This work describes the Semiconductor Wafer Representation (SWR) for representing and manipulating wafer state during process and device simulation. The goal of the SWR is to provide an object-oriented interface to a collection of functions designed for developing and integrating Technology CAD (TCAD) applications. By providing functions which can be common across many applications, we aim to greatly reduce tool development and integration time. Corporate, vendor, and university TCAD developers have worked together under the auspices of the CAD Framework Initiative to create an architecture and C++ programming interface for an SWR 1.0 draft standard. Here we describe this architecture and the results of creating and using a prototype implementation of the standard both to integrate existing TCAD tools and to develop simple new tools.>

The role of point defects during silicon dopant diffusion at high dopant concentrations is considered. Starting from the basic reaction equations for the formation of dopant-defect pairs, the effective dopant diffusivity is derived. Consideration of these equations shows why a concentration-dependent diffusivity model is often sufficient for modeling diffusion. Consideration of these equations also shows the effect of processes such as oxidation, which inject defects at the surface. Analysis of oxidation-enhanced diffusivity experiments under extrinsic conditions allows the silicon self-interstitial energy levels to be extracted directly at diffusion temperatures.>

A two-dimensional method based on numerical solution of the Boltzmann transport equation has been developed for calculating ion implantation profiles. The method is capable of treating arbitrarily contoured surfaces containing multiple layers of different materials. Calculations yield the concentration profile of the implanted ion, an estimate of the damage distribution, and concentration profiles from recoiled target atoms. Substantial differences are seen from one-dimensional and point-response two-dimensional methods when the interfaces are far from planar.

The Boltzmann transport equation approach for ion implantation simulation has been enhanced to allow the calculation of channeling effects. Simple models are used for scattering into channeling directions and for motion along channels in order to obtain useful results without requiring excessive amounts of computation time. Comparison with experimental profiles show good agreement for boron implantation intoandsilicon based on experimental values for electronic stopping powers. Where stopping data is not available, parameters can be adjusted to fit the experimental profiles.