ETCHING DEVICE

1 . An etching device configured to etch a semiconductor wafer by photoelectrochemical etching, the etching device comprising:

a reservoir storing an etchant;

a support member configured to support the semiconductor wafer in a state where a first surface of the semiconductor wafer is immersed in the etchant;

a light source configured to irradiate the first surface of the semiconductor wafer supported by the support member with light emitted from the light source;

an electrode disposed in the reservoir; and

a power source configured to apply a current between the electrode and the semiconductor wafer supported by the support member, the current changing between a first current value and a second current value larger than the first current value.

2 . The etching device of claim 1 , wherein

the current changes periodically between the first current value and the second current value.

3 . The etching device of claim 2 , wherein

the current is a pulse current.

4 . The etching device of claim 2 , wherein

the first current value is larger than zero.

5 . The etching device of claim 2 , wherein

the second current value is larger than zero and the first current value is smaller than zero.

6 . The etching device of claim 1 , wherein

the semiconductor wafer is constituted of silicon carbide.

7 . The etching device of claim 6 , wherein

the first surface of the semiconductor wafer is a C-plane.