Thin film metallic resistors formed by surface treatment of insulating layer

A method for fabricating a device, comprising:

• forming a stack of insulating layers on a substrate;
• patterning the stack of insulating layers to form an opening in the stack of insulating layers down to the substrate, wherein the opening comprises vertical sidewalls;
• laterally recessing exposed sidewall surfaces of every other insulating layer in the stack of insulating layers to a recess depth D to form a meandering sidewall topology on the vertical sidewalls;
• depositing a conformal layer of insulating material over the patterned stack of insulating layers, wherein the conformal layer of insulating layer is formed with an initial thickness T, and wherein the conformal layer of insulating material comprises Ta3N5 insulating material;
• applying a surface treatment to a surface of the conformal layer of insulating material to convert the surface of the conformal layer of insulating material to a layer of conductive TaN metallic material of thickness T1, which is less than T;
• patterning the layer of conductive metallic material to form a thin film metallic resistor layer;
• depositing a layer of dielectric material to form an insulating air gap in the opening in the stack of insulating layers;
• and
• forming device contacts in the layer of dielectric material in contact with portions of the thin film metallic resistor layer.