[en] Ion implantation when used as a doping technique introduces damage to the surface of a silicon wafer. This damage in turn may result in formation of dislocation loops or stacking faults, depending upon the subsequent heat treatment. These defects in turn may degrade electrical properties in a P-N junction. The importance of the location of defects on the P-N junction performance has not been studied in detail. In this work, P-N junctions were fabricated, tested electrically, and analyzed with transmission electron microscopy (TEM). Two types of defects, dislocation loops and stacking faults, were introduced into P-N junction. Sometimes dog-bone shape stacking faults were produced. TEM analysis revealed that the dog-bone fault is a stacking fault decorated by precipitates. High magnification (200K) revealed two kinds of precipitates, individual plates and colony clusters. Colonies exhibited Moire fringes that were used to characterize their crystallographic structures. X-ray Energy Dispersive Spectroscopic data from these two precipitates showed that colonies consisted of Ni, Cu and Si, while the plate contained Ni and Si only. It was concluded that the plate type is pure NiSi₂ and that the colonies are metastable (Ni/sub x/, Cu/sub 1-x/)Si₂ due to Cu alloying

[en] The experimental study of determining defect size by ultrasonic testing with artificial reference block and maximum echo is described in this report. The design and fabrication of various necessary calibration blocks being used artificial block were carried out according to exciting ASME code and standard. A container for Co 60, 10 Ci was designed to apply radioisotope for radiographic testing. Neutron radiographic testing using thermal neutron flux (1.7 x 10^6-7 N/cm²-sec) produced from the reactor (250 KW) was attempted and compared with X-ray radiographic testing. The study of thickness measurement of boiler tubes for paper mill was successfully carried out

[en] 1. Fatigue Crack Sizing by Neutron, X-ray and Ultrasonics. For the purpose of sizing fatigue cracks, fatigue crack were measured by X-ray, ultrasonics and neutron beam. After fatigue cracks were formed in aluminum specimen, cracks measured by scale were 14.0 and 23.5mm and those by neutron radiography which was the closest values to those measured by scale, were 12.5 and 23.5mm. These results by neutron radiography were obtained by penetrating Cd(NO₃)₂-4H₂O as neutron absorbent. Therefore if proper penetrant is selected per specimen, neutron radiography is the most effective method to get good results of all nondestructive testing methods. 2. Discussion of Mechanized Ultrasonic Examination for RPV Outlet Nozzle-to-Shell Weld. Mechanized ultrasonic examination methods for the Kori unit 1 RPV outlet nozzle-to-shell weld were reviewed. The result from the preservice inspection and the second inservice inspection were compared with respect to the ultrasonic methods, calibration blocks, calibration methods and applied ASME codes. Ultrasonic attenuotion measurement was performed and calibration methods were simulated by using two calibration blocks. (Author)