Electrical properties of buried B/Si surface phases

Conductivity and Hall-effect measurements have been carried out at 24 K for a set of various layered structures with buried B/Si surface phases used as delta-doped layers. Evidence is found for hole mobility enhancement as a consequence of boron dopant ordering. The electrical measurements reveal a basic difference in room temperature adsorption for boron on Si(100) and Si(111) surfaces. The characterization of the samples containing buried B/Si(111) interfaces and extra-thin Ge layers suggests promise for improving the structure and electrical properties of the buried surface phases. The hole mobility in epi-Si/Ge/B/Si(111) structures is found to be about 2.5 times higher than in epi-Si/B/Si(111) samples.