3-DIMENSIONAL TOPOGRAPHY SIMULATION-MODEL - ETCHING AND LITHOGRAPHY

A new etching model is introduced. In this model, topography is derived by solving a modified diffusion equation. This model is simple and makes it possible to simulate three-dimensional (3D) topography accurately and quickly. Based on this model, a 3D topography simulator has been developed, which can be applied in the development of photolithography and isotropic/anisotropic etching. With this simulator, it is possible to simulate the series processes and multi-layer etching, such as contact hole and trench etching. By simulating photolithography, diffraction and standing-wave effects can be found clearly in the 3D topography of the developed photoresist. In the case of the etching process which is restricted by diffusion, we inspected the dependence of the etch front topography on the window width of the mask. © 1990 IEEE