Ferroelectric based memory devices utilizing low curie point ferroelectrics and encapsulation

Claim 2

A ferroelectric memory cell for storing information, said memory cell operating to store said information at a temperature less than a first temperature, said memory cell comprising: a bottom contact; a dielectric layer comprising a ferroelectric material having a Curie point greater than said first temperature and less than 400° C., said ferroelectric material having a remnant polarization below said first temperature, said information being stored by altering said remnant polarization, said dielectric layer having a top surface, a bottom surface, and first and second side surfaces; a top contact, said dielectric layer being sandwiched between said bottom contact and said top contact, said top contact being in contact with said top surface of said dielectric layer and said bottom contact being in contact with said bottom surface of said dielectric layer; and an encapsulating layer comprising an oxygen impermeable material, said encapsulating layer preventing oxygen from entering or leaving said dielectric layer through said first and second side surfaces of said dielectric layer.

Claim 3

The ferroelectric memory cell of claim 1 wherein said ferroelectric material comprises lead zirconium titanate.

Claim 4

The ferroelectric memory cell of claim 1 wherein said bottom contact comprises a platinum electrode.

Claim 5

The ferroelectric memory cell of claim 3 wherein said top contact comprises a platinum electrode.

Claim 6

A ferroelectric memory cell for storing information, said memory cell operating to store said information at a temperature less than a first temperature, said memory cell comprising: a bottom contact; a dielectric layer comprising a ferroelectric material having a Curie point greater than said first temperature and less than 400° C., said ferroelectric material having a remnant polarization below said first temperature, said information being stored by altering said remnant polarization, said dielectric layer having a top surface, a bottom surface, and side surfaces; a top contact, said dielectric layer being sandwiched between said bottom contact and said top contact, said top contact being in contact with said top surface of said dielectric layer and said bottom contact being in contact with said bottom surface of said dielectric layer; and an encapsulating layer comprising an oxygen impermeable material, said encapsulating layer preventing oxygen from entering or leaving said dielectric layer through said side surfaces of said dielectric layer, wherein said bottom contact comprises a platinum electrode and wherein said top contact comprises a semiconducting layer and first and second top electrodes, said first and second top electrodes being spaced apart on said semiconducting layer.

Claim 7

A ferroelectric memory cell for storing information, said memory cell operating to store said information at a temperature less than a first temperature, said memory cell comprising: a bottom contact; a dielectric layer comprising a ferroelectric material having a Curie point greater than said first temperature and less than 400° C., said ferroelectric material having a remnant polarization below said first temperature, said information being stored by altering said remnant polarization, said dielectric layer having a top surface, a bottom surface, and side surfaces; a top contact, said dielectric layer being sandwiched between said bottom contact and said top contact, said top contact being in contact with said top surface of said dielectric layer and said bottom contact being in contact with said bottom surface of said dielectric layer; and an encapsulating layer comprising an oxygen impermeable material, said encapsulating layer preventing oxygen from entering or leaving said dielectric layer through said side surfaces of said dielectric layer, wherein said bottom contact comprises a platinum electrode and wherein said top contact comprises a semiconducting layer and first and second top electrodes, said first and second top electrodes being spaced apart on said semiconducting layer.

Claim 8

The ferroelectric memory cell of claim 1 wherein said oxygen impermeable material comprises an oxide of titanium.

Claim 9

The ferroelectric memory cell of claim 2 wherein said ferroelectric material is doped with an element having an oxidation state greater than +4.

Claim 10

The ferroelectric memory cell of claim 7 wherein said doping element is chosen from a group consisting of Nb, Ta, and W.

Claim 11

The ferroelectric memory cell of claim 7 wherein said doping element is present in a concentration of between 1% and 8%.

Claim 12

The ferroelectric memory cell of claim 1 wherein said top contact comprises a semiconducting layer and first and second top electrodes, said first and second top electrodes being spaced apart on said semiconducting layer.