EP1825516A2

EP1825516A2 - Organic field effect transistor gate

Info

Publication number: EP1825516A2
Application number: EP05850139A
Authority: EP
Inventors: Robert Blache; Walter Fix; Jürgen FICKER
Original assignee: PolyIC GmbH and Co KG
Current assignee: PolyIC GmbH and Co KG
Priority date: 2004-12-10
Filing date: 2005-12-06
Publication date: 2007-08-29
Also published as: TWI333701B; WO2006061000A3; KR20070085953A; DE102004059467A1; MX2007006725A; WO2006061000A2; CN101076893A; US20080197343A1; CA2595114A1; TW200640050A; AU2005313714A1; JP2008523595A

Abstract

The invention relates to an electronic component, especially an RFID transponder that comprises at least one logic gate (3). Said logic gate (3) is constituted of a plurality of layers applied to a common substrate (10). The layers comprise at least two electrode layers, at least one, especially organic, semiconductor layer (13, 23) applied from a liquid, and an insulating layer (14, 24) and are configured in such a manner that the logic gate comprises at least two differently structured field effect transistors (1, 2). Said field effect transistors (1, 2) are configured from a plurality of functional layers that can be applied to a carrier substrate (10) by a printing or doctor blade process.

Description

Gate made of organic field effect transistors

The invention relates to an electronic component, in particular RFID transponder, with at least one logic gate formed from organic field effect transistors.

The simplest logic gate is the inverter, from which all complex logic gates, such as ANDs, NANDs, NORs and the like can be formed by combination with other inverters and / or other electronic components. Organic logic gates with only one type of semiconductor - typically p-type semiconductors - as an active layer are susceptible to parameter variations of the individual components. This may mean that these circuits will operate unreliably or not at all, as individual components, such as transistors, can not sufficiently meet the circuit design specifications due to variations in the manufacturing process. In addition, in these semiconductor type based circuits, depending on the circuit design used, a dissipative current flows at least during half of the operating time. a current that is not due to the function of the circuit. As a result, the power consumption is much higher than actually necessary.

Such logic gates are unsuitable, for example, for RFID transponders (RFID = Radio Frequency Identification), because the RFID transponders obtain their supply voltage from a radio-frequency signal received with a small antenna and then rectified. RFID transponders are increasingly being used to provide goods or security documents with electronically readable information. For example, they can be used as an electronic barcode for consumer goods, as a luggage tag for identifying luggage or as a cover of a passport Built-in security element that stores authentication information.

In the document KLAUK, H. et al .: Pentacene Thin Film Transistors and Inverter Circuits. In: IEDM tech. Dig., Dec. 1997, pp. 539-542, an inverter with similar organic field effect transistors is described which is formed of a charging field effect transistor and a switching field effect transistor connected in series. The production of the field effect transistors is provided by thermal deposition of the organic semiconductor material.

Combinations of different semiconductors are also known for logic gates, but so far only organic ones with inorganic semiconductors have been described, for example in the document BONSE, M. et al .: Integrated a-Si: H / Pentacene Inorganic / Organic Complementary Circuits. In: IEEE IEDM 98, 1998, pp. 249-252, or organic linked to metal-organic semiconductors, such as the document CRONE, B.K. et al,: Design and fabrication of organic complementary circuits. In: J. Appl. Phys. Vol. 89 May 2001, pp. 5125-5132. As a production method for the field-effect transistors thermal deposition of the organic semiconductor is also provided in both documents.

The object of the present invention is to provide an improved electronic component using field-effect transistors.

According to the invention this object is achieved by an electronic component is formed with at least one logic gate, wherein the logic gate is formed of a plurality of layers applied to a common substrate, the at least two electrode layers, at least one applied from a liquid, in particular organic, semiconductor layer and an insulator layer and which are formed so that the logic gate comprises at least two differently constructed field effect transistors.

The term liquid includes, for example, suspensions, emulsions, other dispersions or solutions. Such liquids can For example, be applied by printing process, with parameters such as viscosity, concentration, boiling temperature and surface tension determine the pressure behavior of the liquid. Field-effect transistors are understood in the following to mean field-effect transistors whose semiconductor layers have been essentially applied from the abovementioned liquids.

By forming two different in their structure, in particular organic field effect transistors on a common carrier with at least one liquid layer deposited from the semiconductor layer logic gates can be formed with properties that are not otherwise achievable.

In this way, faster logic gates can be realized than by the previous training with only one semiconductor. Thus, to this day, it is common practice to build circuits based on only one type of semiconductor on a carrier, i. Silicon-based ICs have only silicon-based transistors. The invention makes it possible to simplify the circuit design, to increase the switching speed, to reduce the power consumption and / or to increase the reliability. At the same time, this ensures that this sort of logic gate can be produced with fast and continuous production processes, for example in a roll-to-roll printing process. Next, the logic gates according to the invention are characterized by greater insensitivity to Hersteilungstoleranzen. Another advantage of the logic gates according to the invention is their lower power consumption compared to conventional in particular organic logic gates.

The development of the circuit layout must therefore no longer take place with the inclusion of reserves, such as by over-dimensioning of the individual components or by inserting redundant components.

In the organic field effect transistor, hereinafter referred to as OFET, it is a field effect transistor having at least three electrodes and an insulating layer. The OFET is arranged on a carrier substrate, which may be formed as a solid substrate or as a foil, for example as a polymer foil can. An organic semiconductor layer forms a conductive channel whose end portions are formed by a source electrode and a drain electrode. The organic semiconductor layer is deposited from a liquid. The organic semiconductors may be polymers dissolved in the liquid. The liquid containing the polymers may also be a suspension, emulsion or other dispersion.

The term "polymer" expressly includes polymeric material and / or oligomeric material and / or "small molecule" material and / or "nano-particle" material. Layers of nanoparticles can be applied, for example, by means of a polymer suspension. Thus, the polymer may also be a hybrid material, for example to form an n-type polymeric semiconductor. These are all types of materials with the exception of the classical semiconductors (crystalline silicon or germanium) and the typical metallic conductors. A restriction in the dogmatic sense to organic material in the sense of carbon chemistry is therefore not provided. Rather, for example, silicones are included. Furthermore, the term should not be limited in terms of molecular size but, as stated above, include "small molecule" or "nano particle". Nanoparticles consist of organometallic organic compounds containing, for example, zinc oxide as a non-organic constituent. It can be provided that the semiconductor layers are formed with different organic material.

The conductive channel is covered with an insulating layer on which a gate electrode is arranged. By applying a gate-source voltage U _G s between the gate electrode and the source electrode, the conductivity of the channel can be changed. The semiconductor layer may be formed as a p-type conductor or as an n-type conductor. The power line in a p-type conductor is almost exclusively due to defect electrons, the power line in an n-type conductor almost exclusively by electrons. The predominantly existing charge carriers are referred to as majority carriers. Although p-type doping is typical for organic semiconductors, it is still possible to n-type the material train. As p-type semiconductor pentacene, polyalkylthiophene, etc. may be provided as n-type semiconductor z. B. soluble fullerene derivatives.

The majority carriers are densified by the formation of an electric field in the insulating layer when a gate-source voltage UQ _{S of} suitable polarity is applied, ie a negative voltage for p-type or a positive voltage for n-type. As a result, the electrical resistance between the drain and the source decreases. It can now form when applying a drain-source voltage UDS, a larger current flow between the source and the drain electrode, as in an open gate electrode. It is in a field effect transistor so a controlled resistance. The logic gate according to the invention avoids the disadvantage of combinations of similar field effect transistors, in particular OFETs, to form a dissipative current, ie to show a current flow if they are not activated, by combining two field effect transistors of different design, in particular OFETs.

Advantageous embodiments of the invention are designated in the subclaims.

It is provided that the at least two different field effect transistors have semiconductor layers which differ in their thickness. The formation of the different thickness can be advantageously provided by soluble semiconductors in a printing process. This can be provided in organic semiconductors, the

Polymer concentration of the semiconductor to vary. In this way, after evaporation of the solvent, a layer thickness of the organic semiconductor which is dependent on the polymer concentration is formed.

It can also be provided that the semiconductor layers of the

Field effect transistors are designed with different conductivity. The conductivity of the particular organic semiconductor layer can be lowered or increased, for example by a hydrazine treatment and / or by targeted oxidation. Thus, the trained with such a semiconductor material Field effect transistor be set so that its off-currents are only about one order of magnitude below the on-currents. The off-current is the current that flows in the field-effect transistor between the source electrode and the drain electrode when no electrical potential is applied to the gate electrode. The on-current is the current flowing in the field-effect transistor between the source electrode and the drain electrode when an electric potential is applied to the gate electrode, for example, a negative potential when it is a p-type field effect transistor.

Furthermore, it is advantageous to use different types of semiconductors or to arrange a different combination of semiconductors next to one another to form an electronic functional layer, and thus to influence properties such as charge mobility, switching speed and power or switching behavior in a targeted manner.

It can also be provided that the field effect transistors differ in the formation of the insulator layer. They may have insulator layers of different thickness and / or different material. The insulator layers of the at least two differently designed field-effect transistors may, however, also differ in their permeability and thus influence the formable charge carrier density in the semiconductor layers or be formed as a dielectric for the capacitive coupling of electrodes, for example for coupling the gate electrode to the source or drain. Electrode of the same field effect transistor.

Particularly cost-effective, the different surface structuring of the layers is possible. This is particularly easy in a printing method, so that in this case the behavior of the field effect transistors can be optimized by the trial-and-error method, without knowing the functional dependencies in detail. The two different field effect transistors may be formed, for example, with different channel widths and / or channel lengths. Preferably, strip-shaped structures can be provided. However, arbitrarily contoured structures can also be provided, for example for the formation of the electrodes of the field-effect transistors, such as Gate electrode. The geometric dimensions are dimensions in the micron range, for example, channel widths of 30 microns to 50 microns with the tendency for even smaller dimensions, in order to obtain high switching speeds and low capacitance between the electrodes. It is known from conventional silicon technology that device capacitances cause high power losses and therefore have a decisive influence on the minimization of the power requirement of the circuit.

In this way, field effect transistors with different switching capacity can be formed, for example, to form different switching behavior.

It can be provided to arrange the at least two different field effect transistors side by side or one above the other. In this way, circuit designs can be transferred to layouts in a particularly simple manner and, for example, vias can be minimized in number. The arrangement of the field-effect transistors can also be provided for functional reasons, for example, to form two field effect transistors with common gate electrode, wherein an arrangement of the two field effect transistors can be particularly advantageous over each other.

The field effect transistors may be arranged with the same or different orientation. It is envisaged that the at least two differently configured field-effect transistors can be arranged with bottom-gate or top-gate orientation.

It can be provided to vary the at least two different field effect transistors so that they are formed with a different resistance characteristic and / or a different switching behavior. The resistance characteristic can be changed for example by changing the thickness of the semiconductor layer, wherein by forming particularly thin layers - preferably in layers in the range of 5 nm can be set to 30 nm additional effects that are not observed in thicker layers in the order of 200 nm.

The at least two different field-effect transistors can be connected to each other in a parallel and / or series connection. It can be provided, for example, that two differently designed field-effect transistors, in particular two OFETs, form the load OFET and the switching OFET in series connection. However, it can also be provided, for example, that load OFET and / or switching OFET are formed by parallel or series connection of two or more different OFETs. In this way, a logic gate embodied as an inverter can be formed, for example, from four-preferably different-field-effect transistors. Such logic gates can be connected to a ring oscillator, which can be used in particular as RFID transponder as logic circuit or vibration generator.

The solution according to the invention is not limited to the galvanic coupling of the field effect transistors. Rather, it may be provided to capacitively couple the field-effect transistors to one another, for example by increasing a gate electrode and a further electrode such that they form a capacitor with sufficient capacitance together with the insulation layer. Because of the possible very small layer thickness of the insulation layer and optionally further layers arranged between the capacitively coupled electrodes, comparatively high capacitance values can be formed despite small electrode areas.

It can also be provided to form the different field-effect transistors with semiconductor layers of different conductivity type, ie with p-type and n-type semiconductor layer. Although p-type semiconductor layers are still preferred for forming OFETs, the application of an n-type layer is not more difficult than the deposition of a p-type layer. In this way, pn junctions can also be formed between the two adjoining layers. The logic gate according to the invention is designed so that it can be produced essentially by printing (for example by gravure printing, screen printing, pad printing) and / or doctoring. The entire structure is thus aimed at forming layers which, in their interaction, form the logic gate and which can be structured by the two methods mentioned. For this purpose, proven equipment is available, as provided, for example, for the production of optical security elements. The gates according to the invention can therefore be produced on the same systems.

The different design of the field effect transistors can be achieved particularly well if the layers of the at least two different field effect transistors, in particular the OFETs, are designed as printable semiconducting polymers and / or printable insulating polymers and / or conductive printing inks and / or metallic layers.

The thickness of the soluble polymeric layer is particularly easy to adjust by their solvent content. However, it can also be provided that the thickness of the soluble organic layer is adjustable by its application amount, for example, when the application of the layer is provided by pad printing or by doctoring. In this way, preferably thicker

Train layers. Alternatively, the layered structure of a layer may be provided. If, for example, the at least two different field-effect transistors have a semiconductor layer of the same material of different thickness, in a first pass the thin layer of one field-effect transistor can be applied and in one or more further passes this base layer for the other field-effect transistor can be amplified. For this purpose, it may be provided to apply the layers with different solvent content, i. the base layer with a high solvent content and the further layer or the further layers with a low solvent content.

Preferably, it can be provided that the electronic component produced in the manner described above is formed by a multilayer flexible film body. The flexibility of the electronic component can be especially resistant, especially when applied to a flexible substrate. Moreover, the inventively designed as a multilayer flexible film body organic electronic components are completely insensitive to shock loads and, in contrast to applied to rigid substrates components used in applications where printed circuit boards are provided, which conform to the contour of the electronic device. These are becoming increasingly popular for devices with irregularly shaped contours, such as cell phones and electronic cameras.

It can be provided to design security elements, merchandise labels or tickets with one or more logic gates according to the invention.

The invention will now be explained in more detail with reference to the drawings. Show it

Fig. 1 and 2 are schematic sectional views of a first

Embodiment;

FIGS. 3a and 3b are basic circuit diagrams of the first embodiments in FIGS. 1 and 2;

Fig. 4 is a schematic sectional view of a second

Embodiment;

Fig. 5 is a schematic sectional view of a third

Embodiment;

Fig. 6 is a schematic sectional view of a fourth

Embodiment;

Fig. 7 is a basic circuit diagram of the embodiments in Figs. 5 and 6; 8 is a schematic current-voltage diagram of a logic

gate;

9a shows a first schematic output characteristic diagram of a logic gate with differently formed organic

Field effect transistors;

9b shows a second schematic output characteristic diagram of a logic gate with differently designed organic field effect transistors.

1 and 2 each show a schematic sectional view of a logic gate 3, formed from two differently formed organic field effect transistors 1, 2, hereinafter referred to as OFET, which are arranged on a substrate 10. It can also be about

Field effect transistors act, which are not or not completely formed of organic semiconductor material. The substrate may be, for example, a platelet-shaped substrate or a film. The film is preferably a plastic film with a thickness of 6 μm to 200 μm, preferably with a thickness of 19 μm to 100 μm, preferably formed as a polyester film.

The first OFET 1 is formed of a first semiconductor layer 13 with a source electrode 11 and a drain electrode 12. On the semiconductor layer 13, an insulator layer 14 is arranged with a gate electrode 15 arranged on this layer.

These layers can already be applied, for example, by a printing process in a partially patterned or patterned manner. For this purpose, it is provided, in particular, to apply the semiconductor layer out of a liquid. The term liquid includes, for example, suspensions, emulsions, other dispersions or solutions. For the preparation of solutions, the organic materials intended for the layers are soluble As is already described above, the term "polymer" also includes oligomers and "small molecules" as well as nano-particles.The organic semiconductor may be, for example, pentacene, Several parameters of the liquid may be varied: - the viscosity of the liquid, it determines the pressure behavior;

the polymer concentration of the ready-to-print mixture determines the layer thickness;

- The boiling temperature of the liquid, it determines which printing process can be used; the surface tension of the ready-to-print mixture determines the wettability of the support substrate or other layers.

It may also be contemplated, as further described above, to form the layers by successively printing with variable layer thickness.

It can also be provided to apply a curable lacquer to the substrate 10 and to structure it before curing in such a way that depressions are formed in which, for example, semiconductor layers are introduced by doctoring. Such method steps may be provided, for example, to combine optical security elements, which are produced using curable lacquer layers, with the logic gates according to the invention.

The electrodes 11, 12 and 15 are preferably made of a conductive metallization, preferably of gold or silver. However, it can also be provided to form the electrodes 11, 12 and 15 from an inorganic electrically conductive material, for example from indium tin oxide, or from a conductive polymer, for example polyaniline or polypyrene.

The electrodes 11, 12 and 15 can in this case for example by a printing process (gravure printing, screen printing, pad printing) or by a coating process already partially and patterned patterned on the substrate 10 and on the organic insulator layer 14 or another im Manufacturing method provided layer can be applied. However, it is also possible to apply the electrode layer on the substrate 10 or another layer provided in the manufacturing process over the entire surface or part of the area and then partially removed again by an exposure and etching or by ablation, for example by means of a pulsed laser and to structure it.

The electrodes 11, 12 and 15 are structures in the micron range. For example, the gate electrode 15 may have a width of 50 μm to 1000 μm and a length of 50 μm to 1000 μm. The thickness of such an electrode may be 0.2 μm or less.

The second OFET 2 is formed of a first organic semiconductor layer 23 having a source electrode 21 and a drain electrode 22. On the organic semiconductor layer 23 is disposed an organic insulator layer 24 having a gate electrode 25 disposed on this layer.

In FIG. 1, the drain electrode 12 of the first OFET 1 is connected to the source electrode 21 of the second OFET 2 and to the gate electrode 25 of the second OFET 2 by way of the electrically conductive connection layers 20.

Further, it is also possible that the gate electrode 25 is connected to the drain electrode 22 instead of the source electrode 21.

In FIG. 2, the gate electrode 15 of the first OFET 1 and the gate electrode 25 of the second OFET 2 and the drain electrode 12 of the first OFET 1 and the drain electrode 22 of the second OFET 2 are connected to electrically conductive connection layers 20 ,

In these exemplary embodiments according to FIGS. 1 and 2, both OFETs 1, 2 lie side by side with the same orientation, ie, for example, the gate electrodes 15, 25 are arranged in one plane. In the case shown, the top-gate orientation is selected for both OFETs, ie, the two gate electrodes 15, 25 are formed as the uppermost layer. But it can also be provided that for both OFET, the bottom-gate orientation is selected, in which the two gate electrodes 15, 25 are arranged directly on the substrate 10.

As can be seen in FIGS. 1 and 2, the organic semiconductor layers 13, 23 determining the electrical properties of the two OFETs 1, 2 and / or the organic insulator layers 14, 24 may be formed with different layer thicknesses, both in the illustrated embodiment OFET 1, 2 are formed with the same total layer thickness. It can preferably be provided that the organic semiconductor layers 13, 23 are applied in strips. To form different electrical behavior of both OFETs 1, 2, it may be provided that the thickness and / or the channel length, i. the distance between the source electrode 11, 21 and the drain electrode 12, 22, and / or the material of the organic semiconductor layers 13, 23 of both OFET 1, 2 differently form. The material of the organic semiconductor layers 13, 23 may for example be doped the same or different degrees. The semiconductor layers 13, 23 may be formed as p-type conductors or as n-type conductors. The power line in a p-type conductor is almost exclusively due to defect electrons, while the current in an n-type conductor is almost exclusively due to electrons. The predominantly existing charge carriers are referred to as majority carriers. Although p-type doping is typical for organic semiconductors, it is still possible to form the material with n-type doping. Thus, for example, the p-type semiconductor may be formed from pentacene, polythiophene, the n-type semiconductor may be formed, for example, from poly-phenylene-vinylene derivatives or fullerene derivatives,

If both organic semiconductor layers 13, 23 have different majority charge carriers, a logic gate 3 with semiconductor layers 13, 23 of complementary conductivity is formed. Such a gate is shown for example in Fig. 2 and is characterized in that each one of the two field effect transistors allows no current flow between the source and drain, as long as the input voltage of the logic gate does not change, ie the gate occupies one of its two switching states. A dissipative cross-flow through the gate flows only during the switching process. As a result, logic circuits with the logic gates according to the invention have a clear lower power consumption than logic circuits formed from identical OFETs. This is particularly advantageous if only low-power sources are available, as is the case for example with RFID transponders, which receive their energy from a rectified antenna signal, which is stored in a capacitor.

FIGS. 3 a and 3 b show the two basic circuits that can be represented with the first exemplary embodiment in FIGS. 1 and 2. For better illustration, the positions in Figs. 1 and 2 have been retained.

Fig. 3a shows a logic gate 3 formed of two different OFETs 1 and 2 with semiconductor layers of the same conductivity type. The two OFETs 1, 2 are connected in series, the drain electrode 12 of the first OFET 1 being connected to the source electrode 21 of the second OFET 2. The gate electrode 15 of the OFET 1 forms the input of the logic gate, the gate electrode 25 of the OFET 2 is connected to the source electrode 21 of the OFET 2. The logic gate may be an inverter with load OFET 2 and switching OFET 1.

3b shows a logic gate 3, formed from two different OFET 1 and 2 of different doping type. As described above, such a logic gate is designed with lower power consumption than a prior art OFET logic gate. The two OFET 1, 2 are connected in series, wherein the drain electrode 12 of the first OFET 1 is connected to the drain electrode 22 of the second OFET 2. The gate electrodes 15 and 25 of the two OFET are connected to each other and represent the input of the logic gate.

4 now shows a second exemplary embodiment, in which the two OFETs 1, 2 are arranged next to one another with different orientation on the substrate 10. In this case, the first OFET 1 is arranged so that the source electrode 11 and the drain electrode 12 are arranged directly on the substrate 10 and successively the semiconductor layer 13, the insulator layer 14, the second, from the first different semiconductor layer 23 and the gate Electrode 15. Such orientation of the OFET is referred to as top-gate orientation. The second OFET 2 is now arranged so that the gate electrode 25 is disposed on the substrate 10 and the source electrode 21 and the drain electrode 22 are disposed on the top of the OFET 2. Such orientation is referred to as bottom-gate orientation. The gate electrode 25 of the OFET 2 is connected to the source contact 21 of OFET 2 and the drain contact 12 of OFET 1 by means of the electrically conductive connection layer 20, which is formed in this embodiment in sections as the substrate 10 extending vertically through hole.

In the illustrated embodiment, it can preferably be provided that the electrodes arranged in each case are formed from the same material, for example from a conductive printing ink or from a sputtered, galvanized or vapor-deposited metal layer. But it can also be provided that they are each formed of different materials, preferably, if it is associated with an advantageous functional effect.

In the exemplary embodiment illustrated in FIG. 4, the semiconductor layers 13 and 23 and the insulator layer 14 are formed as two OFET 1, 2 common layers. In this case, for OFET 1, only the semiconductor layer 13 establishes the connection between source 11 and drain 12. The necessary for the function of OFET 1 conductive channel is formed in this semiconductor layer 13 at the interface to the insulator layer 14. For OFET 2, on the other hand, only the semiconductor layer 23 establishes the connection between source 21 and drain 22. As can be clearly seen in FIG. 4, the OFETs 1, 2 are designed with different geometries, here in particular with different channel lengths. However, it can also be provided that both OFETs 1, 2 are formed with different semiconductor layers and / or insulator layers.

The basic circuits which can be formed with the second exemplary embodiment illustrated in FIG. 4 correspond to the basic circuits shown in FIGS. 2a and 2b. It can be provided that the two OFET 1, 2 are connected to each other by further, not shown in FIGS. 2a, 2b connecting lines, that they are connected to one another or to other components in parallel or series connection.

The basic circuit diagram of the embodiment shown in FIG. 4, in which the two OFETs 1, 2 are formed with common semiconductor layers, which may be formed as p-type conductors or as n-type conductors, is shown in FIG. 2a.

FIG. 2b shows the basic circuit diagram of an embodiment modified with respect to FIG. 4, in which the two semiconductor layers of the OFETs 1, 2 are formed differently and with a complementary conductivity type. This case is apparent from the drawing in Fig. 4, in that the drawn connection 20 connects exclusively the two gate contacts 15 and 25, while additionally one of the connection 20 similar connection between drain contact 22 of OFET 2 and drain 12 of OFET is placed.

FIG. 5 shows a third exemplary embodiment, in which the two OFETs 1, 2 are arranged one above the other on the substrate 10 and are formed with a common gate electrode 15. The source electrode 11 and the drain electrode 12 of the first OFET 1 are therefore arranged directly resting on the substrate 10, the source electrode 21 and the drain electrode 22 are formed as the uppermost layer of the stacked OFET 1, 2. The logic gate formed from the two OFETs 1, 2 is therefore composed of a total of 7 layers. In this case, layers with the same function can be constructed the same or different, it being provided that at least one of the layers of a layer pair is formed differently. For example, it can be provided that the semiconductor layers 13, 23 are formed with different conductivity type (p-type, n-type) and / or different geometry.

The two drain electrodes 12, 22 are connected to the formed as a through-hole electrical conductor 20. 6 shows a fourth exemplary embodiment, in which the two OFETs 1, 2 are arranged one above the other on the substrate 10 and are formed with a common gate electrode 15, but both OFETs 1, 2 are arranged with the same orientation on the substrate , The common gate electrode 15 is formed as the uppermost layer of the logic gate, which is formed like the logic gate shown in Fig. 5 with 7 layers.

The source electrode 11 and the drain electrode 12 of the first OFET 1 are arranged in the illustrated example as a first layer directly on the substrate 10 and covered by the semiconductor layer 13. On the semiconductor layer 13, the insulator layer 14 is arranged. The second OFET 2 is now arranged on the OFET 1 with the same orientation and the same layer sequence, i. the source electrode 21 and the drain electrode 22 are applied to the insulator layer 14 and covered with the semiconductor layer 23, on which the insulator layer 24 of the OFET 2 is applied. On the common gate electrode 15 is arranged as a final layer.

The two drain electrodes 12, 22 are connected to the electrically conductive connection layer 20, which is formed as a via.

But it can also be provided that the arrangement described above is formed so that the common gate electrode 15 is formed as the lowest, directly on the substrate 10 resting layer.

Because of the possibility described above to rotate the arrangement of the logic gate forming layers by 180 °, a particularly advantageous topology interconnected logic gates or other components may be formed and in this way, for example, vias for connecting the logic gates or Avoid components or minimized in number.

FIG. 7 now shows the basic circuit possible with the exemplary embodiments illustrated in FIGS. 5 and 6. The two OFETs 1, 2 each form a logic gate with a common gate electrode 15 and drain electrodes 12, 22 connected to one another in a conductive manner. The two source electrodes 11 and 21 form further terminals of the logic gate for supply voltage and ground. The logic gate shown in FIG. 7 may be formed differently with respect to the conductivity type of the semiconductor layers. These may be semiconductor layers of the same conductivity type or semiconductor layers of complementary conductivity type.

Fig. 8 now shows an example of a current-voltage diagram of an inverter-designed logic gate with OFET. A logic gate with an OFET can form an inverter in which the source electrode is connected to the circuit ground, the gate electrode forms the input of the inverter and the drain electrode forms the output of the inverter and via a load resistor the supply voltage is connected. Now, as soon as the gate electrode is connected to an input voltage, a current flow forms between the source electrode and the drain electrode, whereby the channel resistance of the OFET is reduced to such an extent that the drain electrode has approximately zero potential. As soon as the input voltage at the gate electrode is zero, the channel resistance of the OFET increases so much that the drain electrode has approximately the potential of the supply voltage. In this way, therefore, the input voltage is transformed into an inverted output voltage, i. the input signal of the inverter is inverted. In practice, the load resistance of the inverter is also formed as OFET. For better distinction, this OFET is referred to as a load OFET and the switching OFET as a switching OFET.

The current-voltage diagram in FIG. 8 shows the dependence between the through-current I ₀ through switching OFET or load resistor and the output voltage U _out . 8Oe denotes the on-characteristic and 80a the off-characteristic of the switching OFET and 8Ow the resistance characteristic of the load resistor. The intersection points 82e and 82a of the resistance characteristic 8Ow with a characteristic 8Oe and the off-characteristic curve 80a denote the switching points of the inverter _{consisting of} a voltage swing 82h of the output voltage U spaced apart from each other. With each switching operation of the inverter flows a charge-reversal current whose amount is symbolized by the hatched areas 84e and 84a. Fast and at the same time well and safely switchable logic gates are characterized by the properties of the large voltage swing 82h shown schematically in FIG. 8 and the approximately equal charge transfer currents 84e and 84a.

In Fig. 9a, a first curve of the output voltage U _from the inverter in response to the input voltage U _e j _{n is shown} qualitatively. The inverter of FIG. 8 is assigned to the curve 82k. The location of the off-level 82e is directly dependent on the location of the curves 8Oe and 8Ow in FIG. The inventive design of the logic gates with at least two different OFETs 1, 2, as shown for example in Fig. 2b, the illustrated in Fig. 9a advantageous characteristic curve 86k can be formed by, for example, the two OFET with semiconductor layers 13, 23 with different Thicknesses are formed. The advantage lies in the resulting larger voltage swing 86h compared to 82h.

FIG. 9b shows a second profile of the output voltage U _aU s of the inverter as a function of the input voltage U _e j _n in a qualitative representation. Now, the voltage swing 86h is increased again because the characteristic line 86h includes the output voltage U _aUs = 0. Such an inverter is designed with a particularly low power loss.

Due to the design of the logic gates according to the invention with different field effect transistors, which can be produced by layer-by-layer printing and / or knife coating, the cost-effective mass production of the logic gates according to the invention is made possible. The printing methods have reached such a level that finest structures in the individual layers can be formed, which can be formed with other methods only with great effort.

Claims

claims

1. Electronic component, in particular RFID transponder, with at least one logic gate, characterized in that the logic gate of a plurality of layers on a common substrate (10) is formed, the at least two electrode layers, at least one applied from a liquid, in particular organic, semiconductor layer (13, 23) and an insulator layer

(14, 24) and which are formed so that the logic gate comprises at least two differently constructed field effect transistors (1, 2).

2. Electronic component according to claim 1, characterized in that the at least two different field effect transistors (1, 2) differing in thickness applied from a liquid

Semiconductor layers (13, 23).

3. Electronic component according to claim 1, characterized in that the at least two different field effect transistors (1, 2) have in their semiconductor material different from a liquid applied semiconductor layers (13, 23).

4. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) itself have in their conductivity distinctive applied from a liquid semiconductor layers (13, 23).

5. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) differ in their thickness insulator layers (14, 24).

6. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) have in their insulator material different insulator layers (14, 24).

7. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) differ in their permeability insulator layers (14, 24).

8. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) are formed with different surface structured layers.

9. Electronic component according to claim 8, characterized in that the layers are formed strip-shaped with different length and / or different width.

10. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) are arranged side by side.

11. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) are arranged one above the other.

12. Electronic component according to one of the preceding claims, in particular according to claim 10 or 11, characterized in that the at least two different field effect transistors (1, 2) are arranged with the same orientation.

13. Electronic component according to claim 12, characterized in that the at least two different field effect transistors (1, 2) are arranged with the orientation bottom-gate or top-gate.

14. Electronic component according to one of the preceding claims, in particular according to claim 10 or 11, characterized in that the at least two different field effect transistors (1, 2) are arranged with different orientation.

15. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) have a different profile of the internal resistance and / or a different switching behavior.

16. Electronic component according to one of the preceding claims, characterized in that the at least two field effect transistors (1, 2) are connected to each other in a parallel circuit and / or series connection.

17. Electronic component according to one of the preceding claims, in particular according to claim 16, characterized in that the connection between the at least two field effect transistors (1, 2) by galvanic and / or capacitive coupling between electrodes (11,

12, 15, 21, 22, 25) of the field effect transistors (1,2) is formed.

18. Electronic component according to one of the preceding claims, in particular according to claim 16, characterized in that the at least two different field effect transistors (1, 2) with a common gate electrode (15) are formed.

19. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) are formed with semiconductor material complementary conductivity type, wherein the first field effect transistor (1) with a p-type semiconductor layer (13) and the second field effect transistor (2) is formed with an n-type semiconductor layer (23) or vice versa.

20. Electronic component according to claim 19, characterized in that the directly adjoining semiconductor layers (13, 23) of the at least two different field effect transistors (1, 2) form a zone with p / n junction or vice versa.

21. Electronic component according to one of the preceding claims, characterized in that the at least two different field effect transistors (1, 2) on a substrate (10) are spatially arranged so that the electronic component can be produced essentially by layer-by-layer printing and / or knife coating.

22. Electronic component according to one of the preceding claims, characterized in that the layers of the at least two different field effect transistors (1, 2) are designed as printable semiconducting polymers and / or printable insulating polymers and / or conductive printing inks and / or metallic layers.

23. Electronic component according to one of the preceding claims, characterized in that the electronic component forming layers soluble organic

Layers, including layers of polymeric material and / or oligomeric material and / or material from "small molecules" and / or material of nano-particles have.

24. Electronic component according to one of the preceding claims, in particular according to claim 23, characterized in that the thickness of the soluble organic layer by their

Solvent content is adjustable.

25. Electronic component according to one of the preceding claims, in particular according to claim 23, characterized in that the thickness of the soluble organic layer is adjustable by their order quantity.

26. Electronic component according to one of the preceding claims, characterized in that the electronic component is formed by a multilayer flexible film body.

27. Electronic component according to claim 1, characterized in that that the electronic component is designed as a flexible, the device contour adaptive electronic circuit.