Koninklijke Philips Corporation N.v.

Pieter J Van Der Zaag

Ian D French

Steven Charles Deane

Stephen J Battersby

Eric Alexander Meulenkamp

Jeffrey Alan Chapman

Daan Louis De Kubber

A method for use in the fabrication of active plates for pixellated devices, such as active matrix liquid crystal displays, having pixel electrodes () and associated address lines () formed from a layer of transparent conductive material () through which the conductivity of the address lines is improved. The transparent conductive layer () and a metal layer () are deposited in succession and followed by a shielding layer (), e.g. of photoresist, which is patterned into a configuration of regions () corresponding to the required pixel dielectrodes and address lines with a property of the layer at these respective regions being different. This enables the regions of this layer corresponding to the pixel electrodes to be selectively etched away, thereby allowing the metal at these regions to be selectively removed while leaving metal at the address lines. The method simplifies the production of low mask mount TFT active plates with improved address line conductivity.

Pixellated device with the metal layer atop the address lines

A method of increasing the conductivity of a transparent conductive layer, in which a photoresist layer which patterns the transparent layer is given tapered edges and is partially etched. The partial etching exposing the edge regions of the underlying transparent conductor layer, which are the selectively plated. This method has a single patterning stage of the transparent layer, but uses partial etching of a tapered resist layer in order to expose a small edge region of the transparent layer for coating with a conductive layer (which can be opaque).

Active plate for a display device having a conductive layer with increased conductivity

A method of forming an active plate for a liquid crystal display is disclosed in which the source and drain conductors ( ), pixel electrodes ( ) and column conductors ( ) are formed by depositing and patterning a transparent conductor layer. There is selective plating of areas ( ) of the transparent conductor layer to form a metallic layer for reducing the resistivity of the transparent conductor layer. The plated areas include the column conductors ( ) but exclude the source and drain conductors and the pixel electrodes. This enables the column conductors to be treated to reduce the resistivity, but without altering the channel length of the transistor because the source and drain parts of the layer are shielded from the plating process.

Pixellated devices such as active matrix liquid crystal displays

A method for use in the fabrication of active plates for pixilated devices, such as active matrix liquid crystal displays, having pixel electrodes ( ) and associated address lines ( ) formed from a layer of transparent conductive material ( ) through which the conductivity of the address lines is improved. The transparent conductive layer ( ) and a metal layer ( ) are deposited in succession and followed by a shielding layer ( ), e.g. of photoresist, which is patterned into a configuration of regions ( ) corresponding to the required pixel dielectrodes and address lines with a property of the layer at these respective regions being different. This enables the regions of this layer corresponding to the pixel electrodes to be selectively etched away, thereby allowing the metal at these regions to be selectively removed while leaving metal at the address lines. The method simplifies the production of low mask mount TFT active plates with improved address line conductivity.

Pixellated devices such as active matrix liquid crystal displays and methods of manufacturing such

A method of improving the electrical conductivity of transparent conducting lines ( ) carried on a substrate ( ), particularly address lines on the active plate for a pixellated device such as an active matrix liquid crystal display or the like fabricated using a low mask count process, involves forming the lines on the substrate from a deposited layer of transparent conducting material ( ), e.g. ITO, and provided on their upper surface with a covering layer ( ) extending from at least one end ( ) and partially covering the surface, and then performing an electroplating operation to plate the lines ( ) with a plating potential being applied at that end. The covering layer ( ) assists in achieving a more uniform plated layer ( ) along the length of the line. The covering layer preferably comprises photoresist defined by selective patterning and partial etching of a deposited photoresist layer ( ) used for patterning the transparent layer ( ). In a pixellated device, pixel electrodes ( ) are also defined from the transparent layer.

Method of improving the conductivity of transparent conductor lines

The invention provides a method of manufacturing an electronic device including a vertical thin film transistor. A layer ( ) of semiconductor material is provided over an insulated gate electrode ( ). A negative resist ( ) is used to define source and drain electrodes ( ) which extend over the insulating layer ( ) up to the step formed therein adjacent an edge ( A) of the gate electrode ( ).

Electronic devices comprising thin film transistors

Short channel thin film transistors suffer from unacceptably high leakage currents. The invention provides an electronic device including a thin film transistor in which the length ( ) of the channel of the transistor is 1 &mgr;m or less, and the mobility of the semiconductor material in the channel is less than 0.2 cm /Vs. The selection of a low mobility semiconductor material results in acceptable off-current characteristics and its effect on the switching speed of the device is compensated for by the short channel length ( ) of the device.

Growing community of inventors

Pyrford, United Kingdom

Pieter J Van Der Zaag