Selective area growth of a- and c-plane GaN nanocolumns by molecular beam epitaxy using colloidal nanolithography

Selective area growth of a-plane GaN nanocolumns by molecular beam epitaxy was performed for the first time on a-plane GaN templates. Ti masks with 150 nm diameter nanoholes were fabricated by colloidal lithography, an easy, fast and cheap process capable to handle large areas. Even though colloidal lithography does not provide a perfect geometrical arrangement like e-beam lithography, it produces a very homogeneous mask in terms of nanohole diameter and density, and is used here for the first time for the selective area growth of GaN. Selective area growth of a-plane GaN nanocolumns is compared, in terms of anisotropic lateral and vertical growth rates, with GaN nanocolumns grown selectively on the c-plane.

► We achieve selective area growth of c-plane and a-plane GaN nanocolumns by PAMBE. ► This is the first time a-plane GaN is selectively grown by MBE. ► Selective area growth is performed using masks fabricated by colloidal lithography. ► Under the same growth conditions, we compare the growth rates and morphology of a-plane GaN and c-plane GaN.