Patent ID: 9158139
Filing Date: 2015-10-13
Classification: G02F,H01L

Abstract:
1. A method for manufacturing a Mach-Zehnder modulator comprising the steps of: forming a stacked semiconductor layer on a substrate, the stacked semiconductor layer including a first conductivity type semiconductor layer, a core layer and a second conductivity type semiconductor layer; forming a waveguide mesa by etching the stacked semiconductor layer, the waveguide mesa having a first portion, a second portion and a third portion arranged between the first and second portions, the waveguide mesa extending in a direction of a waveguide axis; forming a first buried region on a top surface and a side surface of the waveguide mesa and on the substrate; forming a mask on the first buried region, the mask having an opening on the third portion of the waveguide mesa; forming an opening in the first buried region by etching the first buried region using the mask to expose a top surface of the third portion of the waveguide mesa through the opening in the first buried region; after removing the mask, etching the second conductivity type semiconductor layer in the third portion of the waveguide mesa through the first buried region as a mask; and removing the first buried region after etching the second conductivity type semiconductor layer, wherein, in the step of forming the opening in the first buried region, the first buried region covers a side surface of the third portion of the waveguide mesa.