CHORD: a modular semiconductor device simulation development tool incorporating external network models

A description is given of CHORD, a semiconductor device simulation development tool created at the University of Waterloo. CHORD is written as several small independent programs which use a centralized database facility and is specifically designed to allow the simple creation, development, and testing of new simulation models and algorithms. Communication between programs is implemented by using a byte-stream process. This allows transfer of information between individual programs running on different machines. CHORD is a general environment in that its models can incorporate any set of user-defined variables of equations. This is illustrated by the development of contact boundary conditions incorporating external circuit elements and circuit-level device models using the modified nodal formulation. Several examples of both steady-state and transient simulations are presented