Modeling and Experimental Study of a Remote Microwave Plasma Source for High-Rate Etching

This study aimed to investigate and optimize a remote microwave plasma source (RMPS) concerning the etching rate, the etching rate distribution, and to simplify its setup to save production costs. A finite element method (FEM) based model of the RMPS was developed to investigate microwave coupling into the plasma chamber and microwave field distribution. The simulations at ignition conditions were compared with the calculated electric field distribution and the experimentally determined electric field. The simulations at operating conditions were validated visually through photographs of the plasma. Also, the etching depth on polymethylmethacrylate (PMMA) substrates was measured with a contact profilometer and normalized with etching time to etching rate.