# Patent

## Title
Multilayer composite body having an electronic function

## Abstract

A multilayer composite body has an electronic function, in particular, an electronic subassembly comprising a plurality of organic electronic components, such as transistors, diodes, capacitors and so on, having at least one common layer, e.g., a semiconductor layer and/or insulation layer, wherein the common layer may be superfluous in one or more of the components. There thus is provided a structure of an entire subassembly such as an RFID tag, wherein the entire tag with all of its components is implemented in one production process.

## Background
The invention relates to a multilayer composite body having an electronic function, in particular an electronic subassembly comprising a plurality of organic electronic components.
Electronic components are disclosed, for example, in WO 02/15264. An electronic component is generally produced by successively applying the various functional layers (conductive layer, semiconductive layer, insulating layer and conductive layer again) to a substrate. A plurality of electronic components can be combined on a printed circuit board, as described, for example, in DE 101 51 440 C1.
The disadvantage of the currently used subassemblies is that a multiplicity of individual components must be individually and successively produced, connected in an electrically conductive manner and arranged in order to form a more complex subassembly. Various costly work steps and process steps are required for this purpose.
It is an object of the present invention to provide a structure for a subassembly, which structure can be implemented simply and cost-effectively in a manner suitable for mass production and in which a multiplicity of essential electronic components, that is to say active and passive components alike, such as a transistor, field effect transistor, electrical contact via, resistor, interconnect resistor, coil, capacitor, rectifier or the like, can be combined in any desired manner and, in particular, with a diode.
The invention relates to a multilayer composite body comprising at least two different electronic components which have at least two layers, which are each applied in one operation and may be homogeneous or patterned, in common.
One of the layers which is common to the components of the composite body according to the invention is, for example, a homogeneous or patterned semiconductive layer and/or other layer, for example also a layer which, on account of its high viscosity, is not patterned during application under certain circumstances.
According to one advantageous refinement of the invention, all of the components of the composite body, that is to say different components and any desired number of the latter, are simultaneously produced on the same substrate, for example in a continuous process. This results in some components comprising layers which have no functionality in the component.
One of the at least two layers, but, in principle, even five or more layers, which is common to the components of the composite body is likewise preferably the carrier layer, that is to say the substrate which is common to all components.
According to one preferred embodiment, all of the components of a multilayer composite body are constructed from cohesive layers, some of the layers being patterned and others being continuously homogeneous layers. These layers are simultaneously produced for all of the components in the composite body and, if necessary, are suitably patterned for the respective component.
Subassemblies which contain at least one diode and an additional different component are preferably implemented with the multilayer composite body.
For example, a simple rectifier is implemented as the multilayer composite body, at least two different components, a diode and a capacitance, being present in the composite body.
A complex rectifier may also be implemented in the multilayer composite body if at least three different components, at least two diodes, a capacitance and a contact via, are contained in the subassembly which forms the composite body.
In order to construct a simple rectifier with a modulator, the multilayer composite body has, for example, at least three different components, a diode, a capacitance and a transistor.
Finally, there are at least four different components, a diode, a capacitance, a transistor and one or more contact vias, for the purpose of constructing a transponder in the multilayer composite body.
The multilayer composite body may, in principle, contain all possible components, such as a transistor, field effect transistor, electrical contact via, resistor, interconnect resistor, coil, capacitor, rectifier or the like, in any desired number and, in particular, such that they can be combined with one or more diodes.
The multilayer composite body preferably has two materials, which are different in terms of their work function, in the two conductive layers. In this case, it is particularly preferred for the conductive layer which is in contact with the semiconductive layer to be composed of silver and for the material of the counterelectrode to then be a material with a different work function, in particular a more base material, for example copper, nickel, chromium, cobalt or the like.
When producing the subassembly, it is particularly preferred for all of the components to be produced in one production process using four patterned layers and their well thought-out superimposition.
In this case, the typical structure, from bottom to top, is the sequence of substrate, conductive layer, semiconductive layer, insulating layer and upper conductive layer. A “bottom-up” layer sequence is also conceivable and is concomitantly included in the concept of the invention.
In this case, it is particularly preferred for the two conductive layers of the composite body to be made of different materials which have, in particular, a different work function or a different Fermi level. This is achieved, for example, by using metallic layers composed of two dissimilar metals and/or alloys. In this case, the use of silver as the electrode which adjoins the semiconductive layer, in particular as the conductive layer in contact with the semiconductor layer, and another metal/alloy with a work function different to that of silver as the counterelectrode is particularly preferred.



The invention will also be explained in more detail below using 4 drawings which schematically represent preferred embodiments of the invention.
FIG. 1 shows a schematic cross section through fully integrated printable electronics as are required, for example, for a complete transponder circuit.
FIG. 2 once again shows all of the components which can also be seen in FIG. 1 but, in this case, the semiconductive layer at the location of the diode is not pulled as far as the level of the upper electrode of the other components but rather the upper electrode of the diode is deeper in this case.
FIG. 3 shows a structure for supplying voltage; in this case, the components of a diode, a capacitor and a contact via are simultaneously produced on a substrate.
FIG. 4 finally shows a composite body which combines an electrical contact via, a transistor and a resistor and/or a coil.



The substrate 1 can be seen at the bottom of FIG. 1. All insulating materials having a smooth surface can be used as the substrate; flexible and rigid materials alike can be used. Flexible films such as PET film or other polymer plastic films, glass, quartz, ceramic or another material are used, for example, at that location.
The layer 2 which follows the substrate 1 is the first conductive layer or the lower electrode 2 which is applied in patterned form. According to one advantageous refinement, the source and drain electrodes which are covered by the subsequent semiconductor layer are produced here. Only conductive materials can be used for the conductive layer 2, in which case it is not important whether they are organic or inorganic materials or a composite material. According to one preferred embodiment, a metal or an alloy having a work function in the range of 4.6-5.2 eV, preferably 4.9 eV, is used as the material for the conductive layer which is in contact with the semiconductive layer. Silver having a work function of 4.9 eV is particularly preferably used at that location. When selecting the material, it is preferably ensured that the work function is matched to the Fermi level of the semiconductor in such a manner that the difference to the Fermi level of the semiconductor is preferably 0.3 eV or less. It is then ensured that the charge carriers pass from the semiconductive material into the conductive material without any problems.
The semiconductive layer 3 which, on account of its viscosity, is applied in unpatterned form under certain circumstances follows the first and lower electrode layer. Organic materials such as P3AT, P3DHTT, regioregular polyalkylthiophenes, polyfluorene derivatives, PPVs, in general, and/or other polymers, for example with a conjugated main chain or a freely mobile electron pair in the main chain, are preferably used as materials for the semiconductive layer. The semiconductive layer 3 may also be applied in patterned form, for example by means of printing.
This is followed, in most electronic components, by an insulating layer 4 which has to be applied in patterned form only insofar as a dielectric layer or insulating layer should be omitted at that/those location(s) on the substrate at which diodes or contact vias are produced because it would interfere. The insulating layer 4 is composed, for example, of a soluble printable material. Organic soluble materials, for example polystyrene derivatives, PMMA or generally insulating polymers, are preferably used as materials for the insulating layer.
As the termination of the essential parts of the electronic components, the patterned insulating layer 4 is followed by an upper conductive layer 5 which in turn is preferably patterned. Conductive organic and inorganic materials and/or composite materials are used in this case. Metals whose work function is different to that of the material of the lower conductive layer (counterelectrode) are preferably used, in particular. According to one embodiment, materials whose work function is in the range of from 3 to 5 eV, in particular from 3.0 eV to 4.6 eV, or above, are used in this case; copper, nickel, chromium, cobalt, manganese etc. are successfully used in this case, for example.
The following components are then implemented on the substrate 1 of FIG. 1, from left to right: an electrical contact via a; following the latter and connected thereto, for example, by means of the upper conductive layer 5 is a transistor b whose source/drain electrodes are in the lower conductive layer 2. A diode c in which the semiconductive layer 3 is pulled up as far as the level of the counterelectrode 5 so that no current/voltage losses are produced is arranged beside the transistor b. A capacitor d can be seen to the right of the diode c and a resistor or a coil e is in turn situated to the right of said capacitor, that is to say on the far right on the outside.
All of the components and all of the layers which can also be seen in FIG. 1 are shown once again in FIG. 2 but in this case the semiconductive layer 3 at the location of the diode c is not pulled as far as the level of the upper electrode 5 of the other components of the electrical contact via a, transistor b, capacitor d and resistor e but rather the upper electrode 5 of the diode c is deeper in this case, at the level of the insulating layer 4.
In FIG. 3, all of the essential components needed to supply voltage to a rectifier are implemented together on a substrate and, if all of the layers are common in all of the components, can be simultaneously produced. The layer sequence corresponds to that from FIG. 1, the same materials or other corresponding materials also being able to be used. The layer 1 is thus the substrate, the layer 2, patterned, is a conductive layer, 3 is the semiconductor layer, 4 is the insulating layer and 5 is the counterelectrode which is in turn patterned.
In this case, the following sequence of components is provided: on the far left on the outside is the contact via 1, the diode c is next to the latter and the capacitor d follows the diode c. An alternating voltage coming from an antenna can be rectified, for example, using the composite body shown here. The semiconductor is applied in a somewhat thicker form in the diode region c; this may be achieved, for example, via a using a decorative print during simultaneous production of the components.
FIG. 4 shows a multilayer composite body which combines an electrical contact via, a transistor and a resistor or a coil. At least PFETs (Polymer Field Effect Transistor), inverters, ring oscillators, flip-flops, frequency dividers and/or counters can be constructed using this layer structure and this arrangement of the components of the electrical contact via a, transistor b and resistor or coil e.
The layer structure again corresponds to that known from the other figures. Although a diode is not implemented in this case, the conductive material of the upper electrode 5 and of the lower electrode 2 may be entirely different, particularly in terms of its work function.
On account of the sensitivity of the device and/or of the materials, encapsulation and/or sealing of the components, which may comprise a wide variety of materials and/or laminates, is still recommended as the uppermost layer or termination. The encapsulation/sealing may be composed of a rigid or flexible material.
The essential parts of electronic devices, such as a transistor, field effect transistor, electrical contact via, resistor, interconnect resistor, inductance, diode, capacitor and rectifier are implemented, can be produced next to one another and/or behind one another on a substrate using this structure by means of layers which are continuously applied in a planar manner and/or patterned layers.
The cost-effective production, which is suitable for mass production, of preferably all components in the subassembly at the same time and in a continuous method makes it possible for individual components to contain layers which, in particular, have no function there; for example, in a field effect transistor and/or in a capacitor, the gate electrode may have a work function that differs from that of the source/drain electrode, the difference in the work function having no functionality in this case.
The capacitor and the interconnect resistors and likewise the contact via contain, for example, a semiconductor which is superfluous at that location and is not functional.
The essential parts of complex electronic devices, such as a field effect transistor, electrical contact via, resistor, interconnect resistor, coil, diode, capacitor and rectifier, can be produced next to one another and/or behind one another on a substrate using the structure shown in the figures by means of layers which are continuously applied in a planar manner and/or patterned layers.
The invention provides, for the first time, a possibility for a structure of an entire subassembly such as an RFID tag, the entire tag with all of the components being able to be implemented in one production process. As a result, a cost-effective production method which is suitable for mass production is described for the first time.

## Claims

1. A multilayer composite body comprising;
a substrate;
a plurality of spaced first electrically conductive electrodes on the substrate each comprising a layer of a given material having a first work function;
a semiconductor layer on the substrate overlying and in contact with the plurality of electrodes;
an insulation layer of a first given material on and overlying the semiconductor layer and over lying at least a portion of the plurality of first electrodes;
a plurality of spaced second electrically conductive electrodes on at least the insulation layer and overlying the semiconductor layer, the second electrodes each comprising a layer of a second given material having a second work function different than the first work function;
the first and second electrodes, the insulation layer and the semiconductor layer forming at least one organic transistor and at least one organic diode;
the transistor and diode each comprising at least two electrically conductive electrode layers and at least one organic semiconductor layer in common with the transistor and diode between the at least two electrically conductive electrode layers.

2. The multilayer composite body as claimed in claim 1 wherein the first electrodes comprise a noble metal layer and the second electrodes comprise a base metal layer.

3. The multilayer composite body as claimed in 2, wherein the base electrodes are copper and the noble electrodes are silver.

4. The multilayer as claimed in claim 1 wherein the first and second electrodes form an electrode and a counterelectrode.

5. The multilayer composite body as claimed in claim 1 which contains a plurality of different components including the transistor and diode and contains at least one further layer which is in common to the different electronic organic components and, although being essential in one of the components, constitutes a superfluous layer in another of the components.

6. The multilayer composite body as claimed in claim 1 wherein the first and second electrodes, the insulation layer and the semiconductor layer further form a capacitor.

7. The multilayer composite body as claimed in claim 1 wherein the first and second electrodes, the insulation layer and the semiconductor layer further form at least two diodes and one capacitor.

8. The multilayer composite body as claimed in claim 1 wherein the first and second electrodes, the insulation layer and the semiconductor layer form at least three different components, including said diode, a capacitor and said transistor.

9. The multilayer composite body as claimed in claim 1 wherein the first and second electrodes, the insulation layer and the semiconductor layer form at least four different types of components.

10. The multilayer composite body as claimed in claim 1 wherein the first and second electrodes, the insulation layer and the semiconductor layer form at least one electronic component selected from the group consisting of an electrical contact via, a resistor, an interconnect resistor, a coil, a capacitor and a rectifier in combination with said diode and said transistor.

11. The multilayer composite body as claimed in claim 1 wherein at least one of the layers is on a substrate in a continuous planar structure.

12. The multilayer composite body as claimed in claim 1 wherein at least one of the layers is printed.

13. The multilayer composite body as claimed in claim 1 comprising a plurality of further components wherein one of the layers has no functionality in one component and comprises a continuous planar structure.

14. The multilayer composite body as claimed in claim 1 further comprising a first plurality of components wherein one of the first plurality of components is a capacitor, the semiconductor layer being in common to a second plurality of components including the capacitor in which capacitor the semiconductor layer is superfluous.

15. A multilayer composite body comprising:
a plurality of components on a substrate;
at least one component of the plurality of components comprising at least one layer; and
a second component of the plurality on the substrate and comprising said at least one layer and which said at least one layer is superfluous in the second component.

16. A multilayer composite body comprising;
at least two different electronic organic components;
each component comprising at least two conductive electrode layers and at least one organic semiconductor layer in common with the at least two different components between the at least two electrode layers;
the at least two electrode layers comprising two corresponding respective materials which have different work functions; and
at least one further layer which is common to the different electronic organic components and, although being essential in one of the components, constitutes a superfluous layer in the other component.

17. A multilayer composite body comprising;
at least four different types of electronic organic components;
each component comprising at least two conductive electrode layers and at least one organic semiconductor layer in common with the at least four components and lying between the at feast two electrode layers;
the at least two electrode layers comprising two corresponding respective materials which have different work functions.

18. A multilayer composite body comprising;
at least two different electronic organic components;
each component comprising at least two conductive electrode layers and at least one organic semiconductor layer in common with each component between the at least two electrode layers;
the at least two electrode layers comprising two corresponding respective materials which have different work functions;
wherein one of the layers has no functionality in one component and comprises a continuous planar structure.