Display device and method of manufacturing display device

A display device, comprising:

• a substrate;
• a first transistor and a second transistor each disposed on the substrate, wherein one of the first transistor or the second transistor includes:
• an oxide semiconductor layer that includes a channel region,
• a first conductive region, and
• a second conductive region,
• wherein the first conductive region and the second conductive region are located on two opposite sides of the channel region, respectively;
• a first insulating layer interposed between the substrate and the oxide semiconductor layer,
• a gate electrode that overlaps the channel region of the oxide semiconductor layer;
• a second insulating layer interposed between the oxide semiconductor layer and the gate electrode;
• and
• a third insulating layer disposed on the second insulating layer and that covers the gate electrode,
• wherein a hydrogen concentration of the oxide semiconductor layer is within a range from about 5×1020 atom/cm3 to about 2×1021 atom/cm3, and
• a value in the channel region of the oxide semiconductor layer of HC according to Equation (1) is less than 30%:
• HC[%](Max−Min)/Avg×100 Equation (1),
• wherein Max represents a maximum hydrogen concentration value detected from a plurality of points within the channel region, Min represents a minimum hydrogen concentration value detected from a plurality of points within the channel region, and Avg represents an average hydrogen concentration value detected from a plurality of points within the channel region,
• wherein the hydrogen concentration is measured in a valid region of the channel region that is separated from edges of the channel region by about 0.15% times a length of the channel region L and by about 0.15% times a width of the channel region.