Semiconductor device and manufacturing method thereof

摘要

A means of forming unevenness for preventing specular reflection of a pixel electrode, without increasing the number of process steps, is provided. In a method of manufacturing a reflecting type liquid crystal display device, the formation of unevenness (having a radius of curvature r in a convex portion) in the surface of a pixel electrode is performed by the same photomask as that used for forming a channel etch type TFT, in which the convex portion is formed in order to provide unevenness to the surface of the pixel electrode and give light scattering characteristics.

主权项

1. A display device comprising:
a first substrate; a transistor over the first substrate, the transistor comprising:
a gate electrode;a semiconductor film over the gate electrode, the semiconductor film comprising a first portion, a second portion, and a recessed portion interposed between the first portion and the second portion, wherein a thickness of the first portion is larger than a thickness of the recessed portion and a thickness of the second portion is larger than the thickness of the recessed portion;a first insulating film interposed between the gate electrode and the semiconductor film;a source electrode over and electrically connected to the semiconductor film; anda drain electrode over and electrically connected to the semiconductor film; a pixel electrode over and electrically connected to one of the source electrode and the drain electrode; a second insulating film over the semiconductor film; a second substrate over the second insulating film; a sealing material between the first substrate and the second substrate; and a terminal portion over the first substrate and outside a portion surrounded by the sealing material, the terminal portion comprising:
a first conductive film; anda second conductive film over and in contact with a top surface of the first conductive film, wherein the second insulating film comprises a region located between the source electrode and the drain electrode, and the region is in contact with a top surface of the first portion, a top surface of the second portion and a top surface of the recessed portion, wherein the gate electrode overlaps with the recessed portion, and wherein a gap between the source electrode and the drain electrode is larger than a width of the recessed portion, wherein a side edge of the semiconductor film extends beyond a side edge of one of the source electrode and the drain electrode, wherein the first conductive film and the gate electrode comprise a same material, and wherein the second conductive film and the pixel electrode comprise a same material.