Origin of n-type conductivity in nominally undoped InN

✍ Scribed by V. Cimalla; V. Lebedev; F. M. Morales; M. Niebelschütz; G. Ecke; R. Goldhahn; O. Ambacher

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 173 KB
• Volume: 37
• Category: Article
• ISSN: 0933-5137
• DOI: 10.1002/mawe.200600082

✦ Synopsis

The influence of different contributions to the high electron concentration in state-of-the-art InN layers grown by molecular-beam epitaxy is investigated. Surface accumulation has a crucial influence for thin InN layers < 300 nm and superimposes the background concentration. For air-exposed InN it can be assigned to a surface near doping by oxygen. For InN layers in the micron range the density of dislocations is the major doping mechanism. Finally, point defects like vacancies and impurities have minor influence on the carrier concentration and would dominate the free electron concentration only for InN > 10 lm.