High-quality aluminum oxide gate dielectrics by ultra-high-vacuum reactive atomic-beam deposition

We demonstrate the potential for ultrathin aluminum-oxide films as alternate gate dielectrics for Si complementary metal-oxide-semiconductor technology. Films are deposited in ultrahigh vacuum utilizing atomic beams of aluminum and oxygen on Si(100) surfaces. We show device-quality Si(100)/Al2O3 interfaces with interfacial trap densities in the 10(10) cm(-2) eV(-1) range, and with leakage current densities five orders of magnitude lower than what is observed in SiO2 insulators at the same equivalent electrical thickness. As-grown films possess an amorphous-to-microcrystalline structure, depending upon the deposition temperature, and any interfacial layers between the Si(100) and Al2O3 layer are < similar to0.5 nm. (C) 2001 American Institute of Physics.