Effects of ion implantation on dielectric charging in PECVD silicon nitride films for RF MEMS switches application

In this work phosphorus or boron ions were implanted into dielectric layer by ion implantation. The impurity energy levels are introduced into the band gap of dielectric layer, thus the scattering processes of trapped charges in the dielectric layer can be changed, which lead to the change of relaxation time. In our experiment, we focus on investigation of the mechanisms of the charge accumulation and recombination after the charge injected into the dielectric layers. Metal-insulator-semiconductor (MIS) structure is used in our experiments. Silicon nitride films as the insulator in MIS structure were deposited by PECVD process. The space charge accumulation and dissipation in the silicon nitride film can be characterized by C-V measurement qualitatively.