A multi-port c-type radio frequency switch based on phase change material

Abstract

The application discloses a kind of multi-port C type radio frequency switches based on phase change material, the multi-port C type radio frequency switch is prepared on Si-SiO2 substrate by monolithic integrated SPST phase change radio frequency switch, with four ports.Multi-port C type radio frequency switch includes substrate layer, bottom electrode layer, phase change switch function layer, top electrode layer, passivation layer and radio frequency transmission layer arranged in sequence from bottom to top.Compared with SPnT phase change radio frequency switch, using multi-port C type radio frequency switch as basic building block, the total number of switches required for reconfigurable radio frequency system can be reduced, to simplify system design, increase the flexibility of system.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing multi-port phase-change radio frequency switches. Specifically, a sulfur-based phase-change thin film material is used as the main functional layer of the phase-change radio frequency switch, and the electrode structure of the two-port SPST phase-change radio frequency switch is optimized. On this basis, a multi-port C-type phase-change radio frequency switch is prepared, thereby improving the switching speed of the phase-change radio frequency switch, reducing the switching power consumption, and increasing the flexibility of the system. Background Art

[0002] Microwave RF switch matrices are a crucial component of satellite payloads. These switch matrices increase satellite capacity and optimize system bandwidth utilization by providing ample and flexible interconnection between receive and transmit signals. Multi-port RF switches are a crucial component of reconfigurable and switchable RF systems. Using multi-port C-type phase-change RF switches instead of SPST phase-change RF switches as basic building blocks, reconfigurable between different ports and channels, further miniaturizes array system components, such as filters and attenuators. In addition to enabling multi-port signal transmission, multi-port C-type phase-change RF switches also serve an important purpose: maintaining system functionality by receiving signals through a backup receiver when one receiver fails.

[0003] Phase-change materials (PCMs) are currently the most promising candidate for building low-cost, low-loss, ultra-wideband millimeter-wave components. PCM-based switches rely on the change in material resistance (phase transition) when heated. Voltage pulses as short as nanoseconds wide can generate sufficient heat (depending on the topology of the PCM switch) to reversibly convert the material between crystalline and amorphous states, resulting in a change in resistance. RF switches based on PCMs offer advantages such as a high on / off ratio, low insertion loss, high isolation, high cutoff frequency, high power handling, excellent linearity, high reliability, and miniaturization. Furthermore, the CMOS process compatibility of PCM-based RF switches facilitates monolithic or heterogeneous integration with other processes, making them highly attractive for the design and implementation of reconfigurable RF devices. These advantages make PCM-based switches highly promising and marketable for applications in multi-port reconfigurable millimeter-wave RF devices and subsystems.

[0004] Designing and developing reliable multi-port RF switches based on phase change materials, and using them as units to develop switch matrix architectures and reconfigurable RF components, thereby introducing new RF switch matrices, is of great significance for the future development of high-speed, low-power, low-loss and miniaturized reconfigurable RF components. Summary of the Invention

[0005] The application aims to provide a multi-port C-type radio frequency switch based on phase change material, which has four ports, can be reconfigurable in a satellite payload, improves flexibility and reliability of a reconfigurable system, reduces power consumption and improves switch speed.

[0006] The technical scheme of the application is:

[0007] A multi-port C-type radio frequency switch based on phase change material, characterized in that the multi-port C-type radio frequency switch comprises, from bottom to top, a Si-SiO2 substrate, a bottom electrode layer, a phase change thin film material layer, a top electrode layer, a passivation layer and a radio frequency transmission layer, and has two input ports and two output ports.

[0008] Step 1: Pretreatment of Si-SiO2 substrate

[0009] The Si-SiO2 substrate is cleaned and dried; the cleaning process is to first ultrasonically clean the Si-SiO2 substrate in an ethanol solution for 5-20 minutes, then ultrasonically clean it in an acetone solution for 5-20 minutes, and finally ultrasonically clean it with deionized water for 5-20 minutes; the drying process is to dry the Si-SiO2 substrate after ultrasonic cleaning using high-purity nitrogen;

[0010] Step 2: Preparation of bottom electrode layer

[0011] After spin-coating photoresist on the Si-SiO2 substrate pretreated in step 1, two bottom electrodes are patterned as input ports and cross marks for the next layer of overlay by electron beam exposure, and then 2-10 nm thick Cr and 40-100 nm thick Au are deposited by magnetron sputtering, the excess material is removed by soaking in acetone solution, and two input ports are obtained;

[0012] Step 3: Preparation of phase change thin film material layer

[0013] Spin-coat photoresist on the bottom electrode layer, align and pattern the phase change material layer by electron beam exposure overlay, then deposit 50-200 nm thick phase change thin film material, remove the excess material by soaking in acetone solution, and obtain the phase change thin film material layer;

[0014] Step 4: Preparation of top electrode layer

[0015] Spin-coat photoresist on the phase change thin film material layer, align and pattern two top electrodes as output ports by electron beam exposure overlay, deposit 50-150 nm thick metal layer by magnetron sputtering, remove the excess material by soaking in acetone solution, and obtain two output ports;

[0016] Step 5: Preparation of passivation layer

[0017] Spin-coat photoresist on the top electrode layer, perform electron beam exposure to overlay patterning of the passivation layer according to the cross mark alignment, deposit a 100-250 nm thick passivation layer film by magnetron sputtering, and remove excess material by soaking in acetone solution to obtain a passivation layer;

[0018] Step 6: Prepare the RF transmission layer

[0019] A photoresist is spin-coated on the passivation layer, and an electron beam exposure is performed according to the cross mark alignment to overlay the patterned radio frequency transmission layer. 5-10 nm of Cr and 100-500 nm of Au are deposited as the radio frequency transmission layer by magnetron sputtering. The excess material is removed by soaking and cleaning with an acetone solution to obtain the multi-port C-type radio frequency switch based on the phase change material.

[0020] The multi-port C-type radio frequency switch has four ports.

[0021] The resistivity of Si-SiO2 is at least 10 5 Ω·cm, SiO2 thickness is 50-500 nm.

[0022] The phase change material is obtained by magnetron sputtering or pulse laser deposition.

[0023] The phase change material is GeTe, Sb, Ge2Sb2Te5, Sb2Te3, Sb2Te, GeSb2Te4, GeTe / Sb2Te3 superlattice, GeTe / Sb superlattice or Ge2Sb2Te5 / Sb superlattice.

[0024] The top electrode material is Au, Cu, Cr, W or Pt.

[0025] The passivation layer material is SiO2, AlN or Si3N4.

[0026] The contact areas of the top electrode and the bottom electrode with the phase change thin film material layer are in tooth shapes.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The present invention's multi-port C-shaped RF switch based on phase change material has four ports and can be further applied to reconfigurable matrix array systems, improving system flexibility. The present invention's multi-port C-shaped RF switch based on phase change material features a direct heating structure with tooth-shaped electrode tips. This reduces the contact area between the phase change material and the electrodes, further improving heating efficiency and thus reducing power consumption. This invention can introduce a new RF switch matrix, providing a novel design approach for the future development of high-speed, low-power, low-loss, and miniaturized reconfigurable RF components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1This is a schematic structural diagram of a multi-port C-type radio frequency switch based on phase change material according to the present invention;

[0030] Figure 2 This is a working schematic diagram of a multi-port C-type radio frequency switch based on phase change material according to the present invention;

[0031] Figure 3 This is a flow chart of a method for preparing a multi-port C-type radio frequency switch based on phase change material according to the present invention;

[0032] Figure 4 This is an insertion loss curve of the multi-port C-type RF switch based on GeTe phase change material in the 1-67 GHz frequency spectrum range according to HFSS simulation (state I);

[0033] Figure 5 This is an isolation curve diagram of the multi-port C-type RF switch based on GeTe phase change material in the 1-67 GHz spectrum range based on HFSS simulation (state I). DETAILED DESCRIPTION

[0034] In the following description, specific details such as particular system structures and techniques are provided for purposes of illustration, not limitation, to facilitate a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

[0035] In order to illustrate the technical solution of the present invention, specific embodiments are provided below.

[0036] A multi-port C-type RF switch based on phase change material is composed of four SPST phase change RF switches (ad) monolithically integrated in a highly compact form factor, including four ports A, B, C, and D. Figure 1 As shown in FIG. The multi-port C-type RF switch comprises, from bottom to top, a Si-SiO2 substrate 101, a bottom electrode layer 102, a phase change thin film material layer 103, a top electrode layer 104, a passivation layer 105, and a RF transmission layer 106. The phase change material used in the multi-port C-type RF switch of this embodiment is GeTe phase change thin film material.

[0037] The two working states of the multi-port C-type RF switch based on phase change material are as follows: Figure 2 State I is when the RF signal is conducted between ports A / B and C / D, and state II is when the RF signal is conducted between ports A / D and C / B.

[0038] The manufacturing process flow chart of the multi-port C-type RF switch based on GeTe phase change thin film material in this embodiment is as follows: Figure 3 As shown, the specific preparation method comprises the following steps:

[0039] (a) Pretreatment of Si-SiO2-based substrates: The Si-SiO2-based substrates were first ultrasonically cleaned in an ethanol solution for 10 minutes, then ultrasonically cleaned in an acetone solution for 10 minutes, and finally ultrasonically cleaned in deionized water for 10 minutes. After ultrasonic cleaning, the substrates were blown dry with high-purity nitrogen gas.

[0040] (b) Preparation of the bottom electrode layer: A high-resistivity single-crystal Si substrate with a 300 nm thick SiO2 surface was selected. After cleaning, drying, and spin-coating with photoresist, the substrate was patterned using electron beam exposure to form two bottom electrodes and a cross mark for the next layer. Subsequently, 10 nm thick Cr and 90 nm thick Au were deposited by magnetron sputtering. Excess material was removed by soaking and cleaning with an acetone solution to obtain two input ports.

[0041] (c) Preparation of GeTe phase change thin film material layer: Spin-coating photoresist on the bottom electrode layer, overlaying the patterned phase change material layer by electron beam exposure according to the cross mark alignment, and depositing 100 nm thick GeTe phase change thin film material by pulsed laser. The excess material is removed by soaking and cleaning with acetone solution to obtain the phase change material layer;

[0042] (d) Preparation of the top electrode layer: Spin-coat photoresist on the GeTe phase-change thin film material layer, overlay pattern the two top electrodes by electron beam lithography according to the cross mark alignment, deposit 100 nm thick Pt by magnetron sputtering, and remove excess material by soaking in acetone solution to obtain two output ports.

[0043] (e) Preparation of a passivation layer: Spin-coating a photoresist on the top electrode layer, patterning the passivation layer by electron beam lithography according to the cross mark alignment, depositing a 200 nm thick SiO2 film by magnetron sputtering, and removing excess material by soaking and cleaning with an acetone solution to obtain a passivation layer;

[0044] (f) Preparation of the RF transmission layer: Spin-coat photoresist on the passivation layer, and pattern the RF transmission layer by electron beam lithography according to the cross mark alignment. Magnetron sputtering is used to deposit 10 nm of Cr and 500 nm of Au as the RF transmission layer. The excess material is removed by soaking in acetone solution to obtain a multi-port C-type RF switch based on GeTe phase change thin film material.

[0045] Figure 4 This is an insertion loss curve of the multi-port C-type RF switch based on GeTe phase change material in the 1-67 GHz spectrum range based on HFSS simulation (state I). The insertion loss is less than 1.7 dB.

[0046] Figure 5This is the isolation curve of the multi-port C-type RF switch based on GeTe phase change material in the 1-67 GHz spectrum range according to HFSS simulation (state I). The isolation is better than 10.6 dB.

[0047] The above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above-described embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included in the scope of protection of the present invention.

Claims

1. A multi-port C-type radio frequency switch based on phase change material, characterized in that: The multi-port C-type RF switch comprises, from bottom to top, a Si-SiO2 substrate, a bottom electrode layer, a phase change thin film material layer, a top electrode layer, a passivation layer, and a RF transmission layer, and has two input ports and two output ports. The preparation thereof comprises the following steps: Step 1: Pretreatment of Si-SiO2-based substrate The Si-SiO2-based substrate is cleaned and dried; the cleaning process is to first ultrasonically clean the Si-SiO2-based substrate in an ethanol solution for 5-20 minutes, then ultrasonically clean it in an acetone solution for 5-20 minutes, and finally ultrasonically clean it with deionized water for 5-20 minutes; the drying process is to dry the Si-SiO2-based substrate after ultrasonic cleaning using high-purity nitrogen; Step 2: Prepare the bottom electrode layer After spin-coating photoresist on the Si-SiO2-based substrate pretreated in step 1, two bottom electrodes as input ports and a cross mark for the next layer of overlay are patterned using electron beam exposure. 2-10 nm thick Cr and 40-100 nm thick Au are then deposited by magnetron sputtering. Excess material is removed by soaking and cleaning with an acetone solution to obtain two input ports. Step 3: Prepare the phase change film material layer Spin-coat photoresist on the bottom electrode layer, perform electron beam exposure and overlay patterning of the phase change material layer according to the cross mark alignment, then deposit a 50-200 nm thick phase change thin film material, and remove excess material by soaking in acetone solution to obtain a phase change thin film material layer; Step 4: Prepare the top electrode layer Spin-coat photoresist on the phase-change thin film material layer, align the cross marks and perform electron beam exposure to overlay patterning to form two top electrodes as output ports. Deposit a 50-150 nm thick metal layer by magnetron sputtering, and remove excess material by soaking in acetone solution to obtain two output ports. Step 5: Prepare the passivation layer Spin-coat photoresist on the top electrode layer, perform electron beam exposure to overlay patterning of the passivation layer according to the cross mark alignment, deposit a 100-250 nm thick passivation layer film by magnetron sputtering, and remove excess material by soaking in acetone solution to obtain a passivation layer; Step 6: Prepare the RF transmission layer A photoresist is spin-coated on the passivation layer, and an electron beam exposure is performed according to the cross mark alignment to overlay the patterned radio frequency transmission layer. 5-10 nm of Cr and 100-500 nm of Au are deposited as the radio frequency transmission layer by magnetron sputtering. The excess material is removed by soaking and cleaning with an acetone solution to obtain the multi-port C-type radio frequency switch based on the phase change material.

2. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The multi-port C-type radio frequency switch has four ports.

3. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The resistivity of Si-SiO2 is at least 10 5 Ω·cm, SiO2 thickness is 50-500 nm.

4. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The phase change material is obtained by magnetron sputtering or pulse laser deposition.

5. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The phase change material is GeTe, Sb, Ge2Sb2Te5, Sb2Te3, Sb2Te, GeSb2Te4, GeTe / Sb2Te3 superlattice, GeTe / Sb superlattice or Ge2Sb2Te5 / Sb superlattice.

6. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The top electrode material is Au, Cu, Cr, W or Pt.

7. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The passivation layer material is SiO2, AlN or Si3N4.

8. The multi-port C-type radio frequency switch based on phase change material according to claim 1, characterized in that: The contact areas of the top electrode and the bottom electrode with the phase change thin film material layer are in tooth shapes.

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