| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥1,800,000 (Direct Cost: ¥1,800,000)
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| Research Abstract |
For detailed crystallographic characterization of crystal surface layrs, we constructed a measurement system with a high accuracy for the X-ray double-crystal method. We designed the hardware for an angular motion control system and an X-ray detecting system (pulse height analyzer (PHA) and pulse counter), and the software for operation, with our originality. The function of this system includes measurement of rocking curves (omega-mode) and 2rheta-mode. The angular accuracy is within 0.02 arcsec for omega-mode and 0.5 arcsec for 2rheta-mode, which have been improved than in last year. For easy and accurate setting of the sample, some unique functions were added : (I) the hand operation as well as automatic operation are feasible, (2) detecting count numbers are displayd on CRT,and (3) the operator can listen to sound output for detection of X-rays. The details of the hardware and software in this system have been presented in "OYOBUTURI", 65,732 (l996) and "The report of rescarch achi
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evementst".
Crystallographic characterization of some heteroepitaxial films has been made using this equipment and the following knowledge was obtained.
(I) The structure and the in-plane epitaxial relationship of Al_xIn_<1-X>N epitaxial layrs grown onto (0001) alpha-Al_2O_3 substrates-by microwave-excited MOVPE were investigated. The results show that the crystal structure of the epitaxial layr is wurzite structure with a-axis lattice constant and c/a ratio decreasing with increasing of chemical composition X,and the epitaxial relationship is [1010] Al_xIn_<1-x>N/ [1010] alpha-Al_2O_3 as well as (0001) Al_xIn_<1-x>N/ (0001) alpha-Al_2O_3.
(2) As a result of investigating ZnSe/GaAs (100), InGaP/GaAs (100), cap-GaAs/InGaP/GaAs (100), and cap-GaAs/AlGaAs/GaAs (100) heterostructure, intensity oscillation in rocking curves is observed only for the epitaxial films with high crystalline quality. This oscillation is attributed to some dynamical diffraction effect of X-rays.
(3) Since the constructed equipment enables us to measure total reflection of X-rays, we wish to apply this ability to characterization of crystal surface, for the future. Less
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