MULTI-STEP CRYSTALLIZATION OF SILICON EPILAYERS UNDER Ar ATMOSPHERE

摘要

The paper presents the results of the investigation on the liquid phase epitaxy growth of silicon thin films carried out in one-step and two-step modes. The new approach to the process of LPE growth has been applied, based on the fact that the saturation and growth occur in the separate steps under Ar atmosphere, i.e. the sample substrate is introduced into the tube after the saturation step and cooling the apparatus to the room temperature. The results show that ELO layers of the maximum value of the aspect ratio were obtained in case of the application of 0.5 ℃/min cooling rate and supercooling equal △T = 60 ℃ in two-step mode of growth. The defect density of the ELO layers determined by Secco etching was smaller approximately by the factor of 100 than the defect density of the Si substrates used, reaching 4.110~3 cm~(-2). The comparison of the results of growth performed in one-step and two-step modes has also been done. It shows that the ELO layers grown in the result of the two-step experiments are characterized by almost twice as high values of the aspect ratio as the layers obtained in the case of the one-step mode of growth on the Si substrates with masks revealing parallel silicon open windows.