a method of modulating grain size in a polysilicon layer and devices fabricated with the method . the method comprises forming the layer of polysilicon on a substrate ; and performing an ion implantation of a polysilicon grain size modulating species into the polysilicon layer such that an average resultant grain size of the implanted polysilicon layer after performing a pre - determined anneal is higher or lower than an average resultant grain size than would be obtained after performing the same pre - determined anneal on the polysilicon layer without a polysilicon grain size modulating species ion implant .