Development of HfO2/Al2O3 Stack for On-Chip Capacitor Applications

We presented the development and characterization of high-k stack HfO2/Al2O3 capacitor, fabricated directly on chip. The capacitor is based on nanolaminate material directly grown by plasma-assisted Atomic Layer Deposition (ALD)in a single reactor chamber. The deposition process was performed at a single temperature (250°C). We tested the various numbers of layers in the stack, compared the electrical and material characterizations. Using the optimal deposition conditions, we obtained a structure with nanolaminates of single thickens 5 Å, capacitance density of 1.10⁻¹² F.μm⁻² and leakage current density of $1.10^{-9}$ A.cm⁻².