title: Critical aspects of substrate nanopatterning for the ordered growth of GaN nanocolumns.
abstract: Precise and reproducible surface nanopatterning is the key for a successful ordered growth of GaN nanocolumns. In this work, we point out the main technological issues related to the patterning process, mainly surface roughness and cleaning, and mask adhesion to the substrate. We found that each of these factors, process-related, has a dramatic impact on the subsequent selective growth of the columns inside the patterned holes. We compare the performance of e-beam lithography, colloidal lithography, and focused ion beam in the fabrication of hole-patterned masks for ordered columnar growth. These results are applicable to the ordered growth of nanocolumns of different materials.
authors.affiliation: ISOM and Electrical Engineering Dept, (DIE), Escuela Técnica Superior de Ingenieros de Telecomunicaciónes (ETSIT), Universidad Politécnica de Madrid s/n, Madrid, 28040, Spain. fbarbagini@isom.upm.es.
authors.forename: Francesca
authors.initials: F
authors.lastname: Barbagini
authors.forename: Ana
authors.initials: A
authors.lastname: Bengoechea-Encabo
authors.forename: Steven
authors.initials: S
authors.lastname: Albert
authors.forename: Javier
authors.initials: J
authors.lastname: Martinez
authors.forename: Miguel Angel
authors.initials: MA
authors.lastname: Sanchez García
authors.forename: Achim
authors.initials: A
authors.lastname: Trampert
authors.forename: Enrique
authors.initials: E
authors.lastname: Calleja