METHOD FOR POROSIFYING (Al,In,Ga)N/(Al,In,Ga)N MESAS

A method for porosifying (Al,In,Ga)N/(Al,In,Ga)N mesas comprising the following steps:

• a) providing a structure comprising a base substrate covered with (Al,In,Ga)N/(Al,In,Ga)N mesas,
• the base substrate comprising:
• a support layer,
• a first layer of non-doped GaN, disposed on the support layer,
• an additional layer of heavily doped GaN, disposed on the first layer of non-doped GaN,
• a second layer of doped GaN, disposed on the additional layer of heavily doped GaN,
• the (Al,In,Ga)N/(Al,In,Ga)N mesas comprising:
• a third layer of heavily doped (Al,In,Ga)N, and
• a fourth layer of non-doped or lightly doped (Al,In,Ga)N,
• a part of the second layer of doped GaN being extended in the mesas or a part of the third layer of heavily doped (Al,In,Ga)N being extended in the base substrate,
• b) electrically connecting the structure and a counter-electrode to a voltage or current generator,
• c) immersing the structure and the counter-electrode in an electrolytic solution,
• d) applying a voltage or a current between the structure and the counter-electrode so as to porosify the third layer of heavily doped (Al,In,Ga)N of the mesas.