Electrical measurements in GaN: Point defects and dislocations

Citation
Dc. Look et al., Electrical measurements in GaN: Point defects and dislocations, MRS I J N S, 5, 2000, pp. NIL_454-NIL_464
Citations number
23
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
MRS INTERNET JOURNAL OF NITRIDE SEMICONDUCTOR RESEARCH
ISSN journal
10925783 → ACNP
Volume
5
Year of publication
2000
Supplement
1
Pages
NIL_454 - NIL_464
Database
ISI
SICI code
1092-5783(2000)5:<NIL_454:EMIGPD>2.0.ZU;2-K
Abstract
Defects can be conveniently categorized into three types: point, Line, and areal. In GaN, the important point defects are vacancies and interstitials; the line defects are threading dislocations; and the areal defects are sta cking faults. We have used electron irradiation to produce point defects, a nd temperature-dependent Hall-effect (TDH) and deep level transient spectro scopy (DLTS) measurements to study them The TDH investigation has identifie d two paint defects, an 0.06-eV donor and a deep acceptor, thought to be th e N vacancy and interstitial, respectively. The DLTS study has found two po int-defect electron traps, at 0.06 eV and 0.9 eV, respectively; the 0.06-eV trap actually has two components, with different capture kinetics. With re spect to line defects, the DLTS spectrum in as-grown GaN includes an 0.45-e V electron trap, which has the characteristics of a dislocation and the TDH measurements show that threading-edge dislocations are acceptor-like in n- type GaN. Finally, in samples grown by the hydride vapor phase technique, T DH measurements indicate a strongly n-type region at the GaN/Al2O3 interfac e, which may be associated with stacking faults. All of the defects discuss ed above can have an influence on the de and/or ac conductivity of GaN.