Книги2 / 1993 P._Lloyd,__C._C._McAndrew,__M._J._McLennan,__S._N
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R.W. Knepper et a1.: Technology CAD at IBM
Seen in Figure 6 is a vertical profile cut through the PoWell region. see the N + source/drain pocket at a junction depth of 0.2 p.m, profile and the heavily-doped P + substrate.
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Figure 6. Vertical profile through the PoWell |
region of Figure 3 showing the |
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N + |
source/drain |
pocket diffusion, |
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the PoWell |
profile, |
and the heavily-doped |
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P + substrate. |
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5.FIELDAY Device Modeling Program
FIELDAY is a 2D/3D finite element device simulation program having the following features:
•Full 3D capability (right prismatic and tetrahedral elements)
•Hydrodynamic model for holes and electrons
•Fermi-Dirac carrier statistics
•Incomplete ionization
36 |
R.W. Knepper et aJ.: Technology CAD at IBM |
•Heat equation
•Generalized velocity limited contacts
•Voltage and current boundary conditions
•Attached circuit elements (R, C, G)
•A.C. small signal analysis
•Steady state and transient simulation
•Heavy doping effects
•Bulk & interface trapped charge in insulator material
•Fully-coupled (DD) and partially-coupled (Hydro) solution strategies
•Direct and iterative matrix solution methods
•FET and bipolar physical models and parameter extraction
•Heterostructure capability
•Gallium Arsenide simulation capability
•Alpha and cosmic particle impact
•Voltage continuation method for negative resistance IV trace
•Band-to-band tunneling and other field-enhanced leakage mech
•Impact ionization and recombination mechanisms
•Isolated silicon regions
The original FIELDAY program was written in the late 1970's by E. Buturla, P. Cottrell and co-workers at the IBM Burlington location [8 -10J and was later rewritten by J. Johnson and S. Furkay at the same location [14]. The program has seen pervasive use throughout IBM for both FET and bipolar device simulation primarily for studying and optimizing device behavior and also in the construction of device models for circuit analysis [15,16,22]' The program is enhanced and re-released on a regular basis by the Technology Modeling project in East Fishkill and the Technology Simulation department in Burlington.
FIELDAY can be run either as a drift-diffusion (DD) simulator, solving the electron and hole continuity equations and Poisson's equation, or it can be run as a complete Hydrodynamic simulation program, in which case the electron and hole energy balance equations are added to the solution algorithm (but decoupled from the DD solution). A recent enhancement allows the user the option of including lattice energy (self heating) in the simulation. The DD, Hydro, and Lattice Energy options are all fully 3D in their implementation, allowing the user the option to run the simulation either in 2D or 3D mode. The program contains numerous mobility models for both FET and bipolar application, from which the user may select a model of choice.
The program can be linked to FEDSS to receive its starting 2D doping profiles, or alternately, the program DOPING can be used to generate 2D (or 3D) starting profiles either analytically or from experimental data, applying these profiles on the starting mesh. Mesh generation is done with one of the tools TRIM, DELAUX, and/or MESH3D and can be refined with REGRID. Outputs are viewed via FEMPLOT and/or VIDS. The program can be accessed and run through the graphics user interface WIZARD, as explained in a later section.
