Thin-film transistor substrate

A thin-film transistor substrate comprising:

• a first oxide semiconductor film;
• a second oxide semiconductor film located upper than the first oxide semiconductor film;
• a first insulating film located lower than the second oxide semiconductor film and covering the first oxide semiconductor film;
• and
• a gate electrode of a first thin-film transistor,
• wherein the first oxide semiconductor film includes a first low-resistive region, a second low-resistive region, and a channel region of the first thin-film transistor that is located between the first low-resistive region and the second low-resistive region and opposed to the gate electrode,
• wherein each of the first low-resistive region and the second low-resistive region includes a source/drain region of the first thin-film transistor,
• wherein the second oxide semiconductor film includes a third low-resistive region, a fourth low-resistive region, and a channel region of a second thin-film transistor that is located between the third low-resistive region and the fourth low-resistive region,
• wherein each of the third low-resistive region and the fourth low-resistive region includes a source/drain region of the second thin-film transistor, and
• wherein a part of the first low-resistive region extending from a source/drain region of the first thin-film transistor is a bottom-gate electrode of the second thin-film transistor opposed to the channel region of the second thin-film transistor.