Abstract: A method of forming patterned polycrystalline silicon having a rounded profile on a substrate comprises providing a defined source of one type conductivity modifiers adjacent the substrate where the silicon is to be formed, depositing a film of polycrystalline silicon over the defined source, diffusing the conductivity modifiers from the defined source into regions of the film adjacent thereto, and then contacting the entire surface of the film with a solvent in which the film is soluble but in which the regions doped with the one type conductivity modifiers are substantially insoluble, thereby removing regions of the film that are substantially void of the one type conductivity modifiers.