Method for fabricating ferroelectric random-access memory on pre-patterned bottom electrode and oxidation barrier

摘要

Structure and method of fabrication of F-RAM cells are described. The F-RAM cell include ferroelectric capacitors forming over and with a pre-patterned barrier structure which has a planarized/chemically and/or mechanically polished top surface. The pre-patterned barrier structure includes multiple oxygen barriers having a structure of a bottom electrode layer over an oxygen barrier layer. The bottom electrode layer forms at least a part of the bottom electrode of the ferroelectric capacitor formed thereon.

主权项

1. A method, comprising:
forming a pre-patterned barrier structure over a first dielectric layer, comprising:
disposing an oxygen (O2) barrier layer over the first dielectric layer;disposing a bottom electrode (BE) layer over the O2 barrier layer;patterning the BE layer and the O2 barrier layer to form at least one BE/O2 barrier structure;disposing a first hydrogen (H2) barrier layer over the at least one BE/O2 barrier structure; andplanarizing the first H2 barrier layer to form a planarized top surface of the pre-patterned barrier structure, wherein a top surface of the at least one BE/O2 barrier structure is exposed; forming a ferroelectric stack (ferro-stack) over the pre-patterned barrier structure; and patterning the ferro-stack to form a ferroelectric capacitor with each of the at least one BE/O2 barrier structure.