Sentaurus Materials Workbench Reference Manual

Introduction

Sentaurus Materials Workbench helps you to create material references and to set up input files for atomistic calculations using DFT calculations, or empirical potentials, or both. It can automate defect generation and includes several techniques and recipes to increase the accuracy of calculations. Furthermore, from the atomistic calculation results, Sentaurus Materials Workbench analyzes the results and generates the Sentaurus model parameters that can be used for different TCAD tools, but in particular for band structure generation needed for Sentaurus Device.

Note

The SMW scripts need to import the package explicitly. In other words, be sure to include a from SMW import * at the beginning of the scripts.

There are different modules or workflows under Sentaurus Materials Workbench. The following content describes its main capabilities.

Material specifications

Using MaterialSpecifications objects you can define computational settings for your calculations. Sentaurus Materials Workbench comes with a MaterialSpecificationsDatabase with predefined MaterialSpecifications for industry relevant materials. This database should be the starting point for most applications.

Bandstructure calibration

Class SentaurusBandstructureCalibration is used to obtain optimized parameters for bandstructure models (e.g., effective mass, k.p) available to the Sentaurus tools by calibrating model bands to first-principles values. The typical calibration workflow is:

  1. Atomistic nanowires or nanoslabs are built with SMW and its DFT bandstructure is calculated. Users input the desired crystal orientations and dimensions (height and width for nanowires, thickness for nanoslabs). All surfaces are passivated with hydrogen.

  2. Finite-element meshes, corresponding to the atomistic nanostructures, and model bandstructures are automatically calculated with Sentaurus tools. Sentaurus Process is used to create structure meshes and Sentaurus Band to calculate model bandstructures.

  3. SMW adjusts the model parameters (effective masses or k.p parameters) iteratively, following a conjugate-gradient minimization algorithm, until the band dispersion from Sentaurus Band matches the DFT bandstructure. Parameters for bulk silicon are used as initial guess.

Class SentaurusBandstructureCalibration supports Silicon rectangular nanowires (Wire) and nanoslabs (Slab). Calibration of both conduction (effective-mass model, SentaurusWireEffectiveMassModel) and valence bands (k.p model, SentaurusWireKdotPmodel) are available for nanowires. Only calibration of valence bands (SentaurusSlabKdotPmodel) is supported.

Single defect specification and convergence studies

Formation energies and trap energy levels for a variety of defects and supercell sizes can be done with ChargedPointDefect. An overview of how to specify particular defects and perform convergence studies can be read at the ChargedPointDefect Notes.

The available defect classes are:

All to be run with:

Multilayer Builder

For an overall explanation on the multilayer builder features see Notes.

The available classes are:

GrainBoundaryScattering

The GrainBoundaryScattering calculates grain boundary resistances and specific resistivities of metal grain boundaries. For an overall explanation on the grain boundary scattering features see Notes.

The available classes are:

Full SMW package