Three-Dimensional Triangle-Based Simulation of Etching Processes and Applications

Oliver LENHART
Eberhard BAR

Publication
IEICE TRANSACTIONS on Electronics   Vol.E86-C    No.3    pp.427-432
Publication Date: 2003/03/01
Online ISSN: 
DOI: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on the 2002 IEEE International Conference on Simulation of Semiconductor Processes and Devices (SISPAD'02))
Category: 
Keyword: 
process simulation,  etching,  3D string algorithm,  surface mesh,  

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Summary: 
A software module for the three-dimensional simulation of etching processes has been developed. It works on multilayer structures given as triangulated surface meshes. The mesh is moved nodewise according to rates which, in this work, have been determined from isotropic and anisotropic components. An important feature of the algorithm is the automatic detection of triple lines along mask edges and the refinement of triangles at these triple lines. This allows for the simulation of underetching. The capabilities of the algorithm are demonstrated by several examples such as the simulation of glass etching for the fabrication of a phase shift mask for optical lithography and the etching of an STI trench structure. Moreover, etch profiles of a silicon substrate covered by an oxide mask are shown for different parameters of the etch components. Spacer etching has also been performed. Furthermore, a specific algorithm for the simulation of purely isotropic etching is described and demonstrated.