Thermal and chemical stabilities of In- and N-polar InN surfaces

• Published in: Physica Status Solidi (b) 2007-06, Vol.244 (6), p.1834-1838
• Main Authors: Naoi, H., Muto, D., Hioka, T., Hayakawa, Y., Suzuki, A., Araki, T., Nanishi, Y.
• Format: Article
• Language: English
• Subjects: 61.80.Lj; 68.55.Jk; 68.60.Dv; 81.15.Hi; 81.40.Ef; 81.65.Cf; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0370-1972; 1521-3951
• DOI: 10.1002/pssb.200674923

We have investigated the thermal and the chemical stabilities of In‐ and N‐polar InN surfaces by treating InN films in several environments: annealing in vacuum, etching in KOH solution, and irradiating with atomic hydrogen (H*). For the annealing case, In‐polar films mostly disappeared after 5 min at 550 °C and In‐droplets of various sizes were left on the surface of the samples, whereas N‐polar films showed no noticeable change in thickness and only tiny In‐droplets were formed on the surface. For the KOH case, N‐polar films developed rough surface morphologies by the emergence of hexagonal pyramids, whereas In‐polar films were not etched noticeably. In‐polar films also exhibited a much lower reactivity to H* than that of N‐polar films. As a result, the N‐polar surface was thermally more stable than the In‐polar surface, whereas the In‐polar surface appeared to be chemically more stable than the N‐polar surface. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)