Effects of Mg doping on wet etching of N-polar GaN are illustrated and analysed.

Etching process model of Mg-doped N-polar GaN in KOH solution is purposed.

It is found that Mg doping can induce tensile strain in N-polar GaN film.

N-polar p-GaN film with a hole concentration of 2.4 × 10¹⁷ cm⁻³ is obtained.