Analysis of doping concentration and composition in wide bandgap AlGaN:Si by wavelength dispersive x-ray spectroscopy. (13th February 2017)

• Record Type: Journal Article
• Authors: Kusch, Gunnar; Mehnke, Frank; Enslin, Johannes; Edwards, Paul R; Wernicke, Tim; Kneissl, Michael; Martin, Robert W
• Is Part Of: Semiconductor science and technology. Volume 32:Number 3(2017:Mar.)
• Publication Date: 2017-02-13
• Subjects: nitrides -- Si doping -- WDX -- AlGaN -- SEM analysis; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1361-6641/aa58cf
• Languages: English
• ISSNs: 0268-1242

Abstract

Abstract: Detailed knowledge of the dopant concentration and composition of wide band gap Al x Ga 1 − x N layers is of crucial importance for the fabrication of ultra violet light emitting diodes. This paper demonstrates the capabilities of wavelength dispersive x-ray (WDX) spectroscopy in accurately determining these parameters and compares the results with those from high resolution x-ray diffraction (HR-XRD) and secondary ion mass spectrometry (SIMS). WDX spectroscopy has been carried out on different silicon-doped wide bandgap Al x Ga 1 − x N samples ( x between 0.80 and 1). This study found a linear increase in the Si concentration with the SiH4 /group-III ratio, measuring Si concentrations between 3 × 10 18 cm −3 and 2.8 × 10 19 cm −3, while no direct correlation between the AlN composition and the Si incorporation ratio was found. Comparison between the composition obtained by WDX and by HR-XRD showed very good agreement in the range investigated, while comparison of the donor concentration between WDX and SIMS found only partial agreement, which we attribute to a number of effects.