Method to eliminate top metal corner shaping during bottom metal patterning for MIM capacitors

A method for fabricating a metal-insulator-metal capacitor comprising:

• providing an insulating layer overlying a semiconductor substrate;
• depositing a first metal layer over said insulating layer;
• depositing a capacitor dielectric layer overlying said first metal layer;
• depositing a second metal layer overlying said capacitor dielectric layer and patterning said second metal layer to form a top metal electrode;
• depositing a flowable material layer overlying said capacitor dielectric and said top metal electrode;
• anisotropically etching away said flowable material layer to leave said flowable material layer only as spacers on sidewalls of said top metal electrode wherein said spacers have a thickness of at least 500 Angstroms;
• forming a photoresist mask overlying said capacitor dielectric and said top metal electrode wherein said spacers provide extra photoresist thickness at said sidewalls of said top metal layer;
• patterning said capacitor dielectric layer and said first metal layer using said photoresist mask wherein patterned said first metal layer forms a bottom metal electrode and wherein said spacers protect said top metal layer from etching during said patterning;
• and
• removing said photoresist mask to complete fabrication of said metal-insulator-metal capacitor.

A method for fabricating a metal-insulator-metal capacitor comprising:

• providing an insulating layer overlying a semiconductor substrate;
• depositing a barrier metal layer over said insulating layer;
• depositing a first metal layer over said barrier metal layer;
• depositing a capacitor dielectric layer overlying said first metal layer;
• depositing a second metal layer overlying said capacitor dielectric layer and patterning said second metal layer to form a top metal electrode;
• depositing a flowable material layer overlying said capacitor dielectric and said top metal electrode;
• anisotropically etching away said flowable material layer to leave said flowable material layer only as spacers on sidewalls of said top metal electrode wherein said spacers have a thickness of at least 500 Angstroms;
• forming a photoresist mask overlying said capacitor dielectric and said top metal electrode wherein said spacers provide extra photoresist thickness at said sidewalls of said top metal layer;
• patterning said capacitor dielectric layer and said first metal layer using said photoresist mask wherein patterned said first metal layer forms a bottom metal electrode and wherein said spacers protect said top metal layer from etching during said patterning;
• and
• removing said photoresist mask to complete fabrication of said metal-insulator-metal capacitor.