Active matrix substrate and method for manufacturing same

An active matrix substrate having a display region including a plurality of pixel areas and a non-display region arranged around the display region, the active matrix substrate comprising:

• a substrate;
• and
• a plurality of oxide semiconductor TFTs supported on the substrate and provided in the display region or the non-display region, each of the plurality of oxide semiconductor TFTs includes an oxide semiconductor layer and a gate electrode arranged on a part of the oxide semiconductor layer with a gate insulating layer interposed between the oxide semiconductor layer and the gate electrode, wherein
• the oxide semiconductor layer has a first region covered with the gate electrode with the gate insulating layer interposed between the oxide semiconductor layer and the gate electrode,
• a first TFT and a second TFT are included in the plurality of oxide semiconductor TFTs,
• in the first TFT, in at least a part of the first region of the oxide semiconductor layer, a layered structure including a high mobility oxide semiconductor film having a relatively high mobility and a low mobility oxide semiconductor film arranged on the high motility oxide semiconductor film and having, a relatively lower mobility than the high mobility oxide semiconductor film is provided,
• in the second TFT, in the first region of the oxide semiconductor layer, throughout, of the high mobility oxide semiconductor film and the low mobility oxide semiconductor film, one oxide semiconductor film is provided an another oxide semiconductor film is not provided,
• each of the plurality of oxide semiconductor TFTs further includes a source electrode and a gain electrode,
• the oxide semiconductor layer of each of the plurality of oxide semiconductor TFTs has a first contact region and a second contact region located on both sides of the first region, the first contact region is electrically connected to the source electrode, and the second contact region is electrically connected to the drain electrode,
• at least one electrode of the source electrode and the drain electrode of the second TFT is arranged on the substrate side of the oxide semiconductor layer of the second TFT with a lower insulating layer interposed between the at least one electrode and the oxide semiconductor layer,
• in the first region of the second TFT, the low mobility oxide semiconductor film is provided and the high mobility oxide semiconductor film is not provided, and
• in at least one of the first contact region and the second contact region in the second TFT, a layered structure including the low mobility oxide semiconductor film and a connection layer made of the high mobility oxide semiconductor film is provided, and the connection layer is electrically connected to the at least one electrode in an opening in the lower insulating layer.

An active matrix substrate having a display region including a plurality of pixel areas and a non-display region arranged around the display region, the active matrix substrate comprising:

• a substrate;
• and
• a plurality of oxide semiconductor TFTs supported on the substrate and provided in the display region or the non-display region, each of the plurality of oxide semiconductor TFTs includes an oxide semiconductor layer and a gate electrode arranged on a part of the oxide semiconductor layer with a gate insulating layer interposed between the oxide semiconductor layer and the gate electrode, wherein
• the oxide semiconductor layer has a first region covered with the gate electrode with the gate insulating layer interposed between the oxide semiconductor layer and the gate electrode,
• a first TFT and a second TFT are included in the plurality of oxide semiconductor TFTs,
• in the first TFT, in at least a part of the first region of the oxide semiconductor layer, a layered structure including a high mobility oxide semiconductor film having a relatively high mobility and a low mobility oxide semiconductor film arranged on the high mobility oxide semiconductor film end having a relatively lower mobility than the high mobility oxide semiconductor film is provided,
• in the second TFT, in the first region of the oxide semiconductor layer, throughout, of the high mobility oxide semiconductor film and the low mobility oxide semiconductor film, one oxide semiconductor film is provided and another oxide semiconductor film is not provided,
• each of the plurality of oxide semiconductor TFTs further includes a source electrode and a drain electrode,
• the oxide semiconductor layer of each of the plurality of oxide semiconductor TFTs has a first contact region and a second contact region located on both sides of the first region, the first contact region is electrically connected to the source electrode, and the second contact region is electric connected to the drain electrode,
• a third TFT is further included in the plurality of oxide semiconductor TFTs,
• in the first TFT, in each of the first region, the first contact region, and the second contact region, the layered structure is provided, and
• in the third TFT, in the at least a part of the first region, the layered structure is provided, but in each of the first contact region and the second contact region, the low mobility oxide semiconductor film is provided and the high mobility oxide semiconductor film is not provided.