Patterning oxidation resistant electrode in crossbar array circuits

A method of manufacturing an RRAM-based crossbar array circuit comprising:

• providing a substrate;
• forming a bottom electrode on the substrate;
• forming a patterned mask layer on the bottom electrode;
• thermal oxidizing the bottom electrode layer via the patterned mask layer by applying a thermal process and a first plasma;
• removing a gaseous status of the bottom electrode oxide by a first vacuum purge;
• removing a solid status of the bottom electrode oxide by applying a second plasma;
• removing the gaseous status of the bottom electrode oxide and the solid status of the bottom electrode oxide by a second vacuum purge to form a patterned bottom electrode;
• removing the patterned mask layer;
• forming a filament forming layer on the patterned bottom electrode;
• and
• forming a top electrode on the filament forming layer, wherein the filament forming layer is configured to form a filament within the filament forming layer when applying a switching voltage upon the filament forming layer.