An Experimental Study of Dislocation Dynamics in GaN

Autor: Eugene B. Yakimov, Yury O. Kulanchikov, Pavel S. Vergeles
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Micromachines, Vol 14, Iss 6, p 1190 (2023)
Druh dokumentu: article
ISSN: 2072-666X
DOI: 10.3390/mi14061190
Popis: The dynamics of dislocations introduced through indentation or scratching at room temperature into a few GaN layers that were grown using the HVPE, MOCVD and ELOG methods and had different dislocation densities were studied via the electron-beam-induced current and cathodoluminescence methods. The effects of thermal annealing and electron beam irradiation on dislocation generation and multiplication were investigated. It is shown that the Peierls barrier for dislocation glide in GaN is essentially lower than 1 eV; thus, it is mobile even at room temperature. It is shown that the mobility of a dislocation in the state-of-the-art GaN is not entirely determined by its intrinsic properties. Rather, two mechanisms may work simultaneously: overcoming the Peierls barrier and overcoming localized obstacles. The role of threading dislocations as effective obstacles for basal plane dislocation glide is demonstrated. It is shown that under low-energy electron beam irradiation, the activation energy for the dislocation glide decreases to a few tens of meV. Therefore, under e-beam irradiation, the dislocation movement is mainly controlled by overcoming localized obstacles.
Databáze: Directory of Open Access Journals