Radio frequency switch and its manufacturing method

Abstract

The present invention provides a radio frequency device and a manufacturing method thereof, including: a substrate, the substrate having a control region, a clearance region, and a radio frequency region arranged in sequence along a first direction, the clearance region extending along a second direction; a control device and a radio frequency device, respectively located on the substrate in the control region and the radio frequency region; a plurality of isolation structures, arranged side by side along the second direction on the substrate in the clearance region; a dielectric layer, located on the substrate and conformally covering the control device, the radio frequency device, and the remaining substrate in the clearance region, the dielectric constant of the dielectric layer being greater than the dielectric constant of the isolation structure. The isolation structure can reduce the capacitive coupling effect between the control device and the radio frequency device, thereby reducing signal crosstalk and producing a good isolation effect on the signals.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular, to a radio frequency switch and a preparation method thereof. Background Art

[0002] Radio frequency devices greatly facilitate the applications in the field of wireless communication within a certain range. A wireless communication circuit composed of a suitable controller and a radio frequency device can be integrated on a very small circuit board and applied to many fields such as wireless digital audio, digital video data transmission systems, wireless remote control and telemetry systems, wireless data acquisition systems, wireless networks, and wireless security prevention systems.

[0003] When the control device and the radio frequency device are formed on the same substrate, the performance of the device may be very unstable. This is mainly because the operating voltages of the control device and the radio frequency device differ greatly, resulting in a large difference in the amplitude and frequency between the control signal emitted by the control device and the radio frequency signal emitted by the radio frequency device. The control signal will cause crosstalk of the radio frequency signal. In addition, there is capacitive coupling between the control device and the radio frequency device, which will affect the performance of the device. Especially for high-voltage radio frequency devices, the high-voltage radio frequency device with a higher operating voltage may cause the control device to burn out.

[0004] Generally, a clearance area is reserved between the control device and the radio frequency device to reduce the capacitive coupling between the control device and the radio frequency device. In order to achieve effective signal isolation, a clearance area with a relatively large size is generally set, but a clearance area with a relatively large size is not conducive to reducing the size of the radio frequency switch. Summary of the Invention

[0005] The purpose of the present invention is to provide a radio frequency switch and a preparation method thereof to improve the signal isolation performance between the radio frequency device and the controller, reduce the size of the clearance area, and thus reduce the size of the radio frequency switch.

[0006] To achieve the above object, the present invention provides a radio frequency switch, including:

[0007] A substrate having a control area, a clearance area, and a radio frequency area arranged in sequence along a first direction, and the clearance area extends along a second direction;

[0008] A control device and a radio frequency device, both located on the substrate and respectively located in the control area and the radio frequency area;

[0009] A plurality of isolation structures arranged side by side along the second direction on the substrate of the clearance area and at least covering a part of the substrate of the clearance area in the first direction;

[0010] A dielectric layer is located on the substrate and conformally covers the control device, the radio frequency device, and the remaining substrate in the clearance area. The dielectric constant of the dielectric layer is greater than that of the isolation structure.

[0011] Optionally, the radio frequency switch further includes:

[0012] A metal interconnect structure, including a first part, a second part, and a metal interconnect line. Both the first part and the second part include a plurality of stacked metal connectors, and the first part and the second part are respectively located in the dielectric layer of the control area and the radio frequency area, and lead out the control device and the radio frequency device respectively;

[0013] The metal interconnect line is located in the dielectric layer between the isolation structures, and both ends extend to electrically connect any one of the metal connectors of the first part and the second part.

[0014] Optionally, the width of the clearance area in the first direction is 35 μm to 100 μm.

[0015] Optionally, the width of the isolation structure in the first direction is 50% to 80% of the width of the clearance area in the first direction.

[0016] Optionally, the radio frequency switch further includes:

[0017] A nitride layer conformally covers the dielectric layer and the bottom surface of the isolation structure.

[0018] Optionally, the dielectric constant of the isolation structure is 2.5 to 3.4.

[0019] Based on the same inventive concept, the present invention also provides a method for manufacturing a radio frequency switch, including:

[0020] Providing a substrate, the substrate having a control area, a clearance area, and a radio frequency area arranged in sequence along a first direction, and the clearance area extending along a second direction;

[0021] Forming a control device and a radio frequency device on the substrate, the control device and the radio frequency device being respectively located in the control area and the radio frequency area;

[0022] Forming a plurality of isolation structures and a dielectric layer on the substrate. The plurality of isolation structures are arranged side by side along the second direction on the substrate in the clearance area, and at least cover a part of the substrate in the clearance area in the first direction. The dielectric layer conformally covers the control device, the radio frequency device, and the remaining substrate in the clearance area. The dielectric constant of the dielectric layer is less than that of the isolation structure.

[0023] Optionally, the dielectric layer includes multiple stacked sub-dielectric layers, and the steps of forming the dielectric layer include:

[0024] Successively form sub-dielectric material layers on the substrate. After forming each sub-dielectric material layer, form a metal connecting member in the sub-dielectric material layer in the control region and the radio frequency region respectively. The multiple metal connecting members in the control region and the radio frequency region are stacked and electrically connected to form a first part and a second part respectively, and the first part and the second part lead out the control device and the radio frequency device respectively;

[0025] When forming any metal connecting member, a metal interconnection line is also formed synchronously. Both ends of the metal interconnection line extend to any metal connecting member that electrically connects the first part and the second part. The first part, the second part and the metal interconnection line constitute a metal interconnection structure; and,

[0026] Etch the sub-dielectric material layer outside the metal interconnection line on the clearance area to form several openings arranged side by side along the second direction and exposing the substrate. One remaining sub-dielectric material layer constitutes one sub-dielectric layer.

[0027] Optionally, the steps of forming the isolation structure include:

[0028] Form a nitride layer on the substrate, and the nitride layer conformally covers the top surface of the dielectric layer and the inner wall of the opening;

[0029] Form an isolation material layer in the opening, and the isolation material layer at least fills the opening. The isolation material layer in the opening constitutes the isolation structure.

[0030] Optionally, after forming the isolation structure, it further includes:

[0031] Perform ultraviolet irradiation on the isolation material layer.

[0032] The present invention provides a radio frequency switch and a manufacturing method thereof, including: a substrate having a control region, a clearance region, and a radio frequency region arranged in sequence along a first direction, wherein the clearance region extends along a second direction; a control device and a radio frequency device, respectively located on the substrate in the control region and the radio frequency region; a plurality of isolation structures arranged side by side in the second direction on the substrate in the clearance region; a dielectric layer located on the substrate and conformally covering the control device, the radio frequency device, and the remaining substrate in the clearance region, and the dielectric constant of the dielectric layer is greater than that of the isolation structure. The isolation structure can effectively isolate the signals emitted by the control device and the radio frequency device, reduce signal crosstalk, and the isolation structure can reduce the capacitive coupling effect between the control device and the radio frequency device, protect the control device from being burned by high voltage, and ensure the reliability of the performance of the radio frequency switch; at the same time, after introducing the isolation structure, the size of the clearance region can be appropriately reduced, thereby reducing the size of the radio frequency switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 FIG. is a flowchart of a manufacturing method of a radio frequency switch provided by an embodiment of the present invention;

[0034] Figures 2 to 6 FIG. is a schematic structural diagram corresponding to the corresponding steps of a manufacturing method of a radio frequency switch provided by an embodiment of the present invention, wherein, Figure 6 FIG. is a schematic structural diagram of the radio frequency switch provided by an embodiment of the present invention;

[0035] Wherein, the reference numerals are:

[0036] A - control region; B - radio frequency region; C - clearance region;

[0037] x - second direction; y - first direction;

[0038] 100 - substrate; 101 - control device; 102 - radio frequency device; 103 - metal connecting member; 104 - dielectric layer; 105 - opening; 106 - nitride layer; 107 - isolation material layer; 108 - isolation structure; 109 - sub-dielectric material layer; 110 - first part; 111 - second part; 112 - metal interconnection line. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will describe the specific embodiments of the present invention in more detail with reference to the schematic diagrams. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are all in a very simplified form and use non-precise scales, only for the purpose of facilitating and clearly assisting in explaining the purpose of the embodiments of the present invention.

[0040] In the following text, the terms "first", "second", etc. are used to distinguish between similar elements and are not necessarily used to describe a specific order or time sequence. It is understood that, where appropriate, these terms used in this way may be interchanged. Similarly, if the methods described herein include a series of steps, and the steps presented herein are not necessarily the only order in which these steps can be performed, and some of the described steps may be omitted and / or some other steps not described herein may be added to the method.

[0041] Figure 5 and Figure 6 FIG. is a schematic structural diagram of a radio frequency switch provided in this embodiment, where Figure 6 is Figure 5 a schematic cross-sectional structure diagram along the A - A' direction, as Figure 5 and Figure 6 shown, the radio frequency switch provided in this embodiment includes: a substrate 100, a dielectric layer 104, a plurality of isolation structures 108, and a metal interconnect structure.

[0042] Specifically, the substrate 100 has a control region A, a radio frequency region B, and a clearance region C arranged in sequence along the first direction y, the clearance region C extends along the second direction x, a control device 101 and a radio frequency device 102 are further arranged on the substrate 100, and the control device 101 and the radio frequency device 102 are respectively located in the control region A and the radio frequency region B; a plurality of the isolation structures 108 are arranged side by side on the substrate 100 in the clearance region C along the second direction x, and the isolation structures 108 at least cover a part of the substrate 100 in the clearance region C in the first direction y; the dielectric layer 104 is located on the substrate 100 and conformally covers the control device 101, the radio frequency device 102, and the remaining substrate 100 in the clearance region C.

[0043] Wherein, the dielectric constant of the dielectric layer 104 is greater than the dielectric constant of the isolation structure 108, the dielectric constant of the isolation structure 108 is 2.5 - 3.4, and the dielectric strength of the isolation structure 108 is 100 kV / mm - 300 kV / mm.

[0044] The metal interconnect structure includes a first part 110, a second part 111, and metal interconnect lines, as Figure 6 shown, the first part 110 and the second part 111 include a plurality of stacked metal connectors 103, and the first part 110 and the second part 111 are respectively located in the dielectric layer 104 on the control region A and the radio frequency region B, and are respectively electrically connected to the control device 101 and the radio frequency device 102 to lead out the control device 101 and the radio frequency device 102; as Figure 5As shown by the circle, the metal interconnect line is located within the dielectric layer 104 between the isolation structures 108, and both ends thereof extend to any metal connector 103 that is electrically connected to the first portion 110 and the second portion 111, so that the control device 101 is electrically connected to the RF device 102.

[0045] The RF device provided in this embodiment further includes: a nitride layer that conformally covers the bottom surfaces of the dielectric layer and the isolation structure.

[0046] In common RF switches, there is a large difference in the operating voltages between the control device 101 and the RF device 102. Especially in high-power RF switches, the operating voltage of the control device 101 is generally -2.5V to 2.5V, and the maximum operating voltage of the RF device 102 can reach 85V. When the RF device 102 and the control device 101 are operating, they will respectively emit RF signals and control signals. When the RF device 102 and the control device 101 are disposed on the same substrate 100, the control signal with strong negative voltage oscillation emitted by the control device 101 will cause serious crosstalk to the RF signal emitted by the RF device 102, damaging the RF signal and deteriorating the operating performance of the RF switch; at the same time, in high-power RF switches, the capacitive coupling effect between the control device 101 and the high-voltage RF device 102 is relatively strong, which may cause the control device to burn out.

[0047] The clearance area C between the control area A and the RF area B can reduce the crosstalk and capacitive coupling between the RF device 102 and the control device 101. However, since the dielectric layer 104 on the clearance area C is formed synchronously with the dielectric layer 104 in the control area A and the RF area B, the isolation effect of the dielectric layer 104 is relatively limited, and it is difficult to achieve effective isolation between the control signal and the RF signal. Moreover, the size of the clearance area C is generally 70μm to 150μm, and the relatively large size of the clearance area C is not conducive to reducing the size of the RF switch.

[0048] In this embodiment, the isolation structure 108 is provided in the clearance area C, and the dielectric constant of the isolation structure 108 is made smaller than that of the dielectric layer 104, so that the isolation structure 108 has a good isolation effect on the control signal and the RF signal, reducing signal crosstalk; increasing the dielectric strength of the isolation structure 108 can also improve the breakdown voltage performance of the RF switch and improve the reliability of the device.

[0049] In addition, continue to refer to Figure 6, after introducing the isolation structure 108, the size of the clearance area C can be appropriately reduced. In this embodiment, the width of the clearance area C in the first direction y is 35 μm to 100 μm. At the same time, in order to avoid damage to the control device 101 or the radio frequency device 102 when the isolation structure 108 is formed, the width of the isolation structure 108 in the first direction y is less than the width of the clearance area C, so as to keep a certain distance between the isolation structure 108 and the radio frequency device 102 and the control device 101. Preferably, the width of the isolation structure 108 in the first direction y is 50% to 80% of the width of the clearance area C in the first direction y.

[0050] Based on this, this embodiment also provides a manufacturing method of a radio frequency switch, Figure 1 which is a flowchart of the manufacturing method of the radio frequency switch. As Figure 1 shown, the manufacturing method of the radio frequency switch includes:

[0051] Step S1: Provide a substrate, which has a control area, a clearance area, and a radio frequency area arranged in sequence along the first direction, and the clearance area extends along the second direction;

[0052] Step S2: Form a control device and a radio frequency device on the substrate, and the control device and the radio frequency device are respectively located in the control area and the radio frequency area;

[0053] Step S3: Form a plurality of isolation structures and a dielectric layer on the substrate. The plurality of isolation structures are arranged side by side in the second direction on the substrate of the clearance area, and at least cover a part of the substrate of the clearance area in the first direction. The dielectric layer conformally covers the control device, the radio frequency device, and the remaining substrate of the clearance area, and the dielectric constant of the dielectric layer is less than the dielectric constant of the isolation structure.

[0054] Figures 2 to 6 It is a schematic structural diagram corresponding to the corresponding steps of a manufacturing method of a radio frequency switch provided in this embodiment. The following combines the attached Figures 2 to 6 to describe in more detail the manufacturing method of a radio frequency switch provided in this embodiment, in which the preferred embodiment of the present invention is illustrated.

[0055] Figure 3 is Figure 2 a schematic cross-sectional structure diagram along the A - A' direction. As Figures 2 to 3As shown, a substrate 100 is provided. The substrate 100 has a control region A, a radio frequency region B, and a clearance region C arranged in sequence along the first direction y. The clearance region C extends along the second direction x. A control device 101 and a radio frequency device 102 are formed on the substrate 100. The control device 101 and the radio frequency device 102 are respectively located in the control region A and the radio frequency region B.

[0056] A plurality of sub-dielectric material layers 109 are sequentially formed on the substrate 100. The sub-dielectric material layers 109 cover the control device 101, the radio frequency device 102, and the substrate 100. After each sub-dielectric material layer 109 is formed, the sub-dielectric material layer 109 is etched and metal connectors 103 are respectively formed in the sub-dielectric material layers 109 in the control region A and the radio frequency region B. Among them, the metal connectors 103 on the control device 101 and the radio frequency device 102 are stacked and electrically connected to form a first part 110 and a second part 111. The first part 110 and the second part 111 are respectively electrically connected to the control device 101 and the radio frequency device 102, and respectively lead out the control device 101 and the radio frequency device 102.

[0057] When forming any of the metal connectors 103, a metal interconnection line 112 is also synchronously formed. As Figure 2 shown, both ends of the metal interconnection line 112 extend to electrically connect the first part 110 and the second part 111. The first part 110, the second part 111, and the metal interconnection line 112 constitute a metal interconnection structure. It should be understood that the metal interconnection line 112 is located in the sub-dielectric material layer 109, Figure 2 only showing the connection relationship between the metal interconnection line 112 and the first part 110 and the second part 111.

[0058] After forming the metal interconnection structure, a passivation layer can also be formed on the sub-dielectric material layer 109. The passivation layer conformally covers the metal interconnection structure and the sub-dielectric material layer 109 to prevent subsequent processes from damaging the surface of the metal interconnection structure.

[0059] As Figure 4 shown, the sub-dielectric material layer outside the metal interconnection line on the clearance region C is etched, and a plurality of openings 105 are formed in the sub-dielectric material layer on the clearance region C. The plurality of openings 105 are arranged side by side along the second direction x and expose the substrate 100. One remaining sub-dielectric material layer constitutes one sub-dielectric layer, and all the sub-dielectric layers are stacked to form a dielectric layer 104. In other alternative embodiments, the opening 105 can extend into the substrate 100.

[0060] As shown Figures 5 to 6 in FIG. 1, a nitride layer 106 is formed on the substrate 100, and the nitride layer 106 covers the dielectric layer 104 and the inner wall of the opening 105. Then, an isolation material layer 107 is formed in the opening 105, and the isolation material layer 107 at least fills the opening 105. In this embodiment, the isolation material layer 107 fills the opening 105 and extends to cover the nitride layer 106. Further, ultraviolet light irradiation is performed on the isolation material layer 107 to cure the isolation material layer 107, so as to further stabilize the performance of the isolation material layer 107. The isolation material layer 107 in the opening 105 constitutes an isolation structure 108. As shown Figure 5 in FIG. 2, a plurality of the isolation structures 108 are arranged in parallel along the second direction x on the substrate 100 in the clearance area C. Figure 5 Metal interconnections are formed in the dielectric layer 104 circled by the circle in FIG. 3.

[0061] Among them, the dielectric constant of the isolation material layer 107 is 2.5 to 3.4, and the dielectric strength of the isolation material layer 107 is 100 kV / mm to 300 kV / mm. The material of the isolation material layer can be polyimide. The temperature during ultraviolet light irradiation is 350 °C to 400 °C.

[0062] Since the material of the dielectric layer 104 is generally silicon oxide, and the dielectric constant of silicon oxide is generally about 4, the isolation material layer 107 has a smaller dielectric constant than the dielectric layer 104. Therefore, the isolation structure 108 can effectively isolate the signals emitted by the control device 101 and the radio frequency device 102, and reduce signal crosstalk. Moreover, the isolation structure 108 has good high-voltage resistance performance, and can better protect the control device 101 from the influence of the high voltage of the radio frequency device 102. After introducing the isolation structure 108, the size of the clearance area C can be appropriately reduced, and then the size of the radio frequency switch can be reduced.

[0063] In addition, since the isolation material layer 107 has good insulation performance, the isolation material layer 107 on the silicon nitride 106 can further protect the radio frequency switch from external corrosion, and further ensure the service life and performance reliability of the radio frequency switch.

[0064] In summary, the embodiment of the present invention provides a radio frequency switch and a preparation method thereof, including: a substrate 100, the substrate 100 has a control region A, a radio frequency region B, and a clearance region C arranged in sequence along the first direction y, and the clearance region C extends along the second direction x; a control device 101 and a radio frequency device 102, both located on the substrate 100 and respectively located in the control region A and the radio frequency region B; a plurality of isolation structures 108, arranged side by side along the second direction x on the substrate 100 of the clearance region C, and the isolation structures 108 at least cover a part of the substrate 100 of the clearance region C in the first direction y; a dielectric layer 104, located on the substrate 100 and conformally covering the control device 101, the radio frequency device 102, and the remaining substrate 100 of the clearance region C, and the dielectric constant of the dielectric layer 104 is greater than the dielectric constant of the isolation structures 108. The isolation structures 108 can effectively isolate the signals emitted by the control device 101 and the radio frequency device 102, reduce signal crosstalk, and the isolation structures 108 can reduce the capacitive coupling effect between the control device 101 and the radio frequency device 102, protect the control device 101 from being burned by high voltage, and ensure the reliability of the performance of the radio frequency switch; at the same time, after introducing the isolation structures 108, the size of the clearance region C can be reduced, and then the size of the radio frequency switch can be reduced.

[0065] The above is only the preferred embodiment of the present invention and does not impose any limitation on the present invention. Any person skilled in the art, without departing from the technical solution of the present invention, makes any form of equivalent replacement or modification and other changes to the technical solution and technical content disclosed by the present invention, which are all within the content of the technical solution of the present invention and still fall within the protection scope of the present invention.

Claims

1. A radio frequency switch, characterized in that, Comprising: A substrate having a control region, a clearance region, and a radio frequency region arranged in sequence along a first direction, wherein the clearance region extends along a second direction; A control device and a radio frequency device, both located on the substrate and respectively located in the control region and the radio frequency region; A plurality of isolation structures arranged side by side along the second direction on the substrate of the clearance region and at least covering a part of the substrate of the clearance region in the first direction; A dielectric layer located on the substrate and conformally covering the control device, the radio frequency device, and the remaining substrate of the clearance region, the dielectric constant of the dielectric layer being greater than the dielectric constant of the isolation structure. Wherein, the dielectric layer includes multiple stacked sub-dielectric layers, and the steps of forming the dielectric layer include: Successively forming sub-dielectric material layers on the substrate. After forming each sub-dielectric material layer, a metal connection member is respectively formed in the sub-dielectric material layer of the control region and the radio frequency region. The multiple metal connection members in the control region and the radio frequency region are stacked and electrically connected to respectively form a first part and a second part, and the first part and the second part respectively lead out the control device and the radio frequency device; When forming any one of the metal connection members, a metal interconnection line is also synchronously formed. Both ends of the metal interconnection line respectively extend to electrically connect any one of the metal connection members that electrically connect the first part and the second part. The first part, the second part, and the metal interconnection line constitute a metal interconnection structure; and, Etching the sub-dielectric material layer outside the metal interconnection line on the clearance region to form a plurality of openings arranged side by side along the second direction and exposing the substrate. One remaining sub-dielectric material layer constitutes one sub-dielectric layer; The steps of forming the isolation structure include: Forming a nitride layer on the substrate, the nitride layer conformally covering the top surface of the dielectric layer and the inner wall of the opening; Forming an isolation material layer in the opening, the isolation material layer at least filling the opening, and the isolation material layer in the opening constitutes the isolation structure.

2. The RF switch according to claim 1, wherein Further comprising: A metal interconnection structure including a first part, a second part, and a metal interconnection line. The first part and the second part both include multiple stacked metal connection members, and the first part and the second part are respectively located in the dielectric layer of the control region and the radio frequency region and respectively lead out the control device and the radio frequency device; The metal interconnection line is located in the dielectric layer between the isolation structures, and both ends respectively extend to electrically connect any one of the metal connection members that electrically connect the first part and the second part.

3. The RF switch according to claim 1, characterized in that, The width of the clearance region in the first direction is 35μm to 100μm.

4. The RF switch according to claim 1 or 3, characterized in that, The width of the isolation structure in the first direction is 50% to 80% of the width of the clearance region in the first direction.

5. The RF switch according to claim 1, wherein Further comprising: A nitride layer conformally covering the bottom surface of the dielectric layer and the isolation structure.

6. The RF switch according to claim 1, wherein The dielectric constant of the isolation structure is 2.5 to 3.

4.

7. A preparation method of a radio frequency switch, characterized in that Comprising: A substrate is provided, which has a control region, a clearance region, and a radio frequency region arranged in sequence along a first direction, and the clearance region extends along a second direction; A control device and a radio frequency device are formed on the substrate, and the control device and the radio frequency device are respectively located in the control region and the radio frequency region; A plurality of isolation structures and a dielectric layer are formed on the substrate. The plurality of isolation structures are arranged side by side along the second direction on the substrate in the clearance region, and at least cover a part of the substrate in the clearance region in the first direction. The dielectric layer conformally covers the control device, the radio frequency device, and the remaining substrate in the clearance region. The dielectric constant of the dielectric layer is greater than that of the isolation structure. The dielectric layer includes a plurality of stacked sub-dielectric layers. The step of forming the dielectric layer includes: Sub-dielectric material layers are sequentially formed on the substrate. After each sub-dielectric material layer is formed, a metal connection member is respectively formed in the sub-dielectric material layer in the control region and the radio frequency region. The plurality of metal connection members in the control region and the radio frequency region are stacked and electrically connected to respectively form a first part and a second part, and the first part and the second part respectively lead out the control device and the radio frequency device; When forming any one of the metal connection members, a metal interconnection line is also synchronously formed. Two ends of the metal interconnection line respectively extend to any one of the metal connection members that electrically connect the first part and the second part. The first part, the second part, and the metal interconnection line constitute a metal interconnection structure; and, Etch the sub-dielectric material layer outside the metal interconnection line in the clearance region to form a plurality of openings that are arranged side by side along the second direction and expose the substrate. One remaining sub-dielectric material layer constitutes one sub-dielectric layer. The step of forming the isolation structure includes: A nitride layer is formed on the substrate, and the nitride layer conformally covers the top surface of the dielectric layer and the inner wall of the opening; An isolation material layer is formed in the opening, and the isolation material layer at least fills the opening. The isolation material layer in the opening constitutes the isolation structure.

8. The manufacturing method of the radio frequency switch according to claim 7, characterized in that, After forming the isolation structure, it further includes: Ultraviolet irradiation is performed on the isolation material layer.

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