Poly α-amino acid and ferroelectric memory element using same

Patent metadata

Field	Value
Publication number	US-9464167-B2
Application number	US-201314076363-A
Country	US
Kind code	B2
Filing date	Nov 11, 2013
Priority date	May 12, 2011
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

Ferroelectric memory elements which contain a poly α-amino acid which is a copolymer containing a glutamic acid-γ-ester unit represented by the formula (I), defined herein, and a glutamic acid-γ-ester unit represented by the formula (II), defined herein, in a molar ratio of units of formula (I) to units of formula (II) of 10/90-90/10 are useful as recording elements such as RFID and the like.

First claim

The invention claimed is:

1. A ferroelectric memory element, comprising a ferroelectric layer, wherein said ferroelectric layer comprises a poly α-amino acid which is a copolymer comprising:
(i) a glutamic acid-γ-ester unit represented by formula (I):

wherein R 1 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a benzyl group optionally substituted by a halogen atom, an alkoxy group or a nitro group; and either
(iia) a glutamic acid-γ-ester unit represented by formula (II):

wherein R 2 is an unsubstituted alkyl group having 3 to 16 carbon atoms, or an alkyl group having 1 to 6 carbon wherein a part or all of the hydrogen atoms are substituted by a halogen atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a phenyl group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, a phenyl alkoxy group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, or a phenylalkyl carbamate group in which a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group, provided that R 2 is not the same as R 1 ; or
(iib) an alanine, phenylalanine or N-substituted lysine unit represented by formula (III):

wherein R 3 is a methyl group, a benzyl group or a —(CH 2 ) 4 —NHX group (wherein X is a benzyloxycarbonyl group optionally substituted by a halogen atom or an alkoxy group, an alkylcarbonyl group optionally substituted by a halogen atom, an allyloxycarbonyl group, a fluorenylalkoxycarbonyl group, a benzenesulfonyl group optionally substituted by an alkyl group or a nitro group, or an alkyloxycarbonyl group),
wherein the molar ratio of units of formula (I) to units of formula (II) or units of formula (III), (I)/(II) or (I)/(III), is 10/90 to 90/10.

2. A ferroelectric memory element according to claim 1 , wherein:
in formula (I), R 1 is a methyl group or a benzyl group;
in formula (II), R 2 is an unsubstituted alkyl group having 6 to 16 carbon atoms or an alkyl group having 1 to 6 carbon atoms wherein part or all of the hydrogen atoms are substituted by a halogen atom or an alicyclic hydrocarbon group having 3 to 12 carbon atoms; and
in formula (III), R 3 is a methyl group, a benzyl group or a —(CH 2 ) 4 —NHX group, wherein X is a benzyloxycarbonyl group.

3. A ferroelectric memory element according to claim 1 , wherein said poly α-amino acid is a copolymer comprising units of formula (I) and units of formula (II).

4. A ferroelectric memory element according to claim 3 , wherein said poly α-amino acid is obtained by polymerizing an N-carboxy-α-glutamic acid-γ-ester anhydride comprising an ester group represented by the formula: —COOR 1 wherein R 1 is as defined above introduced therein and an N-carboxy-α-glutamic acid-γ-ester anhydride comprising an ester group represented by the formula: —COOR 2 wherein R 2 is as defined above introduced therein.

5. A ferroelectric memory element, comprising a ferroelectric layer, wherein said ferroelectric layer comprises:
(i) a poly α-amino acid which is a homopolymer of a glutamic acid-γ-ester unit represented by formula (IV):

wherein each R 4 is independently an alkoxy group having 1 to 12 carbon atoms, an alkyl group having 1 to 12 carbon atoms wherein part or all of the hydrogen atoms are substituted by a halogen atom, or an alkylcarbonyl group wherein the alkyl group has 1 to 12 carbon atoms, l is an integer of 6 to 12, and m is an integer of 1 to 3; or
(ii) a copolymer of a glutamic acid-γ-ester unit represented by formula (IV) and a glutamic acid-γ-ester unit represented by formula (I):

wherein R 1 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a benzyl group optionally substituted by a halogen atom, an alkoxy group or a nitro group,
wherein the content of said glutamic acid-γ-ester unit represented by formula (IV) is not less than 40 mol % based on the total moles in said copolymer.

6. A ferroelectric memory element according to claim 5 , wherein said poly α-amino acid is a copolymer comprising units of formula (I) and units of formula (IV), R 1 in formula (I) is a methyl group or a benzyl group, and the content of said glutamic acid-γ-ester unit represented by formula (IV) in the copolymer is not less than 80 mol % based on the total moles in said copolymer.

7. A ferroelectric memory element according to claim 5 , wherein said poly α-amino acid is obtained by:
(a) polymerizing an N-carboxy-α-glutamic acid-γ-ester anhydride comprising an ester group represented by formula: —COOR 5 wherein R 5 is

wherein R 4 , l and m are as defined above, introduced therein; or
(b) polymerizing said N-carboxy-α-glutamic acid-γ-ester anhydride and an N-carboxy-α-glutamic acid-γ-ester anhydride comprising an ester group represented by formula: —COOR 1 wherein R 1 is as defined above introduced therein.

8. A ferroelectric memory element according to claim 1 , wherein said poly α-amino acid has a number average molecular weight of 2,000 to 50,000.

9. A ferroelectric memory element according to claim 1 , which exhibits a memory property at 100° C.

10. A ferroelectric memory element according to claim 1 , which is a transistor type.

11. A ferroelectric memory element according to claim 10 , comprising a ferroelectric layer, a gate electrode, a semiconductor layer, a source electrode, and a drain electrode on a substrate.

12. Ae ferroelectric memory element according to claim 11 , wherein said source electrode and said drain electrode are configured on said semiconductor layer.

13. A tag, comprising a ferroelectric memory element according to claim 1 .

14. A method of producing a ferroelectric memory element, comprising:
(a) dissolving one or more kinds of poly α-amino acids selected from the group consisting of
(A-1) a poly α-amino acid which is a copolymer comprising a glutamic acid-γ-ester unit represented by formula (I):

wherein R 1 is a substituted or unsubstituted alkyl group having 1 to 8 carbon atoms, or a benzyl group optionally substituted by a halogen atom, an alkoxy group or a nitro group; and
a glutamic acid-γ-ester unit represented by formula (II):

wherein R 2 is an unsubstituted alkyl group having 3 to 16 carbon atoms, or an alkyl group having 1 to 6 carbon wherein part or all of the hydrogen atoms are substituted by a halogen atom, an alicyclic hydrocarbon group having 3 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, a phenyl group (wherein a part or all of the hydrogen atoms are optionally substituted by a halogen atom or an alkoxy group), a phenylalkoxy grou

Assignees

• Ajinomoto Kk

Inventors

• Ohashi Satoru
• Uemura Sei
• Kitazawa Manabu
• Kamata Toshihide

Classifications

• H10D30/701

  IGFETs having ferroelectric gate insulators, e.g. ferroelectric FETs · CPC title

• H01L29/78391

  Electricity · mapped topic

• B82Y10/00 Primary

  Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic · CPC title

• G11C11/22 Primary

  using ferroelectric elements · CPC title

• G11C11/221

  using ferroelectric capacitors · CPC title