Simplified bottom electrode-barrier structure for making a ferroelectric capacitor stacked on a contact plug
AssigneesInteruniversitair Microelektronica Centrum vzw (IMEC vzw), STMicroelectronics S.r.l.
InventorsDirk Wouters, Jean-Luc Everaert, Judit Lisoni
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Abstract
The present invention is related to the realization of a simplified bottom electrode stack for ferroelectric memory cells. More particularly, the invention is related to ferroelectric memory cells wherein the ferroelectric capacitor is positioned directly on top of a contact plug. The bottom electrode stack is prepared by depositing a ferroelectric film atop an Ir or Ru metal electrode layer, then annealing the ferroelectric layer in an oxygen ambient wherein the partial pressure of oxygen is controlled at a level sufficient to oxidize the ferroelectric layer but not at a level sufficient to oxidize the metal electrode layer
Claims27
A memory cell, the memory cell comprising:
- a semiconductor chip, the semiconductor chip comprising a contact;
- and
- a capacitor, the capacitor comprising:
- a ferroelectric film,
- a top electrode, and
- a bottom electrode, wherein the bottom electrode comprises a single nonoxidized, conductive, oxygen diffusion barrier layer in contact with the ferroelectric film and the contact.
A capacitor, the capacitor comprising:
- a ferroelectric film;
- a first electrode;
- and
- a second electrode, the second electrode consisting of a nonoxidized conductive, oxygen diffusion barrier layer.
A capacitor, the capacitor comprising:
- a ferroelectric film;
- a first electrode;
- and
- a second electrode, the second electrode comprising a nonoxidized conductive, oxygen diffusion barrier layer in contact with the ferroelectric film.
A method of fabricating a capacitor, the capacitor comprising a ferroelectric film in contact with a conductive, oxygen diffusion barrier electrode layer, the method comprising the steps of:
- forming a conductive, oxygen diffusion barrier electrode layer;
- depositing a ferroelectric layer atop the conductive, oxygen diffusion barrier electrode layer;
- and
- annealing the ferroelectric layer in an oxygen ambient, wherein a partial pressure of oxygen in the oxygen ambient pO2 is controlled at a level sufficient to oxidize the ferroelectric layer but not at a level sufficient to oxidize the conductive, oxygen diffusion barrier electrode layer.
Dependencies are inferred from the claim text.