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Glide of threading dislocations in (In)AlGaAs on Si induced by carrier recombination: Characteristics, mitigation, and filtering

Authors :
Rushabh D. Shah
Eamonn T. Hughes
Kunal Mukherjee
Source :
Hughes, Eamonn T; Shah, Rushabh D; & Mukherjee, Kunal. (2019). Glide of threading dislocations in (In)AlGaAs on Si induced by carrier recombination: Characteristics, mitigation, and filtering. Journal of Applied Physics. UC Santa Barbara: Retrieved from: http://www.escholarship.org/uc/item/1d28b1jf, Journal of Applied Physics, vol 125, iss 16, JOURNAL OF APPLIED PHYSICS, vol 125, iss 16
Publication Year :
2019
Publisher :
AIP Publishing, 2019.

Abstract

III-V optoelectronics grown epitaxially on Si substrates have large networks of dislocations due to a lattice constant mismatch between the device layers and the substrate. Recombination-enhanced dislocation glide (REDG) allows these dislocations to move and increase in length during device operation, which degrades performance. In this paper, we study REDG dynamics of threading dislocations in situ in (In)AlGaAs double heterostructures grown on Si substrates using scanning electron microscopy cathodoluminescence. The driving force for REDG arises due to the coefficient of thermal expansion differences between Si and the III-V layers leading to large residual strains in the films. Tracking of threading dislocations as moving dark spot defects reveals glide characteristics that vary based on the nature of the dislocation. Remarkably, the alloying of a few atom percent of indium using metamorphic structures arrests threading dislocation glide by more than two orders of magnitude. Finally, we present REDG-based filtering as a pathway to reducing the threading dislocation density in select areas, removing a large fraction of the mobile dislocations. Together, these techniques will enable the understanding of dislocation–dislocation and carrier–dislocation interactions that have so far remained elusive during device operation, leading to reliable III-V integrated optoelectronics on silicon.III-V optoelectronics grown epitaxially on Si substrates have large networks of dislocations due to a lattice constant mismatch between the device layers and the substrate. Recombination-enhanced dislocation glide (REDG) allows these dislocations to move and increase in length during device operation, which degrades performance. In this paper, we study REDG dynamics of threading dislocations in situ in (In)AlGaAs double heterostructures grown on Si substrates using scanning electron microscopy cathodoluminescence. The driving force for REDG arises due to the coefficient of thermal expansion differences between Si and the III-V layers leading to large residual strains in the films. Tracking of threading dislocations as moving dark spot defects reveals glide characteristics that vary based on the nature of the dislocation. Remarkably, the alloying of a few atom percent of indium using metamorphic structures arrests threading dislocation glide by more than two orders of magnitude. Finally, we present REDG-ba...

Details

ISSN :
10897550 and 00218979
Volume :
125
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi.dedup.....1b0ed2c4d939bb48c782d4d1bb1b7ce2