Manufacturing method of active matrix substrate, active matrix substrate and liquid crystal display device

Abstract

A method of manufacturing an active matrix substrate is provided that uses a technique of transferring a thin film device. In forming thin film transistors and pixel electrodes on an original substrate before transfer, an insulator film such as an interlayer insulation film or the like, is previously removed before the pixel electrodes are formed. Further, the original substrate is separated by exfoliation to transfer the device to a transfer material to cause the pixel electrodes to partially appear in the surface or the vicinity of the surface of the device. This portion permits application of a voltage to a liquid crystal through the pixel electrode.

1. A method of manufacturing an active matrix substrate comprising a pixel portion including thin film transistors connected to scanning lines and signal lines arranged in a matrix, and pixel electrodes connected to terminals of the thin film transistors, the method comprising the steps of:
 forming a separation layer on a substrate;    forming the thin film transistors over the separation layer;    forming an insulation film on the thin film transistors and over the separation layer;    selectively removing at least a portion of the insulation film where each of the pixel electrodes is to be formed;    forming each of the pixel electrodes on the insulation film and the separation layer in the region where at least a portion of the insulation film has been removed;    adhering the thin film transistors to a transfer material with an adhesive layer;    producing exfoliation in the separation layer and/or at an interface of the separation layer and the substrate to separate the substrate from the separation layer; and    removing any portion of the separation layer remaining on the pixel electrodes to form an active matrix substrate using the transfer material as a new substrate.    
     
     
       2. The method of manufacturing an active matrix substrate according to  claim 1 , wherein the step of selectively removing at least a portion of the insulation film comprises forming contact holes for electrically connecting the pixel electrodes to the thin film transistors. 
     
     
       3. The method of manufacturing an active matrix substrate according to  claim 2 , further comprising connecting the pixel electrodes directly to an impurity layer which constitutes the thin film transistors. 
     
     
       4. The method of manufacturing an active matrix substrate according to  claim 2 , further comprising the steps of:
 forming electrodes connected to an impurity layer which constitutes the thin film transistors; and    connecting the pixel electrodes to the corresponding electrodes connected to the impurity layers.    
     
     
       5. The method of manufacturing an active matrix substrate according to  claim 1 , further comprising the step of forming at least one of a color filter and a light shielding film after the step of forming the pixel electrodes. 
     
     
       6. The method of manufacturing an active matrix substrate according to  claim 1 , wherein in selectively removing at least a portion of the insulation film, at least a portion of the insulation film is selectively removed from a region where an external connection terminal is to be provided. 
     
     
       7. The method of manufacturing an active matrix substrate according to  claim 6 , further comprising the step of forming the external connection terminal as a conductive layer made of a same material as the pixel electrodes or a same material as an electrode connected to an impurity layer which constitutes the thin film transistors. 
     
     
       8. A method of manufacturing an active matrix substrate comprising a pixel portion including thin film transistors connected to scanning lines and signal lines arranged in a matrix, and pixel electrodes connected to terminals of the thin film transistors, the method comprising the steps of:
 forming a separation layer on a substrate;    forming an intermediate layer on the separation layer;    forming the thin film transistors on the intermediate layer;    forming an insulation film on the thin film transistors and the intermediate layer;    selectively removing at least a portion of the insulation film where each of the pixel electrodes is to be formed;    forming each of the pixel electrodes on the insulation film and the separation layer in the region where at least a portion of the insulation film is removed;    adhering the thin film transistors to a transfer material with an adhesive layer;    producing exfoliation in the separation layer and/or at an interface of the separation layer and the substrate to separate the substrate from the separation layer; and    removing any portion of the separation layer remaining on the intermediate layer and the pixel electrodes to form an active matrix substrate using the transfer material as a new substrate.    
     
     
       9. The method of manufacturing an active matrix substrate according to  claim 8 , wherein the step of selectively removing at least a portion of the insulation film comprises forming contact holes for electrically connecting the pixel electrodes to the thin film transistors. 
     
     
       10. The method of manufacturing an active matrix substrate according to  claim 9 , further comprising connecting the pixel electrodes directly to an impurity layer which constitutes the thin film transistors. 
     
     
       11. The method of manufacturing an active matrix substrate according to  claim 9 , further comprising the steps of:
 forming electrodes connected to an impurity layer which constitutes the thin film transistors; and    connecting the pixel electrodes to the corresponding electrodes connected to the impurity layers.    
     
     
       12. The method of manufacturing an active matrix substrate according to  claim 8 , further comprising the step of forming at least one of a color filter and a light shielding film after the step of forming the pixel electrodes. 
     
     
       13. The method of manufacturing an active matrix substrate according to  claim 8 , wherein in selectively removing at least a portion of the insulation film, at least a portion of the insulation film is selectively removed from a region where an external connection terminal is to be provided. 
     
     
       14. The method of manufacturing an active matrix substrate according to  claim 13 , further comprising the step of forming the external connection terminal as a conductive layer made of a same material as the pixel electrodes or a same material as an electrode connected to an impurity layer which constitutes the thin film transistors. 
     
     
       15. A method of manufacturing an active matrix substrate comprising a pixel portion including thin film transistors connected to scanning lines and signal lines arranged in a matrix, and pixel electrodes connected to terminals of the thin film transistors, the method comprising the steps of:
 forming a separation layer on a transmissive substrate;    forming the thin film transistors over the separation layer or on an intermediate layer formed on the separation layer;    forming an insulation film on the thin film transistors;    forming the pixel electrodes made of a conductive material on the insulation film;    forming a light shielding layer that is overlapped with the thin film transistors, and not overlapped with at least a portion of the pixel electrodes;    adhering the thin film transistors and the light shielding layer to a transmissive transfer material with a transmissive adhesive layer;    irradiating the separation layer through the transmissive substrate to produce exfoliation in the separation layer and/or at an interface of the separation layer and the transmissive substrate to separate the transmissive substrate from the separation layer;    forming a photoresist on a surface obtained by separating the transmissive substrate or the surface of a layer appearing after removing any remaining portion of the separation layer;    irradiating light to expose only a predetermined portion of the photoresist using the light shielding layer as a mask, followed by development to form a desired photoresist mask;    selectively removing at least a portion of the intermediate layer and the insulation film or at least a portion of the insulation film by using the photoresist mask; and    removing the photoresist mask to form an active matrix substrate using the transfer material as a new substrate.    
     
     
       16. A method of manufacturing an active matrix substrate comprising a pixel portion including thin film transistors connected to scanning lines and signal lines arranged in a matrix, and pixel electrodes connected to terminals of the thin film transistors, the method comprising the steps of:
 forming a separation layer on a substrate;    forming the pixel electrodes over the separation layer or on an intermediate layer formed on the separation layer;    forming an insulation film on the pixel electrodes, and forming the thin film transistors on the insulation film to respectively connect the thin film transistors to the pixel electrodes;    adhering the thin film transistors to a transmissive transfer material with a transmissive adhesive layer;    producing exfoliation in the separation layer and/or at an interface of the separation layer and the substrate to separate the substrate from the separation layer; and    removing any portion of the separation layer remaining on the intermediate layer to form an active matrix substrate using the transfer material as a new substrate.    
     
     
       17. The method of manufacturing an active matrix substrate according to  claim 16 , further comprising forming a conductive material layer on the separation layer or on the intermediate layer at a position where an external connection terminal is to be formed. 
     
     
       18. An active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 1 . 
     
     
       19. An active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 8 . 
     
     
       20. An active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 15 . 
     
     
       21. An active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 16 . 
     
     
       22. A liquid crystal display device comprising an active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 1 . 
     
     
       23. A liquid crystal display device comprising an active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 8 . 
     
     
       24. A liquid crystal display device comprising an active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 15 . 
     
     
       25. A liquid crystal display device comprising an active matrix substrate manufactured by the method of manufacturing an active matrix substrate according to  claim 16 . 
     
     
       26. A device comprising:
   a substrate;        an adherent layer formed over the substrate;        a thin film device being attached to the substrate by the adherent layer;        at least one of an insulation film, which is positioned over the thin film device with respect to the adherent layer, and an intermediate layer, which is positioned between the thin film device and the adherent layer, the one of the insulation film and the intermediate layer having an opening where no thin film device is formed; and        a pixel electrode connected with the thin film device, the pixel electrode being positioned over the adherent layer and substantially exposed through the opening.     
     
     
       27. A device according to  claim 26 , wherein a contact hole is provided in the intermediate layer and the pixel electrode is connected with the thin film device through the contact hole. 
     
     
       28. A device according to  claim 26 , further comprising an other electrode exposed through an other opening in the at least one of the insulating film and the intermediate layer, the other electrode including an external connection terminal that connects with an external circuit. 
     
     
       29. A device according to  claim 26 , wherein the thin film device is selected from the group including a thin film transistor ( TFT ) , a thin film diode, an electrode, a switching device, a memory, an actuator, magnetic recording thin film head, a coil, an inductor, a filter, a reflector, dichroic mirror and combination thereof.   
     
     
       30. A device according to  claim 26 , further comprising a light shielding layer being positioned over the thin film device. 
     
     
       31. The device according to  claim 28 , the other electrode being electrically connected to the same thin film device as the pixel electrode. 
     
     
       32. The device according to  claim 28 , the pixel electrode being formed from a substantially transparent electrically conductive material. 
     
     
       33. The device according to  claim 26 , further comprising an alignment layer formed over the pixel electrode.