Semiconductor guided-wave optical device and method of fabricating

Abstract

After a shadow mask that is separate from a semiconductor substrate is used and is arranged over the semiconductor substrate via a wafer holder installed in a reaction chamber of a vapor-phase epitaxial system so that a predetermined space d can be secured, a semiconductor thin film crystal including a core layer and a cladding layer is grown by organometallic vapor-phase epitaxy. A core layer wherein the thickness of a grown film in an area which is opposite to a masking part of the shadow mask on the semiconductor substrate is reduced in the tapered shape can be readily obtained by introducing this process for growth in a normal process for fabricating a semiconductor guided-wave optical device. A semiconductor guided-wave optical device and a method of fabricating thereof wherein the thickness of a film which is to be a waveguide is tapered and the width of the waveguide is tapered without deteriorating crystallinity by a new crystal growing method using this shadow mask are obtained. It is desirable that the surface of the shadow mask be coated with a dielectric cap layer. Hereby, a beam expander-integrated laser diode which can be fabricated by an extremely simple method and enables extremely efficient optical coupling with a fiber can be realized.