OPTICAL-PROPERTIES OF ION-IMPLANTED SI LAYERS STUDIED BY SPECTROSCOPIC ELLIPSOMETRY

The damage produced in crystalline Si by As+ ion implantation at 80 keV has been studied using spectroscopic ellipsometry (SE). A linear regression analysis (LRA) and a Bruggeman effective-medium approximation (EMA) require a multilayer-structure (four-phase) model: ambient (air), first and second damaged Si layers and Si substrate. Each damaged layer consists of volume fractions of crystalline and amorphous Si and voids. The LRA-EMA analysis suggests that the buried fully amorphized layer with a partially amorphized overlayer begins to form around approximately 9 X 10(14) cm-2 dose. Results on the isothermal annealing have also been presented. SE has been proven to be an easy, fast and nondestructive technique which can be used to assess important ion-implantation parameters.