Nanoscale Materials Characterization of Degradation in VCSELs

David T. Mathes, Robert Hull, Kent Choquette, Kent Geib, Andy Allerman, Jim Guenter, Bobby Hawkins, Bobby Hawthorne

Research output: Contribution to journalConference articlepeer-review


Significant advancements have been made in the characterization and understanding of the degradation behavior of the III-V semiconductor materials employed in Vertical Cavity Surface Emitting Laser (VCSEL) diodes. Briefly, for the first time a technique has been developed whereby it is possible to view the entire active region of a solid state laser in a Transmission Electron Microscope (TEM) using a novel Focussed Ion Beam (FIB) prepared plan-view sample geometry. This technique, in conjunction with TEM cross-section imaging has enabled a three-dimensional characterization of several of the degradation mechanisms that lead to laser failure. It is found that there may occur an initial drop in laser power output due to the development of cracks in the upper mirror layers. In later stages of degradation, dislocations are punched out at stress-concentrating sites (e.g. oxide aperture tips) and these dislocations can then extend over the active region in a manner consistent with recombination enhanced dislocation motion. Alternatively, complex three-dimensional dislocation arrays which exhibited dendritic-like growth and which cover the entire active region can nucleate on a single defect.

Original languageEnglish (US)
Pages (from-to)67-82
Number of pages16
JournalProceedings of SPIE - The International Society for Optical Engineering
StatePublished - 2003
EventVertical-Cavity Surface-Emitting Lasers VII - San Jose, CA, United States
Duration: Jan 29 2003Jan 30 2003


  • Failure analysis
  • III-V material degradation
  • Nanoscale characterization
  • Vertical Cavity Surface Emitting Lasers

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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