Mechanical/Structural Properties of ALD Zirconium Oxide (ZrO_2) Thin Films for High-Tech Applications

摘要

Zirconium oxide (ZrO_2) films of varying thickness were deposited on p-type Si (100) substrates using Atomic layer deposition (ALD) with 200, 300, and 500, ALD cycles. The 300 ALD deposition cycle films were further annealed at 600 ℃. We tested these ZrO_2 films for structural and nanomechanical properties using nanoindentation and investigated the surface morphology by AFM. The structural and surface properties were explored using scanning field emission electron microscopy (FE-SEM) and atomic force microscopy (AFM). We discuss the influence of the deposition technique on the structure and properties of the ZrO_2 films resulting from ALD synthesis. The nanoindentation results indicate that the films become consistently softer as the number of ALD deposition cycles increase and the film thickness grows larger. Further annealing of the films slightly enhanced the hardness and fracture toughness of the films. The annealed ALD films depicted shorter radial cracks compared to the films under the same applied stress, which were not annealed in forming gas.