Finite-length mask effects in the isolation oxidation of silicon

Abstract

A moving-boundary problem modelling the two-dimensional isolation oxidation of silicon is analysed in the limit of reaction-controlled oxidation for a finite-length nitride mask. Encroachment under the mask caused by silicon oxidation then occurs from both sides to produce two 'bird's beaks', and it is the interaction between these beaks on which attention is focused. This effect, termed 'bird's beak punchthrough', is currently of interest in submicron silicon-isolation technologies.

Unstable sixth-order thin film equation: I. Blow-up similarity solutions

“…In [32,33], a more general form of this equation (now allowing for a reaction at the underlying solid interface) is shown to arise in the industrial application of the isolation oxidation of silicon. Analysis for a finite length elastica or plate is given in [21], whilst a numerical scheme (in the form of a Keller-Box method) with subsequent parameter investigation of the more general system is given in [22]. A survey and a detailed analysis of interface propagation for sixth-order TFEs can be found in [24].…”

Invariance of the support of solutions for a sixth-order thin film equation

“…The equation (1.1) arises in the industrial application of the isolation oxidation of silicon [4][5][6]. The pure sixth-order thin film equation (without the lower-order term) also arises when considering the motion of a thin film of viscous fluid driven by an overlying elastic plate [7,9].…”