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 arranged into a nanolaminate of sub-layers comprising the first dielectric material and sub-layers comprising the 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, after annealing, distribution of the first dielectric material and distribution of the second dielectric material within the first layer are both uniform,wherein the memory cell is operable to switching between two resistive states when a switching signal is applied to the memory cell.