A SMOOTHED BOUNDARY-CONDITION FOR REDUCING NONPHYSICAL FIELD EFFECTS

In this paper, we examine the problem associated with abruptly mixing boundary conditions in the contest of a two-dimensional semiconductor device simulator, Explicitly, this paper addresses the transition betw een an ohmic-type Dirichlet condition and a passivated Neumann boundar y. In the traditional setting, the details of the transition between t he two boundary types are not addressed and an abrupt transition is as sumed, Subsequently, the calculated observables (most notably the pote ntial) exhibit discontinuous derivatives near the surface at the point where the boundary type switches, This paper proposes an alternative condition which models the progression between the two boundary types through the use of a finite length, smoothed boundary whereby the nume rical discontinuities are eliminated, The physical and mathematical ba sis for this smoothed boundary condition is discussed and examples of the technique's implementation given. It is round that the proposed bo undary condition is numerically efficient and can be implemented in pr e-existing device simulators with relative ease.