Thin film transistor, active matrix substrate, display device and electronic equipment

Abstract

Provided is a thin film transistor which has an off-state current reduced to an extremely low level, and has an outstanding reliability, and is preferably applicable to a pixel driver of a super high definition indicator, peripheral circuits or the like, to provide an active matrix substrate provided with the thin film transistor, and to provide a display. Thin film transistor comprises a semiconductor layer 42 provided on a substrate main body 10a, a gate electrode 32, a drain electrode 17, and a source electrode 16. The semiconductor layer 42 is connected with the drain electrode 17. It is so constituted that there are provided a high concentration drain region 1e where impurity is heavily diffused, a low concentration drain region 1c provided at the gate electrode 32 side of the high concentration drain region 1e where the impurity is lightly diffused, and a region provided at the gate electrode 32 side of the low concentration drain region 1c where the impurity is diffused in a minute amount concentration, or alternatively an offset region 1a2 set as an intrinsic semiconductor region.

Description

technical field [0001] The invention relates to thin film transistors, active matrix substrates, display devices and electronic equipment. Background technique [0002] In the field of display devices including liquid crystal devices, there is an increasing demand for higher brightness and higher definition. For example, digitalization of photographs is now progressing. image display device. However, current technology cannot yet realize such an ultra-high-definition display device. The main reason for this is that the off-state current of transistors used in pixels cannot be reduced. [0003] Conventionally, the semiconductor layer of a thin film transistor of a liquid crystal device is formed from amorphous silicon (amorphous silicon), a method of forming a low-temperature polysilicon film, or a method of forming a high-temperature polysilicon film. The method of manufacturing with a low-temperature polysilicon film has the advantages of being able to form an image sign...

AI Technical Summary

Problems solved by technology

However, in an ultra-high-definition display device, the liquid crystal capacitance decreases proportionally to the area of ​​the pixel, thereby significantly reducing the retention characteristics. Therefore, it is difficult to suppress the above-mentioned reduction in the retention characteristics only by the effect of reducing the off-state current of the LDD structure.

[0007] In addition, in a thin film transistor with a compensation structure, it is possible to obtain an off-state current characteristic superior to that of a thin film transistor with an LDD structure, but the characteristic degradation due to hot carriers is significant, and it is difficult to ensure reliability.

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