Patent ID: 7981760
Filing Date: 2011-07-19
Classification: H01L

Abstract:
1. A manufacturing method of a nonvolatile storage element which includes a connecting electrode layer which is conductive, a lower electrode layer which is made of a non-noble metal nitride and is conductive, an upper electrode layer which is formed above the lower electrode layer and is made of a noble metal, and a variable resistance layer disposed between the lower electrode layer and the upper electrode layer and whose resistance value varies reversibly based on an electrical signal applied between the lower electrode layer and the upper electrode layer, wherein the variable resistance layer includes electron holes and oxygen which move upon application of a charge in etching plasma, said method comprising: depositing, in sequence, the connecting electrode layer, the lower electrode layer, the variable resistance layer, the upper electrode layer, and a mask layer; forming the mask layer into a predetermined shape, using a photoresist film as a mask; performing three-layer etching on the upper electrode layer, the variable resistance layer, and the lower electrode layer, using the mask layer that has been formed into the predetermined shape as a mask, to form the upper electrode layer, the variable resistance layer, and the lower electrode layer into the predetermined shape, so as to expose a region of the connecting electrode layer, the etching being performed with a higher etching rate for the non-noble metal nitride than an etching rate for the noble metal of the upper electrode layer; and removing, simultaneously, the mask layer and the region of the connecting electrode layer exposed in said performing of the three-layer etching.