Process for making light waveguide element

DETAILED DESCRIPTION Accordingly, it is an object of the invention to provide a process for making a light waveguide element enabling precise optical axis alignment.
According to the invention there is provided a process for making a light waveguide element mounted on a mount board along with an optical fiber and photoelectric components, comprises the steps of forming a core as a light path on a substrate serving as a lower clad layer and forming a T-shaped upper clad layer having a central section elevated from opposite-side optical axis height-adjusting sections to cover said core.
According to the first embodiment of the invention there is provided a process for making a light waveguide element mounted on a mount board along with an optical fiber and photoelectric components, comprises the steps of forming a core on a substrate serving as a lower clad layer; patterning an etching stopper film on opposite sides of said core including an area of said optical axis height-adjusting sections; forming a first upper clad layer over an entire surface including said etching stopper film, said core, and said substrate; forming an etching mask on said first upper clad layer so as to cover an area above said core; etching off a portion of said first upper clad layer that is other than said area covered by said etching mask until said etching stopper film is exposed; removing said etching stopper film and said etching mask; and forming a second upper clad layer over an entire surface including said first upper clad layer and said substrate.
According to the second embodiment of the invention there is provided a process for making a light waveguide element, wherein said T-shaped clad layer-forming step comprises the steps of forming both said core and a first height-adjusting layer on said substrate; patterning an etching stopper film on said first height-adjusting layer; forming a first upper clad layer over an entire surface including said core and said etching stopper film; forming an etching mask on said first clad layer to cover an area above said core; etching off a portion of said first upper clad layer that is other than said area covered by said etching mask until said etching stopper film is exposed; removing only said etching mask; and forming a second upper clad layer over an entire surface including said etching stopper film, said first upper clad layer