Methods of forming integrated circuit capacitors having composite titanium oxide and tantalum pentoxide dielectric layers therein and capacitors formed thereby

A method of forming an integrated circuit capacitor, comprising the steps of:

• forming a first capacitor electrode over a substrate;
• forming a titanium nitride layer on the first capacitor electrode;
• forming a tantalum pentoxide dielectric layer on the titanium nitride layer;
• annealing the tantalum pentoxide dielectric layer in an oxygen ambient to convert the titanium nitride layer into the titanium oxide layer;
• and
• forming a second capacitor electrode on the tantalum pentoxide layer, opposite the first capacitor electrode.

A method of forming an integrated circuit capacitor, comprising the steps of:

• forming a first capacitor electrode over a substrate;
• forming a titanium nitride layer on the first capacitor electrode;
• removing a portion of titanium nitride layer to expose the first portion of the first capacitor electrode;
• annealing the substrate in a nitrogen ambient;
• forming a tantalum pentoxide dielectric layer on the remainder of the titanium nitride layer and the exposed first capacitor;
• annealing the tantalum pentoxide dielectric layer in an oxygen ambient to convert titanium nitride layer into a titanium oxide layer and to form a silicon oxynitride layer on the exposed first capacitor electrode;
• and
• forming a second capacitor electrode on the tantalum pentoxide layer.

An integrated circuit capacitor, comprising

• a first capacitor electrode;
• a silicon oxynitride layer on said first capacitor electrode;
• a titanium oxide layer on said silicon oxynitride layer;
• a tantalum pentoxide layer on said silicon oxynitride layer;
• and
• a second capacitor electrode on said tantalum pentoxide.

An integrated circuit capacitor, comprising

• a first capacitor electrode;
• a silicon oxynitride layer on a first portion of said first capacitor electrode;
• a titanium oxide layer on a second portion of said first capacitor electrode;
• a tantalum pentoxide layer on said silicon oxynitride layer and said titanium oxide layer, opposite said first capacitor electrode;
• and
• a second capacitor electrode on said tantalum pentoxide layer, opposite said silicon oxynitride layer and said titanium oxide layer.