A semiconductor device with a superlattice and method of making same includes forming a layer of amorphous silicon over a substrate, and forming a layer of nanocrystals by laser thermal annealing the layer of amorphous silicon. A gate dielectric is formed between the layer of amorphous silicon and the substrate. A dielectric layer is formed on the layer of amorphous silicon. The steps of forming the layer of amorphous silicon and forming the dielectric layer can be repeated. The thickness of the dielectric layer is between about 25 to 40 angstroms, and the thickness of the amorphous silicon layer is between about 30 to 50 angstroms. The average diameter of the nanocrystals is less than 40 angstroms.