JP2013197499A - Molecular memory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable molecular memory.SOLUTION: A molecular memory according to an embodiment comprises: first electrodes; second electrodes; and resistance change type molecular chains arranged between the first electrodes and the second electrodes. The first electrodes each include: a core material made of a first conductive material; and side walls formed on the side faces of the core material and made of a second conductive material which is different from the first conductive material. The second electrodes are each made of a third conductive material which is different from the first conductive material. The resistance change type molecular chains are coupled to the first conductive materials.

Description

  Embodiments of the invention relate to molecular memory.

  Conventionally, in a nonvolatile memory device such as a NAND flash memory, the recording density has been improved by miniaturizing a memory cell. However, miniaturization of memory cells is approaching the limit due to limitations of lithography technology. Therefore, research on molecular memory using resistance change type molecular chains as memory elements is underway. The resistance change type molecular chain is a molecule whose electric resistance value changes when an electric signal such as voltage or current is input, and since its size is small, there is a possibility that the memory cell can be greatly miniaturized. In order to commercialize such a molecular memory, ensuring reliability is an important issue.

US Patent Application Publication No. 2007/0045615

  An object of the present invention is to provide a molecular memory with high reliability.

  The molecular memory according to the embodiment includes a first electrode, a second electrode, and a resistance variable molecular chain disposed between the first electrode and the second electrode. The first electrode includes: a core material made of a first conductive material; and a side wall made of a second conductive material that is formed on a side surface of the core material and is different from the first conductive material. Have. The second electrode is made of a third conductive material different from the first conductive material. The resistance variable molecular chain is bonded to the first conductive material.

1 is a perspective view illustrating a molecular memory according to a first embodiment. 1 is a cross-sectional view illustrating a molecular memory according to a first embodiment. It is a figure which illustrates the resistance change type molecular chain in 1st Embodiment. (A)-(d) is process sectional drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment. (A)-(d) is process sectional drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment. (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). (A)-(c) is process drawing which illustrates the manufacturing method of the molecular memory which concerns on 1st Embodiment, (a) is a top view, (b) is AA shown to (a). It is sectional drawing by a line, (c) is sectional drawing by the BB 'line shown to (a). It is sectional drawing which illustrates the molecular memory which concerns on a comparative example. FIG. 6 is a perspective view illustrating a molecular memory according to a second embodiment. It is sectional drawing which illustrates the molecular memory which concerns on 2nd Embodiment. It is a figure which illustrates the general formula of the resistance change type molecular chain which concerns on a modification. (A)-(f) is a figure which illustrates the molecular unit which can comprise the molecule | numerator which (pi) conjugated system extended in the one-dimensional direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 is a perspective view illustrating a molecular memory according to this embodiment.
FIG. 2 is a cross-sectional view illustrating a molecular memory according to this embodiment.
FIG. 3 is a diagram illustrating a resistance variable molecular chain in the present embodiment.
In order to make the drawing easier to see, only the conductive portion is shown in FIG. 1, and the insulating portion is not shown.

  As shown in FIGS. 1 and 2, in the molecular memory 1 according to the present embodiment, an interlayer insulating film 10 is provided on a silicon substrate (not shown), and a wiring layer 11 and a memory layer are formed thereon. 12 and the wiring layer 13 are laminated in this order. Hereinafter, this stacking direction is referred to as “Z direction”. In the wiring layer 11, a plurality of wirings 21 extending in one direction (hereinafter referred to as “X direction”) are periodically arranged. In the wiring layer 13, a plurality of wirings 22 that intersect with the X direction, for example, in a direction orthogonal to the X direction (hereinafter referred to as “Y direction”) are periodically arranged. The X direction, the Y direction, and the Z direction are orthogonal to each other.

  In the wiring 21, a core member 24 extending in the X direction is provided, and a pair of side walls 25 are formed on both sides in the width direction of the core member 24, that is, on both side surfaces facing the Y direction. The core member 24 and the side wall 25 are in contact with each other. On the other hand, the wiring 22 is not divided into a core material and a side wall, but is formed integrally. The core member 24 is made of, for example, tungsten (W). On the other hand, the side wall 25 and the wiring 22 are made of, for example, molybdenum (Mo). A convex portion 22 p is formed in a region facing the wiring 21 on the lower surface of the wiring 22. In addition, in FIG. 1, the convex part 22p is abbreviate | omitting illustration. A gap 41 is formed in the closest part between the wiring 21 and the wiring 22, that is, in the region immediately below the convex portion 22p.

  In the memory layer 12, an organic molecular layer 32 including a plurality of resistance variable molecular chains 31 is provided for each closest portion between the core member 24 and the wiring 22. That is, the organic molecular layer 32 is disposed in the space 41 and directly above the core material 24. The resistance change type molecular chain 31 is a molecule that changes an electric resistance value when an electric signal such as voltage or current is inputted. Each organic molecular layer 32 includes, for example, about several tens to several hundreds of resistance change type molecular chains 31. In the molecular memory 1, an inter-wiring insulating film 35 is provided so as to embed the wiring 21, the wiring 22, and the organic molecular layer 32. The interlayer insulating film 10 and the inter-wiring insulating film 35 are formed of an insulating material such as silicon oxide, alumina, or silicon nitride, for example.

  As shown in FIG. 3, the resistance-change molecular chain 31 is, for example, 4- [2-amino-5-nitro-4- (phenethylenyl) phenethylenyl] benzenethiol, and one end thereof has a thiol group (R-SH). ) Is provided. The sulfur atom (S) of the thiol group is easily bonded to the tungsten atom (W). On the other hand, the resistance variable molecular chain 31 does not include a group that easily binds to a molybdenum atom (Mo). For this reason, the resistance variable molecular chain 31 is easier to bond with tungsten than with molybdenum.

  Therefore, the resistance variable molecular chain 31 is bonded to the core material 24 containing tungsten, but is not bonded to the side wall 25 and the wiring 22. As a result, each resistance variable molecular chain 31 has one end bonded to the surface of the core material 24 facing the wiring 22 and starts from this one end to the wiring 22 in the direction (Z direction). Is extended. The length of the resistance variable molecular chain 31 is, for example, about 2 nm. However, the other end portion of the resistance change type molecular chain 31 does not reach the wiring 22 and is separated from the wiring 22 with a gap of about 1 nm, for example. Further, the resistance change type molecular chain 31 is not bonded to the side wall 25 made of molybdenum, and therefore is not disposed between the side wall 25 and the wiring 22.

Next, a method for manufacturing the molecular memory 1 according to this embodiment will be described.
4A to 4D and FIGS. 5A to 5D are process cross-sectional views illustrating a method for manufacturing a molecular memory according to this embodiment.
6 (a)-(c), FIG. 7 (a)-(c), FIG. 8 (a)-(c), FIG. 9 (a)-(c), FIG. 10 (a)-(c), FIGS. 11A to 11C and FIGS. 12A to 12C are process diagrams illustrating a method for manufacturing a molecular memory according to this embodiment.
4 (a) to 5 (d) show different processes arranged in time series. On the other hand, FIGS. 6A to 6C show the same process. 6A is a plan view, FIG. 6B is a cross-sectional view taken along line AA ′ shown in FIG. 6A, and FIG. 6C is a cross-sectional view taken along line B- shown in FIG. It is sectional drawing by a B 'line. The same applies to FIGS. 7A to 12C.

First, as shown in FIG. 4A, an interlayer insulating film 10 made of an insulating material such as silicon oxide or alumina is formed on a silicon substrate (not shown). Next, a conductive material such as tungsten is deposited, and a conductive film 24 a is formed on the interlayer insulating film 10.
Next, as shown in FIG. 4B, the conductive film 24a is processed into a line shape using a lithography technique. Thereby, a plurality of core members 24 extending in the X direction are formed.

Next, as shown in FIG. 4C, a conductive material different from tungsten, for example, molybdenum is deposited, and a conductive film 25 a is formed so as to cover the core material 24.
Next, as shown in FIG. 4D, anisotropic etching is performed to remove a portion of the conductive film 25a disposed on the upper surface of the interlayer insulating film 10 and a portion disposed on the upper surface of the core member 24. To do. At this time, the part arrange | positioned on the side surface of the core material 24 in the electrically conductive film 25a remains. Thereby, the side walls 25 are formed on both side surfaces of the core member 24. At this time, the upper part of the side wall 25 is thinner than the middle part and the lower part.

Next, as shown in FIG. 5A, an insulating material is deposited, and an insulating film 35 a is formed on the interlayer insulating film 10 so as to embed the core material 24 and the sidewall 25.
Next, as shown in FIG. 5B, a flattening process such as CMP (chemical mechanical polishing) is performed using the core member 24 as a stopper to flatten the upper surface of the insulating film 35a. At this time, after the core member 24 is exposed, a flattening process is continuously performed for a predetermined time, and the upper portion of the side wall 25, that is, a relatively thin portion is removed together with the upper portion of the core member 24. Thereby, the side wall 25 is exposed reliably. A wiring 21 is formed by the core member 24 and a pair of side walls 25 formed on both side surfaces thereof. Further, the wiring layer 11 is formed by the plurality of wirings 21 and the insulating film 35a remaining therebetween.

Next, as shown in FIG. 5C, a material different from the core material 24, the sidewall 25, and the insulating film 35 a, for example, silicon oxide, alumina, or silicon nitride is deposited and sacrificed on the wiring layer 11. A film 40 is formed.
Next, as shown in FIG. 5D, a conductive material different from tungsten, for example, molybdenum is deposited, and a conductive film 22 a is formed on the sacrificial film 40.

  Next, as shown in FIGS. 6A to 6C, the conductive film 22a and the sacrificial film 40 are patterned by using a lithography technique. Thereby, the conductive film 22a and the sacrificial film 40 are processed into a line-shaped stacked body extending in the Y direction.

  Next, as shown in FIGS. 7A to 7C, an insulating material different from the sacrificial film 40, for example, silicon oxide, alumina, or silicon nitride is deposited to form the insulating film 35b. Next, a planarization process such as CMP is performed using the conductive film 22a as a stopper to planarize the upper surface of the insulating film 35b. As a result, the insulating film 35b is removed from the upper surface of the conductive film 22a, and the insulating film 35b is embedded between the stacked bodies of the sacrificial film 40 and the conductive film 22a.

  Next, as shown in FIGS. 8A to 8C, the conductive film 22a, the sacrificial film 40, and the insulating film 35b are processed into lines extending in the X direction by using a lithography technique. As a result, the laminated body composed of the sacrificial film 40 and the conductive film 22a is divided along both the X direction and the Y direction to form a plurality of island-shaped portions arranged in a matrix. The insulating film 35b is also divided along both the X direction and the Y direction, and is disposed between the stacked body including the sacrificial film 40 and the conductive film 22a adjacent in the X direction. That is, in the region immediately above the wiring 21, the above-described stacked body and the insulating film 35b are alternately arranged.

  Next, as shown in FIGS. 9A to 9C, for example, wet etching is performed to remove the sacrificial film 40 (see FIGS. 8A and 8B). Thereby, after the sacrificial film 40 is removed, the air gap 41 is formed. The wiring 21 is disposed below the gap 41, the conductive film 22a is disposed above, the insulating film 35b is disposed on both sides in the X direction, and both sides in the Y direction are open.

  Next, a chemical solution including the resistance change type molecular chain 31 (see FIG. 3) is caused to enter the gap 41. As a result, the thiol group of the resistance variable molecular chain 31 is bonded to the tungsten atom (W) included in the core material 24 of the wiring 21, and one end of the resistance variable molecular chain 31 is bonded to the core material 24. On the other hand, the resistance variable molecular chain 31 is not bonded to the sidewall 25 and the conductive film 22a made of molybdenum. Next, a treatment such as drying is performed to remove the liquid contained in the chemical liquid from the gap 41. As a result, an organic molecular layer 32 is formed at each closest portion between the core member 24 and the conductive film 22a. Each organic molecular layer 32 includes, for example, several tens to several hundreds of resistance variable molecular chains 31. At this time, since the resistance variable molecular chain 31 is not bonded to the sidewall 25 and the conductive film 22a, the organic molecular layer 32 is not disposed between the sidewall 25 and the conductive film 22a.

  Next, as shown in FIGS. 10A to 10C, an insulating material such as silicon oxide, alumina, or silicon nitride is deposited to form the insulating film 35c. Next, a planarization process such as CMP is performed using the conductive film 22a as a stopper to planarize the upper surface of the insulating film 35c. Thereby, the insulating film 35c is embedded between the stacked bodies including the gap 41, the organic molecular layer 32, and the conductive film 22a. At this time, the insulating material hardly penetrates into the gap 41 and remains as the gap 41. Therefore, the insulating material does not enter between the resistance change type molecular chains 31 formed in the gap 41. As a result, the insulating film 35 c is disposed immediately above the insulating film 35 a, and the insulating film 35 b is disposed in the area directly above the wiring 21 between the gaps 41.

  Next, as shown in FIGS. 11A to 11C, a conductive material different from tungsten, for example, molybdenum is deposited to form a conductive film 22b. The conductive film 22b is in contact with the conductive film 22a.

  Next, as shown in FIGS. 12A to 12C, the conductive film 22b is processed into a plurality of lines extending in the Y direction by using a lithography technique. At this time, the conductive film 22b is left so as to pass through the region immediately above the conductive film 22a. Next, an insulating material (not shown) is deposited so as to embed the conductive film 22b. In this way, the molecular memory 1 according to this embodiment is manufactured.

  In the molecular memory 1, the conductive film 22 a and the conductive film 22 b are wirings 22. The conductive film 22 a corresponds to the convex portion 22 p of the wiring 22. The insulating films 35 a to 35 c and the insulating material deposited thereafter become a part of the inter-wiring insulating film 35. In the Z direction, the area where the wiring 22 is arranged becomes the wiring layer 13, and the area between the wiring layer 11 and the wiring layer 13, that is, the area where the air gap 41 and the organic molecular layer 32 are formed is the memory layer. 12

  In addition, a memory cell including one organic molecular layer 32 is formed for each closest portion of the wiring 21 and the wiring 22. Thereby, the memory cells are arranged in a matrix along the X direction and the Y direction. Then, by applying a predetermined voltage between one wiring 21 and one wiring 22, the electronic state of the resistance change type molecular chain 31 included in the organic molecular layer 32 between them changes, and the electric resistance The value changes. Thereby, information can be written in each memory cell. Further, the written information can be read by detecting the electrical resistance value between the wiring 21 and the wiring 22.

Next, the effect of this embodiment is demonstrated.
As shown in FIG. 2, in the molecular memory 1 according to this embodiment, a core member 24 and a side wall 25 are provided on the wiring 21, and the core member 24 and the side wall 25 are in contact with each other. For this reason, as the wiring for transmitting the electrical signal, the core member 24 and the side wall 25 function integrally as the wiring 21, and when a potential is applied to the wiring 21, Electric field concentrates. On the other hand, the core member 24 and the side wall 25 are formed of different conductive materials, and the resistance variable molecular chain 31 is easier to bond to the core member 24 than the side wall 25. For this reason, the resistance variable molecular chain 31 is disposed between the core member 24 and the wiring 22, whereas the resistance variable molecular chain 31 is not disposed between the sidewall 25 and the wiring 22. As described above, since the resistance variable molecular chain 31 is not bonded to the side wall 25 where the electric field concentrates, it is possible to prevent the resistance variable molecular chain 31 from being deteriorated due to current concentration. As a result, a highly reliable molecular memory can be realized.
Further, by forming the side wall 25 from a material that the resistance variable molecular chain 31 is difficult to bond, the above-described configuration can be formed in a self-aligning manner.

Next, a comparative example will be described.
FIG. 13 is a cross-sectional view illustrating a molecular memory according to this comparative example.
As shown in FIG. 13, in the molecular memory 101 according to this comparative example, the wiring 121 is not divided into a core material and a side wall, and is integrally formed of tungsten. Moreover, the wiring 22 is integrally formed of molybdenum. For this reason, the resistance variable molecular chain 31 is arranged in the entire region where the wiring 121 and the wiring 22 overlap as viewed from the Z direction.

  When a potential is applied to the wiring 121, the electric field applied to the edge portion E of the wiring 121, that is, both ends in the width direction, is stronger than the electric field applied to the center portion in the width direction. For this reason, even if the resistance variable molecular chains 31 are uniformly formed in the width direction of the wiring 121, current flows intensively through the resistance variable molecular chains 31 coupled to the edge portion E. The resistance variable molecular chain 31 tends to deteriorate. When the resistance variable molecular chain 31 deteriorates, there is a high possibility that a malfunction such as an increase in leakage current occurs. Therefore, the reliability of the molecular memory 101 is low.

Next, a second embodiment will be described.
FIG. 14 is a perspective view illustrating a molecular memory according to this embodiment.
FIG. 15 is a cross-sectional view illustrating a molecular memory according to this embodiment.
In order to make the drawing easier to see, only the conductive portion is shown in FIG. 14, and the insulating portion is not shown. In FIGS. 14 and 15, the protrusions 22p of the wiring 22 (see FIG. 2) are not shown.

  As shown in FIGS. 14 and 15, in the molecular memory 2 according to the present embodiment, a plurality of wiring layers 11, storage layers 12, and wiring layers 13 are provided. The wiring layers 11 and the wiring layers 13 are alternately stacked along the Z direction with the memory layer 12 interposed therebetween. That is, the wiring layer 11, the memory layer 12, the wiring layer 13, the memory layer 12, the wiring layer 11, the memory layer 12, the wiring layer 13,. Such a molecular memory 2 can be manufactured by repeating the steps shown in FIGS. 4A to 12C a plurality of times.

  According to the present embodiment, the memory cells can be arranged in the Z direction by stacking a plurality of wiring layers 11, memory layers 12, and wiring layers 13. That is, the memory cells can be arranged in a three-dimensional matrix along the X direction, the Y direction, and the Z direction. As a result, it is possible to improve the degree of integration of the memory cells and increase the recording density of the molecular memory. The configuration, manufacturing method, and operational effects other than those described above in the present embodiment are the same as those in the first embodiment described above.

Hereinafter, the modification of the material in each above-mentioned embodiment is demonstrated.
FIG. 16 is a diagram illustrating a general formula of a resistance variable molecular chain according to a modification,
FIGS. 17A to 17F are diagrams illustrating molecular units that can form molecules in which a π-conjugated system extends in a one-dimensional direction.

  In each of the above-described embodiments, an example in which the resistance-change molecular chain 31 is 4- [2-amino-5-nitro-4- (phenethylenyl) phenethylenyl] benzenthiol shown in FIG. 3 is shown, but the present invention is not limited thereto. The resistance variable molecular chain 31 may be any molecule having a function of changing resistance. For example, the resistance-change molecular chain 31 may be a derivative of 4- [2-amino-5-nitro-4- (phenylthynyl) benzynethiol as shown in FIG. 16 as a general formula.

In the general formula shown in FIG. 16, the combination of X and Y is fluorine (F), chlorine (Cl), bromine (Br), iodine (I), cyano group (CN), nitro group (NO ₂ ). , An amino group (NH ₂ ), a hydroxyl group (OH), a carbonyl group (CO), and a carboxy group (COOH). Rn (n = 1 to 8) is an arbitrary atom excluding an atom whose outermost electron is d electron or f electron, and a characteristic group such as hydrogen (H), fluorine (F), chlorine ( Cl), bromine (Br), iodine (I), and a methyl group (CH ₃ ).

  Further, the resistance variable molecular chain 31 may be a molecule in which a π-conjugated system extends in a one-dimensional direction other than the molecular structure represented by the general formula in FIG. For example, a paraphenylene derivative, an oligothiophene derivative, an oligopyrrole derivative, an oligofuran derivative, or a paraphenylene vinylene derivative can be used.

  The molecular unit capable of constituting a molecule having a π-conjugated system extending in the one-dimensional direction may be paraphenylene shown in FIG. 17A or thiophene shown in FIG. The pyrrole shown in (c), the furan shown in FIG. 17 (d), the vinylene shown in FIG. 17 (e), or the alkyne shown in FIG. 17 (f) may be used. May be. In addition, a hetero 6-membered ring compound such as pyridine may be used.

  However, when the length of the π-conjugated system is short, the electrons injected from the electrode escape without staying on the molecule, so that it is a molecule of a certain length in order to accumulate charges. Preferably, it is desirable to calculate 5 or more in units of —CH═CH— in the one-dimensional direction. In the case of a benzene ring (paraphenylene), this corresponds to 3 or more. Note that the diameter of the benzene ring is about twice the spread width of polaron, which is a π-conjugated carrier. On the other hand, when the length of the π-conjugated system is long, a voltage drop due to charge conduction in the molecule becomes a problem. For this reason, it is desirable that the length of the π-conjugated system is 20 or less calculated by the unit of —CH═CH— in the one-way direction. This corresponds to 10 or less in the case of a benzene ring.

  In each of the above-described embodiments, the core material 24 is formed of tungsten, and the sidewall 25 and the wiring 22 are formed of molybdenum. However, the present invention is not limited to this. A suitable conductive material for forming the core material 24, the side wall 25, and the wiring 22 differs depending on the molecular structure of one end portion of the resistance variable molecular chain 31.

  For example, as shown in FIG. 3, when one end of the resistance variable molecular chain 31 is a thiol group, the material of the core material 24, that is, the material of the portion where the resistance variable molecular chain 31 is to be chemically bonded is In addition to the above-mentioned tungsten (W), gold (Au), silver (Ag), copper (Cu), tungsten nitride (WN), tantalum nitride (TaN) or titanium nitride (TiN) is preferable. In particular, tungsten (W), gold (Au), or silver (Ag) that easily forms a chemical bond is desirable. On the other hand, the material of the side wall 25 and the wiring 22, that is, the material of the portion where the resistance change type molecular chain 31 is not desired to be chemically bonded is tantalum (Ta), molybdenum nitride (MoN), or Silicon (Si) is desirable. The material of the side wall 25 and the material of the wiring 22 may be different from each other.

  For example, when one end portion of the resistance variable molecular chain 31 is an alcohol group or a carboxyl group, the material of the portion where the resistance variable molecular chain 31 is to be chemically bonded is tungsten (W) or tungsten nitride (WN). Tantalum (Ta), tantalum nitride (TaN), molybdenum (Mo), molybdenum nitride (MoN), or titanium nitride (TiN), among which tantalum (Ta) and tantalum nitride are particularly easy to form chemical bonds. (TaN), molybdenum nitride (MoN), or titanium nitride (TiN) is desirable. On the other hand, it is desirable that the material of the portion where the resistance variable molecular chain 31 is not desired to be chemically bonded is gold (Au), silver (Ag), copper (Cu), or silicon (Si).

  Further, for example, when one end portion of the resistance change type molecular chain 31 is a silanol group, the material of the portion where the resistance change type molecular chain 31 is to be chemically bonded is preferably silicon (Si) or a metal oxide. . On the other hand, the material of the portion where the resistance change type molecular chain 31 is not desired to be chemically bonded is gold (Au), silver (Ag), copper (Cu), tungsten (W), tungsten nitride (WN), tantalum (Ta), Tantalum nitride (TaN), molybdenum (Mo), molybdenum nitride (MoN), or titanium nitride (TiN) is desirable. Further, when the wiring material is a compound, the composition of the compound can be selected as appropriate. Further, for example, graphene or carbon nanotubes can be applied as the wiring material.

  According to the embodiment described above, a highly reliable molecular memory can be realized.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and the equivalents thereof.

1, 2: Molecular memory, 10: Interlayer insulating film, 11: Wiring layer, 12: Memory layer, 13: Wiring layer, 21, 22: Wiring, 22a, 22b: Conductive film, 22p: Projection, 24: Core material 24a: conductive film, 25: sidewall, 25a: conductive film, 31: resistance variable molecular chain, 32: organic molecular layer, 35: inter-wiring insulating film, 35a, 35b, 35c: insulating film, 40: sacrificial film, 41: gap, 101: molecular memory, 121: wiring, E: edge portion

Claims (5)

A first wiring extending in a first direction;
A second wiring made of molybdenum and extending in a second direction intersecting the first direction;
A resistance variable molecular chain disposed between the first wiring and the second wiring;
With
The first wiring is
A core material extending in the first direction and made of tungsten;
Side walls made of molybdenum, disposed on both sides in the second direction as viewed from the core material on the side surface of the core material,
Have
The molecular memory in which the resistance variable molecular chain is bonded to the core material. A first electrode;
A second electrode;
A resistance variable molecular chain disposed between the first electrode and the second electrode;
With
The first electrode is
A core made of a first conductive material;
A side wall formed on a side surface of the core material and made of a second conductive material different from the first conductive material;
Have
The second electrode is made of a third conductive material different from the first conductive material,
The molecular memory in which the variable resistance molecular chain is bonded to the first conductive material.   The molecular memory according to claim 2, wherein the composition of the second conductive material is the same as that of the third conductive material. The first conductive material comprises tungsten;
The molecular memory according to claim 2, wherein the second and third conductive materials include molybdenum. The first electrode is a wiring extending in a first direction;
The second electrode is a wiring extending in a second direction intersecting the first direction;
The molecular memory according to claim 2, wherein the side walls are arranged on both sides in the second direction when viewed from the core material.

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