CN1624846A

CN1624846A - Microwave/radio-frequency micromechanical switch and manufacturing method thereof

Info

Publication number: CN1624846A
Application number: CN 200310111073
Authority: CN
Inventors: 张万里; 蒋洪川; 彭斌; 张文旭; 杨仕清; 张金平
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2003-12-03
Filing date: 2003-12-03
Publication date: 2005-06-08
Anticipated expiration: 2023-12-03
Also published as: CN1269168C

Abstract

The invention a microwave / radio-frequency micro-mechanic switch. It includes: the anchor shoe, the substrate, the signal wire, the cantilever beam, the contact metal layer, the signal wire, the extra magnetic field conducting wire, and the magnetostriction. On the substrate the anchor shoe, the extra magnetic field conducting wire and the signal wire are paralleled arranged; the fixing end of the cantilever beam is on the anchor shoe, the suspension part is located above the extra magnetic field conduction wire and the signal wires; on the cantilever beam is the magnetostriction; the contact metal layer is under the suspension part of the cantilever beam. This invention has the characteristic of low driving pressure and the short response time.

Description

A kind of microwave/rf micromechanical switch and preparation method thereof

Technical field

The invention belongs to electronic technology field, particularly microwave/radio-frequency devices field.

Background technology

Along with microwave or the fast development of radio-frequency communication technology, for improving subsystem, machine performance and integrated level, reduce cost, microwave/radio frequency passive device there is urgent demand.Micromechanics (MEMS) microwave/radio-frequency devices is the research focus in nearest MEMS field, and it has made full use of the advantage of microelectronics and micro mechanical technology, and micro mechanical technology is applied to microwave/RF application, becomes a class new type of microwave/radio-frequency (RF) component.Microwave/rf micromechanical switch is compared with traditional microwave component such as PIN microwave switch, has low-loss, high isolates, volume is little, low cost of manufacture, be easy to and IC compatibility and reliability advantages of higher [seeing document 1～5].The execution mechanism of microwave/rf micromechanical switch has two kinds: electrostatic interaction and electromagnetic action.The advantage of electrostatic interaction is to need not operating current, thereby low in energy consumption, but carries out the voltage height, sees

document

4,6 greater than 20V[usually].The advantage of electromagnetic action is that execution voltage is low, but needs bigger operating current, thereby power consumption is bigger.The static driven type that mostly is greatly microwave/rf micromechanical switch on probation at present, as shown in Figure 1, its driving voltage height, long (Millisecond) [7] of response time, limited the further raising and the application thereof of subsystem integrated level, therefore carry out low current, low voltage drive type microwave/rf micromechanical switch research to the miniaturization of system, integrated crucial meaning arranged.

Magnetostrictive effect is owing to have advantages such as large deformation (hundreds of ppm), low driving voltage (millivolt level), big electromechanical conversion efficiency, high response speed (nanosecond) and contactless driving, thereby wide application prospect [seeing document 7～9] is arranged in MEMS.At present, people have utilized the higher magnetostrictive strain coefficient of material, have produced all kinds of MEMS servers, as precision positioning device, micro motor, fluid control systems (Micropump, little valve etc.).The magnetostrictive thin film material has excellent low driving voltage and high characteristics such as response speed, and this thin-film material is applied to microwave/rf micromechanical switch, just known to the inventor, does not see relevant report both at home and abroad.

[1] MEMS and Si-micromachined components for low power, high frequencycommunications systems.IEEE MTT-S Digest TU4C0-6,1998:331-333. Chinese translation: " MEMS and the Si microfabrication element that are used for low-power, high-frequency communication system ", this article have mainly been discussed the MEMS that is used for low-power, high-frequency communication system and preparation, processing and the characteristic of Si microfabrication element.

[2] Performance of low-loss RF MEMS capacitive switches[J] .IEEE Microwaveand Guided Wave Letters, 8 (8), 1998:269-271. Chinese translation: " performance study of low-loss RF MEMS capacitance switch ".This article has mainly been discussed characteristic, the advantage of electrostatic RF MEMS capacitance switch.

[3] Micromachined low-loss microwave switches[J], IEEE of MicromechanicalSystems, 8 (2), the 1999:129-1333. Chinese translation: " microfabrication of low-loss microwave switch ", as long as this article has been discussed the fine machining method of microwave switch.

[4] Measurement and modeling of surface micromachined, electrostaticallyactuated micro-switches[A] .Proc IEEE Transducers 97[C], 1997:1145-1148. Chinese translation: " the surperficial microfabrication modeling and the measurement of electrostatic micro switch ", this article has mainly been discussed the surperficial microfabrication modeling and the performance measurement of electrostatic micro switch.

[5] Contact physics of gold microcontacts for MEMS switches[J] .IEEE Transon Components and Packaging Technology, 22 (3), 1999. Chinese translation: " the contactant Neo-Confucianism of golden little contact of mems switch ", this article have mainly been discussed the physical property influence of gold to mems switch.

[6] preparation of micromechanics microwave/radio-frequency (RF) switch and functional measurement research, Semiconductor Technology, Vol.27 (111), 2002:11-14, this article have mainly discussed the preparation of electrostatic micromechanics microwave/radio-frequency (RF) switch and the method for measurement of performance.

[7] A fast, robust and simple 2-D micro-optical scanner based on contactlessmagnetostrictive actuation, IEEE of Micromechanical Systems, 2000:715-720. Chinese translation: " a kind of non-contact type, quick, lasting, simple two-dimensional micro scanner that activates based on magnetostriction ", as long as this article has been discussed preparation, the performance that activates the low-light scanner based on magnetostriction.

[8] No-linear actuation of cantilevers using giant magnetostrictive thinfilms, Ultrasonics, No.38,2000:64-66. Chinese translation: " non-linear actuation of giant magnetostrictive driver film cantilever beam ", this article has mainly been discussed the intrinsic resonance characteristic of magnetostrictive thin film cantilever beam.

[9] giant magnetostrictive thin film material and application thereof, the China YouSe Acta Metallurgica Sinica, vol.10 (supplementary issue 1), 2000:266-269. this article has mainly been discussed the present Research and the characteristic thereof of magnetostrictive thin film material, the application in Micropump, ultrasonic line motor, transducer.

Summary of the invention

The purpose of this invention is to provide a kind of microwave/rf micromechanical switch and preparation method thereof, adopt the microwave/rf micromechanical switch of the inventive method preparation to have low driving voltage and high characteristics such as response speed.

A kind of microwave/rf micromechanical switch provided by the invention (as shown in Figure 2), it comprises: anchor position 1, substrate 2, holding wire 5, cantilever beam 6, contact metal layer 7, holding wire 8 is characterized in that it also comprises externally-applied magnetic field lead 9, magnetostrictive layer 10; In substrate 2, be arranged in parallel for anchor position 1, externally-applied magnetic field lead 9 and holding wire 5 and 8; The stiff end of cantilever beam 6 is on anchor position 1, and overhanging portion is positioned at directly over externally-applied magnetic field lead 9 and holding wire 5 and 8; On the magnetic cantilever beam 6 for causing stretchable layer 10; Contact metal layer 7 be positioned at cantilever beam 6 overhanging portions under.

Need to prove that substrate 2 can be adopted insulating material such as alumina ceramic plate, silicon nitride; Cantilever beam 6 can adopt high-strength materials such as silicon, silicon nitride; Contact metal layer 7 can adopt conductivity good metal such as gold, silver, platinum; Externally-applied magnetic field lead 9 can adopt conductivity good metal such as gold, silver, platinum; Holding wire 5 and 8 can adopt conductivity good metal such as gold, silver, platinum; Magnetostrictive layer 10 can adopt TbFe (terbium iron), TbDyFe (terbium dysprosium ferrum) magnetostrictive thin film, also can adopt TbFe/Fe (terbium iron/iron), TbDyFe/Fe (terbium dysprosium ferrum/iron) magnetostriction multilayer film.

The operation principle of a kind of microwave/rf micromechanical switch provided by the invention is: feed direct current by the externally-applied magnetic field lead, generation is along the horizontal magnetic field of cantilever beam horizontal direction, magnetostrictive thin film is adding the elongation strain that produces horizontal direction under the action of a magnetic field, cause that cantilever beam is bent downwardly the connection signal line, the conducting microwave signal realizes opening of signal; Behind the externally-applied magnetic field failure of current, magnetostrictive effect disappears, and cantilever beam restores to the original state, and microwave signal can not conducting, the pass of realizing signal.

The preparation method of microwave/rf micromechanical switch of the present invention is characterized in that it comprises following step:

Step 1 adopts photoetching process to form holding wire 5 and 8, externally-applied magnetic field lead 9 mould shapes in substrate 2, shown in figure a;

Step 2 is by conductivity good metal such as magnetron sputtering method deposition one deck gold, silver or platinum, shown in figure b;

Step 3 adopts acetone to soak and peels off formation holding wire 5 and 8, externally-applied magnetic field lead 9, shown in figure c;

Step 4 adopts photoetching process to form anchor position 1 mould shape in substrate 2, shown in figure d;

Step 5 is by magnetron sputtering method deposition one deck silicon or silicon nitride, shown in figure e;

Step 6 adopts acetone to soak and peels off formation anchor position 1, shown in figure f;

Step 7 adopts the way of whirl coating to apply the micromechanics organic sacrificing layer, shown in figure g;

Step 8 adopts photoetching process to form contact metal layer 7 mould shapes on sacrifice layer, shown in figure h;

Step 9 is by conductivity good metal such as magnetron sputtering method deposition one deck gold, silver or platinum, shown in figure i;

Step 10 adopts acetone to soak and peels off formation contact metal layer 7, shown in figure j;

Step 11 adopts photoetching process to form cantilever beam 6 mould shapes, shown in figure k;

Step 12 is by cantilever beam materials such as magnetron sputtering method depositing silicon or silicon nitrides, shown in figure l;

Step 13 is by mangneto self-adhering film or magnetostriction multilayer films such as magnetron sputtering method deposition one deck TbFe, TbDyFe, TbFe/Fe, TbDyFe/Fe, shown in figure m;

Step 14 adopts acetone to soak and peels off formation cantilever beam 6 and magnetostrictive layer 10, shown in figure n;

Step 15 adopts the special-purpose liquid of removing of sacrificial layer material to soak the removal sacrifice layer, shown in figure o;

Through after the above-mentioned steps, just can prepare magnetostriction type microwave/rf micromechanical switch of the present invention.

Magnetostriction type microwave/rf micromechanical switch of the present invention has the advantages that driving voltage is low, the response time is short.

Description of drawings

Electrostatic microwave/rf micromechanical switch structural representation that Fig. 1 is traditional

The 1-anchor position, 2-substrate, 3-top electrode, 4-ground wire, 5-holding wire, 6-cantilever beam, 7-contact metal layer, 8-holding wire;

Fig. 2 magnetostriction type microwave of the present invention/rf micromechanical switch structural representation

The 1-anchor position, 2-substrate, 5-holding wire, 6-cantilever beam, 7-contact metal layer, 8-holding wire, 9-externally-applied magnetic field lead, 10-magnetostrictive layer;

Fig. 3 magnetostriction type microwave/rf micromechanical switch preparation technology schematic flow sheet

Wherein, figure a is that photoetching forms holding wire 5 and 8, externally-applied magnetic field lead 9 mould shape schematic diagrames;

Figure b is by conductivity good metal schematic diagrames such as magnetron sputtering method deposition one deck gold, silver or platinum;

Figure c soaks to peel off to form holding wire 5 and 8, externally-applied magnetic field lead 9 schematic diagrames;

Figure d adopts photoetching process to form anchor position 1 mould shape schematic diagram in substrate 2;

Figure e is by magnetron sputtering method deposition one deck silicon or silicon nitride schematic diagram;

Figure f adopts acetone to soak to peel off formation anchor position 1 schematic diagram;

Figure g adopts the way of whirl coating to apply micromechanics organic sacrificing layer schematic diagram;

Figure h adopts photoetching process to form contact metal layer 7 mould shape schematic diagrames on sacrifice layer;

Figure i is by conductivity good metal schematic diagrames such as magnetron sputtering method deposition one deck gold, silver or platinum;

Figure j adopts acetone to soak to peel off formation contact metal layer 7 schematic diagrames;

Figure k adopts photoetching process to form cantilever beam 6 mould shape schematic diagrames;

Figure l is by cantilever beam material schematic diagrames such as magnetron sputtering method depositing silicon or silicon nitrides;

Figure m is by magnetron sputtering method deposition one deck TbFe, TbDyFe magnetostrictive thin film or TbFe/Fe, TbDyFe/Fe magnetostriction multilayer film schematic diagram;

Figure n adopts acetone to soak to peel off formation cantilever beam 6 and magnetostrictive layer 10 schematic diagrames;

Figure o adopts the special-purpose removal of sacrificial layer material liquid to soak to remove the sacrifice layer schematic diagram.

Embodiment

At substrate 20 * 20 * 0.5mm ³Make microwave/radio-frequency switch array on the alumina ceramic plate:

(1) adopts 20 * 20 * 0.5mm ³Alumina ceramic plate is as substrate, and photoetching forms holding wire, externally-applied magnetic field wire module shape after cleaning, and the thick gold of sputter one deck 0.5 μ m forms holding wire, externally-applied magnetic field lead through peeling off;

(2) adopt photoetching process in substrate, to form anchor position mould shape,, form the anchor position through peeling off by the thick silicon of magnetron sputtering method deposition one deck 2.5 μ m;

(3) in substrate, apply the thick micromechanics of 2 μ m PiRLIII polyimide sacrificial layer by lacquering technique;

(4) form the contacting metal layer pattern by photoetching on sacrifice layer, the thick gold of sputter one deck 0.1 μ m is through peeling off the formation contact metal layer;

(5) form the cantilever beam figure by photoetching, the thick TbDyFe magnetostrictive thin film layer of silicon that sputter one deck 20 μ m are thick and 2 μ m forms cantilever beam, magnetostrictive thin film layer through peeling off successively;

(6) adopt the PiRLIII polyimide sacrificial layer material special use liquid that removes photoresist to remove sacrifice layer, discharge cantilever beam;

Photoresist is selected the thick glue of AZ-9260 micromechanics for use, by the acceleration of control whirl coating and the thickness that linear velocity is controlled photoresist.

The critical size of switch: anchor position 100 * 100 μ m ²20 μ m are wide for the externally-applied magnetic field lead; 20 μ m are wide for holding wire, and middle ware is wide apart from 30 μ m; Contact metal layer 50 * 50 μ m ²Cantilever beam 100 * 50 μ m ²

Claims

1, a kind of microwave/rf micromechanical switch, it comprises: anchor position (1), and substrate (2), holding wire (5), cantilever beam (6), contact metal layer (7), holding wire (8),, it is characterized in that it also comprises externally-applied magnetic field lead (9), magnetostrictive layer (10); Going up in substrate (2) is that anchor position (1), externally-applied magnetic field lead (9) and holding wire (5) and (8) are arranged in parallel; The stiff end of cantilever beam (6) is on anchor position (1), and overhanging portion is positioned at directly over externally-applied magnetic field lead (9) and holding wire (5) and (8); Magnetic cantilever beam (6) is gone up and is magnetostrictive layer (10); Contact metal layer (7) be positioned at cantilever beam (6) overhanging portion under.

2, a kind of microwave/rf micromechanical switch according to claim 1, it is characterized in that described magnetostrictive layer 10 can adopt TbFe (terbium iron) magnetostrictive thin film, TbDyFe (terbium dysprosium ferrum) magnetostrictive thin film, also can adopt TbFe/Fe (terbium iron/iron) magnetostriction multilayer film, TbDyFe/Fe (terbium dysprosium ferrum/iron) magnetostriction multilayer film.

3,, it is characterized in that described externally-applied magnetic field lead 9 can adopt conductivity good metal such as gold, silver, platinum according to the described a kind of microwave/rf micromechanical switch of claim 1.

4, a kind of microwave/rf micromechanical switch according to claim 1 is characterized in that the preparation method of described a kind of microwave/rf micromechanical switch comprising following step:

Step 1 adopts photoetching process to form holding wire 5 and 8, externally-applied magnetic field lead 9 mould shapes in substrate 2;

Step 2 is by conductivity good metal such as magnetron sputtering method deposition one deck gold, silver or platinum;

Step 3 adopts acetone to soak and peels off formation holding wire 5 and 8, externally-applied magnetic field lead 9 shows;

Step 4 adopts photoetching process to form anchor position 1 mould shape in substrate 2;

Step 5 is by magnetron sputtering method deposition one deck silicon or silicon nitride;

Step 6 adopts acetone to soak and peels off formation anchor position 1;

Step 7 adopts the way of whirl coating to apply the micromechanics organic sacrificing layer;

Step 8 adopts photoetching process to form contact metal layer 7 mould shapes on sacrifice layer;

Step 9 is by conductivity good metal such as magnetron sputtering method deposition one deck gold, silver or platinum;

Step 10 adopts acetone to soak and peels off formation contact metal layer 7;

Step 11 adopts photoetching process to form cantilever beam 6 mould shapes;

Step 12 is by cantilever beam materials such as magnetron sputtering method depositing silicon or silicon nitrides;

Step 13 is by mangneto self-adhering film or magnetostriction multilayer films such as magnetron sputtering method deposition one deck TbFe, TbDyFe, TbFe/Fe, TbDyFe/Fe;

Step 14 adopts acetone to soak and peels off formation cantilever beam 6 and magnetostrictive layer 10;

Step 15 adopts the special-purpose liquid of removing of sacrificial layer material to soak the removal sacrifice layer.