Method of patterning a FeRAM capacitor with a sidewall during bottom electrode etch
AssigneesTexas Instruments Incorporated, Agilent Technologies, Inc.
InventorsScott R. Summerfelt, Guoqiang Xing, Luigi Colombo, Sanjeev Aggarwal, Theodore S. Moise, IV
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Abstract
A method of fabricating a ferroelectric capacitor is disclosed. The method comprises the patterning of a top electrode layer and a dielectric layer to form a capacitor stack structure having sidewalls associated therewith. Prior to patterning the bottom electrode layer, a protective film is formed on the sidewalls of the capacitor stack structure in order to protect the dielectric material from conductive contaminants associated with a subsequent patterning of the bottom electrode layer.
Claims38
A method of forming an FeRAM capacitor, comprising:
- forming a bottom diffusion barrier layer over a substrate;
- forming a bottom electrode layer over the bottom diffusion barrier layer;
- forming a ferroelectric dielectric layer over the bottom electrode layer;
- forming a top electrode layer over the ferroelectric dielectric layer;
- patterning the top electrode layer and the ferroelectric dielectric layer to form a capacitor stack structure having a top portion and sidewalls associated therewith, the capacitor stack structure overlying a first portion of the bottom electrode layer and leaving a second portion of the bottom electrode layer exposed;
- forming a protection layer over the stack structure and the second portion of the bottom electrode layer, wherein the protection layer covers the sidewalls associated with the capacitor stack structure;
- etching the protection layer, wherein the etching removes a portion of the protection layer on the top portion of the capacitor stack structure and a portion of the protection layer on the second portion of the bottom electrode layer, but leaves at least a portion of the protection layer on the sidewalls of the capacitor stack structure, thereby leaving a protective sidewall layer on the sidewalls of the capacitor stack structure;
- removing the second portion of the bottom electrode layer, whereby the protective sidewall layer on the sidewalls of the capacitor stack structure prevent contamination associated with the removed second portion of the bottom electrode layer from interfering with the capacitor stack structure.
A method of forming an FeRAM capacitor, comprising:
- forming a bottom electrode layer, a ferroelectric dielectric layer and a top electrode layer over a substrate;
- patterning the top electrode layer and the ferroelectric dielectric layer, thereby defining sidewalls associated therewith;
- forming a protection layer on the sidewalls of the top electrode layer and the ferroelectric dielectric layer;
- and
- patterning the bottom electrode layer after forming the protection layer, thereby protecting the sidewalls of the top electrode layer and the ferroelectric layer from contamination associated with the patterning of the bottom electrode layer.
Dependencies are inferred from the claim text.