Optical coupling structure manufacturing using Ni2Si as mask material on silicon substrate

In this work, we present a new fabrication process to obtain deep etching structures in a <;100> silicon wafers using an alternative material (Ni₂Si) deposited at low temperature (200 e 250°C) as mask for alkaline solutions (KOH-27%-60°C). V-grooves (60μm deep) and waveguides were fabricated, showing that the Ni₂Si is an appropriate alternative mask material, when compared with traditional ones as SiO₂ or Si₃N₄ The V-grooves (60 μm deep) were obtained by KOH anisotropic etching (27%-60°C). During this process, the etching rate of the silicon substrate was 33.1 μm/h. A SEM analysis was made with the V-grooves and then they were aligned with a simple optical waveguide to verify the possibility of an optical coupling.