Piezoelectric memory

Patent metadata

Field	Value
Publication number	US-12396376-B2
Application number	US-202217978954-A
Country	US
Kind code	B2
Filing date	Nov 1, 2022
Priority date	Nov 1, 2022
Publication date	Aug 19, 2025
Grant date	Aug 19, 2025

Abstract

A non-volatile memory apparatus includes a first hydrogen reservoir, which is electrically conductive; a charge of hydrogen, which is captured in the first hydrogen reservoir; a dielectric layer that has a first side that is adjacent to the first hydrogen reservoir and a second side that is opposite from the first hydrogen reservoir; a second hydrogen reservoir that is adjacent to the second side of the dielectric layer, is electrically conductive, and has a side that is opposite from the dielectric layer; and a piezoelectric layer that is adjacent to the side of the second hydrogen reservoir and that has a side that is opposite from the second hydrogen reservoir.

First claim

What is claimed is:

1. A non-volatile memory apparatus that comprises:
a first hydrogen reservoir, wherein the first hydrogen reservoir is electrically conductive;
a charge of hydrogen, which is captured in the first hydrogen reservoir;
a dielectric layer that has a first side that is adjacent to the first hydrogen reservoir and a second side that is opposite from the first hydrogen reservoir;
a second hydrogen reservoir that is adjacent to the second side of the dielectric layer, wherein the second hydrogen reservoir is electrically conductive and has a side that is opposite from the dielectric layer; and
a piezoelectric layer that is adjacent to the side of the second hydrogen reservoir and that has a side that is opposite from the second hydrogen reservoir.

2. The apparatus of claim 1 , wherein each of the first and second hydrogen reservoirs comprises a metal.

3. The apparatus of claim 2 , wherein each of the first and second hydrogen reservoirs comprises a same metal.

4. The apparatus of claim 2 , wherein each of the first and second hydrogen reservoirs comprises a metal selected from the list consisting of: palladium, platinum, vanadium, tungsten, hafnium, zirconium, niobium, tantalum, and titanium.

5. The apparatus of claim 1 , wherein the dielectric layer comprises phosphosilicate glass.

6. The apparatus of claim 1 , further comprising:
a first programming contact that is electrically connected to the first hydrogen reservoir;
a second programming contact that is electrically connected to the second hydrogen reservoir;
a conductive neutral layer that is adjacent to the side of the piezoelectric layer that is opposite from the second hydrogen reservoir, and a readout circuit that is electrically connected to at least one of the first and second hydrogen reservoirs.

7. The apparatus of claim 6 , wherein the readout circuit is connected across the first and second hydrogen reservoirs.

8. The apparatus of claim 6 , wherein the readout circuit is connected across the second hydrogen reservoir and the neutral layer.

9. The apparatus of claim 6 , wherein the readout circuit comprises an operational amplifier.

10. The apparatus of claim 9 , wherein the readout circuit comprises a sense amplifier.

11. The apparatus of claim 10 , wherein the readout circuit comprises a latch circuit.

12. The apparatus of claim 1 , wherein each of the first and second hydrogen reservoirs comprises a film of metal that is between about 10 nm and about 50 nm thick and wherein a longest dimension of each reservoir is about 50 nm to about 100 nm.

13. The apparatus of claim 1 , wherein the piezoelectric layer comprises a material selected from the list consisting of: lead zirconate titanate, barium niobate, and ferroelectric hafnium oxide.

14. A method for operating a non-volatile memory apparatus, which comprises first and second hydrogen reservoirs, a dielectric layer that partitions the hydrogen reservoirs, a piezoelectric layer that is adjacent to the second hydrogen reservoir, and a neutral layer that is at a side of the piezoelectric layer opposite from the second hydrogen reservoir, the method comprising:
setting a high bit on the memory apparatus by inducing a strain on the piezoelectric layer, wherein inducing the strain comprises:
moving hydrogen from the first hydrogen reservoir through the dielectric layer to the second hydrogen reservoir, wherein moving the hydrogen comprises:
applying an electric field across the hydrogen reservoirs.

15. The method of claim 14 , further comprising:
reading the high bit from the memory apparatus by connecting a readout circuit to at least one of the hydrogen reservoirs.

16. The method of claim 15 , wherein connecting the readout circuit comprises connecting the readout circuit across the hydrogen reservoirs.

17. The method of claim 15 , wherein connecting the readout circuit comprises connecting the readout circuit across the second hydrogen reservoir and the neutral layer.

18. The method of claim 15 , wherein connecting the readout circuit comprises connecting a pair of operational amplifiers across the hydrogen reservoirs, wherein the pair of operational amplifiers form part of a high-input-impedance amplifier.

19. A piezoelectric memory apparatus comprising:
a piezoelectric layer;
programmable means for placing and removing a strain on the piezoelectric layer so as to store a value directly in the piezoelectric layer; and
a readout circuit that is connected to the programmable means to read out the value stored directly in the piezoelectric layer.

20. A piezoelectric memory apparatus comprising:
a piezoelectric layer;
programmable means for placing and removing a strain on the piezoelectric layer; and
a readout circuit that is connected to the programmable means;
wherein the programmable means comprise a dielectric layer, a first hydrogen reservoir that is disposed at a first side of the dielectric layer, a second hydrogen reservoir that is disposed at a second side of the dielectric layer that is opposite from the first hydrogen reservoir and between the dielectric layer and the piezoelectric layer, and a charge of hydrogen in at least one of the hydrogen reservoirs.

Assignees

• IBM

Inventors

• Cohen Guy M
• Ando Takashi
• Gong Nanbo

Classifications

• G11C2213/55

  Structure including two electrodes, a memory active layer and at least two other layers which can be a passive or source or reservoir layer or a less doped memory active layer · CPC title

• G11C2213/31

  Material having complex metal oxide, e.g. perovskite structure · CPC title

• G11C2013/0095

  Write using strain induced by, e.g. piezoelectric, thermal effects · CPC title

• H10N70/8836

  Complex metal oxides, e.g. perovskites, spinels · CPC title

• H10N70/24 Primary

  based on migration or redistribution of ionic species, e.g. anions, vacancies · CPC title