Modeling two-dimensional solid-phase epitaxial regrowth using level set methods

Modeling the two-dimensional (2D) solid-phase epitaxial regrowth (SPER) of amorphized Si (variously referred to as solid-phase epitaxial growth, solid-phase epitaxy, solid-phase epitaxial crystallization, and solid-phase epitaxial recrystallization) has become important in light of recent studies which have indicated that relative differences in the velocities of regrowth fronts with different crystallographic orientations can lead to the formation of device degrading mask edge defects. Here, a 2D SPER model that uses level set techniques as implemented in the Florida object oriented process simulator to propagate regrowth fronts with variable crystallographic orientation (patterned material) is presented. Apart from the inherent orientation dependence of the SPER velocity, it is established that regrowth interface curvature significantly affects the regrowth velocity. Specifically, by modeling the local SPER velocity as being linearly dependent on the local regrowth interface curvature, data acquired from transmission electron microscopy experiments matches reasonably well with simulations, thus providing a stable model for simulating 2D regrowth and mask edge defect formation in Si.