Patent ID: 8110833
Filing Date: 2012-02-07
Classification: H01L

Abstract:
1. A display device comprising: a transparent substrate; gate electrodes which are stacked on the transparent substrate; semiconductor films which are stacked above the gate electrodes and constitute thin film transistors together with the gate electrodes; source electrodes and drain electrodes which are formed above the semiconductor films; an insulation film which is stacked between the source electrodes and the semiconductor films and between the drain electrodes and the semiconductor films; and contact holes which are formed in the insulation film so as to connect the source electrodes and the drain electrodes with the semiconductor films, wherein: each of the semiconductor films includes a connection region which is positioned at least below the contact hole and is connected with one of the source electrodes, and a connection region which is positioned at least below one of the contact holes and is connected with one of the drain electrodes, and impurities are implanted into the connection regions, wherein the impurities are implanted into each of the semiconductor films such that density of impurities in a peripheral region around the connection region is lower than density of the impurities in the connection region, and wherein a size of each of the contact holes is made smaller corresponding to the increase of a depth of the contact hole, and an amount of impurities implanted into each of the semiconductor films at each position of the peripheral region is decreased corresponding to the increase of distance in the direction perpendicular to the transparent substrate from the position of the peripheral region to the contact hole.