Deposited poly-Si as on-demand linewidth compensator for on-chip Fabry-Perot interferometer and vertical linear variable optical filter bandpass and passband manipulation

摘要

Deep reactive ion etching (DRIE) is an important process for etching vertical structures for microelectromechanical systems. Due to the sidewall profile of some photoresists as well as effects from upstream processes, bulk micromachined structures, to a certain extent, could differ from expected. Concerning photonics applications, minute deviations from the intended design might alter its optical characteristics. The most popular approach is to introduce a compensation factor during mask design. However, such a method is not robust enough to accommodate batch variations due to varying process conditions.