. . "e and manufacturing method thereof and method for writing memory elementUS828819725 Abr 200616 Oct 2012Semiconductor Energy Laboratory Co., Ltd.Method for manufacturing a semiconductor device including a memory device comprising an insulator mixture region in a conductive layerUS829510413 Nov 200923 Oct 2012Semiconductor Energy Laboratory Co., Ltd.Semiconductor deviceUS83998819 May 201119 Mar 2013" . .