Nanometer-scale cathodoluminescence analysis of GaAs and its application to the assessment of laser diode

✍ Scribed by Hosokawa, Teppei ;Fujimura, Shinya ;Yabuuchi, Yasufumi ;Tsukamoto, Yoshiaki ;Porporati, Alessandro Alan ;Zhu, Wenliang ;Pezzotti, Giuseppe

• Book ID: 105365991
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 811 KB
• Volume: 208
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/pssa.201000358

✦ Synopsis

Abstract

We studied steep gradients of both chemical composition and residual stress in a Si‐doped GaAs blocking layer of a laser diode by means of spectrally and spatially resolved cathodoluminescence (CL) spectroscopy. Using a low‐energy electron beam as an excitation source for the CL emission, a spatial resolution in the sub‐micron scale could be achieved. The knowledge of local doping concentration, local stress state, and their distribution on the nanometer scale is crucial in diode design since lasing characteristics and near‐field width. Emphasis was placed in making quantitative the CL spectroscopic assessments in GaAs by means of a set of preliminary calibrations, regarding both probe size and material composition. These procedures enabled extracting from the CL spectra and quantitatively mapping values of both carrier concentration and residual stress in the diode device. The visualization of those parameters into highly spatially resolved maps (i.e., recorded with nanometer‐scale resolution) required the implementation of a spectroscopic algorithm that was purposely built up in this study and preliminarily validated according to the shown sets of calibration procedures.