Capacitor array and method for forming the same

A method for forming a capacitor array, comprising:

• depositing a first nitride layer, a first oxide layer, and a second nitride layer in sequence over first and second contacts on a substrate;
• etching the first nitride layer, the first oxide layer, and the second nitride layer to form first and second openings exposing the first and second contacts;
• conformally depositing a bottom electrode layer over the first nitride layer, the first oxide layer, and the second nitride layer and on the first and second contacts;
• forming a mask layer on a first portion of the bottom electrode layer above the first and second contacts, while leaving a second portion of the bottom electrode layer laterally between the first and second contacts exposed;
• with the mask layer in place, etching the second nitride layer and the first oxide layer to form a third opening having a bottom position higher than a top surface of the first nitride layer;
• after etching the second nitride layer and the first oxide layer, removing the mask layer from the bottom electrode layer;
• after removing the mask layer, removing the first oxide layer through the third opening;
• forming a capacitor dielectric layer over the bottom electrode layer;
• and
• forming a top electrode layer over the capacitor dielectric layer.