A mask includes a substrate and an electrochromic layer that overlap each other. The electrochromic layer includes an electrochromic material.

A display device is provided. The display device includes a first conductor; a first insulating layer covering the first conductor; and a first semiconductor layer and a second conductor, both disposed on the first insulating layer, wherein the first conductor includes a gate line, a gate electrode connected to the gate line, and a storage line separated from the gate line, wherein the first semiconductor layer includes a channel region overlapping the gate electrode and a first antireflective pattern overlapping the storage line, and wherein the second conductor includes a data line, a source electrode at least partially disposed on the channel region and connected to the data line, and a drain electrode at least partially disposed on the channel region and separated from the source electrode.

A liquid crystal display device includes a transistor, a pixel electrode, and a common electrode. The transistor includes a first gate electrode on a first substrate, a second gate electrode having a region overlapping the first gate electrode, an oxide semiconductor layer between the first gate electrode and the second gate electrode, a first insulating layer between the first gate electrode and the oxide semiconductor layer, a second insulating layer between the oxide semiconductor layer and the second gate electrode, and a first oxide conductive layer and a second oxide conductive layer disposed between the first insulating layer and the oxide semiconductor layer and disposed with the first gate electrode and the second gate electrode sandwiched from both sides. The pixel electrode is disposed between the first and the second insulating layer; the common electrode is disposed a region overlapping with the pixel electrode and on the second insulating layer.

According to one embodiment, a display device includes a plurality of scanning lines, a plurality of signal lines, a plurality of pixels, a pixel electrode and a common electrode, wherein the pixel electrode includes a first trunk portion and a plurality of first branch portions extending from the first trunk portion, the common electrode includes a second trunk portion and a plurality of second branch portions extending from the second trunk portion, the plurality of first branch portions and the plurality of second branch portions are arranged alternately, and the signal lines and the pixel electrodes are formed of a same material and by a same process.

A display device includes a switching element having a pixel connection portion, a first insulating film having a first pixel contact hole formed therein so as to be in a place overlapping at least a part of the pixel connection portion, a common line, an intermediate electrode composed of the same conducting film as the common line, disposed to overlap the first pixel contact hole, and connected to the pixel connection portion, a common electrode not connected to the intermediate electrode but connected to the common line, a second insulating film having a second pixel contact hole formed therein so as to be in a place overlapping at least a part of the intermediate electrode, and a pixel electrode disposed so that at least a part of the pixel electrode overlaps the second pixel contact hole.

A mask includes a substrate and an electrochromic layer that overlap each other. The electrochromic layer includes an electrochromic material.

Provided is a method to manufacture a liquid crystal display device in which a contact hole for the electrical connection of the pixel electrode and one of the source and drain electrode of a transistor and a contact hole for the processing of a semiconductor layer are formed simultaneously. The method contributes to the reduction of a photography step. The transistor includes an oxide semiconductor layer where a channel formation region is formed.

Provided is a method to manufacture a liquid crystal display device in which a contact hole for the electrical connection of the pixel electrode and one of the source and drain electrode of a transistor and a contact hole for the processing of a semiconductor layer are formed simultaneously. The method contributes to the reduction of a photography step. The transistor includes an oxide semiconductor layer where a channel formation region is formed.

In a semi-transmission liquid crystal display device, two resist masks are required to form a reflective electrode and a transparent electrode; therefore, cost is high. A transparent electrode and a reflective electrode which function as a pixel electrode are stacked. A resist pattern which includes a region having a thick film thickness and a region having a thinner film thickness than the aforementioned region is formed over the reflective electrode by using a light exposure mask which includes a semi-transmission portion. The reflective electrode and the transparent electrode are formed by using the resist pattern. Therefore, the reflective electrode and the transparent electrode can be formed by using one resist mask.

To provide a semiconductor device, a liquid crystal display device, and an electronic device which have a wide viewing angle and in which the number of manufacturing steps, the number of masks, and manufacturing cost are reduced compared with a conventional one. The liquid crystal display device includes a first electrode formed over an entire surface of one side of a substrate; a first insulating film formed over the first electrode; a thin film transistor formed over the first insulating film; a second insulating film formed over the thin film transistor; a second electrode formed over the second insulating film and having a plurality of openings; and a liquid crystal over the second electrode. The liquid crystal is controlled by an electric field between the first electrode and the second electrode.