Abstract

Two-dimensional film growth models were introduced by Henderson et al.¹ and Dirks and Leamy.² These early models displayed several effects commonly observed in conventionally deposited thin films: columnar microstructure and the tangent rule relating the angle of columnar growth to the angle of vapor incidence. A model of this general type has been under development at the Optical Sciences Center for several years. The model incorporates mobility parameters for the condensing molecules, oblique angles of vapor incidence, substrate rotation effects, evaporant molecules of varying sizes, and various substrate defects. Recently the scale of the simulation has been expanded to realistic dimensions, of the order of an optical wavelength, which permits the inclusion of substrate variation effects up to this scale. The film growth model propagates substrate defects through a multilayer coating. Assuming a perfectly flat substrate surface, the dominant feature is an intrinsic film roughness. If a departure from perfection of the substrate surface is assumed, in a range of conditions diminution of the defect amplitude is observed as the defect propagates through the multilayer.

© 1986 Optical Society of America