Title :
Ultrasonic influence on point defects in a dislocation free Si
Author :
Ostrovskii, Igor V. ; Olikh, O.J. ; Nadtochii, Andrei B.
Author_Institution :
Phys. Fac., Kiev Shevchenko Univ., Ukraine
Abstract :
Ultrasound (US) influence on dislocation free (DF) silicon is investigated. Ultrasonic waves attenuation (α), mobility of intentionally induced superficial dislocations, and minority carriers diffusion length (L) are measured from a dislocation free Cz-Si as a function of US amplitude. The general results consist of some changes in the properties under study that takes place in a threshold way. Under US deformation S>10-5 attenuation a becomes nonlinear, dislocation mobility and so microplasticity vary significantly, and L increases up to 2 times. US in DF Cz-Si can effectively interact with a system of point defects. The acoustostimulated changes in DF Cz-Si properties under study are connected to ultrasonically activated transformations in a system of crystal point defects and their complexes. We find there are two thresholds of US deformation: S1 ~10-6 and S2~10-5. Under deformation S<S1 the defect system rests unchanged, at S 1<S<S2 recombination properties and electrical activity of defects are modified, deformations S>S2 the process redistribution takes place
Keywords :
carrier lifetime; dislocation motion; elemental semiconductors; minority carriers; point defects; silicon; ultrasonic effects; Si; dislocation mobility; dislocation-free Czochalski silicon crystal; electrical activity; microplasticity; minority carrier diffusion length; point defect; recombination properties; ultrasonic deformation; ultrasonic wave attenuation; Attenuation measurement; Crystalline materials; Crystallization; Impurities; Lattices; Physics; Silicon; Ultrasonic imaging; Ultrasonic variables measurement; Vibrations;
Conference_Titel :
Ultrasonics Symposium, 2000 IEEE
Conference_Location :
San Juan
Print_ISBN :
0-7803-6365-5
DOI :
10.1109/ULTSYM.2000.922602
