Doped Oxide Dielectrics for Resistive Random Access Memory Cells

摘要

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.

主权项

1. A method of fabricating a memory cell, the method comprising:
forming a first layer using atomic layer deposition (ALD) or chemical vapor deposition (CVD),
wherein the first layer comprises a first dielectric material and a second dielectric material,wherein a dielectric constant of the first dielectric material is less than a dielectric constant of the second dielectric material,wherein a concentration of the first dielectric material in the first layer is greater than a concentration of the second dielectric material in the first layer; annealing the first layer in a first environment comprising an oxygen source; after annealing the first layer in the first environment, forming a second layer over the first layer,
wherein the second layer is operable as an electrode; and annealing the first layer and the second layer in a second environment comprising a nitrogen source,
wherein the memory cell is operable to switching between two resistive states when a switching signal is applied to the memory cell.