## aTCAD Lab

### Device Simulation

### Drift Diffusion Lab

The Drift Diffusion Lab in aTCADlab enables a user to understand the basic concepts of drift and difusion of carriers inside a semiconductor slab using different kinds of experiments. Experiments like shining light on the semiconductor, applying bias and both can be performed. This tool provides important information about carrier densities, transient and steady state currents, fermi-levels and electrostatic potentials. It is supported by two related homework assignments #1 and #2 in which Students are asked to explore the concepts of drift, diffusion, quasi Fermi levels, and the response to light.

Exercises:

### PN Junction Lab

PN-Junction Lab in aTCADlab: Everything you need to explore and teach the basic concepts of P-N junction devices. Edit the doping concentrations, change the materials, tweak minority carrier lifetimes, and modify the ambient temperature. Then, see the effects in the energy band diagram, carrier densities, net charge distribution, I/V characteristic, etc.

There is a significant set of associated resources available for this tool.

- a demo of this tool
- a Primer on Semiconductor Device Simulation.
- a Learning Module entitled PN Junction Theory and Modeling which walks students through the PN junction theory and let’s them verify concepts through on-line simulation.
- Homework assignment on the depletion approximation
- Homework assignment on the depletion approximation

Exercises:

- PN Diode Exercise: Series Resistance
- Exercise: PIN Diode
- PN Diode Exercise: Graded Junction
- Basic operation of a PN diode - Theoretical exercise
- PN diode - Advanced theoretical exercises
- Schottky diode - Theoretical exercises

### Bipolar Junction Transistor Lab

The Bipolar Junction Lab in aTCADlab allows Bipolar Junction Transistor (BJT) simulation using a 2D mesh. It allows user to simulate npn or pnp type of device. Users can specify the Emitter, Base and Collector region depths and doping densities. Also the material and minority carrier lifetimes can be specified by the user. It is supported by a homework assignment in which Students are asked to find the emitter efficiency, the base transport factor, current gains, and the Early voltage. Also a qualitative discussion is requested.

Exercises:

### MOScap

The MOScap Tool in aTCADlab tool enables a semi-classical analysis of MOS Capacitors. Simulates the capacitance of bulk and dual gate capacitors for a variety of different device sizes, geometries, temperature and doping profiles.

Exercises:

- Exercise: CV curves for MOS capacitors
- MOSCAP - Theoretical Exercises 1
- MOSCAP - Theoretical Exercises 2
- MOSCAP - Theoretical Exercises 3
- MOS Capacitors: Theory and Modeling

### Schred

Schred Tool in aTCADlab calculates the envelope wavefunctions and the corresponding bound-state energies in a typical MOS (Metal-Oxide-Semiconductor) or SOS (Semiconductor-Oxide-Semiconductor) structure and a typical SOI structure by solving self-consistently the one-dimensional (1D) Poisson equation and the 1D Schrodinger equation.

Exercises:

- Schred: Exercise 1
- SCHRED: Exercise 2
- Schred: Exercise 3
- Quantum Size Effects and the Need for Schred
- Schred Tutorial Version 2.1

### MOSfet Lab

The MOSfet Lab in aTCADlab tool enables a semi-classical analysis of current-voltage characteristics for bulk and SOI Field Effect Transistors (FETs) for a variety of different device sizes, geometries, temperature and doping profiles.

Exercises:

- MOSFET Exercise
- Exercise: Basic Operation of n-Channel SOI Device
- MOSFET - Theoretical Exercises
- MOSFET Operation Description

### PADRE

PADRE in aTCADlab is a 2D/3D simulator for electronic devices, such as MOSFET transistors. It can simulate physical structures of arbitrary geometry—including heterostructures—with arbitrary doping profiles, which can be obtained using analytical functions or directly from multidimensional process simulators such as . A variety of supplemental documents are available that deal with the PADRE software and TCAD simulation:

- User Guide
- Abbreviated First Time User Guide
- FAQ
- A set of course notes on Computational Electronics with detailed explanations on bandstructure, pseudopotentials, numerical issues, and drift diffusion.
- Introduction to DD Modeling with PADRE
- MOS Capacitors – Description and Semiclassical Simulation With PADRE
- A Primer on Semiconductor Device Simulation

Exercises: