WO2008040572A1

WO2008040572A1 - Information memory

Info

Publication number: WO2008040572A1
Application number: PCT/EP2007/055721
Authority: WO
Inventors: Ralph Pätzold; Manfred Rührig; Günter Schmid; Joachim Wecker
Original assignee: Siemens Aktiengesellschaft
Priority date: 2006-09-29
Filing date: 2007-06-11
Publication date: 2008-04-10
Also published as: DE102006046499A1; DE102006046499B4

Abstract

The invention relates to an information memory wherein information storage is stored by means of the magnetisation of material of the information memory. The information can be read out by identifying the magnetisation. A first layer (1) consists of a plurality of strip conductors (4, 5, 6) to which a current can be applied. At least one other layer (7) consisting of a magnetisable material is associated with the first layer, said at least one other layer (7) being used for the information storage. A layer (10) is associated, in turn, with the at least one other layer (7), comprising a plurality of integrated organic sensors (11, 12) by which means the magnetisation states of the magnetisable material of the at least one other layer (7) can be read out.

Description

description

information store

The present invention relates to an information storage according to the preamble of claim 1.

Such information stores are known in the context of computers. Such magnetic memories are used, for example, as so-called floppy disks or else as hard disks integrated in the computer. The hard disks can also be connected as independent components to corresponding interfaces of a computer.

There are also theoretical approaches to the realization of volatile or non-volatile storage based on organic polymers and molecules (including organometallic) known. With regard to a technical realization, the materials based on PVDF (poly-vinylidene difluoride) are the most advanced. In particular, the copolymer with trifluoroethylene (PVDF-PtrFE; 70:30) exhibits the properties sufficient for medium to low density storage applications. The ferroelectricity of this material class serves as the basis for the storage application. For documentation, see the publications A. Bune, S. Ducharme, V. Fridkin, L. Blinov, S. Palto, N. Petukhova, S. Yudin in Appl. Phys. Lett. 67 (26) (1995) 3975 and to A. Bune, V. Fridkin, S. Ducharme, L. Blinov, S. Palto, A. V. Sorokin, S. Yudin, A. Zlatkin in Nature 391 (1998) 874.

Based on inorganic materials, concepts for changing the conductivity by phase transformation to chalcogenides or ion diffusion in glasses are used. For the chalcogenides, please refer to the website: http://www.ovonyx.com/ovonyxtech.html. For ion diffusion in glasses, see the publication of the ASU Center for Solid State Research; Axon Technologies Corp. under http: // www. eas.asu. edu / ~ ers / research / ersresearch / index .html and http: // intraweb .eas.asu. edu / research / award. cfm? awd = 200338.

Analog storage concepts can also be found for organic materials. The donor-acceptor complex of 1,4-phenylenediamine and 3-nitrobenzalmalonic acid dinitrile shows conductivity differences in the amorphous and crystalline phases, respectively. Doping and dedoping of an organic π-conjugated semiconductor by salt addition also leads to a change in the conductivity of layers.

For example, see the publications H.J. Gao, K. Sohlberg, Z. Q. Xue, H.Y. Chen, S.M. Hou, L.P. Ma, X.W. Fang, S.J. Pang, S.J. Pennycook in Phys. Rev. Lett. 84 (2000) 1780-1783 and H.J. Krieger, S.V. Trubin, S.B. Vaschenko, N.F. Yudanov in Syn. Met. 122 (2001) 199-202.

Circuit phenomena have also been observed in purely organic films of substantially dielectric character. The prior art may be referred to K. Sakai, H. Matsuda, H. Kadaada, K. Eguchi, T. Nakagiri in Appl. Phys. Lett. 53 (14) (1988) 1274-1276 and to C. P. Collier, E.W.

Wong, M. Belohradsky, FM Raymo, JF Stoddart, PJ Kuekes, RS Williams, JR Heath in Science 285 (1999) 391, and D. Ma, M. Aguiar, JA Freire, IA Hummelgen in Adv. Mater. 12 (14) (2000) 1063-1066. There, it is mentioned, for example, that anthracene units which are attached to a polymethacrylate backbone can serve as a sink for charge carriers (trap). If these are filled by applying an electric field, current paths with increased charge-carrier mobility arise. The conductivity is essentially determined by hole conduction. The present invention is based on the object to propose alternatives for the design of an information store.

This object is achieved according to the present invention according to claim 1, by an information storage, in which by a magnetization of material of the information storage is carried information storage, wherein the information is readable by a detection of the magnetization, a first layer is present, consisting of a plurality of conductor tracks wherein this layer is associated with at least one further layer of a magnetizable material, wherein this at least one further layer of information storage is used, said at least one further layer is in turn assigned a layer having a plurality of integrated organic sensors with where the magnetization states of the magnetizable material of the at least one further layer can be read out.

The further layer of the magnetizable material is electrically decoupled from the first layer.

According to the arrangement of the conductor tracks in the first layer, the further arrangement can consist of an arrangement of elements made of thin ferromagnetic layers (for example alloys of NiFe or amorphous CoFeNi or of composite layers of polymers and magnetic particles). These elements are assigned to the conductor tracks so that the individual elements can be magnetized differently by energizing the individual conductor tracks.

Alternatively, the further layer may also be continuous and have only local magnetization transitions (domains), which then cause a stray field ("memory cell array") .In this case, the junctions must be arranged corresponding to the conductor tracks. The individual elements of the magnetizable layer or the regions delimited by the magnetization transitions are assigned integrated organic sensors which detect the magnetization of the corresponding region of the magnetizable layer by means of the magnetoresistive effect.

In the embodiment according to claim 2, the first layer again consists of a plurality of individual layers which have conductor tracks which run in a non-parallel direction to each other, wherein the conductor tracks of the individual layers are insulated from one another.

Due to the non-parallel direction of the conductor tracks, current matrices are produced, via which corresponding magnetic fields for magnetization can be generated by a corresponding energization of the conductor tracks at the individual points.

Particularly advantageously, the non-parallel conductor tracks are oriented perpendicular to each other. As a result, the highest possible precision in the local resolution of the magnetic fields can advantageously be achieved.

In the embodiment according to claim 3, the integrated organic sensors on a Biasschichtmagnetisierung.

According to the direction of the bias magnetization, the information storage magnetic field is amplified or attenuated. This advantageously improves the signal quality in the case of the resistance signals of the sensor.

In the embodiment according to claim 4, the Biasschichtmagnetisierung is generated by integrated conductor tracks.

As a result, the bias field can advantageously be set comparatively precisely. In the embodiment according to claim 5, a readout of the magnetization state of the magnetizable material by the characteristic of the integrated organic sensor is shifted.

The single figure shows the structure of an information store in the individual layers.

It can be seen a first layer 1, which in turn has a plurality of individual layers 2, 3, wherein in these individual layers 2, 3 each conductor tracks 4, 5, 6 are present. These individual layers 2, 3 and especially the printed conductors 4, 5, 6 of these individual layers 2, 3 are insulated from each other.

It can be seen that the interconnects 4, 5 of the first single layer 2 are oriented perpendicular to the interconnects 6 of the second single layer 3. In the illustrated embodiment, only one interconnect 6 can be seen. However, in this second individual layer 3, there are a plurality of conductor tracks which run parallel to the illustrated conductor track 6.

The conductor tracks 4, 5, 6 can be used to represent a current matrix with which, given suitable energization of the individual conductor tracks 4, 5, 6, a limited number of different magnetic fields can be displayed. This is due to the fact that the magnetic fields of the currents in the respective printed conductors 4, 5 and 6 overlap at the crossing points of the superimposed interconnects 4, 5 and 6.

There is another layer 7 which consists of a magnetizable material. The material may for example consist of a matrix arrangement of thin ferromagnetic layers (for example NiFe alloy or amorphous Co-FeNi alloy) or also of composite layers of polymers and magnetic particles. Due to the matrix arrangement, this further layer 7 is subdivided into individual elements 8, 9. The matrix arrangement with the individual elements 8, 9 is assigned to the intersecting conductor tracks 4, 5, 6 of the first layer 1.

As an alternative to this matrix arrangement of the individual elements 8, 9, the further layer 7 can also be implemented continuously, with only local magnetization transitions being present, which then cause a stray field ("memory cell array").

Furthermore, a layer 10 is provided, which is constructed from integrated organic sensors 11, 12. These sensors are assigned to the matrix elements or the local magnetization transitions of the further layer 7. The sensors may be transistors, for example. The sensors can also be constructed such that their resistances are evaluated. The resistors in this case have an asymmetrical characteristic with respect to the field zero point.

It can be seen in the illustrated embodiment that the individual sensors 11, 12 are themselves constructed of individual layers. The lowest of these layers is a layer with a bias magnetization. Depending on the orientation of the magnetic field, which arises as a result of information storage, this magnetic field of the storage layer is amplified or attenuated. This results in different resistance signals of the integrated organic sensor.

As an alternative to this layer with the bias magnetization, the bias magnetic field can also be generated by means of integrated conductor tracks, through which a current flows. As a result, the bias field can advantageously be set precisely with a good spatial resolution.

Alternatively, the information can also be read out by the integrated organic sensor (OMR sensor) being a transistor whose characteristic is shifted.

Claims

claims

1. Information memory in which information is stored by a magnetization of material of the information memory, the information being readable by a detection of the magnetization, characterized in that a first layer (1) is present, which consists of a plurality of conductor tracks (4, 5, 6), which can be acted upon by current, that this layer (1) at least one further layer (7) is assigned from a magnetizable material, said at least one further layer (7) of the information storage is used, said at least one further Layer (7) in turn is associated with a layer (10) having a plurality of integrated organic sensors (11, 12), with which the magnetization states of the magnetizable material of the at least one further layer (7) can be read out.

2. Information store according to claim 1, characterized in that the first layer (1) in turn consists of a plurality of individual layers (2, 3), the conductor tracks (4, 5, 6) which extend in non-parallel direction to each other, wherein the conductor tracks ( 4, 5, 6) of the individual layers (2, 3) are insulated from one another.

3. Information store according to claim 1 or 2, characterized in that the integrated organic sensors (11, 12) have a Biasschichtmagnetisierung.

4. Information store according to claim 3, characterized in that the Biasschichtmagnetisierung is generated by integrated conductor tracks.

5. Information memory according to claim 1 or 2, characterized in that a readout of the magnetization states of the magnetizable material by the characteristic of the integrated organic sensor (11, 12) is moved.