Channel Waveguides Through Silicon Wafers for Optically Coupled 3D Integrated Circuits

Design of IR waveguides through a n-type conductive silicon wafers by aluminum thermomigration method (process of temperature gradient zone melting) is reported. Refraction index change between core and cladding waveguide is 0.01. The light transmission efficiency for stray light decreased by one order of magnitude by increasing the horizontal spacing up to the size of waveguide core (50 μm).