Robust method of forming a cylinder capacitor for DRAM circuits

A method of forming capacitors, comprising the steps of:

• providing a substrate having a first surface and a contact region on said first surface;
• forming a layer of first dielectric on said first surface of said substrate;
• forming a layer of second dielectric on said layer of first dielectric;
• forming a layer of third dielectric having a top surface on said layer of second dielectric;
• etching a first hole having sidewalls in said layer of first dielectric, said layer of second dielectric, and said layer of third dielectric thereby exposing said contact region of said first surface of said substrate;
• filling said first hole in said layer of first dielectric, said layer of second dielectric, and said layer of third dielectric with a protective material thereby covering said contact region of said first surface of said substrate with said protective material;
• etching a second hole having sidewalls in said in said layer of third dielectric using said layer of second dielectric as an etch stop, wherein said first hole lies within the periphery of said second hole, thereby removing said protective material from said second hole in said layer of third dielectric;
• removing the remaining said protective material thereby exposing said contact region of said first surface of said substrate;
• forming a layer of conductive material on said top surface of said layer of third dielectric, said sidewalls of said second hole in said layer of said third dielectric, said sidewalls of said first hole in said layer of second dielectric, said sidewalls of said first hole in said layer of first dielectric, and said contact region of said first surface of said substrate;
• and
• patterning said layer of conductive material thereby forming a first capacitor plate.