A radio frequency switch device based on phase change material and a method for manufacturing the same

Abstract

The application discloses a radio frequency switch device based on a phase change material and a preparation method thereof, and belongs to the technical field of radio frequency switches; the device comprises, from bottom to top, a substrate layer, a substrate isolation layer, an electrode layer, a phase change material layer and a phase change isolation layer; the electrode layer comprises a radio frequency electrode and a phase change operation electrode located on the same plane; electrode tips of a radio frequency input electrode and a radio frequency output electrode of the radio frequency electrode are respectively connected to opposite two ends of the phase change material layer to form a radio frequency transmission path; electrode tips of a phase change operation positive electrode and a phase change operation negative electrode are respectively connected to the other opposite two ends of the phase change material layer to form a phase change operation path; and the opening and closing of the radio frequency transmission path are controlled by controlling the resistance state of the phase change material layer on the phase change operation path. The application can reduce the parasitic capacitance between the radio frequency electrode and the phase change operation electrode; in addition, the application has a simple structure and can realize a radio frequency switch device with lower parasitic capacitance at a lower process difficulty.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of radio frequency switch, more particularly, relates to a radio frequency switch device based on phase change material and a preparation method thereof. BACKGROUND

[0002] Radio frequency switches and switching networks are widely used as basic components in satellite payloads and wireless communication systems for controlling the transmission of radio frequency signals; with the gradual development of wireless communication networks, the importance of radio frequency switches is increasingly prominent.

[0003] The existing radio frequency switches mainly have two types, semiconductor device type and micro-electromechanical system type, but both have certain problems, the semiconductor type radio frequency switch has problems such as high insertion loss, low power handling capacity, etc.; the micro-electromechanical system type cannot lock the switch state, has large size, reliability, etc. The phase change radio frequency switch is prepared based on phase change material, does not have static power consumption for maintaining the switch state, is compatible with COMS process, and has advantages in switch speed, switch ratio, durability, insertion loss, isolation and other aspects.

[0004] The existing phase change radio frequency switch device mainly has two types, two-terminal device type and four-terminal device type. Among them, the phase change operation electrode and the radio frequency transmission electrode of the two-terminal device are the same group of electrodes, but the selection of the heating electrode metal requires high thermal stability, and the radio frequency transmission electrode requires excellent signal transmission performance, so the two-terminal device cannot balance the thermal stability and signal transmission performance. In order to solve the above problems, the four-terminal device uses radio frequency transmission electrodes and phase change heating electrodes, but the existing four-terminal device will form an overlap between the phase change operation electrode and the radio frequency transmission electrode in space whether using indirect heating or direct heating, which will produce a non-negligible parasitic capacitance, mostly distributed in the order of 1-10fF, or even larger, and the process difficulty of the existing four-terminal device is high, the process cost is high, and it is difficult to realize actual mass production in the market. SUMMARY

[0005] In view of the above defects or improvement needs of the prior art, the present application provides a radio frequency switch device based on phase change material and a preparation method thereof, to solve the technical problem that the prior art cannot realize a radio frequency switch device with lower parasitic capacitance at lower process difficulty.

[0006] In order to achieve the above purpose, the present application provides a radio frequency switch device based on phase change material, comprising: a substrate layer, a substrate isolation layer, an electrode layer, a phase change material layer and a phase change isolation layer arranged in sequence from bottom to top;

[0007] The electrode layer includes a radio frequency electrode and a phase change operation electrode on the same plane; the radio frequency electrode includes a signal transmission electrode and a common electrode;

[0008] The signal transmission electrode comprises a radio frequency input electrode and a radio frequency output electrode; the electrode tips of the radio frequency input electrode and the radio frequency output electrode are connected to opposite ends of the phase change material layer respectively, forming a radio frequency transmission path;

[0009] The phase change operation electrode comprises a phase change operation positive electrode and a phase change operation negative electrode; the electrode tips of the phase change operation positive electrode and the phase change operation negative electrode are connected to the other opposite ends of the phase change material layer respectively, forming a phase change operation path;

[0010] The phase change operation electrode is used to control the resistance state of the phase change material layer on the phase change operation path to control the open and close state of the radio frequency transmission path.

[0011] Further preferably, the radio frequency transmission path and the phase change operation path are perpendicular to each other.

[0012] Further preferably, the materials of the radio frequency electrode and the phase change operation electrode are different.

[0013] Further preferably, the material of the radio frequency electrode is one or more of copper, gold and aluminum.

[0014] Further preferably, the material of the phase change operation electrode is one or more of tungsten, tantalum, nickel and chromium.

[0015] Further preferably, the phase change isolation layer covers the phase change material layer; the area of the phase change isolation layer is larger than the area of the phase change material layer.

[0016] Further preferably, the material of the substrate layer is one or more of Si, SiC, GaAs and sapphire.

[0017] Further preferably, the material of the substrate isolation layer is one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride and silicon carbide.

[0018] Further preferably, the material of the phase change material layer is one or more of GeTe, Ge2Se2Te5 and Sb2Te3.

[0019] In a second aspect, the present application provides a preparation method of the above-mentioned radio frequency switch device, comprising the following steps:

[0020] S1, preparing a substrate isolation layer on a substrate;

[0021] S2, preparing an electrode layer on the substrate isolation layer;

[0022] S3, preparing a phase change material layer on the upper surface of the sample obtained in step S2;

[0023] S4, preparing a phase change isolation layer on the upper surface of the phase change material layer, thereby obtaining the above-mentioned radio frequency switch device.

[0024] In summary, the above-described technical solutions conceived in this invention can achieve the following beneficial effects:

[0025] 1. This invention provides a radio frequency (RF) switch device based on phase change materials (PCM), wherein the RF electrode and the PCM operating electrode are fabricated on the same plane, effectively reducing the parasitic capacitance between the RF electrode and the PCM operating electrode. Simultaneously, the PCM layer is directly connected to the PCM operating electrode, avoiding the capacitance structure generated by a dielectric layer between the PCM layer and the PCM operating electrode. Furthermore, the RF switch device provided by this invention has a simple structure, greatly simplifying the manufacturing process of four-terminal devices, reducing process costs, and enhancing the market compatibility of the device. Therefore, this invention can achieve an RF switch device with lower parasitic capacitance with lower process difficulty.

[0026] 2. In the radio frequency switching device based on phase change material provided by the present invention, the radio frequency electrode and the phase change operating electrode are made of different metal materials. The radio frequency electrode is made of a metal material with good radio frequency signal transmission performance, and the phase change operating electrode is made of a metal material with good thermal stability. This solves the trade-off between heating efficiency and radio frequency transmission performance caused by electrode selection, and can take into account both thermal stability and signal transmission performance. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the longitudinal interface of a radio frequency switch device based on phase change materials provided in Embodiment 1 of the present invention;

[0028] Figure 2 This is a schematic cross-sectional view of a radio frequency switch device based on phase change materials provided in Embodiment 1 of the present invention;

[0029] Figure 3 This is a longitudinal cross-sectional schematic diagram of an existing four-terminal phase-change radio frequency switch device provided by the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Example 1

[0032] A schematic diagram of the longitudinal interface of a radio frequency switching device based on phase change material is shown below. Figure 1 As shown, it includes: a substrate layer 1, a substrate isolation layer 2, an electrode layer, a phase change material layer 5, and a phase change isolation layer 6 arranged sequentially from bottom to top;

[0033] Specifically, a schematic view of a lateral cross section of the radio frequency switch device is shown in FIG. 1. Figure 2 As shown, the electrode layer includes a radio frequency electrode and a phase change operation electrode in the same plane, and there is no spatial overlap in the direction perpendicular to the upper surface of the substrate isolation layer;

[0034] The radio frequency electrode includes a signal transmission electrode and a common electrode 3-1; the signal transmission electrode includes a radio frequency input electrode 3-2 and a radio frequency output electrode 3-3; the electrode tips of the radio frequency input electrode 3-2 and the radio frequency output electrode 3-3 are respectively connected to opposite ends of the phase change material layer 5, forming a radio frequency transmission path;

[0035] The phase change operation electrode includes a phase change operation positive electrode 4-1 and a phase change operation negative electrode 4-2; the electrode tips of the phase change operation positive electrode 4-1 and the phase change operation negative electrode 4-2 are respectively connected to the other opposite ends of the phase change material layer 5, forming a phase change operation path;

[0036] The present application uses the performance of the phase change material to realize the on and off states in the radio frequency transmission process, and controls the resistance state of the phase change material layer 5 on the phase change operation path by applying a voltage to the phase change operation electrode to heat the phase change material layer on the phase change operation path, thereby controlling the on-off state of the radio frequency transmission path;

[0037] The area of the phase change isolation layer is larger than the area of the phase change material layer, which can cover the entire phase change material layer and part of the radio frequency electrode and the phase change operation electrode, and is used to isolate the phase change material layer from the external environment, prevent the phase change material layer from contacting the external environment, and increase the heating efficiency.

[0038] Preferably, the radio frequency transmission path and the phase change operation path are perpendicular to each other.

[0039] Preferably, the materials of the radio frequency electrode and the phase change operation electrode are different; the radio frequency electrode is selected from a metal material with good radio frequency signal transmission performance, such as one or more of copper, gold, and aluminum; the phase change operation electrode is selected from a metal material with good thermal stability, such as one or more of tungsten, tantalum, nickel, and chromium.

[0040] Optionally, the substrate layer can be one or more of Si, SiC, GaAs, and sapphire with a thickness greater than 1000 μm.

[0041] Optionally, the substrate isolation layer can be any one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, and silicon carbide with a thickness of 300 nm, which is grown by magnetron sputtering or vapor deposition PECVD.

[0042] Optionally, the material of the phase change material layer is one or more of GeTe, Ge2Se2Te5, Sb2Te3, or a single substance or a dopant thereof.

[0043] In summary, the radio frequency electrode and the phase change operation electrode in the application are prepared on the same substrate isolation layer, and there is no overlap between any electrode in the vertical direction of the radio frequency signal transmission, which effectively reduces the off-state parasitic capacitance. Compared with the traditional two-terminal phase change radio frequency switch device, the application adopts a four-terminal device to effectively improve the radio frequency transmission performance. Compared with the existing four-terminal device, the radio frequency electrode and the phase change operation electrode in the application are prepared in the same plane, which effectively reduces the off-state parasitic capacitance, increases the isolation degree, simplifies the process difficulty, and effectively reduces the process cost.

[0044] Embodiment 2,

[0045] The embodiment provides a preparation method of the radio frequency switch device provided in Embodiment 1, and the method comprises the following steps:

[0046] S1, a substrate isolation layer is prepared on a substrate to obtain a first sample; specifically, in an optional embodiment, a thickness of 300 nm of any one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, and silicon carbide is grown on the substrate by magnetron sputtering or vapor deposition to obtain the first sample.

[0047] S2, an electrode layer is prepared on the substrate isolation layer; wherein the electrode layer comprises a radio frequency electrode and a phase change operation electrode in the same plane.

[0048] In the embodiment, the radio frequency electrode is any one or more of copper, gold, and aluminum grown by magnetron sputtering or electron beam evaporation; and the phase change operation electrode is any one or more of tungsten, tantalum, nickel, and chromium grown by magnetron sputtering or electron beam evaporation.

[0049] It should be noted that the preparation sequence of the radio frequency electrode and the phase change operation electrode is not limited, and the embodiment is described as follows: the radio frequency electrode is prepared first, and then the phase change operation electrode is prepared.

[0050] Specifically, in an optional embodiment, the process of preparing the radio frequency electrode on the substrate isolation layer comprises the following steps: the topography of the radio frequency electrode is photoetched on the surface of the substrate isolation layer of the first sample, the electrode is grown by magnetron sputtering or evaporation, and then a stripping process is performed to obtain a complete radio frequency electrode and obtain a second sample. In another optional embodiment, the electrode is grown on the surface of the substrate isolation layer of the first sample by magnetron sputtering or evaporation, and then a photoetching and etching process is performed, and then stripping is performed to also obtain a complete radio frequency electrode and obtain a second sample. Optionally, the radio frequency electrode is gold with a thickness of 50 nm.

[0051] The process of preparing the phase-change operating electrode on the substrate isolation layer is: as an optional embodiment, the specific steps are: growing the electrode on the second sample by magnetron sputtering or evaporation, and then performing a stripping process to obtain a complete phase-change operating electrode, thereby obtaining a third sample. As another optional embodiment, the electrode is grown on the second sample by magnetron sputtering or evaporation, and then a photolithography and etching process is performed, and then stripping is performed, so that a complete phase-change operating electrode can also be obtained, thereby obtaining a third sample. Optionally, the phase-change operating electrode is tungsten with a thickness of 50 nm.

[0052] S3, preparing a phase-change material layer on the upper surface of the sample obtained in step S2;

[0053] As an optional embodiment, the specific steps are: performing photolithography on the third sample to obtain a designed phase-change material layer pattern, generating the phase-change material layer by magnetron sputtering or atomic layer deposition, and then stripping to obtain a phase-change material layer with a designed size, thereby obtaining a fourth sample. As another optional embodiment, the specific steps are: generating the phase-change material layer by magnetron sputtering or atomic layer deposition, and then performing a photolithography and etching step to obtain a phase-change material layer with a designed size, thereby obtaining a fourth sample. Optionally, the phase-change material layer is one or more of GeTe, Ge2Se2Te5, and Sb2Te3 in a pure substance or a dopant with a thickness of 100 nm.

[0054] S4, preparing a phase-change isolation layer on the upper surface of the phase-change material layer, thereby obtaining the radio frequency switch device.

[0055] As an optional embodiment, the specific steps are: performing photolithography on the fourth sample to obtain a designed phase-change isolation layer pattern, generating the isolation layer material by sputtering or vapor deposition, and then stripping to expose the operation area of the electrode layer, thereby obtaining a fifth sample, i.e., the radio frequency switch device in embodiment 1. As another optional embodiment, the isolation layer material can be generated by sputtering or vapor deposition, and then a photolithography and etching step is performed to expose the operation area of the electrode layer, thereby obtaining a fifth sample, i.e., the radio frequency switch device in embodiment 1. Optionally, the phase-change isolation layer is any one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, and silicon carbide with a thickness of 100 nm, and the specific function is to isolate the phase-change material layer from the external environment, prevent the phase-change material layer from contacting the external environment, and increase the heating efficiency.

[0056] It should be noted that, as Figure 3The longitudinal sectional schematic view of a prior art four-terminal phase change radio frequency switch device is shown, and it can be seen from the figure that the electrodes of the prior art four-terminal device have electrode overlap in the direction perpendicular to the radio frequency signal transmission direction, and the phase change heating electrode is located below or above the radio frequency transmission electrode, thereby inevitably introducing parasitic capacitance between the two electrodes, and the crystallized phase change material layer increases this parasitic capacitance, and the size of the parasitic capacitance can be calculated by a simplified parallel plate capacitance formula C = εS / (4πkd). The electrodes used in the present application are all prepared in the same plane, effectively reducing the parasitic capacitance between the radio frequency electrode and the phase change operation electrode; and the phase change material layer is directly connected to the phase change operation electrode, avoiding the generation of the capacitance structure due to the medium layer between the phase change material layer and the phase change operation electrode. The parameters of the parasitic capacitance calculation formula in the radio frequency transmission direction of the present application correspond to d, which is the distance between the radio frequency input electrode and the radio frequency output electrode, S is the product of the thickness of the signal transmission electrode and the width of the signal transmission electrode tip, and through calculation verification, the parasitic capacitance of the phase change radio frequency switch device prepared according to the embodiment based on the present application is 0.01 fF order, while the parasitic capacitance of other four-terminal devices is 1-10 fF order or even larger. In addition, the design of the present application simplifies the manufacturing process of the four-terminal device, reduces the process cost, and enhances the market compatibility of the device.

[0057] In summary, the phase change operation electrode and the radio frequency electrode of the present application use different metal materials respectively, and the two electrodes are prepared in the same plane, thereby avoiding the parasitic capacitance of different electrodes in the spatial stacking direction, increasing the off-state isolation, solving the electrode compromise problem existing in the current two-terminal phase change radio frequency switch and the parasitic capacitance problem existing in the four-terminal phase change radio frequency switch, and at the same time, reducing the process difficulty of the four-terminal device, reducing the process cost and being beneficial to realize mass production.

[0058] Those skilled in the art will readily understand that the above description is only a preferred embodiment of the present application and is not intended to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A radio frequency switching device based on a phase change material, characterized in that, The application relates to a radio frequency switch device. The device comprises a substrate layer, a substrate isolation layer, an electrode layer, a phase change material layer and a phase change isolation layer arranged in sequence from bottom to top. The electrode layer comprises a radio frequency electrode and a phase change operation electrode in the same plane; the radio frequency electrode comprises a signal transmission electrode and a common electrode; the common electrode and the signal transmission electrode are in the same plane and annularly surround the signal transmission electrode and the phase change operation electrode. The signal transmission electrode comprises a radio frequency input electrode and a radio frequency output electrode; the electrode tips of the radio frequency input electrode and the radio frequency output electrode are oppositely arranged and respectively connected to opposite ends of the phase change material layer to form a radio frequency transmission path. The phase change operation electrode comprises a phase change operation positive electrode and a phase change operation negative electrode; the electrode tips of the phase change operation positive electrode and the phase change operation negative electrode are oppositely arranged and respectively connected to the other opposite ends of the phase change material layer to form a phase change operation path. The radio frequency transmission path and the phase change operation path are perpendicular to each other. The phase change material layer completely covers the area surrounded by the electrode tips of the radio frequency input electrode, the phase change operation positive electrode, the radio frequency output electrode and the phase change operation negative electrode. There is a spacing space between the signal transmission electrode and the phase change operation electrode. The phase change operation electrode is used for controlling the resistance state of the phase change material layer on the phase change operation path to control the opening and closing state of the radio frequency transmission path.

2. The radio frequency switching device of claim 1, wherein, The materials of the radio frequency electrode and the phase change operation electrode are different.

3. The radio frequency switching device of claim 2, wherein, The material of the radio frequency electrode is one or more of copper, gold and aluminum.

4. The radio frequency switching device of claim 2, wherein, The material of the phase change operation electrode is one or more of tungsten, tantalum, nickel and chromium.

5. The radio frequency switching device of any of claims 1-4, wherein, The phase change isolation layer covers the phase change material layer; the area of the phase change isolation layer is larger than that of the phase change material layer.

6. The radio frequency switching device of any of claims 1-4, wherein, The material of the substrate layer is one or more of Si, SiC, GaAs and sapphire.

7. The radio frequency switching device of any of claims 1-4, wherein, The material of the substrate isolation layer is one or more of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride and silicon carbide.

8. The radio frequency switching device of any of claims 1-4, wherein, The material of the phase change material layer is one or more of GeTe, Ge2Se2Te5 and Sb2Te3.

9. A preparation method of the radio frequency switch device according to any one of claims 1-8, comprising the following steps: S1, preparing a substrate isolation layer on a substrate; S2, preparing an electrode layer on the substrate isolation layer; S3, preparing a phase change material layer on the upper surface of the sample obtained in the step S2; S4, preparing a phase change isolation layer on the upper surface of the phase change material layer to obtain the radio frequency switch device.

Images