Leakage Current Mechanisms in Epitaxial Gd[sub 2]O[sub 3] High-k Gate Dielectrics

Abstract

We report on leakage current mechanisms in epitaxial gadolinium oxide (Gd(2)O(3)) high-k gate dielectrics suitable for low standby power logic applications. The investigated p-type metal-oxide-semi con doctor capacitors are gated with complementary-metal-oxide-semiconductor-compatible fully silicided nickel silicide electrodes. The Gd(2)O(3) thickness is 5.9 nm corresponding to a capacitance equivalent oxide thickness of 1.8 nm. Poole-Frenkel conduction is identified as the main leakage mechanism with the high-frequency permittivity describing the dielectric response on the carriers. A trap level of Phi(T) = 1.2 eV is extracted. The resulting band diagram strongly suggests hole conduction to be dominant over electron conduction.