Method for manufacturing a metal-to-metal capacitor utilizing only one masking step

A method of fabricating a capacitor on a semiconductor substrate utilizing only a single masking step, said method comprising:

• forming a first capacitor electrode on the semiconductor substrate and forming a planar insulating layer over said first capacitor electrode;
• forming a photoresist layer over said planar insulating layer and patterning said photoresist layer in an only masking step to form an opening over said first capacitor electrode;
• through said opening, etching said planar insulating layer to form a trench in said planar insulating layer aligned with said first capacitor electrode;
• thereafter, forming a capacitor dielectric layer directly on said planar insulating layer and in said trench;
• forming a second capacitor electrode over said capacitor dielectric layer and in alignment with said first capacitor electrode, wherein forming said second capacitor electrode comprises forming a conductive layer in said trench and extending out of said trench, such that at least a portion of said conductive layer is formed over both said capacitor dielectric layer and said planar insulating layer;
• and
• after forming said second capacitor electrode, planarizing to expose said planar insulating layer.

A method of fabricating a capacitor on a semiconductor substrate utilizing only a single masking step, said method comprising:

• forming a first capacitor electrode on the semiconductor substrate and forming a planar insulating layer over said first capacitor electrode;
• forming a photoresist layer over said planar insulating layer and patterning said photoresist layer utilizing an only mask to form an opening over said first capacitor electrode;
• through said opening, etching said planar insulating layer;
• thereafter, forming a capacitor dielectric layer;
• forming a second capacitor electrode having a generally U-shaped structure and a trench aligned with said first capacitor electrode over said capacitor dielectric layer and in alignment with said first capacitor electrode;
• spinning on photoresist to fill said trench;
• and
• after spinning on the photoresist, planarizing to expose said planar insulating layer.