What's it about?

The effect of oxygen partial pressure on the properties of Al₂O₃ films deposited by electron beam evaporation has been investigated through a combination of spectrophotometric and interferometric characterization techniques. As oxygen partial pressure increases, a decrease in the refractive index is observed, as well as a shift towards less tensile films once they are exposed to ambient conditions. This decrease in tensile stress was observed to be correlated with water content in the films. Increasing oxygen partial pressure during deposition improved film stoichiometry, absorption, and laser induced damage threshold (LIDT) at 351 nm.

1. INTRODUCTION

Al₂O₃ coatings are well known for their appealing material properties such as high dielectric constant, wide bandgap, excellent chemical and thermal stability, high hardness, high melting point, and wear resistance^1-5. These films are used in many applications such as semiconductor and optoelectronic devices, cutting tool instruments, and coatings for optics, diffusion barriers, and corrosion resistance^6-9. Al₂O₃ is an essential dielectric material used in...