A study of the point defects in various wafers using positron annihilation

The microdefect in Si often effects on gettering of metal impurities, so it is becoming important to elucidate the behavior of this defect and to control that. At present, this microdefect is detected by using transmission electron microscope (TEM) or infrared laser scattering tomography however, it is difficult to detect the microdefect of several nanometer or less. On the other hand, the positron annihilation method has been studied for an ion implantation defect and has detected the microdefects. It has also been used as an effective means about the behavior of the defect under crystal pulling. This paper proposes the distribution of point defective concentration within a field and the generation of secondary defect after heat treatment by using the positron annihilation method.