Semiconductor wafer and electronic device

A semiconductor wafer comprising

• a wafer;
• a nitride crystal layer formed of one or more crystal layers of group III nitride;
• and
• a cap layer, wherein
• the wafer, the nitride crystal layer and the cap layer are positioned in an order of the wafer, the nitride crystal layer and the cap layer,
• a layer that is of the nitride crystal layer and that is in contact with the cap layer, and a layer near the layer function as active layers of a field-effect transistor, and
• the cap layer is a silicon nitride layer having crystallinity and has a thickness that is equal to or larger than a thickness in which a gate of the field-effect transistor is to be embedded.

An electronic device in which a semiconductor wafer is used, wherein

• the semiconductor wafer comprises a wafer;
• a nitride crystal layer formed of one or more crystal layers of group III nitride;
• and a cap layer, the wafer, the nitride crystal layer and the cap layer are positioned in an order of the wafer, the nitride crystal layer and the cap layer, and the cap layer is a silicon nitride layer having crystallinity and has a thickness of 5 nm or more,
• the electronic device has a gate structure of a field-effect transistor or a wiring structure that is connected to the nitride crystal layer, and
• a height of the gate structure or the wiring structure is smaller than a thickness of the cap layer.

An electronic device in which a semiconductor wafer is used, wherein

• the semiconductor wafer comprises a wafer;
• a nitride crystal layer formed of one or more crystal layers of group III nitride;
• and a cap layer, the wafer, the nitride crystal layer and the cap layer are positioned in an order of the wafer, the nitride crystal layer and the cap layer, a layer that is of the nitride crystal layer and that is in contact with the cap layer, and a layer near the layer function as active layers of a field-effect transistor, and the cap layer is a silicon nitride layer having crystallinity and has a thickness that is equal to or larger than a thickness in which a gate of the field-effect transistor is to be embedded,
• the electronic device comprises a gate structure of a field-effect transistor or a wiring structure that is connected to the nitride crystal layer, and
• a height of the gate structure or the wiring structure is smaller than a thickness of the cap layer.