A manufacturing method for a semiconductor device, the method including forming a thin film transistor by forming a polysilicon thin film on an insulating substrate, forming a gate electrode via a gate insulating film, and forming source/drain regions and a channel region by ion implantation in the polysilicon thin film by using the gate electrode as a mask, forming an interconnection layer on an interlayer dielectric film covering this thin film transistor and forming a first contact to be connected to the thin film transistor through the interlayer dielectric film, forming a silicon hydronitride film on the interlayer dielectric film so as to cover the interconnection layer, forming a lower electrode on this silicon hydronitride film and forming a second contact to be connected to the interconnection layer through the silicon hydronitride film, and forming a ferroelectric layer on the lower electrode.