Semiconductor device and method for manufacturing the same

1 . A method for manufacturing a semiconductor device comprising:

a photoelectrochemical etching step comprising:

immersing a substrate having a GaN surface in a catalyst metal solution containing potassium hydroxide and a plating catalyst metal salt while the GaN surface is irradiated with ultraviolet light such that Ga from the GaN surface dissolves in the catalyst metal solution and creates electrons and the plating catalyst metal of the plating catalyst metal salt is deposited on the GaN surface using the electrons; and

an electroless plating step comprising:

forming a metal film on the GaN surface having the plating catalyst metal deposited thereon by immersing the substrate in an electroless plating solution.

2 . The method for manufacturing a semiconductor according to claim 1 , wherein the ultraviolet light has a wavelength of 365 nm or less.

3 . The method for manufacturing a semiconductor according to claim 1 , wherein an ion concentration of a catalyst metal in the catalyst metal solution is from 0.1 mmol/L to 2.0 mmol/L.

4 . The method for manufacturing a semiconductor according to claim 1 , wherein temperature of the catalyst metal solution is from 10° C. to 50° C.

5 . The method for manufacturing a semiconductor according to claim 1 , wherein time of treatment with the catalyst metal solution is from 1 minute to 5 minutes.

6 . The method for manufacturing a semiconductor according to claim 1 , wherein a treatment with the catalyst metal solution is carried out dividedly into multiple times with water washing step in-between.

7 . The method for manufacturing a semiconductor according to claim 1 , wherein temperature of the electroless plating solution is 70° C. to 90° C.