Hafnium oxide (HfO₂)

Hafnium oxide (HfO₂) is a wide‑bandgap, high‑κ dielectric (κ ≈ 20–25) valued for its large breakdown field, thermal/chemical stability, and excellent CMOS compatibility. It is deposited by magnetron sputtering for dense optical and protective coatings, and by atomic layer deposition (ALD) when ultra-thin, conformal, and thickness-precise films are required on high-aspect-ratio structures, such as FinFETs, 3D NAND, and trench capacitors. In semiconductors, it is the standard high‑κ gate dielectric in high‑κ/metal‑gate stacks, a capacitor dielectric in DRAM, a robust passivation/barrier layer, and the active switching medium in resistive RAM; doped or strain‑stabilized HfO₂ (e.g., with Zr, Si, Al) also exhibits ferroelectric/antiferroelectric phases, enabling FeFET non‑volatile memories and ferroelectric capacitors. Optically, HfO₂ offers a high refractive index with low absorption from the UV through the NIR and a high laser-damage threshold, supporting durable anti-reflective/high-reflective multilayers, mirrors, protective windows, and waveguide or cavity coatings. Beyond electronics and optics, its hardness, corrosion resistance, and radiation tolerance make it a suitable material for MEMS passivation, diffusion barriers, biocompatible protective layers, and coatings in harsh environments. Overall, HfO₂ combines precise process control (especially via ALD), mechanical and thermal robustness, and a tunable electric-field response, making it a cornerstone material for thin films across semiconductor, photonic, and engineering applications.

ALD Deposition of Hafnium Oxide

Thin films of hafnium oxide, HfO₂, can be deposited both in the ALD1 and the ALD2 (PEALD). However, it is preferred to use the ALD1.

More information about hafnium oxide deposition can be found here:

ALD deposition of HfO₂ in ALD1

ALD deposition of HfO₂ in ALD2.

Deposition of hafnium oxide

	ALD1	ALD2 (PEALD).
Generel description	Atomic Layer Deposition	(Plasma enhanced) Atomic Layer Deposition
Stoichiometry	HfO₂	HfO₂
Film Thickness	0 nm - 100 nm	0 nm - 50 nm
Deposition rate	At 150 ^oC: 0.11 nm/cycle At 250 ^oC: 0.0827 nm/cycle	At 250 ^oC: 0.0804 nm/cycle At 250 ^oC on trenches: 0.954-1.22 nm/cycle
Step coverage	Very good.	Very good
Temperature window	150 ^oC - 300 ^oC	150 ^oC - 300 ^oC
Substrate size	1-5 100 mm wafers (only good uniformity for the top wafer) 1-5 150 mm wafer (only good uniformity for the top wafer) 1 200 mm wafer Several smaller samples	1 100 mm wafer 1 150 mm wafer 1 200 mm wafer Several smaller samples
Allowed materials	Silicon Silicon oxide, silicon nitride Quartz/fused silica Metals (use dedicated carrier wafer) III-V materials (use dedicated carrier wafer) Polymers (depending on the melting point/deposition temperature, use carrier wafer)	Silicon Silicon oxide, silicon nitride Quartz/fused silica Metals (use dedicated carrier wafer) III-V materials (use dedicated carrier wafer) Polymers (depending on the melting point/deposition temperature, use carrier wafer)