Doped oxide dielectrics for resistive random access memory cells

Abstract

Provided are methods of fabricating memory cells such as resistive random access memory (ReRAM) cells. A method involves forming a first layer including two high-k dielectric materials such that one material has a higher dielectric constant than the other material. In some embodiments, hafnium oxide and titanium oxide form the first layer. The higher-k material may be present at a lower concentration. In some embodiments, a concentration ratio of these two high-k materials is between about 3 and 7. The first layer may be formed using atomic layer deposition. The first layer is then annealed in an oxygen-containing environment. The method may proceed with forming a second layer including a low-k dielectric material, such as silicon oxide, and forming an electrode. After forming the electrode, the memory cell is annealed in a nitrogen containing environment. The nitrogen anneal may be performed at a higher temperature than the oxygen anneal.