Display Device And Manufacturing Method of The Same

Abstract

A display device includes a capacitive element configured so that a portion of a semiconductor layer which is made conductive constitutes one electrode, an insulation film which covers the semiconductor layer constitutes a dielectric film, and a conductive layer which includes a portion which is formed over the insulation film and is overlapped to the one electrode constitutes another electrode. The conductive layer has an extension portion which extends outside of a region where the semiconductor layer is formed from the inside of the region where the semiconductor layer is formed, and is formed over the insulation film. The insulation film has, in a region where the insulation film is overlapped to both the semiconductor layer and the extension portion of the conductive layer, a film thickness which is larger than a film thickness at a portion thereof which is overlapped to the one electrode.

1 . A display device comprising:
 a capacitive element which is configured such that a portion of a semiconductor layer which is made conductive constitutes one electrode;   an insulation film which covers the semiconductor layer constitutes a dielectric film; and   a conductive layer which includes a portion which is formed over the insulation film and is overlapped to the one electrode constitutes another electrode;   wherein the conductive layer has an extension portion which is integrally connected with the conductive layer of the portion which is overlapped to the one electrode, is also extended to the outside of a region where the semiconductor layer is formed from the inside of the region where the semiconductor layer is formed, and is formed over the insulation film; and   wherein the insulation film has, in a region where the insulation film is overlapped to both the semiconductor layer and the extension portion of the conductive layer, a film thickness which is larger than a film thickness at a portion thereof which is overlapped to the one electrode.   
   
   
       2 . A display device according to  claim 1 , wherein the semiconductor layer has, in a region where the semiconductor layer is overlapped to the extension portion of the conductive layer which is extended to the outside of the region where the semiconductor layer is formed from the inside of the region where the semiconductor layer is formed, an impurities concentration which is made smaller than an impurities concentration of the portion which constitutes the one electrode. 
   
   
       3 . A display device according to  claim 1 , wherein the extension portion of the conductive layer is a wiring layer which applies a potential to the another electrode. 
   
   
       4 . A display device according to  claim 1 , wherein the display device is a liquid crystal display device. 
   
   
       5 . A display device according to  claim 1 , wherein the semiconductor layer in the region of the insulation film in which the film thickness of the insulation film is larger than the film thickness at the portion of the insulation film which is overlapped to the one electrode, has implanted impurities. 
   
   
       6 . A display device comprising:
 a first region and a second region which are formed in a region of a semiconductor layer which is covered with an insulation film;   a thin film transistor which uses the insulation film formed over an upper surface of a portion of the first region as a gate insulation film; and   a capacitive element which uses the insulation film which is formed over an upper surface of a portion of the second region as a dielectric film;   wherein the capacitive element is configured such that the second region of the semiconductor layer is doped with impurities thus constituting one electrode, a conductive layer which is formed over an upper surface of the insulation film over the second region constitutes another electrode, and the another electrode is formed in a state that the another electrode is connected with a wiring layer which is extended from the outside of a region where the semiconductor layer is formed;   wherein at least a region of the semiconductor layer to which the wiring layer is overlapped includes a third region which has an impurities concentration smaller than an impurities concentration of the second region which constitutes the one electrode; and   wherein the insulation film over the second region has a film thickness s smaller than a film thickness of the insulation film over the first region and the third region.   
   
   
       7 . A display device according to  claim 6 , wherein the second region of the semiconductor layer which is doped with impurities has implanted impurities.