Desenvolvimento de processo litográfico tri-dimensional para aplicação em microóptica integrada.

Abstract

This work aims at developing an electron-beam lithography process for the fabrication of microoptical elements using the negative tone chemically amplified resist SU-8 on Si substrate. A study of the proximity effect parameters α, β and η is carried out to model and control the electron scattering both in the resist and in the substrate, and the SU-8 standard processing conditions are changed to achieve a low contrast process. The determination of the SU-8 / Si proximity effect parameters and its dependence with resist depth is done employing an experimental method and through Monte Carlo simulations. First, α, β and η are obtained comparing exposed patterns calculated by the software PROXY. β, the parameter which measures the backscattering of the electrons by the substrate, is equal to 4µm and the value of η, the ratio of the dose contribution of backscattered electrons to that of the forward scattered (related to α), is 0.7. The extrapolation of exposed patterns data is used to estimate the SUMÁRIO