|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)
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
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  Al_xIn_<1-x>N/  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