Cathodoluminescence imaging for the determination of dislocation density in differently doped HVPE GaN

• Published in: Journal of crystal growth 2012-02, Vol.340 (1), p.78-82
• Main Authors: Meissner, E., Schweigard, S., Friedrich, J., Paskova, T., Udwary, K., Leibiger, G., Habel, F.
• Format: Article
• Language: English
• Subjects: A1. Defects; B1. Nitrides; B2. Semiconductor III–V Materials; Cathodoluminescence; Counting; Crystal defects; Dislocation density; Dopants; Gallium nitrides; Vapour
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2011.12.043

In this study we report the potential and limitations of the cathodoluminescence dark spot (DS) counting as a method for the determination of dislocation density and distribution in GaN, produced by the hydride vapour phase epitaxy (HVPE). Different GaN sample series (s.i. GaN:Fe and n-type GaN:Si) were used, in order to study the dependence of the results of the DS-counting on the dopant type and concentration. By the direct comparison of these results to classical defect selective etching, the DS-measurements were validated. It could be shown that each of the both methods have their particular restrictions, which must be considered in their application. ► Direct comparison of dark spot counting and defect selective etching for s.i. GaN. ► Evaluation of the potential and limitations for both of the methods for s.i. GaN. ► Study of dislocation density and relative error as a function of dopant content. ► Maximum dopant concentration for DS counting in s.i. GaN is 1×10 18/cm 3.