Display device and electronic device

A semiconductor device comprising:

• a first substrate;
• a first insulating layer over the first substrate;
• a second insulating layer over the first insulating layer;
• a first oxide semiconductor layer over the second insulating layer which a transistor comprises a channel formation region in;
• a second oxide semiconductor layer over the second insulating layer which is configured to be a first electrode of a capacitor;
• a third insulating layer over the first oxide semiconductor layer;
• a fourth insulating layer over the second oxide semiconductor layer and the third insulating layer;
• a transparent conductive film over the fourth insulating layer which is configured to be a second electrode of the capacitor;
• a color filter layer;
• wherein the transparent conductive film is electrically connected to one of a source and a drain of the transistor,
• wherein the first insulating layer is not in contact with the first oxide semiconductor layer nor the second oxide semiconductor layer,
• wherein an upper surface of the second insulating layer is in contact with each of the first oxide semiconductor layer, the second oxide semiconductor layer, and the third insulating layer,
• wherein a side surface of the third insulating layer is in contact with the fourth insulating layer,
• wherein the fourth insulating layer comprises a region which is not in contact with the channel formation region and is in contact with the second insulating layer, and
• wherein the second oxide semiconductor layer comprises a region which is in contact with the fourth insulating layer and have a concentration of hydrogen more than twice as high as a concentration of hydrogen of the channel formation region.