Furnace O-2 Annealing Growth of Er2O3 Thin Film for Gate Stack Capacitance at Low Temperature

Abstract

Erbium oxide (Er2O3) films have been grown by O-2 annealing on Si(100) in a furnace. The impact of Si surface passivation on the O-2 growth during annealing was investigated. We further studied the variation in surface composition of Er2O3 with a variety of furnace annealing temperatures and amounts of O-2 gas. Prolonged annealing of Er2O3 thin films resulted in the formation of a thick layer of Er2O3 at the surface, while shorter annealing times produced a thin film of Er metal. The thick Er2O3 layer was generated from a sputter deposited Er layer, which was oxidized by heating at 200 to 400 degrees C in O-2 gas (20 sccm). Stable Er2O3 thin film characteristics were achieved at an annealing temperature of 400 degrees C. For Er thin films, the extent of reduction varies with the thermal history of the samples, and prolonged annealing produced a more reproducible surface. Er2O3 thin films grown from an Er metal layer showed diffusion of lattice oxygen, which influenced the characteristics of the thin films.