1995 Fiscal Year Final Research Report Summary
CHARACTERIZATION OF CRYSTAL SURFACE LAYERS AND THIN EPITAXIAL FILMS BY X-RAY DIFFRACTION
| Project/Area Number |
06650026
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
Applied materials science/Crystal engineering
|
|---|
| Research Institution | OSAKA PREFECTURE UNIVERSITY |
|---|
Principal Investigator |
ITOH Noboru OSAKA PREFECTURE UNIVERSITY,COLLEGE OF ENGINEERING,LECTURER, 工学部, 講師 (80081305)
|
|---|
| Project Period (FY) |
1994 – 1995
|
| Keywords | X-ray diffraction / Double-crystal method / Crystallographic characterization / Crystal surface layr / Heteroepitaxial film / Al_xIn_<1-x>N / Epitaxial relationships / Total reflection |
|---|
| 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
… More
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
|
