Thin film transistor, method of manufacturing thin film transistor, display unit, and electronic device

1. A thin film transistor comprising:

a gate electrode;

a pair of source/drain electrodes;

a first oxide semiconductor layer provided between the gate electrode, and the pair of source/drain electrodes, and forming a channel; and

a second oxide semiconductor layer on a side of the first oxide semiconductor layer and in a region facing a separation groove between the pair of source/drain electrodes, the second oxide semiconductor layer having a polarity different from that of the first oxide semiconductor layer.

2. The thin film transistor according to claim 1 , wherein the polarity of the first oxide semiconductor layer is an n-type, and the polarity of the second oxide semiconductor is a p-type.

3. The thin film transistor according to claim 1 , comprising: the gate electrode; the first oxide semiconductor layer; the second oxide semiconductor layer; and the pair of source/drain electrodes in this order on a substrate.

4. The thin film transistor according to claim 1 , wherein

a metal layer is provided continuously with the second oxide semiconductor layer in an in-plane direction between the second oxide semiconductor layer and the pair of source/drain electrodes, and

the second oxide semiconductor layer is made of a metal oxide constituting the metal layer.

5. The thin film transistor according to claim 1 , further comprising a protective film on the second oxide semiconductor layer, wherein

the pair of source/drain electrodes are provided from above the first oxide semiconductor layer to the protective film.

6. The thin film transistor according to claim 1 , wherein the second oxide semiconductor layer in the region facing the separation groove is buried in a part on the pair of source/drain electrodes side of the first oxide semiconductor layer.