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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Characterization of AlxGa1-xN/GaN grown on GaN-template by plasma-assisted MBE

Chen, Yu-chih 01 July 2009 (has links)
In order to develop high speed photo-electronic device, first, we grew one layer of GaN by MOPVE to decline lattice mismatch. Then we used PA-MBE to grow AlxGa1-xN/GaN heterostructure III-V semiconductor. Via changing the content of aluminum, we can confer the characteristic of these samples. In these samples, we controlled the content of aluminum by changing the vapor of aluminum. And then we used X-ray diffraction, SEM, AFM, low temperature Hall measurement and SdH to study the characteristic of these samples. Throughout X-ray diffraction, the aluminum content x are 1.76%, 2.3%, 14.33%, 22.03% and 37.26%. Due to (004) AlGaN Rocking Curve F.W.H.M. are only 300 arcsec, the quality of the five samples are extraordinary. In addition, SEM and AFM measurement indicate that this series samples¡¦ interface are very smooth, and the roughest sample is only 2nm. It can make sure that samples were grown in mode of two-dimensional (2D). With low temperature Hall measurement, we can find out the Coulomb scattering which is from the defect are very small in the sample A, B, C, D. And the mobility of this series samples are very high, the highest mobility is sample A at 8K which is 19593 cm2/Vs. We can observe the oscillation of the sample C, D obviously in SdH measurement indicate that the 2DEG is confined in the potential well.

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