Display device

Abstract

An object of the present invention is to provide a display device where small thin film transistors with a lower off current can be formed. The present invention provides a display device where thin film transistors are formed on a substrate, and in the above described thin film transistors, a gate electrode is formed on a semiconductor layer with a gate insulating film in between, the above described thin film transistors are formed of at least a first thin film transistor and a second thin film transistor, and the above described semiconductor layer is divided into individual regions for each film transistor, the above described semiconductor layer is provided with a common region shared either by the drain region of the above described first thin film transistor and the source region of the above described second thin film transistor or by the source region of the above described first thin film transistor and the drain region of the above described second thin film transistor, in the first thin film transistor and the second thin film transistor, the semiconductor layer is provided with LDD regions where the impurity concentration is lower than in the above described drain region and the above described source region, between the channel region and the drain region, as well as between the channel region and the source region, and the above described gate electrode is formed so as to overlap with the above described common region in the above described semiconductor layer and face at least the above described channel region and the above described LDD regions of the above described first thin film transistor and the above described channel region and the above described LDD regions of the above described second thin film transistor.

Description

[0001] This application claims the benefit of Japanese Patent Application Japanese Patent Application No. 2008-202525 filed on August 6, 2008, the contents of which are hereby incorporated by reference. technical field [0002] The present invention relates to a display device, in particular to a display device with a thin film transistor formed in a substrate. Background technique [0003] For example, in an active matrix liquid crystal display device, a thin film transistor including a switching element is formed in the region of each pixel on the substrate. [0004] In this case, the thin-film transistor is preferably a so-called bottom-gate transistor in which a gate electrode is disposed on the substrate side with a gate insulating film interposed therebetween relative to the semiconductor layer. This is because the gate electrode functions as a light-shielding film, which prevents light from the backlight from being irradiated to the semiconductor layer, and constitute...

AI Technical Summary

Problems solved by technology

[0010] Therefore, in the thin film transistor TFT constituted by the above structure, there is a limit in reducing its size

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