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.

What is claimed is:  
     
       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 transfer method for transferring a thin film device formed on a substrate onto a transcriptional body, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming the thin film device over the separation layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         selectively removing at least a portion of the insulation film; and  
       
       
         forming at least one of a first electrode connected to the thin film device and an external connection terminal in an area where the insulation film is removed. 
       
     
     
       27. The transfer method according to  claim 26 , further comprising: 
       
         adhering the thin film device to a transfer material with an adhesive layer. 
       
     
     
       28. The transfer method according to  claim 27 , further comprising: 
       
         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. 
       
     
     
       29. The transfer method according to  claim 28 , further comprising: 
       
         removing any portion of the separation layer remaining on the first electrode to form an active matrix substrate using the transfer material as a new substrate. 
       
     
     
       30. The transfer method according to  claim 26 , selectively removing at least a portion of the insulation film including forming at least one contact hole for electrically connecting the first electrode to the thin film device. 
     
     
       31. The transfer method according to  claim 30 , further comprising connecting the first electrode directly to an impurity layer which constitutes the thin film device. 
     
     
       32. The transfer method according to  claim 30 , further comprising: 
       
         forming at least one of a second electrode connected to an impurity layer which constitutes the thin film device; and  
       
       
         connecting the first electrode to the corresponding second electrode connected to the impurity layer. 
       
     
     
       33. The transfer method according to  claim 26 , further comprising forming at least one of a color filter and a light shielding film after forming the first electrode. 
     
     
       34. The transfer method according to  claim 26 , selectively removing at least a portion of the insulation film includes selectively removing at least a portion of the insulation film from a region where an external connection terminal is to be provided. 
     
     
       35. The transfer method according to  claim 34 , further comprising forming the external connection terminal as a conductive layer made of a same material as the first electrode or a same material as a second electrode connected to an impurity layer which constitutes the thin film device. 
     
     
       36. A transfer method for transferring a thin film device formed over a substrate onto a transcriptional body, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming an intermediate layer over the separation layer;  
       
       
         forming the thin film device over the intermediate layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         selectively removing the intermediate layer; and  
       
       
         forming at least one of a first electrode connected to the thin film device and an external connection terminal in an area where the insulation film is removed. 
       
     
     
       37. The transfer method according to  claim 36 , further comprising: 
       
         adhering the thin film device to a transfer material with an adhesive layer. 
       
     
     
       38. The transfer method according to  claim 37 , further comprising: 
       
         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. 
       
     
     
       39. The transfer method according to  claim 38 , further comprising: 
       
         removing any portion of the separation layer remaining on the intermediate layer and the first electrode to form an active matrix substrate using the transfer material as a new substrate. 
       
     
     
       40. The transfer method according to  claim 37 , selectively removing at least a portion of the insulation film including forming contact holes for electrically connecting the electrode to the thin film device. 
     
     
       41. The transfer method according to  claim 40 , further comprising connecting the first electrode directly to an impurity layer which constitutes the thin film device. 
     
     
       42. The transfer method according to  claim 40 , further comprising: 
       
         forming at least one second electrode connected to an impurity layer which constitutes the thin film device; and  
       
       
         connecting the first electrode to the corresponding second electrode connected to the impurity layer. 
       
     
     
       43. The transfer method according to  claim 37 , further comprising forming at least one of a color filter and a light shielding film after forming the first electrode. 
     
     
       44. The transfer method according to  claim 37 , selectively removing at least a portion of the insulation film includes selectively removing at least a portion of the insulation film from a region where an external connection terminal is to be provided. 
     
     
       45. The transfer method according to  claim 44 , further comprising forming the external connection terminal as a conductive layer made of a same material as the first electrode or a same material as a second electrode connected to an impurity layer which constitutes the thin film device. 
     
     
       46. A transfer method for transferring a thin film device formed on a substrate onto a transcriptional body, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming the thin film device over the separation layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         forming at least one of an electrode connected to the thin film device and an external connection terminal over the insulation film;  
       
       
         transferring at least one of the thin film device, the electrode, and the external connection terminal onto a transcriptional body; and  
       
       
         selectively removing the insulation layer to expose at least one of the electrode and the external connection terminal. 
       
     
     
       47. The transfer method according to  claim 46 , further comprising: 
       
         forming a light shielding layer that is overlapped with the thin film device, and not overlapped with at least a portion of the electrode. 
       
     
     
       48. The transfer method according to  claim 47 , transferring at least one of the thin film device, the electrode, and the external connection terminal onto a transcriptional body including: 
       
         adhering the thin film device and the light shielding layer to a transmissive transfer material with a transmissive adhesive layer; and  
       
       
         irradiating the separation layer through the transmissive substrate to produce exfoliation in the separation layer and the transmissive substrate to separate the transmissive substrate from the separation layer. 
       
     
     
       49. The transfer method according to  claim 48 , selectively reviewing the insulation layer to expose at least one of the electrode and the external connection terminal including: 
       
         forming a photoresist on a surface obtained by separating the transmissive substrate;  
       
       
         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; and  
       
       
         selectively removing at least a portion of the insulation film by using the photoresist mask. 
       
     
     
       50. The transfer method according to  claim 49 , further comprising: 
       
         removing the photoresist mask to form an active matrix substrate using the transfer material as a new substrate. 
       
     
     
       51. A transfer method for transferring a thin film device formed on a substrate onto a transcriptional body, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming at least one of an electrode connected to the thin film device and an external connection terminal on the separation layer;  
       
       
         forming at least one of the electrode and the external connection terminal and then forming the thin film device; and  
       
       
         transferring at least one of the thin film device, the electrode, and the external connection terminal onto a transcriptional body to expose at least one of the electrode and the external connection terminal. 
       
     
     
       52. The transfer method according to  claim 51 , further comprising: 
       
         adhering the thin film device to a transmissive transfer material with a transmissive adhesive layer. 
       
     
     
       53. The transfer method according to  claim 52 , further comprising: 
       
         producing exfoliation in the separation layer to separate the substrate from the separation layer. 
       
     
     
       54. The transfer method according to  claim 51 , further comprising forming a conductive material layer on the separation layer where an external connection terminal is to be formed. 
     
     
       55. A method of manufacturing a device, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming the thin film device over the separation layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         selectively removing at least a portion of the insulation film; and  
       
       
         forming at least one of a first electrode connected to the thin film device and an external connection terminal in an area where the insulation film is removed. 
       
     
     
       56. A method of manufacturing a device, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming an intermediate layer over the separation layer;  
       
       
         forming the thin film device over the intermediate layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         selectively removing the intermediate layer; and  
       
       
         forming at least one of a first electrode connected to the thin film device and an external connection terminal in an area where the insulation film is removed. 
       
     
     
       57. A method of manufacturing a device, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming the thin film device over the separation layer;  
       
       
         forming an insulation film over the thin film device and the separation layer;  
       
       
         forming at least one of an electrode connected to the thin film device and an external connection terminal over the insulation film;  
       
       
         transferring at least one of the thin film device, the electrode, and the external connection terminal onto a transcriptional body; and  
       
       
         selectively removing the insulation layer to expose at least one of the electrode and the external connection terminal. 
       
     
     
       58. A method of manufacturing a device, the method comprising: 
       
         forming a separation layer over a substrate;  
       
       
         forming at least one of an electrode connected to the thin film device and an external connection terminal on the separation layer;  
       
       
         forming at least one of the electrode and the external connection terminal and then forming the thin film device; and  
       
       
         transferring at least one of the thin film device, the electrode, and the external connection terminal onto a transcriptional body to expose at least one of the electrode and the external connection terminal.