Effect of Introducing β-FeSi2 Template Layers on Defect Density and Minority Carrier Diffusion Length in Si Region near p-β-FeSi2/n-Si Heterointerface

Abstract

The electrical properties of defects in a p-β-FeSi2/n-Si heterostructures were investigated by deep level transient spectroscopy (DLTS) and the electron-beam-induced current (EBIC) technique. DLTS revealed the presence of trap levels for holes, caused by defects in the n-Si layer near the interface during the β-FeSi2 film fabrication. The defect density became small when a 20-nm-thick β-FeSi2 template layer was grown on the n-Si prior to molecular beam epitaxy (MBE) of a 700-nm-thick β-FeSi2 layer. The diffusion length of minority carriers in the n-Si was found to be approximately 15 µm by EBIC. This is much larger than the value of approximately 3 µm for the n-Si obtained when the template layer was not inserted.