| 摘要 |
PURPOSE:To extremely reduce the variability of element characteristics by reducing the variability of the width of an active layer with forming the low electric resistance, the low oscillation thereshold value and the good shape of beam. CONSTITUTION:A clad layer 5, an active layer 10 of a stripe region and a second clad layer 9 are formed on a crystal of a substrate 6 in the above order. At this time, the active layer 10 or the vicinity including said layer 10 is held by the crystal plane making an angle of 90 deg.+ or -10 deg. with a main surface of the active layer 10 from the both sides. The upper surface of the clad layer 9 is formed more widely than the active layer 10. Consequently, the variability of the active layer 10 in a wafer becomes + or -0.1mum or less and the yield of elements fabrication is increased. |
