Modeling of ultrafast metal–semiconductor–metal photodetectors

1991 ◽  
Vol 69 (3-4) ◽  
pp. 520-526 ◽  
Author(s):  
D. Landheer ◽  
Z.-M. Li ◽  
S. P. McAlister ◽  
D. A. Aruliah
Keyword(s):  
Transmission Lines ◽  
Drift Diffusion Model ◽  
Drift Diffusion ◽  
One Dimensional ◽  
Deep Traps ◽  
Duty Cycles ◽  
Metal Semiconductor Metal ◽  
Pile Up ◽  
Strained Layer Superlattice ◽  
Msm Photodetectors

We have simulated the transient response of metal–semiconductor–metal (MSM) photodetectors to an optical impulse, using a two-dimensional (2-D) drift-diffusion model that incorporates deep traps and appropriate boundary conditions. We incorporate the external circuit using a method originally developed to describe photoconductors in transmission lines. Initially a one-dimensional (1-D) simulation is used to verify our model comparing our results to previous 1-D calculations and experimental results for GaAs MSM detectors. Then a full 2-D analysis is used to predict the performance of a novel MSM wave-guide photodetector whose structure incorporates a Si–Si0.5Ge0.5 strained-layer superlattice. We show that this device can have a response as fast as 50 ps, although pulse pile-up due to slow diffusion of carriers may be a problem at high duty cycles.

scholarly journals Testing Hydrodynamical Models on the Characteristics of a One-Dimensional Submicrometer Structure

VLSI Design ◽  
1998 ◽  
Vol 6 (1-4) ◽  
pp. 155-160
Author(s):  
A. M. Anile ◽  
O. Muscato ◽  
S. Rinaudo ◽  
P. Vergari
Keyword(s):  
High Speed ◽  
Relaxation Times ◽  
Drift Diffusion Model ◽  
Drift Diffusion ◽  
Industrial Environment ◽  
Hydrodynamical Models ◽  
One Dimensional ◽  
Simulation Tools ◽  
Speed Performance ◽  
Output Characteristics

Recent advances in technology leads to increasing high speed performance of submicrometer electron devices by the scaling of both process and geometry. In order to aid the design of these devices it is necessary to utilize powerful numerical simulation tools. In an industrial environment the simulation codes based on the Drift-Diffusion models have been widely used. However the shrinking dimension of the devices causes the Drift-Diffusion based simulators to become less accurate. Then it is necessary to utilize more refined models (including higher order moments of the distribution function) in order to correctly predict the behaviour of these devices. Several hydrodynamical models have been considered as viable simulation tools. It is possible to discriminate among the several hydrodynamical models on the basis of their results on the output characteristics of the electron device which are measurable (I-V curves). We have analyzed two classes of hydrodynamical models: i) HFIELDS hydrodynamical models and HFIELDS drift-diffusion model; ii) self-consistent extended hydrodynamical models with relaxation times determined from Monte Carlo simulations.

The combined semi-classical and relaxation limit in a quantum hydrodynamic semiconductor model

2010 ◽  
Vol 140 (1) ◽  
pp. 119-134 ◽  
Author(s):  
Yeping Li
Keyword(s):  
Diffusion Model ◽  
Hydrodynamic Model ◽  
Drift Diffusion Model ◽  
Smooth Solutions ◽  
Drift Diffusion ◽  
One Dimensional ◽  
Quantum Hydrodynamic Model ◽  
Highly Nonlinear ◽  
Isentropic Euler Equations ◽  
Quantum Hydrodynamic

We discuss the combined semi-classical and relaxation limit of a one-dimensional isentropic quantum hydrodynamical model for semiconductors. The quantum hydrodynamic equations consist of the isentropic Euler equations for the particle density and current density, including the quantum potential and a momentum relaxation term. The momentum equation is highly nonlinear and contains a dispersive term with third-order derivatives. The equations are self-consistently coupled to the Poisson equation for the electrostatic potential. With the help of the Maxwell-type iteration, we prove that, as the relaxation time and Planck constant tend to zero, periodic initial-value problems of a scaled one-dimensional isentropic quantum hydrodynamic model have unique smooth solutions existing in the time interval where the classical drift-diffusion model has smooth solutions. Meanwhile, we justify a formal derivation of the classical drift-diffusion model from the quantum hydrodynamic model.

ASYMPTOTIC BEHAVIORS AND CLASSICAL LIMITS OF SOLUTIONS TO A QUANTUM DRIFT-DIFFUSION MODEL FOR SEMICONDUCTORS

2010 ◽  
Vol 20 (06) ◽  
pp. 909-936 ◽  
Author(s):  
SHINYA NISHIBATA ◽  
NAOTAKA SHIGETA ◽  
MASAHIRO SUZUKI
Keyword(s):  
Diffusion Model ◽  
Initial Boundary ◽  
Initial Boundary Value Problem ◽  
Singular Limit ◽  
Drift Diffusion Model ◽  
Planck Constant ◽  
Drift Diffusion ◽  
One Dimensional ◽  
Unique Existence ◽  
Initial Boundary Value

This paper discusses a time global existence, asymptotic behavior and a singular limit of a solution to the initial boundary value problem for a quantum drift-diffusion model of semiconductors over a one-dimensional bounded domain. Firstly, we show a unique existence and an asymptotic stability of a stationary solution for the model. Secondly, it is shown that the time global solution for the quantum drift-diffusion model converges to that for a drift-diffusion model as the scaled Planck constant tends to zero. This singular limit is called a classical limit. Here these theorems allow the initial data to be arbitrarily large in the suitable Sobolev space. We prove them by applying an energy method.

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