Phase change radio frequency switch, preparation method thereof and wireless communication device

Abstract

The invention discloses a phase change radio frequency switch and a preparation method thereof and a wireless communication device, the phase change radio frequency switch comprises a substrate, a resistance region and a phase change region, a first region is formed at one side of the substrate, a resistance layer is arranged at the first region of the substrate, a phase change layer is arranged at one side, far away from the substrate, of the resistance layer, and the phase change region is arranged at the other side of the substrate. The impedance of the resistive layer to radio frequency signals is R1, R1 is larger than or equal to 800 ohms and smaller than or equal to 2000 ohms, the impedance of the resistive layer to direct current signals is R2, and R2 is larger than or equal to 3 ohms and smaller than or equal to 20 ohms. The phase-change material is heated by adopting a mode of directly heating the resistive layer, so that the heat transfer is faster, the heating efficiency is higher, the phase-change material can be crystallized and non-crystallized in a shorter time, and the switching speed of the switch is improved. The high-impedance thin-film resistor material is directly contacted with the phase-change material, so that the parasitic capacitance can be reduced, and the off-state isolation of the radio frequency switch is improved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a phase-change radio frequency switch and a preparation method thereof, and a wireless communication device. Background Art

[0002] In modern wireless communication systems, such as satellites, radars, mobile communications, electronic countermeasures, etc., RF modules are widely used as essential front-end components. With the rapid development of millimeter wave (MMW) technology, the demand for RF switches has become more diversified. Phase change RF switches have shown unparalleled advantages and application potential since their birth.

[0003] Most existing RF switches have a dielectric layer between the phase change material and the thin film resistor material. A parasitic capacitor is formed between the phase change layer and the thin film resistor layer, which deteriorates the off-state isolation of the RF switch. In addition, the phase change material has low thermal efficiency and a slow switching rate. Summary of the invention

[0004] The main purpose of this application is to propose a phase change radio frequency switch and its preparation method and wireless communication device, aiming to improve the problems in the prior art such as reduced thermal efficiency of thin film materials, slow switching speed, and formation of a parasitic capacitance between the phase change layer and the thin film resistor layer, which deteriorates the off-state isolation of the radio frequency switch.

[0005] To achieve the above objectives, the present application proposes a phase change radio frequency switch, comprising:

[0006] a substrate having a first region formed on one side thereof;

[0007] a resistance layer disposed in the first region of the substrate; and

[0008] A phase change layer is provided on a side of the resistance layer away from the substrate;

[0009] The impedance of the resistance layer to the radio frequency signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistance layer to the direct current signal is R2, 3Ω≤R2≤20Ω.

[0010] By heating the phase change material directly through the resistor layer, the heat transfer is faster and the heating efficiency is higher, which can make the phase change material crystallize and amorphize in a shorter time, thereby improving the switching speed of the switch. The use of high-impedance thin-film resistor material in direct contact with the phase change material can reduce parasitic capacitance, thereby improving the off-state isolation of the RF switch. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0012] Figure 1 The following are a cross-sectional view (a) and a structural schematic view (b) of a phase-change radio frequency switch in the prior art;

[0013] Figure 2 The cross-sectional view of the phase change radio frequency switch in the prior art of the present application (a), the crystal filaments formed during the crystallization process (b), and the schematic diagram of the amorphization of part of the crystal filaments during the amorphization process (c);

[0014] Figure 3 A cross-sectional view of a phase-change radio frequency switch according to an embodiment of the present application;

[0015] Figure 4 This is a working principle diagram of a phase change radio frequency switch according to an embodiment of the present application;

[0016] Figure 5 A cross-sectional view of a phase-change radio frequency switch according to an embodiment of the present application;

[0017] Figure 6 for Figure 5 Equivalent circuit diagram of phase change RF switch;

[0018] Figure 7 This is a flow chart of a method for preparing a phase-change radio frequency switch according to an embodiment of the present application;

[0019] Figure 8 The present invention is a schematic diagram of a process flow of a method for preparing a phase-change radio frequency switch according to an embodiment of the present application.

[0020] Description of reference numerals:

[0021] 100 phase change radio frequency switch; 1 substrate; 2 resistance layer; 3 phase change layer; 4 first metal conductive layer; 5 dielectric layer; 6 second metal conductive layer; 7 passivation layer; 8 isolation layer. DETAILED DESCRIPTION

[0022] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conditions recommended by the normal conditions or the manufacturers. If the reagents or instruments used do not specify the manufacturer, they are all conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, taking "A and / or B" as an example, including scheme A, or scheme B, or schemes that A and B meet at the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of the technical solutions is contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist, and is not within the scope of protection required by the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0023] In modern wireless communication systems, such as satellites, radars, mobile communications, electronic countermeasures, etc., RF modules are widely used as essential front-end components. With the rapid development of millimeter wave (MMW) technology, the demand for RF switches has become more diversified.

[0024] In addition to the high on-off ratio, RF switches also require low on-resistance, low off-capacitance, fast switching speed, high RF power capacity, high linearity, low power consumption, and miniaturization. Since RF systems are often implemented in modern designs through integrated circuits, the compatibility of RF switches with standard complementary metal oxide semiconductor (CMOS) processes is also an important factor to consider. Since its birth, phase change RF switches have shown unparalleled advantages and application potential, with low on-state insertion loss, large on-off resistance ratio, high off-state isolation, high cut-off frequency, high power capacity, good linearity, high reliability, and miniaturization. In addition, due to the compatibility of phase change RF switches and CMOS processes, they are very easy to be integrated with other processes in a monolithic or heterogeneous manner, which is very attractive for the design and installation of reconfigurable RF devices. In addition, based on the non-volatility of phase change materials, phase change switches can achieve static zero power consumption, that is, no DC power is required to maintain the switching state. The above characteristics make phase change switches have great potential and market in the application field of millimeter wave multi-port reconfigurable RF devices and subsystems.

[0025] like Figure 1As shown, most of the existing phase change RF switches 100 are provided with a dielectric layer 5 between the phase change layer 3 and the resistor layer 2. When heated, the heat needs to be transferred to the phase change material of the phase change layer 3 through the insulating material of the resistor layer 2. There will be heat loss during the transfer process, which reduces the thermal efficiency of the thin film material of the resistor layer 2. The switching time of the switch under the same conditions is relatively long, that is, the switching speed of the switch is slow. Due to the presence of the dielectric layer 5, a parasitic capacitance is formed between the phase change layer 3 and the resistor layer 2 in the off state, which makes the off-state isolation of the phase change RF switch 100 worse.

[0026] like Figure 2 As shown, in the existing phase-change RF switch 100, a vertical two-port device that directly heats the phase-change material is designed to have a vertical structure, with two upper and lower electrodes, and a DC pulse is applied to the phase-change material, and the heat generated by the phase-change material is used to cause the material to undergo a phase change, thereby realizing the switching function of the device. However, when in the on state, the resistance of the phase-change material is relatively small, and it is not easy to generate heat that can cause it to undergo a phase change. It is necessary to increase the pulse voltage and pulse duration, which will also increase the switching time or increase the DC power consumption, and will cause the phase-change material to produce longitudinal crystal filaments during the phase change process, making the on-state resistance larger and the off-state resistance smaller, resulting in a relatively small switch, and a larger on-state insertion loss. Because it is a vertical structure, it is not friendly to the device packaging process, and will increase the device packaging cost.

[0027] In view of this, if Figure 3 As shown, the present application proposes a phase change radio frequency switch 100, comprising:

[0028] A substrate 1, a first region being formed on one side thereof;

[0029] A resistance layer 2 is arranged in the first region of the substrate; and

[0030] A phase change layer 3 is provided on a side of the resistor layer 2 away from the substrate 1;

[0031] The impedance of the resistance layer 2 to the radio frequency signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistance layer 2 to the direct current signal is R2, 3Ω≤R2≤20Ω.

[0032] like Figure 4As shown, taking GeTe phase change material as an example, the working principle of the phase change RF switch 100 is described. GeTe is composed of two elements, Ge and Te, in a suitable chemical ratio, such as 50:50. Similar to other chalcogenide compounds, it has two stable and interchangeable phases, crystalline and amorphous, at room temperature. Both phases are non-volatile. Unlike semiconductor switches, it does not require energy consumption to maintain a certain state, and static zero power consumption can be achieved. Amorphous GeTe is a p-type semiconductor with a band gap (Eg) width of 0.8eV, very high resistivity and extremely low optical reflectivity, while the crystalline GeTe band gap is narrower, with a width of 0.1 to 0.2eV, and a Fermi level of 0.3 to 0.5eV in the valence band. Therefore, it has low resistivity and high optical reflectivity in the crystalline state, and its properties are similar to those of metals. The phase change RF switch based on GeTe uses the two-state electrical characteristics of GeTe to achieve switching. When the phase change layer 3 is in a crystalline state, the RF signal can pass smoothly, the entire switch is in an on state, and the insertion loss is very small due to the low resistance. When the phase change layer 3 is in an amorphous state, the RF signal is blocked and cannot be transmitted, and is reflected back to the input end. The entire switch is in an off state. At this time, the isolation between the input and output ports is very high due to the very high resistance.

[0033] The phase change process of GeTe phase change material belongs to thermal phase change. When the temperature reaches a certain level, the atomic arrangement and bonding in the phase change layer 3 film will change accordingly, thereby showing differences in electrical and optical properties on a macro scale. When the thin film phase change material is crystalline, a narrow pulse of a higher amplitude is applied to the thin film resistor material so that the heat generated can heat the phase change material to above its melting point. The phase change material film changes from solid to liquid, and the resistivity is lower in the liquid state. In order to realize an amorphous thin film phase change material, the temperature is quickly lowered and quenched. After a suitable quenching time, the film is in an amorphous state, the internal lattice arrangement is disorderly, and a high resistivity is presented to the outside, corresponding to the off state of the phase change RF switch 100. In order to transform the amorphous state back to the crystalline state, it is necessary to provide the atoms with sufficient energy and time to rearrange and bond. By applying low-amplitude and wide electric pulses to the high-resistance thin film material, when the heat generated exceeds the crystallization temperature and is lower than the melting temperature, the film begins to crystallize. After a period of time, it reaches a crystalline state, with atoms arranged neatly and orderly, presenting low resistivity to the outside, corresponding to the on state of the phase change RF switch 100.

[0034] In the technical solution of the present application, the phase change material of the phase change layer 3 is heated by directly heating the thin film resistance material of the resistance layer 2, which has faster heat transfer and higher heating efficiency, and can make the phase change material crystallize in a shorter time, thereby improving the switching speed of the phase change RF switch 100. At the same time, a non-isolation layer process is adopted, that is, the resistance layer 2 of the high impedance thin film resistance material is in direct contact with the phase change layer 3 of the phase change material. Since there is no medium between the two layers, the parasitic capacitance can be reduced to a certain extent, thereby improving the off-state isolation of the phase change RF switch 100. Since 800Ω≤R1≤2000Ω, the impedance of the resistance layer 2 to the RF signal is at a large value. When the RF signal is sent, the resistance layer 2 generates a large amount of heat due to its large resistance. This heat is directly transferred to the phase change layer 3, so that the phase change material of the phase change layer 3 is crystallized in a shorter time, reducing the heat transfer time and reducing the heat loss, thereby improving the switching speed of the phase change RF switch 100. And when the phase change RF switch 100 is in the off state, the RF signal is not easy to leak, thereby achieving high off-state isolation. At the same time, 3Ω≤R2≤20Ω can reduce the blocking of the DC signal by the resistor layer 2. Among them, the value of R1 can be 800Ω, 900Ω, 1000Ω, 1100Ω, 1200Ω, 1300Ω, 1400Ω, 1500Ω, 1600Ω, 1700Ω, 1800Ω, 1900Ω or 2000Ω. The value of R2 can be 3Ω, 4Ω, 5Ω, 6Ω, 7Ω, 8Ω, 9Ω, 10Ω, 11Ω, 12Ω, 13Ω, 14Ω, 15Ω, 16Ω, 17Ω, 18Ω, 19Ω or 20Ω.

[0035] In any implementation manner of the present application, 1000Ω≤R1≤1500Ω. Within this range, the isolation of the phase-change RF switch 100 in the off state can be improved, the process difficulty can be reduced, and the qualified rate can be improved.

[0036] 5Ω≤R2≤10Ω. Within this range, the switching function of the phase change RF switch 100 is realized under the state of low DC power consumption, which reduces the process difficulty and improves the qualified rate.

[0037] It should be noted that the above 1000Ω≤R1≤1500Ω and 5Ω≤R2≤10Ω can be satisfied at the same time or one of them can be satisfied. When they are satisfied at the same time, the isolation of the phase change RF switch 100 in the off state can be further improved, the switching function of the phase change RF switch 100 can be realized under the state of low DC power consumption, the process difficulty can be reduced, and the qualified rate can be improved.

[0038] In any embodiment of the present application, the material of the resistor layer 2 includes at least one of tungsten, tantalum, nickel, chromium, tungsten nitride, tantalum nitride, nickel nitride and chromium nitride. Using at least one of the above materials as the material of the resistor layer 2 can increase the resistance of the resistor layer 2 to the radio frequency signal, so that the resistance of the resistor layer 2 to the radio frequency signal is within a suitable range. It should be noted that when the resistor layer 2 is formed by doping multiple materials, the resistance of the resistor layer 2 to the radio frequency signal and the DC signal is more suitable.

[0039] In any embodiment of the present application, one side of the substrate 1 further has a second region located on both sides of the first region, a first metal conductive layer 4 is provided on the second region, and a dielectric layer 5 is further provided between the first metal conductive layer 4 and the phase change layer 3;

[0040] A second metal conductive layer 6 is disposed on a side of the phase change layer 3 away from the resistance layer 2 , and the second metal conductive layer 6 is separated from the first metal conductive layer 4 by the dielectric layer 5 .

[0041] The second metal conductive layer 6 and the first metal conductive layer 4 are separated by the dielectric layer 5, so that a capacitor structure is formed between the second metal conductive layer 6 and the first metal conductive layer 4, thereby forming a radio frequency path. Since the existence of the capacitor structure plays a role in isolating DC pulses, the radio frequency signal and the DC pulse signal can share a pair of pins, namely the left and right ends of the first metal conductive layer 4, that is, the input and output ends of the device, such as Figure 5 As shown, the two-port design has a higher switching speed, a smaller area of ​​the phase-change RF switch 100, and a lower cost of the phase-change RF switch 100. Compared with the traditional four-port phase-change RF switch, its direct heating design makes the thermal efficiency of the DC pulse higher, and a faster material phase change can be achieved under the same pulse conditions. The response speed of the phase-change RF switch 100 is further improved; and the two-port design allows the RF signal and the DC power supply to use the same metal conductive layer, avoiding the additional DC power supply design, thereby reducing the area of ​​the phase-change RF switch 100. There is no need to design the routing of the DC pulse, so that the volume and area of ​​the phase-change RF switch 100 are further reduced, so that the phase-change RF switch 100 can occupy a smaller area when in use. Due to the reduction in area, the production cost of the device can be reduced to a certain extent compared with the traditional four-port phase-change RF switch 100, and the packaging difficulty and cost are reduced compared with the vertical two-port device.

[0042] like Figure 6 As shown, when the second metal conductive layer 6 and the first metal conductive layer 4 are separated by the dielectric layer 5, an equivalent circuit diagram is formed, wherein L s , R s1 , R s2Produced by the electrode lead parasitic, C p It is generated by the parasitic between the metal conductive layer and the substrate 1. RF is the designed DC blocking capacitor, R heater is the resistance of the thin film resistor material of the heating resistor layer 2. R c is the contact resistance between the phase change material of the phase change layer 3 and the resistance material of the resistance layer 2, R I2 and C I2 is the parasitic generation between the phase change material and the metal conductive layer, R I The resistance in the on state is generally small, while in the off state, the parasitic capacitance C between the electrodes on both sides is I Play a leading role.

[0043] By embedding the resistor layer 2 in the middle of the first metal conductive layer 4, the two ends of the resistor layer 2 are the first metal conductive layer 4, that is, the resistor layer 2 divides the first metal conductive layer 4 into two parts, and the DC signal passes through the resistor layer 2 from the first metal conductive layer 4 at one end to the first metal conductive layer 4 at the other end, thereby realizing the transmission of the DC signal, while the RF signal passes through the dielectric layer 5 through the first metal conductive layer 4 at one end to reach the second metal conductive layer 6 at one end, and then passes from the second metal conductive layer 6 to the second metal conductive layer 6 at the other end through the phase change layer 3, and then passes through the dielectric material layer 5 to the first metal conductive layer 4 at the other end.

[0044] In any embodiment of the present application, the dielectric constant of the dielectric layer 5 is ε, 9≤ε≤50. When the dielectric constant of the dielectric layer 5 is 9-50, the dielectric constant is relatively large, and a suitable capacitor structure can be formed between the first metal conductive layer 4 and the second metal conductive layer 6, thereby blocking the passage of the DC signal. The dielectric constant can be 9, 10, 15, 20, 25, 30, 35, 40, 45 or 50.

[0045] In any embodiment of the present application, the material of the dielectric layer 5 includes at least one of titanium oxide, aluminum oxide, hafnium oxide and molybdenum disulfide. Using at least one of the materials of the dielectric layer 5 can provide a suitable dielectric constant, form a capacitor between the first metal electrode layer 4 and the second metal electrode layer 6, and block DC signals.

[0046] In any embodiment of the present application, the material of the first metal conductive layer 4 includes at least one of titanium, aluminum, gold or nickel. At least one of titanium, aluminum, gold or nickel has good electrical conductivity.

[0047] The thickness of the first metal conductive layer 4 is n1, 10nm≤n1≤100nm. Within this thickness range, the power borne by the first metal conductive layer 4 can be increased while reducing the process difficulty and device cost. The thickness of the first metal conductive layer 4 can be 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm or 100nm.

[0048] The material of the second metal conductive layer 6 includes at least one of titanium, aluminum, gold or nickel. At least one of titanium, aluminum, gold or nickel has good conductivity.

[0049] It should be noted that the above-mentioned limitations on the material of the first metal conductive layer 4, the thickness of the first metal conductive layer 4 and the material of the second metal conductive layer 6 can be met at the same time, or one or both can be met. When they are met at the same time, the conductive effect is better.

[0050] In any embodiment of the present application, the material of the phase change layer 3 includes at least one of GeTe, Ge2Se2Te5, Sb2Te3, a dopant of GeTe, a dopant of Ge2Se2Te5, and a dopant of Sb2Te3. The use of at least one of the above phase change materials can make the on-state and off-state conversion efficiency of the phase change RF switch 100 higher;

[0051] The thickness of the phase change layer 3 is n2, 20nm≤n2≤200nm. Within this thickness range, the on-state and off-state switching speeds of the phase change RF switch 100 can be faster, the on-state insertion loss is lower, and the off-state isolation is higher. The thickness of the phase change layer 3 can be 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm or 200nm.

[0052] The phase change temperature of the phase change layer 3 is T, 720°C≤T≤740°C. Within this phase change temperature range, the time for the phase change material to become liquid can be reduced, the time for the phase change material to become amorphous after the DC pulse is removed can be shortened, the shutdown time of the phase change RF switch 100 can be reduced, and the switching speed of the phase change RF switch 100 can be increased. The phase change temperature of the phase change layer 3 can be 720°C, 722°C, 724°C, 726°C, 728°C, 730°C, 732°C, 734°C, 736°C, 738°C or 740°C.

[0053] It should be noted that the above-mentioned limitations on the material of the phase change layer 3, the thickness of the phase change layer 3, and the phase change temperature of the phase change layer 3 can be met at the same time, or one or both can be met. When they are met at the same time, the switching speed of the phase change RF switch 100 between the on and off states can be further made faster, the on-state insertion loss can be lower, and the off-state isolation can be higher.

[0054] It should be noted that, in some embodiments of the present application, the substrate 1 is used to support the growth of the upper thin film, and the film with a thickness of several microns or even several nanometers must be attached to the substrate 1 to avoid being broken or damaged.

[0055] In some embodiments of the present application, an isolation layer 8 may be further included between the resistance layer 2 and the first metal conductive layer 4 and the substrate 1 , and the isolation layer 8 is used to enhance the adhesion and isolation effect of the upper structure thereof.

[0056] In some embodiments of the present application, the second metal conductive layer 6 on the side away from the phase change layer 3 may also include a passivation layer 7, and the passivation layer 7 is used to protect the device, prevent the phase change RF switch 100 from being oxidized and contaminated, and prevent the phase change material from volatilizing too quickly.

[0057] like Figure 7 As shown, the present application also proposes a method for preparing a phase change radio frequency switch 100, comprising the following steps:

[0058] S10, providing a substrate 1, wherein one side of the substrate has a first region;

[0059] S20, forming a resistance layer 2 in a first region of the substrate 1;

[0060] S30, forming a phase change layer 3 on a side of the resistance layer 2 away from the substrate 1;

[0061] The impedance of the resistance layer 2 to the radio frequency signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistance layer 2 to the direct current signal is R2, 3Ω≤R2≤20Ω.

[0062] By forming a resistor layer 2 in the first area of ​​the substrate, a phase change layer 3 is formed on the side of the resistor layer 2 away from the substrate 1, and the impedance of the resistor layer 2 to the RF signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistor layer 2 to the DC signal is R2, 3Ω≤R2≤20Ω, so that the phase change layer 3 directly contacts the resistor layer 2. When receiving the RF signal, the resistor layer 2 generates a large amount of heat due to its large impedance, which is directly transferred to the phase change layer 3, so that the phase change layer 3 undergoes a phase change, so that the RF signal can pass through the phase change layer 3 instead of the resistor layer 2. The phase change material is heated by directly heating the resistor layer 2, and the heat transfer is faster and the heating efficiency is higher, so that the phase change material can be crystallized in a shorter time, thereby improving the switching speed of the phase change RF switch 100. At the same time, a non-isolation layer process is adopted, that is, the high-impedance thin film resistor material is in direct contact with the phase change material. Since there is no medium between the two layers, the parasitic capacitance can be reduced to a certain extent, thereby improving the off-state isolation of the phase change RF switch 100.

[0063] In any embodiment of the present application, the step of forming the resistance layer 2 in the first region of the substrate 1 includes: forming the resistance layer 2 in the first region of the substrate 1 by magnetron sputtering or electron beam evaporation growth;

[0064] The step of forming the phase change layer 3 on the side of the resistance layer 2 away from the substrate 1 includes: forming the phase change layer 3 on the side of the resistance layer 2 away from the substrate 1 by magnetron sputtering or atomic layer deposition.

[0065] The resistor layer 2 is formed by magnetron sputtering or electron beam evaporation growth method, which can improve the bonding strength of the resistor layer 2 and facilitate the control of the thickness of the resistor layer 2 and the composition of the material.

[0066] Forming the phase change layer 3 by magnetron sputtering or atomic layer deposition can improve the bonding strength of the phase change layer 3 and facilitate the control of the thickness of the phase change layer 3 and the composition of the material.

[0067] It should be noted that the above-mentioned steps of forming the resistance layer 2 in the first area of ​​the substrate 1 and the step of forming the phase change layer 3 on the side of the resistance layer 2 away from the substrate 1 can be met at the same time or one of them can be met. When they are met at the same time, it is more conducive to the bonding firmness and thickness control of the resistance layer 2 and the phase change layer 3.

[0068] In any embodiment of the present application, after forming the phase change layer 3 on the side of the resistance layer 2 away from the substrate 1, the step further includes:

[0069] S40, forming a first metal conductive layer 4 on the second region on one side of the substrate 1 and located on both sides of the first region;

[0070] S50, etching a groove between the phase change layer 3 and the first metal conductive layer 4, and forming a dielectric layer 5 in the groove;

[0071] S60 , forming a second metal conductive layer 6 on a side of the phase change layer 3 and the dielectric layer 5 away from the resistance layer.

[0072] The first metal conductive layer 4 is separated from the second metal conductive layer 6 by a dielectric layer to form a capacitor structure, which plays a role in isolating DC signals and reducing the loss of radio frequency signals.

[0073] In any embodiment of the present application, the step of forming the first metal conductive layer 4 on both sides of the resistor 2 and the phase change layer 3 includes: forming the first metal conductive layer 4 on both sides of the resistor layer 2 and the phase change layer 3 by magnetron sputtering or electron beam evaporation;

[0074] The step of etching a groove between the phase change layer 3 and the first metal conductive layer 4 to form the dielectric layer 5 comprises: etching a groove between the phase change layer 3 and the first metal conductive layer 4, and forming the dielectric layer 5 in the groove by magnetron sputtering or metal organic chemical vapor deposition or atomic layer deposition or plasma enhanced vapor deposition;

[0075] The step of forming the second metal conductive layer 6 on the side of the phase change layer 3 and the dielectric layer 5 away from the resistor layer 2 includes: forming the second metal conductive layer 6 on the side of the phase change layer 3 and the dielectric layer 5 away from the resistor layer 2 by magnetron sputtering or electron beam evaporation.

[0076] The molding method of forming the first metal conductive layer 4 by magnetron sputtering or electron beam evaporation, forming the dielectric layer 5 by magnetron sputtering or metal organic chemical vapor deposition or atomic layer deposition or plasma enhanced vapor deposition, and forming the second metal conductive layer 6 by magnetron sputtering or electron beam evaporation can control the size and thickness of each layer and facilitate processing.

[0077] It should be noted that the above-mentioned limitations of forming a first metal conductive layer 4 on both sides of the resistance layer 2 and the phase change layer 3, etching a groove between the phase change layer 3 and the first metal conductive layer 4 to form a dielectric layer 5, and forming a second metal conductive layer 6 on the side of the phase change layer 3 and the dielectric layer 5 away from the resistance layer 2 can be met at the same time or one of them can be met selectively. When met at the same time, it can further help control the size and thickness of each layer and facilitate processing.

[0078] In some embodiments of the present application, the phase change RF switch may simultaneously contain a substrate 1, an isolation layer 8, a resistance layer 2, a phase change layer 3, a dielectric layer 5, a first metal conductive layer 4, a second metal conductive layer and a passivation layer 6, and its preparation process may be as follows: Figure 8 The steps shown in the figure are used to prepare a phase change radio frequency switch with a good morphology. Specifically, the preparation method may be:

[0079] S10, preparing an isolation layer 8 on a substrate 1, the substrate 1 can be made of one or more of Si, SiC, sapphire with a thickness greater than 1000 μm. The isolation layer 8 can be one or more of silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, etc. grown by magnetron sputtering or PECVD with a thickness of about 300 nm.

[0080] S20, preparing a resistor layer 2 on the isolation layer 8, photolithography a pattern of the resistor layer 2, growing one or more of tungsten, tantalum, nickel, tantalum or their nitrides by magnetron sputtering or electron beam evaporation, and adjusting the doping concentration so that the layer presents high impedance to the radio frequency signal.

[0081] S30, photolithography the designed phase change layer 3 pattern on the resistor layer 2, then generate the phase change layer 3 by magnetron sputtering or atomic layer deposition, and then obtain the designed size of the phase change layer 3 by stripping. The phase change layer 3 is one or more of GeTe, Ge2Se2Te5, Sb2Te3 single substance or dopant with a thickness of 100nm.

[0082] S40, photolithography the morphology of the first conductive metal layer 4 on the surface of the sample obtained in S30. The first conductive metal layer 4 is grown by magnetron sputtering or electron beam evaporation, and then a stripping process is performed to obtain a complete first conductive metal layer 4. The electrode material is one or more of 50nm titanium, aluminum, gold, nickel, etc.

[0083] S50, using an etching process to carve out the morphology of the dielectric layer 5 to be deposited on the sample obtained in S40, and then using one or more processes such as magnetron sputtering, MOCVD, ALD, PECVD, etc. to deposit a layer of 20-30nm high dielectric constant dielectric material, such as titanium oxide, aluminum oxide, hafnium oxide or molybdenum disulfide.

[0084] S60, photolithography the morphology of the second conductive metal layer 6 on the sample obtained in S50. The second conductive metal layer 6 is grown by magnetron sputtering or electron beam evaporation, and then a stripping process is performed to obtain a complete second conductive metal layer 6. The electrode material is one or more of 50nm titanium, aluminum, gold, nickel, etc.

[0085] S70, photolithography the morphology of the passivation layer 7 on the upper surface of the sample obtained in S60, and grow a layer of passivation layer 7 by PECVD process. The passivation layer material is one or more of silicon nitride, silicon oxide, aluminum oxide and the like.

[0086] The present application also proposes a wireless communication device, including the phase change RF switch 100 or the phase change RF switch 100 prepared by the preparation method of the phase change RF switch. The wireless communication device has all the technical solutions of the phase change RF switch 100, and thus has all the intended effects, which will not be described in detail in the present application.

[0087] Due to the advantages of high cut-off frequency, low insertion loss, high isolation, easy integration, non-volatility, etc., the phase change RF switch 100 plays an important role in single-chip or heterogeneous integrated millimeter wave RF devices and subsystems such as switch matrices, filters, phase shifters, low noise amplifiers, attenuators, and transceivers. In addition, in military applications, field programmable gate array (FPGA) RF front-end components can be developed based on the phase change RF switch 100 to reduce the R&D cost and time of military communications, electronic warfare, and intelligence systems.

[0088] In any embodiment of the present application, the wireless communication device includes a wireless communication reliability tester, a reconfigurable receiver, a reconfigurable filter, a switch matrix, an adjustable phase shifter or an adjustable attenuator.

[0089] For those skilled in the art, the present application may have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present application shall be included in the patent protection scope of the present application.

Claims

1. A phase change radio frequency switch, characterized in that: include: a substrate having a first region formed on one side thereof; A resistance layer is disposed in the first region of the substrate; as well as A phase change layer is provided on a side of the resistance layer away from the substrate; The impedance of the resistance layer to the radio frequency signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistance layer to the direct current signal is R2, 3Ω≤R2≤20Ω.

2. The phase change radio frequency switch according to claim 1, characterized in that: 1000Ω≤R1≤1500Ω, and / or, 5Ω≤R2≤10Ω.

3. The phase change radio frequency switch according to claim 1, characterized in that: The material of the resistance layer includes at least one of tungsten, tantalum, nickel, chromium, tungsten nitride, tantalum nitride, nickel nitride and chromium nitride.

4. The phase change radio frequency switch according to claim 1, characterized in that: One side of the substrate also has second regions located on both sides of the first region, a first metal conductive layer is provided on the second region, and a dielectric layer is provided between the first metal conductive layer and the phase change layer; A second metal conductive layer is disposed on a side of the phase change layer away from the resistance layer, and the second metal conductive layer is separated from the first metal conductive layer by the dielectric layer.

5. The phase change radio frequency switch according to claim 4, characterized in that: The dielectric constant of the dielectric layer is ε, 9≤ε≤50.

6. The phase-change radio frequency switch according to claim 4, characterized in that: The material of the dielectric layer includes at least one of titanium oxide, aluminum oxide, hafnium oxide and molybdenum disulfide.

7. The phase-change radio frequency switch according to claim 4, characterized in that: The material of the first metal conductive layer includes at least one of titanium, aluminum, gold or nickel; and / or, The thickness of the first metal conductive layer is n1, 10nm≤n1≤100nm; and / or, The material of the second metal conductive layer includes at least one of titanium, aluminum, gold or nickel.

8. The phase change radio frequency switch according to claim 1, characterized in that: The material of the phase change layer includes at least one of GeTe, Ge2Se2Te5, Sb2Te3, a dopant of GeTe, a dopant of Ge2Se2Te5 and a dopant of Sb2Te3; and / or, The thickness of the phase change layer is n2, 20nm≤n2≤200nm; and / or, The phase change temperature of the phase change layer is T, 720°C≤T≤740°C.

9. The method for preparing a phase-change radio frequency switch according to any one of claims 1 to 8, characterized in that: The following steps are involved: Providing a substrate, wherein one side of the substrate has a first region; forming a resistive layer in a first region of the substrate; forming a phase change layer on a side of the resistance layer away from the substrate; The impedance of the resistance layer to the radio frequency signal is R1, 800Ω≤R1≤2000Ω, and the impedance of the resistance layer to the direct current signal is R2, 3Ω≤R2≤20Ω.

10. The method for preparing a phase-change radio frequency switch according to claim 9, characterized in that: The step of forming a resistance layer in the first region of the substrate comprises: forming the resistance layer in the first region of the substrate by magnetron sputtering or electron beam evaporation growth; and / or, The step of forming a phase change layer on the side of the resistance layer away from the substrate includes: forming the phase change layer on the side of the resistance layer away from the substrate by magnetron sputtering or atomic layer deposition.

11. The method for preparing a phase-change radio frequency switch according to claim 9, characterized in that: After forming the phase change layer on the side of the resistance layer away from the substrate, the step further includes: forming a first metal conductive layer on a second region located on both sides of the first region on one side of the substrate; Etching a groove between the phase change layer and the first metal conductive layer to form a dielectric layer in the groove; A second metal conductive layer is formed on a side of the phase change layer and the dielectric layer away from the resistance layer.

12. The method for preparing a phase-change radio frequency switch according to claim 11, characterized in that: The step of forming a first metal conductive layer on both sides of the resistance layer and the phase change layer comprises: forming the first metal conductive layer on both sides of the resistance layer and the phase change layer by magnetron sputtering or electron beam evaporation; and / or, The step of etching a groove between the phase change layer and the first metal conductive layer to form a dielectric layer comprises: etching a groove between the phase change layer and the first metal conductive layer, and forming a dielectric layer in the groove by magnetron sputtering or metal organic chemical vapor deposition or atomic layer deposition or plasma enhanced vapor deposition; and / or, The step of forming a second metal conductive layer on the side of the phase change layer and the dielectric layer away from the resistance layer includes: forming the second metal conductive layer on the side of the phase change layer and the dielectric layer away from the resistance layer by magnetron sputtering or electron beam evaporation.

13. A wireless communication device, characterized in that: A phase change radio frequency switch comprising the phase change radio frequency switch according to any one of claims 1 to 8 or a phase change radio frequency switch prepared by the preparation method of the phase change radio frequency switch according to claims 9 to 12.

14. The wireless communication device according to claim 13, wherein: The wireless communication device includes a wireless communication reliability tester, a reconfigurable receiver, a reconfigurable filter, a switch matrix, an adjustable phase shifter or an adjustable attenuator.

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