| 摘要 |
PURPOSE:To obtain an optical device having a new structure and by a new method of manufacture by controlling a growing speed or a film thickness by changing the rate between an area of an exposed portion of a substrate crystal and an area covered with a film difficult to grow. CONSTITUTION:Exposed grooves 3, 4 in a GaAs substrate layer each have a width of mum order, satisfying a relation the width B > the width A. A GaAs, AlGaAs superlattice layer is grown on the substrate by an organic metal vapor phase growing method for example. Because of the relation B>A, the superlattice layer is grown to be thicker at the portion of the groove 3 than at the portion of the groove 4. Further, a growing period of the superlattice is shorter along the groove 4 compared with the groove 3, i.e., longer as it goes narrower. Hereby, superlattice layers having different optical characteristics are simultaneously formed. Thus, layers having different refractive indexes and band gaps, etc., are well controllably and simultaneously formed along the different width grooves 3, 4. Hereby, an optical device having a new structure is yielded by a new method of manufacture. |
