EFFECT OF A SE MONOLAYER ON INTERFACE PROPERTIES BETWEEN AL_2O_3 AND N-TYPE SI(100)

摘要

An in-situ high-vacuum process has been developed for the preparation of ultrathin Al_2O_3 films on monolayer Se passivated Si(100) surface. The in-situ high-vacuum process prevents the Si surface from adsorbed moisture or native oxide, leading to an Al_2O_3/Si(100) interface without any low-k interfacial layer at 400°C. The Se monolayer terminates the dangling bonds on Si(100) before the formation of the high-k dielectric. The electrical properties of the Al203 film on Se passivated Si(100) are significantly improved in comparison to control samples without Se passivation. The interface trap density is about 5 times lower to 2x10~(11) eV~(-1) /cm~2. The C-V hysteresis is reduced to 80 mV from 160 mV. The leakage current for the same physical dielectric thickness is reduced by more than an order of magnitude.