DE10229118A1 - Process for the inexpensive structuring of conductive polymers by definition of hydrophilic and hydrophobic areas - Google Patents

Abstract

The invention relates to a method for producing conductor lines from an electrically conductive organic material. For this purpose, sections are defined on a substrate surface by printing on a matrix connection, so that a substrate surface with hydrophilic and hydrophobic sections is obtained. A solution of the electrically conductive organic polymer is placed on the structured substrate surface, either only the hydrophilic sections or only the hydrophobic sections being wetted by the solution of the organic polymer. The method enables the display of lines with a line width of less than 10 mum and does not require any photolithographic process steps.

Description

The invention relates to a method for generating structured semiconductor paths from an electrical conductive organic polymer.

Semiconductor chips have a wide range Use in diverse technical applications found. They are mostly based on silicon as a semiconductor substrate, in which in numerous steps Semiconductor components are integrated. The manufacture of semiconductor chips is therefore complex and expensive. The chips are inflexible due to the use of silicon and can only be under great Reduce effort to very thin layers, so that flexible Substrates can be obtained. Microchips are therefore only for demanding Suitable applications where increased costs are accepted can be. Can the cost of This significantly opens the way to reduce the production of microchips the door to a big one Number of applications that are under high cost pressure. examples for such applications are labels for labeling goods, whereby data about on the labels the goods can be saved. This information can for example at a cash register without contact be read out. Electronic stamps are another example or general applications of transponder technology. Another Application is a thin Foil with integrated controls for liquid crystal screens.

A way to reduce costs offers the use of organic semiconductors. These materials are easily accessible and some of them are already commercially available. The materials can are deposited in layers on a substrate so that complex electronic components such as transistors, diodes or capacitors can be produced. To the cost advantages of electrically conductive organic polymers to be able to play However, this requires that inexpensive procedures for applying and structuring such polymer compounds for disposal stand. These procedures should be carried out with high throughput can, so high numbers and thus cost advantages can be achieved. Furthermore, a resolution up to down to a line width of 10 μm required to achieve a sufficient high density of electronic components on the available area to be able to achieve and to achieve high component performance.

The structuring has been done so far with methods such as those from the structuring of semiconductor substrates silicon-based. For example, this can be done electrically conductive Polymer a photoactive component can be added, which after allows exposure of the polymer layer in sections, that selectively only the exposed or only the unexposed areas superseded can be. Furthermore, the layer of the electrically conductive polymer can also first a layer of a photosensitive varnish can be applied by exposure and detachment of the exposed or unexposed sections Areas a mask is made. The one specified by the mask The structure can then be etched transferred into the layer of the electrically conductive polymer become. A slight overetching can the mask at the end of the etching step can also be removed, leaving only a structured layer of the electrically conductive organic polymer remains. However, these methods require a step in which the photosensitive Layer first exposed and then is developed. To do this, the substrate must be in appropriate devices are processed, resulting in an extension of production times and an increase the cost.

Exposure and development To avoid the photosensitive layer, methods have been developed in which the for the etching the electrically conductive organic polymer layer required mask by a screen printing process is produced directly. However, it is still necessary that the structure specified by the mask by etching in the layer of electrical conductive organic polymer transferred becomes. Furthermore, with screen printing, the resolution is on a line width limited to approx. 200 μm. This is only enough for rough structures, such as for conductor tracks or large electrodes. finer Structures such as those used to define the channel length of Transistors are not required by screen printing accessible.

Attempts have also been made to produce the structures directly from the electrically conductive organic polymer. So in the WO 99/39373 describes a method for producing organic semiconductor devices, the organic semiconductor material being applied to a substrate in an ink-jet method. In this way, light-emitting diodes with polyvinyl carbazole as the semiconductor material could be produced, the color of the emitted light being able to be influenced by doping the semiconductor material with dyes, such as coumarins.

In the WO 99/19900 describes a method in which microelectronic arrangements can be produced by dropwise application of a solution of the organic semiconductor.

Even with an order from the electric conductive organic polymer by an ink jet printing process Lines width of the representable structures limited. Especially with very fine structures there is a risk that neighboring lines will converge, before the solvent Completely evaporated.

To improve the resolution in inkjet printing, Sirringhaus, H .; Kawese T .; Friend, R. H.; "High-Resolution Ink-Jet Printing of All-Polymer Transistor Circuits" in: MRS Bulletin / July 2001 proposed to define the areas to be printed on the substrate surface using fine polyimide structures. In the subsequent ink jet printing, the areas wetted by the polyimide structure are not wetted by the solution of the electrically conductive organic polymer, which is why a smaller line width can be represented. However, the polyimide structures are produced photolithographically, so that no great cost advantages can be achieved with these processes. Furthermore, inkjet printing has the general disadvantage that line by line must be printed one after the other, so that only low throughputs can be achieved, which likewise leads to high costs.

The object of the invention is therefore a method for producing structured semiconductor paths from a electrically conductive organic polymer available to put that inexpensively and with high throughputs carried out can be a resolution with line widths of less than 10 μm.

The object is achieved with a method for producing structured semiconductor paths from an electrically conductive organic polymer, which comprises at least the following steps:
Providing a substrate having a substrate surface;
applying a matrix connection in sections to the substrate surface, so that a structured substrate surface with hydrophilic and hydrophobic sections is obtained, the hydrophilic and hydrophobic sections being formed by sections of the matrix connection on the one hand and exposed sections of the substrate surface on the other hand;
Application of an electrically conductive polymer present in the liquid phase, preferably in an aqueous solution or in a suspension, to the structured substrate surface, the liquid phase of the electrically conductive polymer wetting only the hydrophilic sections or only the hydrophobic sections of the structured substrate surface and a wetted substrate surface being obtained , in which structured semiconductor paths are defined from the electrically conductive organic polymer.

The method according to the invention uses the different Wettability of substrate surface and Templating. With a full-surface application of the electrical conductive organic polymer compound are therefore dependent on the polarity of the electrically conductive organic polymer selectively only the hydrophilic or only the hydrophobic Areas of the structured substrate surface wetted. The method according to the invention can therefore be carried out much faster than an inkjet printing process, which is why higher throughputs and thus cost advantages can be achieved. Because of the matrix connection Formed sections are those from the electrically conductive organic Polymer formed lines delimited exactly, being on the border line a transition from hydrophobic to hydrophilic. This allows the electrical conductive organic polymer lines are sharply delimited what again an increase the resolution, i.e. enables the display of finer lines.

Under a matrix connection understood a connection that can be established by suitable methods, e.g. Printing process on the substrate surface can be applied and has sufficient adhesion to the substrate surface, to form stable structures in the form of covered portions of the substrate surface to be able to. The matrix connection can be a single connection, e.g. a silane, or a mixture of several compounds, e.g. on Mixture of a non-polar polymer and an adhesion promoter.

The method is carried out by first providing a substrate. The substrate can have a hydrophilic or a hydrophobic surface. In order to obtain a structure, sections from the matrix connection are now defined on the substrate surface. The matrix connection is selected so that its polarity forms a pair of opposites with the substrate surface. Has the substrate surface hydrophilic. Properties, a material that has hydrophobic properties is selected as the matrix connection. If the substrate material has a hydrophobic surface, a hydrophilic material is selected accordingly as the matrix connection. After the matrix connection has been applied, hydrophilic and hydrophobic sections are thus defined on the substrate surface, with a sharp transition in polarity taking place between the hydrophilic and hydrophobic sections. The electrically conductive organic polymer is then applied in the liquid phase to the structured substrate surface prepared in this way. For this purpose, the electrically conductive organic polymer can be present as a solution or suspension. Depending on the properties of the electrically conductive organic polymer, however, it can also be present, for example, in pasty form. Furthermore, further substances can be added to the electrically conductive organic polymer, with which, for example, the polarity of the liquid phase applied, ie ultimately the wetting properties, can be adjusted. Furthermore, the electrically conductive organic polymer can also be provided with dopants in order, for example, to be able to influence its electrical conductivity. The electrically conductive polymer can also be applied as a precursor which is not yet electrically conductive and is subsequently converted into its electrically conductive form by an appropriate treatment, for example oxidation, reduction or exposure. The matrix connection can also comprise a solvent which ver after the application of the matrix connection on the substrate surface is steaming. Depending on the hydrophilic or hydrophobic properties of the liquid phase comprising the electrically conductive organic polymer, it wets the sections formed from the matrix connection or the exposed sections of the substrate surface. Accordingly, in the first case the exposed sections of the substrate surface and in the second case the sections formed from the matrix connection remain unwetted by the liquid phase of the electrically conductive polymer. With a given arrangement of hydrophilic and hydrophobic sections on the substrate surface, the method according to the invention can therefore be designed as a positive method or as a negative method. The electrically conductive polymer can be applied, for example, by pulling the structured substrate surface through a solution of the electrically conductive organic polymer. However, it is also possible to spray the solution or generally the liquid phase of the electrically conductive organic polymer onto the structured substrate surface. This method must ensure that excess solvent and unbound electrically conductive organic polymer are subsequently removed, for example by allowing the solvent to flow off or by rinsing the substrate surface with a suitable solvent after the electrically conductive organic polymer has been applied. However, it is also possible to transfer the electrically conductive organic polymer to the structured substrate surface using a contact method. For this purpose, the electrically conductive organic polymer is first applied to an auxiliary surface and then the auxiliary surface is brought into contact with the structured substrate surface. The layer of the electrically conductive organic polymer is selectively transferred in the hydrophilic or in the hydrophobic sections from the auxiliary surface to the structured substrate surface.

The method according to the invention can be different Be designed in a way. According to a first embodiment both the matrix connection and the electrical connection remain conductive organic polymer on the substrate surface. To the desired one To get the product, all that has to be done is the electrically conductive organic Solvent containing polymer are evaporated to obtain the structured semiconductor paths. In this variant of the method, it is advantageous if the Formed sections of the structured substrate surface through the matrix connection a printing process can be generated. This way both Matrix connection as well as the electrically conductive organic polymer a high throughput can be applied to the substrate surface. The For this purpose, the matrix connection can be made using a stamp, for example or a printing roller can be transferred to a substrate. This will the matrix connection from a reservoir first to the stamp or Pressure roller applied and then from the stamp or the pressure roller transferred to the substrate surface.

To apply the matrix connection can different printing methods can be used. Particularly preferred the matrix connection is applied to the substrate surface a high pressure process. In the high-pressure process, the printing ones are surfaces sublime. Flexo printing processes, in which by using a flexible printing form even rough surfaces the matrix connection can be coated. Particularly preferred is the matrix connection with a micro contact printing process on the substrate surface applied. In the high-pressure processes mentioned, it is preferred the printing form is designed as a roller, the surface of which is corresponding the structure to be displayed is structured. The production the roller or a stamp is made by known methods, for example with photolithographic processes. Due to the high number of structured Substrate surfaces, that can be produced with the stamp or roller the cost of stamp or roller manufacture per transferred Structure only slight.

The one formed from the matrix connection Structure can be made according to the application of the electrically conductive organic Polymers on the substrate surface remain. To differentiate the substrate surface into hydrophobic and to reach hydrophilic sections, it is sufficient if the matrix compound is applied as a monomolecular layer on the substrate surface becomes. The layer thickness of such a monomolecular layer is approximately 1 nm while the layer of the electrically conductive organic polymer has a thickness in the range of 10 nm to 1 μm. The matrix connection therefore influences the electrical properties of the microelectronic component produced only to a small extent Extent.

To have adequate mechanical stability to reach the sections formed from the matrix connection, the matrix connection is preferably via a covalent bond bound to the substrate surface. To do this, the matrix connection must have a corresponding reactive group exhibit. A corresponding one must then be on the substrate surface Group can be provided as a reaction partner. Unless there are such groups on the substrate surface are present, the substrate surface can be activated accordingly become. The surface can do this the substrate can be etched, for example, by wet or dry chemistry, for example to create hydroxy groups on the substrate surface.

It is particularly advantageous if the intermolecular interaction between the molecules of the template compound is so attractive that a self-assembling monomolecular Layer is formed.

A self-organizing structure is a structure in which through the microscopic interactions between the molecules spontaneously a stable macroscopic external shape, such as a membrane or a double layer is formed.

The matrix connection can be made by purely electrostatic interaction bound to the substrate surface become. However, a more stable structure is obtained if the matrix connection is via a covalent bond is bound to the substrate surface.

To tie the matrix connection to the substrate surface via a To achieve covalent bonding must be appropriate on the substrate surface linking groups to be provided. these can either already be provided on the substrate surface or you can generated by an activation step. You can do this, for example corresponding leaving groups, such as halides, are generated on the substrate surface become.

For example, if the substrate surface exists made of silicon dioxide, so can on the substrate surface through an etching step Silanol groups are generated, which can react with halogen silanes, which in in this case form the matrix connection.

The method according to the invention is preferred performed in the way that the hydrophobic sections are formed from the matrix connection become. The electrically conductive organic polymer is then preferably in a hydrophilic form in front. When applying the electrically conductive organic polymer solution the structured substrate surface then becomes the electrically conductive organic polymer selectively only to the exposed sections the substrate surface bound.

To create a hydrophobic surface to be able the matrix compound preferably comprises alkyl chains with 5 to 20 Carbon atoms. The alkyl chains are preferably linearly dense packed so that the matrix connection on the substrate surface which can form hydrophobic sections.

The hydrophobic properties of the Matrix connection can be strengthened if the matrix connection is at least partially fluorinated. The alkyl chains are preferred perfluorinated the matrix connection.

To connect the matrix connection to the substrate surface via a to be able to achieve covalent bonding, it is advantageous if the matrix connection is a silane. Prefers is the matrix compound a halosilane, which with a the substrate surface arranged hydroxy group reacts so that the template compound is bound to the substrate surface as a siloxane.

In the embodiment described so far the structure formed from the matrix connection remains the substrate surface and the semiconductor path is completed by, for example the solvent is evaporated. However, the method according to the invention can also be carried out in the way that after applying the solution of the electrically conductive organic polymers as the wetted substrate surface Media acts and the electrically conductive polymer from the wetted substrate surface transferred to a carrier becomes. The carrier can do this with the wetted substrate surface be brought into contact, the electrically conductive organic Polymer on the carrier adheres better than on the substrate surface or that of the matrix connection formed areas. Such a transfer of the electrically conductive organic polymer from the substrate surface to the surface of the carrier in a similar way to a printing process.

The electrically conductive organic Polymer can either be applied directly from the substrate surface the wished Transfer carrier become. But it is also possible the electrically conductive organic polymer from the wetted substrate surface first an intermediate beam transferred to and subsequently the electrically conductive transfer organic polymer from the intermediate carrier to the carrier. This process management corresponds essentially to an offset printing process. As an intermediate carrier, for example a flexible intermediate beam, chosen like a rubber sheet, through which roughnesses on the surface of the carrier are compensated, so that a complete Transfer of the electrically conductive organic polymer from the intermediate carrier to the carrier.

The invention is by reference on the attached Figures and explained in more detail using examples. The figures show in individual:

1 Steps which are carried out in the method according to the invention;

2 a first device for performing the method according to the invention;

3 a second device for performing the method according to the invention;

4 a photograph of structures which have been produced using the method according to the invention;

5 a section through an organic transistor, which has been shown with the inventive method;

6 a characteristic curve of an organic transistor produced by the method according to the invention;

7 Characteristic curves of transistors produced by the method according to the invention.

In 1A Working steps of the method according to the invention are shown, this being carried out as a negative print. 1A (a) shows a substrate 1 sections on the substrate surface 2 are separated from the matrix connection. As a substrate 1 all printable materials such as paper, polymer films, glass, silicon, silicon dioxide, aluminum oxide etc. can be used. Suitable polymers are, for example, polystyrene, polyethylene, polyester, polyurethane, polycarbonate, polyacrylate, polyimide, polyet ter, polybenzoxazole or mixtures of these compounds. Compounds can be used as the matrix connections which, on the one hand, have a group attached to the surface of the substrate 1 can bind, wherein the binding can take place via a covalent bond or via a non-covalent bond, for example a dipole-dipole interaction, an ionic interaction or a coordinative bond. On the other hand, the matrix connection must have a remainder which is the sections 2 one to the surface of the substrate 1 gives opposite polarity. Is the surface of the substrate 1 For example, hydrophilic, the matrix connection must be designed so that the sections 2 have hydrophobic properties. On the other hand is the surface of the substrate 1 hydrophobic, the matrix connection must be designed so that the sections 2 Have hydrophilic properties. Compounds suitable as matrix compounds are, for example, halosilanes, haloalkanes, aminoalkanes, thioalkanes, alcohols, sulfonalkanes and carboxylic acids or carboxylates. The matrix connection is made, for example, by printing on the surface of the substrate 1 applied so that sections 2 can be obtained with a defined structure. The thickness of the sections 2 is chosen low. Preferably, only a monolayer of the matrix connection is applied to the surface of the substrate 1 applied. A substrate is obtained in this way 1 with a textured surface, the structure being the sections 2 the matrix connection as well as the sections 3 in which the surface of the substrate 1 exposes.

A solution of an electrically conductive organic polymer is then applied to the structured substrate surface. For this purpose, for example, the entire structured substrate surface, which comprises the sections, can first be 2 and 3 comprises, are covered with the solution of the electrically conductive organic polymer. The substrate 1 can then be tilted so that excess solution of the electrically conductive organic polymer can run off. Any polymer which has the required electrical conductivity and which can be processed as a solution or suspension can be used as the electrically conductive organic polymer. Examples of suitable electrically conductive organic polymers are polyaniline doped with camphorsulfonic acid or poly (dioxyethylene) thiophene (PEDOT: PSS) doped with polystyrene sulfonic acid. These electrically conductive organic polymers have, for example, a hydrophilic character. Examples of suitable solvents are water, alcohols, ketones, ethers. After removing excess solution of the electrically conductive organic polymer, the polymer solution remains 4 only on the sections 3 back in which the surface of the substrate 1 exposed. The sections 2 from the matrix connection remain from the polymer solution 4 unwetted. This is achieved because, for example, the substrate 1 and with it the sections 3 have hydrophilic properties while the sections 2 of the matrix compound have hydrophobic properties. Now becomes the hydrophilic solution 4 of the electrically conductive polymer placed on the structured substrate surface, only the sections are selectively 3 wetted. Excess solvent then becomes from the polymer solution 4 evaporates so that the electrically conductive polymer 5 on the sections 3 the surface of the substrate 1 remains. The thickness of the sections of the electrically conductive polymer 5 is much larger than the monomolecular layer of the matrix connection, which the sections 2 forms. The method was explained using an embodiment in which the electrically conductive polymer was applied directly as a solution to the structured substrate surface. However, it is also possible to apply a solution of an electrically non-conductive precursor to the structured substrate surface and, if necessary, to convert it into the electrically conductive polymer after the solvent has evaporated, for example by oxidizing or reducing the precursor.

In 1B The method steps of the method according to the invention are shown, the method being designed as a positive print. As in 1A is first explained on a substrate 1 a structured substrate surface is created by sections 2 from a matrix connection, for example by printing on the surface of the substrate 1 be applied so that between the sections 2 arranged sections 3 are obtained in which the surface of the substrate 1 is exposed. The further process steps are explained on the basis of a structure in which the substrate 1 has hydrophobic properties during the sections 2 of the matrix compound have hydrophobic properties. On through the sections 2 and 3 structured surface of the substrate 1 will now be a solution 6 applied, which has hydrophobic properties, ie is non-polar. For this purpose, the electrically conductive organic polymer is dissolved or suspended in a non-polar solvent. Now, as with 1A described, the polymer solution is placed on the structured substrate surface and then excess polymer solution is removed, the polymer solution remains 6 only on the non-polar hydrophobic sections 2 back out of the matrix connection while the polar sections 3 the substrate surface are not wetted. Then the solvent of the polymer solution is evaporated, for example by the substrate 1 is heated on a hot plate. Sections of the electrically conductive polymer are again obtained 5 , but in this embodiment of the method on the sections 2 the matrix connection is arranged while in the sections 3 the surface of the substrate 1 exposed. In this embodiment of the method, too, the electrically conductive polymer can first be applied in the form of an electrically non-conductive precursor, which is subsequently given its desired electrical properties by suitable treatment.

If you use a hydrophobic substrate 1 , In this embodiment of the method, the sections 2 the matrix connection be polar and the solution of the electrically conductive organic polymer 6 accordingly also be polar.

The production of the structured substrate surface as described in 1A (a) and 1B (a) is shown below with reference to the 2 explained. On a high pressure roller 7 are raised areas 8th arranged through which the on a substrate 1 structure to be mapped is defined. In a reservoir 9 there is a supply of a solution of the matrix connection. Via a transport roller 10 will release the matrix connection from the reservoir 9 removed, using a scraper 11 excess solution of the matrix connection from the surface of the transport roller 10 is removed so that only a thin film of the matrix connection on the transport roller 11 remains. From the transport roller 11 the matrix connection is on the raised areas 8th on the surface of the high pressure roller 7 transferred by the raised areas 8th in contact with the surface of the transport roller 10 to be brought. On the raised areas 8th the high pressure roller 7 a thin layer of the solution of the matrix connection is now applied. The transport roller 7 moves on, leaving the raised areas 8th with the surface of a substrate 1 come into contact. The substrate 1 this is done continuously via a substrate roller 12 on the surface of the high pressure roller 7 past. The matrix connection is released from the raised areas 8th the high pressure roller 7 on the surface of the substrate 1 transfer. As a substrate 1 For example, a polymer film can be used. After walking past the surface of the high pressure roller 7 therefore faces the surface of the substrate 1 sections 2 which are formed by the matrix connection. The substrate 1 with the sections arranged on its surface 2 the matrix connection can then be processed further by applying a solution of the electrically conductive organic polymer to the structured substrate surface (not shown).

3 shows an apparatus for performing the method according to the invention, wherein only the electrically conductive organic polymer is transferred to a support for the end product, while the sections of the matrix connection form a printing form which is used for printing on the support with the solution of the electrically conductive organic polymer. In the 3 The device shown essentially corresponds to a device such as is used for example for offset printing. On a plate cylinder 13 is an arcuate substrate 1 spanned on which sections 2 are arranged from a matrix connection. The substrate 1 can have, for example, hydrophilic properties, while the sections 2 form hydrophobic sections of the matrix connection. The sections 2 the matrix connection can be formed, for example, from a silicone. Between the sections 2 the matrix connection are sections 3 arranged in which the surface of the substrate 1 exposed. A structured substrate surface is thus obtained, which has, for example, hydrophobic sections 2 and hydrophilic sections 3 includes. An inking unit is applied to the structured substrate surface 14 applied a solution of the electrically conductive organic polymer. The solution of the electrically conductive organic polymer should have hydrophilic properties for the following explanation. The structured substrate surface is on the rollers of the inking unit 14 passed by, leaving the hydrophilic sections 3 covered by the solution of the electrically conductive organic polymer while the sections 2 the matrix connection remain unwetted. After the solution of the electrically conductive organic polymer has been applied to the structured substrate surface, it rotates further and arrives with the surface of a blanket cylinder 15 in contact. The solution of the electrically conductive organic polymer is now on the surface of the blanket cylinder 15 transferred while the structured substrate surface on the plate cylinder 13 back to the inking unit 14 is moved further to take up solution of the electrically conductive organic polymer again. The surface of the blanket cylinder 15 is rotated further, so that it finally meets the surface of a carrier 16 came into contact. To do this, the carrier 16 from a storage container 17 removed and between the blanket cylinder 15 and the impression cylinder 18 passed. This is done on the surface of the blanket cylinder 15 predetermined structure, which is formed from the electrically conductive organic polymer, on the surface of the carrier 16 transfer. The printed carrier 16 is then on a conveyor belt 19 a collecting container 20 fed.

The production of semiconductor lines from an electrically conductive organic polymer was described in 3 using a hydrophilic substrate 1 described on which hydrophobic sections 2 are arranged from the matrix connection and wherein a hydrophilic solution of an electrically conductive organic polymer selectively only the hydrophilic sections 3 covered the substrate surface. However, it is also possible to use a hydrophobic substrate 1 to use on which hydrophilic sections 2 the matrix connection are arranged. In this case, a hydrophobic solution of the electrically conductive organic polymer is used. For example, a solution in an organic non-polar solvent can be used. In this case, the hydrophobic sections 3 , in which the hydrophobic substrate surface is exposed, wetted by the hydrophobic solution of the electrically conductive organic polymer.

That based on 3 The method described was explained as a negative method. However, it is also possible to design the process as a positive process. To do this, the polarity of the solution of the electrical The conductive polymer is chosen to be the same or at least largely similar to the polarity of the sections formed from the matrix connection, so that the solution of the electrically conductive polymer selectively only the sections 2 wetted.

4 shows electron micrographs of conductor tracks made of PEDOT / PSS, which were shown with the inventive method. The conductor tracks have a line width of 10 μm with a distance of 100 μm between adjacent conductor tracks. The 4A to C show different enlargements of the arrangement. 4A shows the arrangement in an overview, with a relatively small magnification selected. Call the surface of a substrate 1 are bright lines 21 arranged, which are formed from the electrically conductive organic polymer. The dark areas 22 which between the bright lines 21 arranged correspond to sections of the substrate surface which have been given hydrophobic properties by treatment with octadecyltrichlorosilane as a matrix compound. The dark areas can be seen in the enlarged illustration 4B 22 which are free of electrically conductive organic polymer. The bright areas 21 , which correspond to the electrically conductive organic polymer, are clearly limited and show a sharp transition to the hydrophobic sections 22 , Even with the 4C The highest resolution shown shows the boundary between the semiconductor paths 21 from the electrically conductive organic polymer and the hydrophobic areas 22 no irregularities. The electrically conductive organic polymer completely fills the hydrophilic areas defined by the matrix connection on the substrate surface, so that a uniform structure is obtained after evaporation of the solvent. The manufacture of the 4 The illustrated structured semiconductor paths are explained in more detail below using examples.

The method according to the invention can also be used for the production of multi-layer microelectronic components, such as for the production of organic field effect transistors or organic diodes. For this purpose, an intermediate layer must be available on which hydrophilic and hydrophobic sections can be produced in order to obtain a structured substrate surface on which the solution of the electrically conductive organic polymer can be applied selectively in the hydrophilic or hydrophobic sections. Suitable intermediate layers are, for example, dielectrics, such as SiO ₂ or organic polymers in organic field effect transistors or ITO (indium tin oxide) in organic light-emitting diodes. The adjustment of different print positions is possible in offset printing in the order of 20 μm. This is sufficient for applications in which organic field effect transistors or organic light-emitting diodes are used. The structure of an organic field effect transistor, as is produced further below in Example 12, is shown in 5 shown. On a surface 23 which can be a polymer film or a silicon wafer, for example, is a gate electrode 24 arranged from an electrically conductive organic polymer. The gate electrode 24 is through a gate dielectric 25 isolated, which can consist for example of a polymer material or an insulating oxide, such as silicon dioxide. On the gate dielectric 25 are source electrode 26 and drain electrode 27 arranged, which are also constructed from an electrically conductive organic polymer. Between source electrode 26 and drain electrode 27 is a ladder track 28 arranged, which is made up of polythiophene, for example, and whose conduction properties can be controlled via the gate electrode.

The execution of the method according to the invention is demonstrated in the following examples.

example 1

Contact angle measurements

The hydrophilic and hydrophobic properties the substrate surface, the sections covered with the matrix connection and the electrical conductive Organic polymers were measured by measuring the contact angle with water detected. Monolayers of the silanes used as the matrix compound were generated by a thermally oxidized silicon wafer for 1 h 100 ° C below Nitrogen flow and a pressure of 200 mbar in an atmosphere of silane was stored. For the contact angle measurements, those in table 1 specified values determined.

Table 1

Example 2

Contact angle measurements for organic substrates

Similar Values for the contact angles as in Example 1 are obtained if one Polyester film (polyethylene naphthalate) for 10 s in an oxygen plasma is treated at 400 W and 0.1 mbar and then analog Example 1 applied a self-organized monolayer of an alkylsilane becomes.

Example 3

stamp production

One is placed on a silicon wafer 25% solution a poly (o-hydroxy) amide spin-coated in N-methylpyrrolidone at 2500 revolutions for 10 s. The layer is at 100 ° C for 60 s pre-dried on a hot plate under a stream of nitrogen. The conversion to polybenzoxazole is carried out by a thermal treatment at 400 ° C while Performed in an inert gas oven for 30 min. The thickness of the polybenzoxazole layer obtained is 1.3 μm.

To structure the polybenzoxazole layer, a silicon-containing i-line photoresist is first spun on at 5000 rpm for 20 s and then dried at 100 ° C. for 60 s. The layer thickness of the photoresist is 1.3 μm. The photoresist film is then exposed through a mask with 60 mJ / cm ² at 365 nm and developed with a 2.38% aqueous solution of tetramethylammonium hydroxide for 60 s at room temperature. The resist structure is transferred into the polybenzoxazole using an oxygen plasma (O ₂ , 400 W, 0.1 mbar). The resist is completely removed from the polybenzoxazole layer by slight overetching. A stamp is now produced from the structure produced in the polybenzoxazole layer by applying a layer of polydimethyldisiloxane with a thickness of 1-3 mm on the structured polybenzoxazole layer. The polydimethyldisiloxane layer is produced according to the manufacturer's specifications. After the polydimethyldisiloxane layer has hardened, the stamp is removed and washed with ethanol and n-hexane alternately for 10 min and 2 min in an ultrasonic bath and dried under a stream of nitrogen.

Example 4

structuring

The stamp produced in Example 3 is steamed with octadecyltrichlorosilane at 100 ° C. at a pressure of 200 mbar in a nitrogen stream. The stamp is then pressed onto the surface of a substrate for 10 s. A silicon wafer is used as the substrate, which is provided with a layer of silicon dioxide on its surface by oxidation. The layer of octadecyltrichlorosilane deposited on the stamp is transferred from the raised areas of the stamp to the substrate, so that a monomolecular layer of octadecyl residues is generated on the surface of the SiO ₂ .

Example 5

structuring

Example 4 is repeated, but instead of octadecyltrichlorosilane tridecafluoro-1,1,2,3-te trahydrooctyltrichlorosilane is used.

Example 6

The stamp obtained in Example 3 is for 10 min in a 3% solution of octadecyltrichlorosilane in dry hexane. The Stamp becomes from the solution removed and excess solvent in a drying cabinet at 60 ° C evaporated under reduced pressure. The one with octadecyltrichlorosilane used stamp is for 10 s on a substrate surface pressed from silicon dioxide so that the octadecyltrichlorosilane transferred from the raised areas of the stamp to the substrate surface is formed and a monomolecular layer on the substrate surface becomes.

Example 7

Example 6 is repeated, with however, instead of octadecyltrichlorosilane, tridecafluoro-1,1,2,2-tetrahydrooctyltrichlorosilane is used.

Example 8

Order of the electrically conductive organic polymer

The ones obtained in Examples 4 to 7 Substrates on their surface Hydrophobic areas are defined in a solution PEDOT / PSS submerged. The not coated with octadecyltrichlorosilane Hydrophilic areas of the substrate surface become even with it PEDOT / PSS wetted while the hydrophobic areas not coated with octadecyltrichlorosilane be wetted. The substrate is removed at an angle of 45 ° solution of the organic polymer, the PEDOT / PSS on the substrate surface only remains in the hydrophilic sections. Then will the wetted substrate for 3 min at 100 ° C dried.

Example 9

Separation of the electrical conductive organic polymer by spraying

The ones obtained in Examples 4 to 7 Substrates are made with a solution sprayed by PEDOT / PSS, the substrate being inclined is held so that excess polymer suspension can expire. The wetted substrates are then min during Dried at 100 ° C, to the solvent to remove.

Example 10

Separation of the electrical conductive organic polymer by spin coating

In the examples 4 to 7 The substrate obtained is a solution of PEDOT / PSS in each case Spin speed of 2000 rpm spun on. Then the substrate is min at 100 ° C dried to the solvent to evaporate.

In 4 sections of the conductor tracks produced in Examples 8 to 10 are shown in different magnifications.

Example 11

electrical characterization

Pentazen is evaporated onto the conductor paths shown in Example 8 at 60 ° C. Transistors with a charge carrier mobility of 0.03 cm ² / Vs, a threshold voltage of 16 V, a sub threshold voltage increase of 3.4 V / decade and an on / off current ratio of 10 ³ are obtained. The measured characteristic curves of the organic transistors obtained in Example 11 are in for various gate-source voltages 6 shown.

Example 12

manufacturing of an organic transistor

On a silicon wafer which was provided with a layer of silicon dioxide on its surface by oxidation, a hydrophilic section is first defined, as described in Example 8, on which the gate electrode is to be deposited. As described in Example 10, a solution of PEDOT / PSS is spun onto the structured substrate surface and then excess solvent is removed by heating. To produce the gate dielectric, a solution of 10% poly-4-hydroxystyrene, 1% crosslinker, 89% n-butanol is spun on at 2500 rpm / 30 s. To evaporate the solvent, the substrate is first heated on a hot plate to 100 ° C. for 1 min and then heated to 200 ° C. for 1 min for crosslinking. As described in Example 8, hydrophilic sections are now created by printing on the layer of the gate dielectric in order to define the sections for the source electrode and the drain electrode. The stamp is adjusted relative to the gate electrode under a microscope, with an accuracy of approx. 100 μm being achieved. For the production of the source and drain electrodes, a solution of the electrically conductive organic polymer is again spun on as described in Example 10 and the substrate is then briefly heated on a hotplate to remove solvent. A 2% solution of poly-3-hexylthiophene in chloroform is spun onto this structure at 1500 rpm for 20 s. The solvent is removed by subsequently heating the substrate to 70 ° on a hot plate for 1 min. The transistors have a charge carrier mobility of 0.001 cm ² / Vs at a threshold voltage of 4 V. The characteristics of the transistors at different gate voltages are in 7 shown.

1

substratum

2

sections the matrix connection

3

exposed Sections of the substrate surface.

4

Polymer solution (polar)

5

electrical conductive polymer

6

Polymer solution (non-polar)

7

High-pressure roller

8th

sublime areas

9

reservoir

10

transport roller

11

scraper

12

substrate roll

13

plate cylinder

14

inking

15

Blanket cylinder

16

carrier

17

reservoir

18

pressure cylinder

19

conveyor belt

20

receptacle

21

lines made of electrically conductive organic polymer

22

hydrophobic areas

23

underground

24

gate electrode

25

gate dielectric

26

source electrode

27

drain

28

active Semiconductor layer

Claims (12)

A method for producing structured semiconductor paths from an electrically conductive organic polymer, comprising at least the following steps: providing a substrate with a substrate surface; applying a matrix connection in sections to the substrate surface, so that a structured Substrate surface with hydrophilic and hydrophobic sections is obtained, the hydrophilic and hydrophobic sections being formed by sections of the matrix connection on the one hand and exposed sections of the substrate surface on the other hand; Applying an electrically conductive polymer present in the liquid phase to the structured substrate surface, the liquid phase of the electrically conductive polymer wetting only the hydrophilic sections or only the hydrophobic sections of the structured substrate surface and obtaining a wetted substrate surface in which structured semiconductor paths from the electrically conductive organic polymer are defined. The method of claim 1, wherein the die connection formed sections of the structured substrate surface a printing process can be generated. The method of claim 2, wherein the printing process is a high pressure process is. 4. The method of claim 3, wherein the high pressure method is a Is micro contact pressure. Method according to one of claims 1 to 4, wherein the matrix connection applied as a monomolecular layer to the substrate surface becomes. Method according to one of claims 1 to 5, wherein the matrix connection via a covalent bond is bound to the substrate surface. Method according to one of the preceding claims, wherein on the substrate surface linking groups for covalent connection the matrix connection are provided. Method according to one of the preceding claims, wherein the hydrophobic sections are formed from the matrix connection. Method according to one of the preceding claims, wherein the matrix compound alkyl chains with 5 to 20 carbon atoms includes. Method according to one of the preceding claims, wherein the matrix compound is at least partially fluorinated. 11: Procedure according to one of the preceding claims, wherein the matrix connection Is silane. Method according to one of the preceding claims, wherein the electrically conductive organic polymer from the wetted substrate surface transmit a carrier becomes. The method of claim 13, wherein the electrically conductive polymer from the wetted substrate surface first on an intermediate carrier and from the intermediate carrier transferred to the carrier becomes.