High ε gate dielectrics Gd2O3 and Y2O3 for silicon

We report on growth and characterization of both epitaxial and amorphous films Gd2O3 of (epsilon=14) and Y2O3 (epsilon=18) as the gate dielectrics for Si prepared by ultrahigh vacuum vapor deposition. The use of vicinal Si (100) substrates is key to the growth of (110) oriented, single-domain films in the Mn2O3 structure. Typical electrical leakage results are 10(-3) A/cm(2) at 1 V for single domain epitaxial Gd2O3 and Y2O3 films with an equivalent SiO2 thickness, t(eq) of 15 Angstrom, and 10(-6) A/cm(2) at 1 V for smooth amorphous Y2O3 films (epsilon=18) with a t(eq) of only 10 Angstrom. For all the Gd2O3 films, the absence of SiO2 segregation at the interface is established from infrared absorption measurements. (C) 2000 American Institute of Physics. [S0003-6951(00)04127-9].