Study of MEMS Devices for Space Applications ~Study Status and Subject of RF-MEMS~

Transcription

1 Study of MEMS Devices for Space Applications ~Study Status and Subject of RF-MEMS~ The 26 th Microelectronics Workshop October, 2013 Maya Kato Electronic Devices and Materials Group Japan Aerospace Exploration Agency 1

2 Outline Introduction Surrounding applications Space applications RF-MEMS - What is RF-MEMS? - Advantage of RF-MEMS switches - Comparison of RF-MEMS switches and other switches - Variation - Applications - Evaluation of commercial switches - In-house research and development - Subject Conclusions 2

3 Introduction MEMS: Micro Electro Mechanical System The technology of very small devices using a microfabrication technique. Advantages of MEMS Devices Downsizing and weight saving For microfabrication applied by a semiconductor process To integrate structure and electronic circuits High functionality To implement various functions on one-chip. Low cost and stable production Similar to the semiconductor process, MEMS can be mass-produced with good and stable quality 3

4 Surrounding applications MEMS applications - Accelerometers : airbag system, game controller, cell phone - gyroscopes : car navigation system, digital camera - inkjet heads : inkjet printers - Bio-MEMS : Lab-On-Chip Gyroscope, Acceleration sensor (display, games) Microphone ( communication ) Gyroscope (position control ) Pressure sensor (engine control) Microphone Acceleration sensor (airbag) Pressure sensor (tire pressure ) inkjet heads Laser radar (distance control) Environment sensor ( temperture and humidity control)

5 Space application MEMS + Integrated circuit = New Device Monitoring of cabin environment and health of astronaut RF RF Circuit Si chip Sensor Micro dynamo System downsizing More system redundancy More space for mission system Wireless test system (reject the test harnesses) Small and lightweight Power saving High-density High-performance

6 RF-MEMS RF-MEMS : Radio Frequency Micro-Electro-Mechanical-Systems For example Phased-array antenna : Several thousand radiating elements required Complex subsystem is high cost Switch matrices: Hundreds of switches required Bulky and heavy Large impact! Small size Lightweight Excellent RF performance Low insertion loss High isolation Low power consumption Low cost New architecture Phased Array type L-band Synthetic. Aperture Radar Switch matrices 1 1 Mojgan Daneshmand, Multi-Port RF MEMS Switches and Switch Matrices, University of Waterloo, Ontario, Canada, 2006

7 RF-MEMS What is RF-MEMS? Radio frequency applications using MEMS. RF-MEMS are expected to provide multiband and low power consumption and downsizing. For example Switch Varactor Inductor Resonator Characteristics Low loss High isolation High variability High linearity High Q factor Variable inductance Applications Multiband by switching circuit construction Wide bandwidth of oscillator circuit, amplifier circuit and matching circuits Low power consumption of oscillator circuit and amplifier circuits High Q factor Downsizing and integration of oscillator circuit downsizing and filter Charactristic and application of RF-MEMS

8 RF-MEMS Advantage of RF-MEMS switch Surface-micromachined devices using mechanical Movements to open and close circuits in the RF transmission-line Very low insertion-loss Very high isolation Power consumption is nearly zero using electrostatic actuator and piezoelectric actuator. By replacing the current space components with RF-MEMS s witches, the system of satellite reduce size and weight.

9 Comparison of RF-MEMS switches and other switches. Parameter PIN Semiconductor Conventional mechanical MEMS Range MHz~ DC~ DC~GHz DC~GHz Size Switch type Advantage of RF-MEMS Small size Low power condumption Excellent RF performance FET Small Small Large Small [1/100-1/1000] [1/100-1/1000] [1] [1/100-1/1000] Voltage (V) Power consumption (mw) (during latch state) RF-MEMS Switching speed ns ns ms μs Isolation Medium Low High High Insertion loss Medium High Low Low Power handling (W) Small Small Large Small

10 RF-MEMS Variation CONDUCTIVE TYPE Contact type : Capacitance type : DRIVE SYSTEM DC~GHz, good property (~30GHz), high isolation, low insertion loss, possible failure mode corrosion, stiction GHz, good property (20-100GHz), possible failure mode dielectric charging Electrostatic actuation : Piezoelectric actuation : Magnetic actuation heat transfer actuation : SWITCH ARCHITECTURE Series type : Shunt type : low power consumption, high actuation voltage, simple to fabricate low power consumption, low actuation voltage low actuation voltage, consumes significant power(>ma) Switches are connected in series ON : close, OFF : open Switches are connected in parallel ON : open, OFF : close We should select the most appropriate RF-MEMS switch. Failure mode analysis and reliability tests are required in each case.

11 RF-MEMS Applications Redundant and reconfigurable switch matrices Since satellite communication system have hundreds of switches integrated in the form of switch matrices to provide system redundancy, any reduction in size and mass would have a significant overall impact. Furthermore, It is expected to realize more advanced redundant systems. Conventional switch matrices 1 Requirements specification Cycles : million Transmission power : ~ tens of W Switching speed : < sec Lifetime : ~15 years Phase shifters of phased array antenna for satellite communication and radar systems Phased Array type L-band Synthetic. Aperture Radar By applying RF-MEMS switches to phase shifters for satellite communication and radar systems, we can achieve high performance, size reduction, and low power consumption. Especially RF-MEMS switches have excellent RF performance relative to semiconductor switches. Requirements specification Cycle : billion Transmission power : ~ tens of W Switching speed : < μsec Lifetime : ~15 years 1 Mojgan Daneshmand, Multi-Port RF MEMS Switches and Switch Matrices, University of Waterloo, Ontario, Canada, 2006

12 RF-MEMS Evaluation of commercial switches

13 RF-MEMS Evaluation of commercial switches Selected samples Omron Corp. in JAPAN Movable electrode Contact point Advantest. in JAPAN The Omron switch is a electrostatically-actuated single-pole double-throw (SPDT) switch released in 2008, the performance of which has been highly praised by researchers from around the world. Movable electrode Contact point The Advantest switch is a piezoelectric SPDT switch driven by PZT, which is expected to be used for high-speed LSI test system. The advantage is high RF performance at 20 GHz. We would like to thank Omron Corp. and Advantest for assistance in the evaluation of switches.

14 Evaluation of commercial switches We conducted some environmental tests on Omron and Advantest switches. Test title Test condition Omron (2SMES-01) Mechanical shock Random vibration Vibration, high frequency Thermal shock 1,500g(peak), Duration of pulse 0.5msec, +X,-X,+Y,-Y,+Z,-Z (for each three times) Overall rms 34.02G, 15minutes, X,Y,Z 20g(peak), 10~2,000Hz, Sweep time 20min, X,Y,Z RF-MEMS -55~+125, 100cyc We are going to add a cycle until it breaks down. Failure; Change in contact resistance level exceeding 1000mΩ Advantest (PMD1+LTCC) 0/3 0/3 0/3 0/3 0/3 0/3 0/4 0/4

15 RF-MEMS Specialized switches for space

16 RF-MEMS In-house research and development To further enhance performance and reliability, we fabricate and evaluate RF-MEMS switches. Switch type : Metal-contact switch The switch was originally designed by Mitsubishi Electric. Their switches were successfully launched and demonstrated in space as a first in Japan. Target Range : ~40GHz Insertion loss : < 0.3dB Switching time: 10 μsec Cycles :10 billion Cantilever RF in Metal contact RF out Actuation electrode Cross-sectional view of a metal-contact switch. We appreciate the help received from Dr. Sang-Seok Lee from Tottori University with valuable discussion and assistance in fabrication.

17 Subject RF-MEMS Earch failure mode analysis There are various types of switches by the conduction systems, and the drive systems, and switch architecture. Long-term system reliability Satellite systems must operate for more than 10 years,without failing. Number of switching cycles Life time Power handling for transmit signals The transmission power within satellites can be very high, due to the need to overcome long transmission paths. Space-specific reliability Reliability tests for space applications are needed. Radiation Thermal cycling Thermal shocks Vibration and mechanical shock Operation in very high vacuum Establish the test method We need to establish an accelerated test method. We confirmed positive results.

18 Other approaches

19 Other approaches MEMS mirror ECO SCAN ESS214A (The Nippon Signal Co., Ltd.) Vibration test :30G MEMS shutter We fabricate a MEMS shutter for irradiation tests of electric devices

20 Other approach MEMS gyro TAG202(Tamagawa Seiki Co.,Ltd.): Tuning-fork type vibration gyro using LiNbO3 oscillator. MEMS mirror ECO SCAN ESS214A (The Nippon Signal Co., Ltd.) : Electromagnetic drive type mirror. Mechanical shock 644G,1msec,xyz Vibration test 30 G drive detection Temperature cycling test -40 ~ +125, 30min, 2000 cyc Vibration test 20~2kHz, 20G, x,y,z Sealing test Mechanical shock 1000G, (half-sine ), x y z High Temperature Operating test 85, 4000h No change in the basic property TAG 234 will be used as a data source for SOFIE SOFIE = SOI-FPGA In-orbit demonstration Equipment

21 Other approach MEMS shutter For irradiation tests on electric devices, we fabricate a MEMS shutter which can control the irradiation area according to the aperture. The purpose is a reduction of the time and expenses required in irradiation tests. Light / Radiation Shutter cover Actuator Test Sample Target area QCM (Quartz Crystal Microbalance) QCM is a mass sensor, which can be used to monitor of spacecraft, but the temperature compensation type is expensive and inflexible. We therefor fabricate the original QCM sensor. Target performance - Temperature: LN2(-196 C) to 100 C - Mass Sensitivity: picogram to nanogram

22 Conclusions MEMS devices are expected to be applicable to space systems owing to their significant advantages. RF-MEMS switches are expected to be particularly applicable to space systems. Advantage Small size Lightweight Low power consumption Excellent RF performance ( low insertion loss, high isolation ) Application Low cost Redundant and reconfigurable switch matrices Phase shifters of phased array antenna for satellite communication and radar system Evaluation of commercial switches To investigate the feasibility of RF-MEMS switches for the space applications, we have performed durability experiments. In-house research and development To improve reliability and performance, we fabricate RF-MEMS switches. Subject Earch failure mode analysis Long-term system reliability Power handling for transmission signals Space-specific reliability Establish the tast method Future : Study the failure mechanism and reliability Enhanced performance and reliability for space applications

23 Thank you for your attention 23