1. Infrared reflectance of GaN films grown on Si(001) substrates.
- Author
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Zhang, Xiong, Hou, Yong-Tian, Feng, Zhe-Chuan, and Chen, Jin-Li
- Subjects
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THIN films , *OPTICAL properties , *INFRARED spectroscopy - Abstract
GaN thin films on Si(001) substrates are studied by infrared reflectance (IRR) spectroscopy at room temperature (RT). Variations in the IRR spectral line shape with the microstructure of GaN/Si(011) film are quantitatively explained in terms of a three-component effective medium model. In this model, the nominally undoped GaN film is considered to consist of three elementary components, i.e., single crystalline GaN grains, pores (voids), and inter-granulated materials (amorphous GaN clusters). Such a polycrystalline nature of the GaN/Si(001) films was confirmed by scanning electron microscopy measurements. It was demonstrated that based on the proposed three-component effective medium model, excellent overall simulation of the RT-IRR spectra can be achieved, and the fine structures of the GaN reststrahlen band in the measured RT-IRR spectra can also be interpreted very well. Furthermore, the volume fraction for each component in the GaN/Si(001) film was accurately deter! mined by fitting the experimental RT-IRR spectra with the theoretical simulation. These results indicate that IRR spectroscopy can offer a sensitive and convenient tool to probe the microstructure of GaN films grown on silicon. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2001
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