Seiko Epson Corporation

Seiko Epson Corporaition

David Russell

Thomas Kugler

Christopher Newsome

Shunpu Li

The invention disclosed relates to the fabrication of electronic devices. A method for fabricating an electronic device is disclosed, comprising embossing a surface of a work-pieceusing an embossing tool, so as to form a microstructure having at least two levels of thickness contrast on the work-piece surface, and depositing fluidcontaining a functional material onto the microstructure. In a preferred embodiment, the step of depositing fluidcomprises ink-jet printing. An embossing toolfor creating a microstructure on a work-pieceis also disclosed, the embossing toolcomprising a first surface and steps of at least two different heights relative to the first surface.

Device fabrication by ink-jet printing materials into bank structures, and embossing tool

The present invention relates to flexible substrates having on their surface a wetting contrast. The wetting contrast comprises adjacent areas of different hydrophilicity and/or oleophilicity. The present invention further relates to methods of production of such substrates and to methods of producing microelectronic components wherein electronically functional material is deposited onto said substrates. According to a first aspect of the present invention, a method of producing a flexible substrate having a wetting contrast is provided. The method includes the step of forming a first area comprising an inorganic material on a flexible substrate precursor to form a substrate wherein the inorganic material is at least partially exposed at the substrate surface and the first area constitutes a pattern on the precursor surface.

Method of producing a substrate having areas of different hydrophilicity and/or oleophilicity on the same surface

According to a first aspect, the present invention provides a method for forming a semiconductor film comprising a first step of providing a solution comprising a first organic semiconductor and a second organic semiconductor on a surface of a substrate. The solution is then dried to form the semiconductor film so that it comprises discrete domains of the first organic semiconductor in a matrix of the second organic semiconductor which electrically connects adjacent domains of the first organic semiconductor. The first and second semiconductors are of the same conductivity type. The mobility of charge carriers in the domains of the first organic semiconductor is higher than the mobility of charge carriers in the matrix of the second organic semiconductor. In alternative aspects, the present invention provides methods forming similar semiconductor film products but in which a solution of the first organic semiconductor is deposited separately from the second organic semiconductor and dried to form discrete domains. The present invention also provides a semiconductor film such as produced by the above methods in which both the first and second organic semiconductors are thiophenes.

Semiconductor film comprising discrete domains of an organic semiconductor and a method of its fabrication

A method of forming an electronic device on a substrate, comprising: embossing the substrate, surface treating the substrate so that unindented portionsrepel a solution of a first material, and depositing a solution of the first materialin indentationson the substrateformed by the embossing. The substrate is then annealed so that level of the first material is the same as the surface of the substrate. The first materialin the indentations can then, for example, be used as the source and drain in the subsequent formation of a TFT.

Micro-embossing fabrication of electronic devices

Provided is a method of depositing a polythiophene semiconductor on a substrate. First, the semiconductor is dissolved in a solvent comprising a halogen-containing aromatic compound. Then, the resulting solution is ink-jet printed onto the substrate. The method is useful in the production of microelectronic components such as thin film transistor devices.

Method of depositing polythiophene semiconductor on a substrate

The present invention relates to a method of dedoping an organic semiconductor comprising the step of contacting a doped organic semiconductor with a compound of formula (1): wherein R-Reach independently represents a hydrogen atom or a C-Calkyl group which may be linear or branched and which may be optionally substituted with one or more hydroxyl groups and/or one or more halogen atoms and/or a C-Calkoxy group;

Dedoping of organic semiconductors

Provided is a method of forming a heterojunction of contiguous layers of organic semiconducting polymers. The method comprises firstly forming a layer of a first organic semiconducting polymer on a substrate. A solution of a film-forming material is then deposited on the layer of the first organic semiconducting polymer. The first organic semiconducting polymer is insoluble in this solution and so is not disturbed by its deposition. The deposited solution is then dried to form a temporary film having a thickness of less then 20 nm formed from the film-forming material. Next a solution of a second organic semiconducting polymer dissolved in an organic solvent is deposited on the temporary film and this solution dried. The solubility of the material forming the temporary film in the organic solvent and the thickness of the temporary film are such that the organic solvent permeates through the thickness of the temporary film during drying of the solution of the second organic semiconducting polymer. This causes the temporary film to break down but without disturbing the layer of the first organic semiconducting polymer so that the layer of the second organic semiconducting polymer is formed contiguously on the layer of the first organic semiconducting polymer.

Method of fabricating a heterojunction of organic semiconducting polymers

Provided is a patterning method capable of fabricating high resolution structures without using a high resolution patterning step. The method comprises the steps of: (i) pre-patterning a layer of material () on a substrate (), (ii) spin-coating a solution of a film-forming substance over the pre-patterned substrate, (iii) drying the spin-coated solution to form a film () of the film-forming substance on the unpatterned areas of the substrate and on the surface and sides of the pre-patterned material, (iv) etching the dried film in such a way that it remains only around the sides of the pre-patterned material, and (v) removing the pre-patterned material to leave ridges () of the film-forming substance on the substrate, the pattern of the ridges corresponding to the outline of the pre-patterned material. A metal layer may then be deposited on the resulting patterned substrate followed by removal of the ridges leaving discrete areas of metal which form latent source and drain electrodes of a thin film transistor. An array of thin film transistors may then be formed by selectively depositing areas of semiconductor, insulator and conductor, the latter forming a gate electrode associated with each pair of source and drain electrodes.

Patterning method for fabricating high resolution structures

The present invention relates to a self-aligning patterning method which can be used to manufacture a plurality of multi-layer thin film transistors on a substrate. The method comprises firstly forming a patterned maskon the surface of a sacrificial layerwhich is part of a multi-layer structurewhich comprises the substrate, a conductive layer, an insulating layerand the sacrificial layer. Unpatterned areas are then etched to remove the corresponding areas of the sacrificial layer, the insulating layerand the conductive layerthereby leaving voids. A layer of dielectricis then deposited over the etched multi-layer structure to at least substantially fill the voids. The deposited dielectric is then etched in order to at least partially expose the sides of the remaining areasof the sacrificial layer. Conductive materialis then deposited on the surface of the etched dielectric. Finally, the remaining areasof the sacrificial layer are removed together with any overlying material. The resulting plurality of multi-layer thin film transistors is preferably in the form of an array which may in turn be formed into a display device by coupling each transistor in the array to a light-emitting cell.

Self-aligning patterning method

Provided is a method forming a desired pattern of electronically functional materialon a substrate. The method comprises the steps of: creating a first layer of patterning materialon the substrate whilst leaving areas of the substrate exposed to define said desired pattern; printing a suspension comprising particles of the electronically functional materialin a liquid dispersant, to which the patterning material is impervious, on the patterning material and the exposed substrate; removing at least some of the liquid dispersant from the suspension to consolidate the particles; and applying a first solvent to said consolidated particles which is capable of solubilizing the patterning materialand to which the consolidated particles are pervious so that the patterning material is removed from the substratetogether with any overlying electronically functional material

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Cambridge, United Kingdom

David Russell