film-diode process – a breakthrough technology for …...over full if-band. rpg 183ghz mixer with...
TRANSCRIPT
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By Dr.-Ing. Oleg [email protected]
Technology Solutions for THz-Electronics
Film-Diode Process –a breakthrough technology for THz-Electronics
ACST GmbHJosef-Bautz-Str. 15, 63457 Hanau
www.acst.de
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eACST GmbH: Company profileACST GmbH: Company profile
Founded in 2006 as a Spin-Off from TU Darmstadt
First European commercial supplier of Schottky components for THz-Applications Originally-developed fabrication technology, particularly developed for mm-wave and THz-applications Discrete and monolithically-integrated Schottky-structures with state-of-the-art performance So far the only European supplier of Zero-Bias Diodes for THz-applications
Close collaboration with leading institutions concerning development of THz-technology Space agencies (ESA, DLR,CNES) Universities (TU Darmstadt, TU Berlin, TU Duisburg, TU Erlangen-Nuremberg, …) International industry partners
Leading Schottky technology with state-of-the-art performance First ultra-wideband Schottky detector (75GHz-1.5THz, in year 2008) First all-European 660GHz Heterodyne receiver with unprecedented performance Integrated RTD-oscillator with highest ever reported oscillation frequency (1,111 THz)
Anticipated participation in ESA MetOp Second Generation Program
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ePlanar and vertical structuresPlanar and vertical structures
Vertical structure
Planar structure
Uniform distribution of the current density across contact areaBack-side processing
required
No back-side process needed
Nonuniform distribution of the current density
Semiconductor
Schottky Ohmic
Semiconductor
Schottky
Ohmic
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eQVD Design ConceptQVD Design Concept
Whisker-Contacted Diodes (WCD)
Quasi-Vertical Diode (QVD)
Vertical structure Low parasitics
Quasi-vertical structure Reduced series resistance Good heat-sink Suitable for integration.
Unreliable contact No integration possible
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eThermal simulationsThermal simulations
Quasi-Vertical Diode (QVD)
Air-bridge5µm anode
Back-side contact pad
Planar Surface Channel Etched Diode (SCE)
Anode-lead5µm anode
Contact pad(flip-chip)
Whisker-contacted diode (WCD)
Whisker
70μm thickGaAs
Whisker
70μm thickGaAs
Contact pad
5µm anode
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eComparative simulation resultsComparative simulation results
0 20 40 60 80 1000
50
100
150
200
250
300
350
Max
. tem
pera
ture
, K
Dissipated power, mW
QVD WCD SCE
0 20 40 60 80 1000
50
100
150
200
Max
. tem
pera
ture
, KDissipated power, mW
h=1m h=2m h=3m h=4m h=5m
The impact of mesa thicknesson thermal performance of a QVD
Comparative results of considered structures
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eACST APD by FDACST APD by FD--processprocess
• Quasi-vertical approach
• Transferred membrane substrate
• Suitable for both discrete structures and integrated circuits
• Accommodates beamleads, MIM-capacitors, two-level wiring…
• Aims at ultimate performance at MM/SubMM waves
APD side-view APD front-view
90µm
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e332GHz Doubler IC332GHz Doubler IC
In collaboration with RPG Radiometer Physics GmbH
Fabricated 332GHz doubler Integrated Circuit
332GHz Doubler IC mounted in a WG332GHz Doubler IC mounted in a WG--BlockBlock
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e332GHz Doubler performance332GHz Doubler performance
• Limited input power of about 40mW-50mW is insufficient to fully characterize the doubler. • No sign of saturation: fully-pumped doubler should provide more output power.• Higher input power would result in a higher output power.
In collaboration with RPG Radiometer Physics GmbH
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e332GHz Tripler IC332GHz Tripler IC
Diodes
Heat-spreader
BeamleadsIC Front-side IC Back-side
In collaboration with RPG Radiometer Physics GmbH
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Typical conversion gain and noise temperature of a 183GHz
subharmonic (LOx2) mixer.
Integration times up to 200 sec. show no sign of instabilities or deviation from the radiometer law.
Allan Variance of a 183GHz mixer, operating in a switched-noise
stabilised radiometer.
Noise temperature less than 500K over full IF-band.
RPG 183GHz mixer with ACST APDRPG 183GHz mixer with ACST APD
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Tsys=1800 K
Tmix=800 to 1200 K
Conversion= –7 dB
LO Power: 5 mW
RPG 424GHz mixer with ACST APDRPG 424GHz mixer with ACST APD
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eFabricated 664GHz Mixer ICFabricated 664GHz Mixer IC
IF-outputLO-input
Supporting Beamleads
APD-Diode
Membrane-Substrate
Side view of a free-standing ICMeasured mixer performance
In collaboration with RPG Radiometer Physics GmbH
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In collaboration with RPG Radiometer Physics GmbH
First allFirst all--European 664GHz receiver systemEuropean 664GHz receiver system
664GHz Mixer mounted with test horn, 332GHz Tripler, Isolator, powerful W-band source (x6 internal)
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eZeroZero--Bias Detector diodesBias Detector diodes
Low video-resistance / high current responsivity; Optically-transparent membrane-substrate ; Suitable for monolithic integration (THz-MIC); The technology is suitable for frequencies well beyond1THz.
DC-Diode characteristicsDiscrete Diode mounted on CPW
Back-side contact pads
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• InGaAs built-in voltage (barrier height) significantly lower than GaAs (0.2eV compared to 0.8eV)
• (Reduced LO power required for SHM at 183 GHz: 0.34 mW (10 dB less!)
183 GHz InGaAs mixer with different LO-power
3.0 mW2.2 mW
0.34 mWLOPower
–5.5 dB–4.2 dB
–6.6 dBConv.Loss
500 K430 K
700 KTmix
GaAsInGaAs183GHz
183GHz mixer with ACST InGaAs diode183GHz mixer with ACST InGaAs diode
In collaboration with RPG Radiometer Physics GmbH
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eAchieved Performance (RPG)Achieved Performance (RPG)
Doubler Input power
Output Power
Efficiency DC Bias
44mW 11mW >20% 7V
Tripler Input power
Output Power
Efficiency DC Bias
67mW 6mW 9% 8V
Frequency Conversion L LO power Noise temperature Noise temperature (old)
183GHz InGaAs -6.5dB (DSB) 0.34 mW Tsys 800K (DSB no correction)Tmix 700K
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183GHz GaAs -4.2dB (DSB) 2 mW Tsys 525K (DSB no correction)Tmix 430K
Tsys 750K (-6.0dB L) RPG
432GHz GaAs -7.0dB (DSB) 5 mW Tsys 1700K (DSB no correction)Tmix 1100K
Tsys 2700K (-9.7dB L) RPG
660GHz GaAs Integrated
-8.0dB (DSB) 4mW Tsys 2300K (DSB no correction)Tmix 1600K
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eACST THz Detector ModuleACST THz Detector Module
Si-Lens
Antenna
Zero Bias Diode
Pre-Amp
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eAntenna integrated ZeroAntenna integrated Zero--Bias diodeBias diode
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eUWB measurements at TUDUWB measurements at TUD
Photoconductive generated CW THz signal modulated with 200kHz.
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eUWB measurement resultsUWB measurement results
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eFTIR measurements at DLRFTIR measurements at DLR
Courtesy of the department THz-Instrumentierung, Institut für Planetenforschung
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eResponse time measurement at ANKAResponse time measurement at ANKA
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eDetector response timeDetector response time
• Real pulse length in the accelerator: about 14ps.• Detector response: about 25ps. The delay is considered to be due to
limitations of the SMA connector.• HTS (YBCO) hi-temperature superconductor. -detector-20ps.
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eRTDRTD--based THzbased THz--MICMIC
Free-standing THz-MICRadiating
Vivaldy-antenna
Slot antenna resonator
Insulator Membrane-substrate
Contact padsfor DC-bias
RTD
In collaboration with TUD
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Mounted circuit by thermo-compression via insulator membrane
Gold-bump Array on contact-pads
Si-Substrate
Thin-filmresistor
Gold-bumps are used to increase local pressure while keeping low total pressure on the pad.
Mounting approachMounting approach
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eAssembled RTDAssembled RTD--oscillatoroscillator
MIM
In collaboration with TUD
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eMeasured resultsMeasured results
Oscillation frequencies up to 1111GHz. This is the highest RTD-oscillation frequency reported so far.
In collaboration with TUD
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Thank You !Thank You !