, and the second defective coupling groove are respectively equal to the thickness of the top metal layer.
A method for manufacturing a filter, suitable for the filter according to any one of claims 1-9, comprising:

A bottom metal layer is formed on the first side of the high resistance silicon dielectric layer, a top metal layer is formed on the second side of the high resistance silicon dielectric layer, the bottom metal layer, the high resistance silicon dielectric layer, and the top layer The metal layer forms a laminated structure;

The laminated structure includes at least one silicon cavity resonant unit; a plurality of through structures are formed at the edge of each silicon cavity resonant unit; the through structures penetrate through the underlying metal layer, the high-resistance silicon dielectric layer, and The top metal layer; the through structure is at least one of a through hole and a through groove;

Forming a metal deposition layer on the inner surface of the penetrating structure;

At least one slot line ladder impedance resonator is formed on the top metal layer, and each slot line ladder impedance resonator includes a plurality of interconnected slot lines formed on the top metal layer; the depth of the slot line and the The thickness of the top metal layer is equal.