Advanced Simulation of Photodetectors using APSYS

Advanced Simulation of Photodetectors using APSYS

Advanced Simulation of Photodetectors
using APSYS
About APSYS
multiplication avalanche photo-diodes (SAGCM APDs) for optic
APSYS, Advanced Physical Models of Semiconductor Devices,
(QWIPs) for remote sensing.
is based on 2D/3D finite element analysis of electrical, optical
fiber communications, and quantum well infrared photodiodes
hv
p-layer
and thermal properties of compound and silicon semiconductor
devices. Emphasis has been placed on band structure
engineering and quantum mechanical effects. Inclusion of various
i "x"-nm Al(.6)Ga(.4)As
Models and Features
i 200-nm GaAs
n+ 300-nm GaAs
(5e18cm-3)
n+ GaAs Substrate
APSYS is a full 2D/3D simulator, which solves, self-consistently,
the Poisson’s equation, the current continuity equations, the carrier
With hot
electron effect
Without
hot electr. effect
Hydrodynamic models for hot carriers
Quantum wells and k.p theory
Thermionic emission model
2
1.5
0.1
1
Energy (eV)
Photocurrent (A/m)
mechanical wave equations, and the scalar wave equations for
Physical Models &
Advanced Features
See: Kwon et al, J. Lightwave
Technol. Vol 23 No 5
(2005) pp 1896-1906
1
energy transport equations (hydrodynamic model), quantum
features.
n-layer
Intrinsic Al0.6Ga0.4As
layer for energy
buildup purpose
p+ 800-nm GaAs
(5e18cm-3)
applications involving photosensitive or light emitting devices.
photo-detectors and avalanche photodiodes include the following
i-layer
p++ 30-nm GaAs
(~1e19cm-3)
optical modules also makes this simulation package attractive for
photonic waveguiding devices. Applicable features for modeling
i-layer
Energy buildup layer Multiplication layer
Al0.6Ga0.4As
GaAs
0.5
0
0.5
-1
-1.5
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Distance (micron)
0.01
0
2
4
6
8
10
12
14
16
18
Reverse Bias (V)
Impact ionization models
Modeling results for InP/InGaAs SAGCM APDS are presented
Intersubband optic absorption
below. The basic InP/InGaAs SAGCM device structure can be
Field dependent mobility model
Doping density dependent lifetime
Interface states and recombination
Temperature dependent model and low
temp(<77K) simulation
A large number of material models
Application Demonstrations
Photodetectors have extensive applications in fields from
astronomical observation, remote sensing imagers and optic fiber
communications etc. Modeling capabilities are here demonstrated
with PIN photo-diodes, separate absorption, grading, charge, and
built up with Crosslight Layer Builder.
Optical absorption is mainly in InGaAs layer and impact ionization
For QWIPs, the single well bound and unbound states from
mainly in n InP layer.
APSYS modeling is presented below.
-
For full QWIP device, the modeling results show good agreement
with experiment.