Image Number 3 for United States Patent #7998356.
The invention relates to a process for manufacturing an integrated optical device. The method involves forming a silicon dioxide multilayer structure on a silicon substrate containing, in a first region a core layer of a waveguide of the optical device. The core includes an electromagnetic radiation inlet/outlet A trench in a second region of the multilayer structure adjacent said first region is formed by a an anisotropic etching, the trench including side walls and a bottom wall spaced from the Substrate. The method further involves forming a coating layer of the side walls and the bottom wall of the trench; defining an opening in the bottom wall by at least partially removing the coating layer in order to expose the lower silicon dioxide of the multilayer structure; performing an isotropic etch through said opening in order to remove, starting from the exposed silicon dioxide, the multilayer structure silicon dioxide until forming a recess in the multilayer structure having a first wall at least one essentially planar portion inclined relative to the substrate. Such inclined portion extends at least partially in the first region, and includes the inlet/outlet port.