Regensburg 2002 – wissenschaftliches Programm

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DS: Dünne Schichten

DS 27: Postersitzung

DS 27.13: Poster

Dienstag, 12. März 2002, 15:30–17:30, Poster Physik B

NEXAFS and Photoemission Investigation of Low-Energy Ion Beam Assisted Nitridation of III-V Semiconductor Surfaces — •J.-D. Hecht¹, F. Frost¹, S. Krasnikow², K.-H. Hallmeier², and T. Chassé¹ — ¹Institut für Oberflächenmodifizierung, Permoserstraße 15, 04318 Leipzig — ²Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig

The subject of this work is the investigation of surface nitridation using in situ X-ray absorption and core level photoemission measurements. GaAs, InAs, InP and InSb (100) surfaces were nitrided using low-energy N₂⁺ bombardment for different ion beam parameters and substrate temperatures. A detailed analysis of the N 1s core level peaks reveals the presence of nitrides and interstitial nitrogen. The evolution of the nitridation process was also studied in dependence on the ion dose. NEXAFS measurements in total electron yield mode were performed at the nitrogen K-edge in order to probe the chemical bonding of the implanted nitrogen species. A sharp and characteristic spectral feature at 401 eV is assigned to interstitial molecular nitrogen. Multiple scattering calculations of the NEXAFS using the FEFF-8 code support this assignment. Extended photoemission studies permit the proposal of a model that describes the surface nitridation.