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| ¡DGeneral
Description: |
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| ¡@This project is to develop the
new micro/nano optoelectronic systems and required
elements and devices. The core technologies include:
(1) System integration technology; (2) Key nano/microoptical
elements and devices; (3) Advanced package technology.
These are the keys to the next generation of nano/micro
optoelectronic system. In the first year, we develop
the Guided Moded Filter and its application in
the biosensor, and photonic crystal circuit in
communication. In the package, we develop the
Au-Si eutectic bonding. In the high-speed (>
40 Gb/s and 30 GHz applications) photonics and
electronics, we have developed and demonstrated
the related high-speed electronics (pHEMTs, HBTs,
SETs and circuits) and photonics (photo-diodes,
QD laser, and PD-TIA). Most of the achievements
have been accepted and published on IEEE related
major journals and IEDMS. The objectives are continuing
to pursue the novel electronics/photonics and
thus integration of both for ultra-high speed
applications using the well established MOE Lab
in phase I.
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¡DBreakthroughs
and Major Achievements: |
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¡@(1) performance enhancement by
using the n+-GaN cap layer and gate recess technology
on the AlGaN/GaN HEMT fabrication, 0.09£gm footprint
T-gate fabrication, and 12.5GHz inverter implemented
by 0.15£gm In0.5Ga0.5As/ In0.5Al0.5As mHEMT.
¡@(2) 1.33 mm quantum dot lasers on GaAs substrate
with output power as high as 138 mW under pulsed
operation, and demonstrating low threshold current
(50 mA) and high internal quantum efficiency (63
%) under continue wave operation. InAs quantum
dot s with emission wavelength of 1.55 mm and
a narrow linewidth (30 meV). And 1.47 mm light-emitting
diodes
¡@(3) novel GaAs and InP HBTs with composite and
non-uniform doping collector for high power linearity
applications and OEIC.
¡@(4) a simple and CMOS-compatible method, selective
oxidation of Si1-xGex-on-insulator, for forming
nanometer scale Germanium (Ge) quantum dots (QDs)
and experimentally demonstrated room-temperature
Ge single electron transistors (SETs)
¡@(5) Two types novel photodiode with record high
bandwidth¡Vefficiency-power product performance:
Partially p-doped photodiode and near-ballistic
uni-traveling-carrier photodiode (NBUTC-PD). 1.01A/W,
50GHz bandwidth, 6dBm RF power at 40GHz.
¡@(6) Si-based GMR device: we sucessfully fabricate
the Si-based GMR device with FWHM of 1.2 nm. It
is a key component of our desighed-biosensor to
come true high sensitivity in DNA hybridation.
¡@(7) Photonic Crystal Device: we use the dielectric
microspheres theoretically reduce the propagation
loss. We also study two-dimensional photonic crystal
beam splitters. The simulation results show that
a large bandwidth of the extinction ratio larger
than 20dB can be obtained as two beams are interfered
in the beam splitters. This enables photonic crystal
beam splitters to be used in fiber optic communication
systems.
¡@(8) Au-Si bonding: the major project is to research
a way in Au-Si eutectic bonding system, that can
provide a reliable, high strength and even a nice
expended bonding interface in fabricating vertical
thin-GaN blue LED devices. Au-Si bonding can become
the major solution to fabricate thin-GaN LED devices
owing to his many advantages.
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¡DResearch
Outcomes: |
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¡@AlGaN/GaN
HEMT and InGaAs/ InAlAs mHEMT
BCB-bridged distributed wideband SPST switch
using 0.25£gm In0.5Al0.5As-In0.5Ga0.5As metamorphic
HEMTs: Insertion loss of less than 5.5 dB, and
isolation larger than 30 dB.
Performance enhancement by using the n+-GaN
cap layer and gate recess technology on the AlGaN/GaN
HEMT fabrication: Ids,max of 1.1 A/mm, a gm, max
of 220 mS/mm, an fT of 43 GHz, an fmax of 68 GHz,
and an output power density of W/mm at 2.4 GHz.
Performance enhancement by the In0.65Ga0.35As
pseudomorphic channel on the In0.5Al0.5As metamorphic
buffer layer: The 1£gm gate-length devices which
dc maximum drain-to-source current and transconductance
enhances from 340 to 490 mA/mm, and from 450 to
670 mS/mm. The RF current gain cut-off frequency
and maximum oscillation frequency increases from
22 to 31 GHz and from 42 to 58 GHz, respectively.
The 0.25£gm gate-length devices that RF current
gain cut-off frequency and maximum oscillation
frequency are 120GHz and 150 GHz.
0.09£gm footprint T-gate fabrication and 12.5GHz
Inverter by 0.15£gm In0.5Ga0.5As/ In0.5Al0.5As
mHEMT.
1.33 mm quantum
dot lasers on GaAs substrate
1.33 mm quantum dot lasers on GaAs substrate
with output power as high as 138 mW under pulsed
operation
1.33 mm quantum dot laser with low threshold
current (50 mA) and high internal quantum efficiency
(63 %) under continue wave operation
InAs quantum dot s with emission wavelength
of 1.55 mm and a narrow linewidth (30 meV)
1.47 mm light-emitting diodes
Novel GaAs and
InP HBTs
Novel GaAs HBTs with non-uniform collector doping
demonstrated improved ac characteristics from
controlled Kirk effect and improved power linearity
as large as 9 dBc at 1.8 GHz.
A novel MESFET with surface oxygen implantation
for passivation was presented.
Ge QDs and Ge SETs
Developing a simple and CMOS-compatible method,
selective oxidation of Si1-xGex-on-insulator,
for forming nanometer scale Germanium (Ge) quantum
dots (QDs) and experimentally demonstrated room-temperature
Ge single electron transistors (SETs).
Clear Coulomb oscillation (peak-to-valley ratio
of 1.9) and staircase are observed at room temperature,
and the extracted addition energy of the Ge QD
is about 125 meV, which is about 4.5 times of
3kBT at room temperature.
High-speed PD and
EAM
We have demonstrated two types novel photodiode
with record high bandwidth¡Vefficiency-power product
performance: Partially p-doped photodiode and
near-ballistic uni-traveling-carrier photodiode
(NBUTC-PD).
We have also established the light-wave component
analyzer system and heterodyne-beating system
for bandwidth measurement and device modeling,
as shown in Fig.2 and 3, respectively.
Guided-mode resonance(GMR)
filter for application in the Biosensor
We sucessfully fabricate the Si-based GMR device
which has a grating period(£N) of 0.5 £gm, grating
depth (h) of 0.1£gm ,waveguide thickness (d) of
0.9£gm, and it demonstate a FWHM of 1.2 nm.
For the biosensor, we immobilize the bovine
serum albumin (BSA) molecule on the SiNx surface
on the GMR device, and sucessfully measured the
peak wavelength shift relative to the thickness
of BSA.
Photonic Crystal
Device
The transmission of the photonic crystal slab
waveguides with microspheres can be enhanced to
be around twice that without microspheres. This
technique to reduce the propagation loss can be
applied to the photonic crystal devices using
superprism, negative index and collimated beam
phenomena.
We studies two-dimensional photonic crystal
beam splitters with two input ports and two output
ports. The beam splitters can be used in photonic
crystal Mach-Zehnder interferometers or switches.
This enables photonic crystal beam splitters to
be used in fiber optic communication systems.
We develop a hollow optical waveguide with omni-directional
reflectors in silicon-based materials. A uniform
propagation loss of the waveguide to be around
1.7dB/cm for C+L band was found for the TE and
TM modes.
Au-Si Eutectic
Bonding
For Au-Si system, the forward voltage¡]Vf¡^for
thin-GaN LED chip, which size is 350¡Ñ350£gm, was
measured to be 3.4V at a forward current of 20
mA. This value is lower than the reported thin-GaN
LED fabricated by different bonding systems.
Moreover, the Au has excellent ductility, so
Au layer provides a good buffering effect for
the transferred GaN epi-layer.
Besides, we also can easily integrate high-quality
optoelectronic devices with Si integrated-circuit
devices, like ESD¡]electrostatic discharge¡^by fully-developed
semiconductor technology.
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Program
of PAEU > Program of PAEU (phase II)
