which are also described by continuum (partial differential) equations.The level set method for evolving interfaces [11] belongs to the geometric type of methods, and it is specially designed for profiles which can develop sharp corners, change of topology and undergo orders Olaparib manufacturer of magnitude changes in speed. It is based on Hamilton-Jacobi type equation for the level set function using techniques developed for solving hyperbolic partial differential equations. This method is free on any implicit assumptions about the nature of the processes that force interface evolution, and the whole physics and chemistry of them are contained in just one parameter-normal component of the surface velocity. During last several years several variants of the level set methods have been developed with application to micro fabrication problems [12,13].

In this study we present an anisotropic etching simulator based on the sparse field method for solving the level set equations. The sparse-field method itself, Inhibitors,Modulators,Libraries developed by Whitaker [14], and broadly used in image processing community, is an alternative to the usual combination of narrow band and fast marching procedures for the computationally effective solving of the level set equations [15,16]. Our primary goal is to develop an accurate, stable and efficient 3D code for tracking of the etching profile evolution that includes different physical effects such as anisotropy and material-dependent Inhibitors,Modulators,Libraries propagation rates, yet being computationally effective to run on desktop PCs.The paper is organized as follows: in Section 2 some aspect of the silicon wet etching process are discussed.

After that, the relations describing the angular dependence of the etching rates, based on an interpolation procedure and silicon Inhibitors,Modulators,Libraries crystal symmetry properties, are derived. In Section 3 the necessary details for the implementation of the sparse field method for solving the level set equations in the case of etching rates defined Inhibitors,Modulators,Libraries AV-951 in Section 2, are described. Section 4 contains simulation results for some interesting initial 3D shapes (cube and sphere), as well as some more practical examples illustrating anisotropic etching simulation in the presence of masks (simple square aperture mask, convex corner undercutting and convex corner compensation, formation of suspended structures).2.

?Anisotropic Etching of Silicon: Angular Dependence of the Etching RateAlthough silicon etching techniques are currently undergoing a revolution driven by the incorporation of plasma etching process, selleck chem Crizotinib anisotropic wet chemical etching is still the most widely used processing technique in silicon technology [1]. Not only the cost of wet etching systems is much lower than that of plasma types, but also certain features can only be realized using anisotropic wet etching.