US 12,720,762 B2 · Ferroelectric memory device comprising a chimney seed structure and method for forming the same

Abstract

Various embodiments of the present disclosure are directed towards a ferroelectric memory device comprising a chimney seed structure. A ferroelectric layer overlies a bottom electrode layer, and a top electrode layer overlies the ferroelectric layer. The top electrode layer, the ferroelectric layer, and the bottom electrode layer form a plurality of memory cells, and a dielectric wall extends through the top electrode layer and segments the top electrode layer into a plurality top electrodes individual to the memory cells. The chimney seed structure underlies the ferroelectric layer and extends through the bottom electrode layer from the ferroelectric layer. The chimney seed structure is configured to seed ferroelectric crystalline growth in the ferroelectric layer to allow the ferroelectric layer to achieve a large remanent polarization with a small thickness. The small thickness increases read speeds, while the large remanent polarization increases a read window and hence reliability.

Claims20

Dependent claims

A method for forming a memory device, the method comprising:

depositing a bottom electrode layer over a substrate;
patterning the bottom electrode layer to form an opening in the bottom electrode layer;
forming a chimney seed structure filling the opening;
depositing a ferroelectric layer overlying the bottom electrode layer and the chimney seed structure;
depositing a top electrode layer overlying the ferroelectric layer;
performing a laser anneal to the chimney seed structure, wherein the laser anneal results in a ferroelectric crystalline phase growing laterally outward from the chimney seed structure into the ferroelectric layer;
and
forming a plurality of memory cells in the bottom electrode layer, the ferroelectric layer, and the top electrode layer, comprising:
patterning the top electrode layer to form a trench surrounding and demarcating the plurality of memory cells;
and
filling the trench with a dielectric material to form a dielectric wall.

8 more elements

A method, comprising:

depositing a bottom electrode layer over a substrate;
performing an etch into the bottom electrode layer to form a plurality of openings in a plurality of rows and a plurality of columns;
forming a plurality of ferroelectric structures in and respectively filling the plurality of openings, wherein the plurality of ferroelectric structures comprise a first ferroelectric structure and a second ferroelectric structure;
depositing a ferroelectric layer over the bottom electrode layer and the plurality of ferroelectric structures;
depositing a top electrode layer overlying the ferroelectric layer;
performing an anneal to grow a ferroelectric phase in the ferroelectric layer;
and
forming a plurality of memory cells in the bottom electrode layer, the ferroelectric layer, and the top electrode layer;
wherein the ferroelectric layer has a first region of ferroelectric phase growth and a second region of ferroelectric phase growth expanding outward respectively from the first and second ferroelectric structures during the anneal, and wherein the first and second regions are spaced from each other at a first time during the anneal and contact each other at a second time during the anneal that is after the first time.

6 more elements

Dependencies are inferred from the claim text.

Ferroelectric memory device comprising a chimney seed structure and method for forming the same

Life of this patent

Ferroelectric memory device comprising a chimney seed structure and method for forming the same

Life of this patent

Abstract

Claims20