Liquid crystal display device and electronic device

A semiconductor device having a pixel portion comprising a plurality of pixels, the pixel portion comprising:

• a common electrode over a first substrate;
• a first conductive layer over the first substrate, the first conductive layer directly connected to the common electrode;
• a transistor over the first substrate, the transistor having a semiconductor layer comprising polycrystalline silicon;
• a gate wiring, a part of the gate wiring being configured to be a gate electrode of the transistor;
• a source wiring, a part of the source wiring being configured to be one of a source electrode and a drain electrode of the transistor;
• a second conductive layer over and in contact with the semiconductor layer;
• an insulating film over the common electrode, the first conductive layer, and the second conductive layer;
• a pixel electrode over the insulating film, the pixel electrode directly connected to the second conductive layer;
• and
• a liquid crystal layer over the common electrode and the pixel electrode,
• wherein the first conductive layer, the source wiring, and the second conductive layer comprise a same material,
• wherein the pixel electrode has a plurality of slits,
• wherein the gate electrode is provided over the semiconductor layer,
• wherein the gate electrode and a first region of the common electrode overlap with each other,
• wherein the one of the source electrode and the drain electrode is provided over and in contact with the semiconductor layer, and
• wherein the one of the source electrode and the drain electrode and a second region of the common electrode and overlap with each other.

A semiconductor device having a pixel portion comprising a plurality of pixels, the pixel portion comprising:

• a common electrode over a first substrate;
• a first conductive layer over the first substrate, the first conductive layer directly connected to the common electrode;
• a transistor over the first substrate, the transistor having a semiconductor layer comprising polycrystalline silicon;
• a gate wiring, a part of the gate wiring being configured to be a gate electrode of the transistor;
• a source wiring, a part of the source wiring being configured to be one of a source electrode and a drain electrode of the transistor;
• a second conductive layer over and in contact with the semiconductor layer;
• an insulating film over the common electrode, the first conductive layer, and the second conductive layer;
• a pixel electrode over the insulating film, the pixel electrode directly connected to the second conductive layer;
• and
• a liquid crystal layer over the common electrode and the pixel electrode,
• wherein the first conductive layer, the source wiring, and the second conductive layer comprise a same material,
• wherein the pixel electrode has a plurality of slits,
• wherein the gate electrode is provided over the semiconductor layer,
• wherein the gate electrode and a first region of the common electrode overlap with each other,
• wherein the one of the source electrode and the drain electrode is provided over and in contact with the semiconductor layer,
• wherein the one of the source electrode and the drain electrode and a second region of the common electrode and overlap with each other, and
• wherein the pixel electrode and a third region of the common electrode overlap with each other.

A semiconductor device having a pixel portion comprising a plurality of pixels, the pixel portion comprising:

• a common electrode over a first substrate;
• a first conductive layer over the first substrate, the first conductive layer directly connected to the common electrode;
• a transistor over the first substrate, the transistor having a semiconductor layer comprising polycrystalline silicon;
• a gate wiring, a part of the gate wiring being configured to be a gate electrode of the transistor;
• a source wiring, a part of the source wiring being configured to be one of a source electrode and a drain electrode of the transistor;
• a second conductive layer over and in contact with the semiconductor layer;
• an insulating film over the common electrode, the first conductive layer, and the second conductive layer;
• a pixel electrode over the insulating film, the pixel electrode directly connected to the second conductive layer;
• and
• a liquid crystal layer over the common electrode and the pixel electrode,
• wherein the first conductive layer, the source wiring, and the second conductive layer comprise a same material,
• wherein the pixel electrode has a plurality of slits,
• wherein the gate electrode is provided over the semiconductor layer,
• wherein the gate electrode and a first region of the common electrode overlap with each other,
• wherein the one of the source electrode and the drain electrode is provided over and in contact with the semiconductor layer,
• wherein the one of the source electrode and the drain electrode and a second region of the common electrode and overlap with each other, and
• wherein each of the common electrode and the pixel electrode comprises a light-transmitting conductive layer.