Mode splitter structure mfr. in semiconductor component - forming parallel tracks, one of which has metallised layer, using second mask to cover edges of tracks completely

摘要

The method involves applying a structured mask (10) to the cover layer (20) on a block of layers of semiconductor material. Tracks (2) are etched into the cover layer (20) using the mask (10). A metallised layer (1,11,12) is then placed over the whole surface of the structure but does not fully cover the sides of the tracks (2). On the surface of one of the tracks (2), part of the metallised layer (1) is covered by another mask (6). This latter mask (6) covers the sides of the track (2). After the uncovered part of the metallised layer (11,2) is removed, the second mask (6) is removed. ADVANTAGE - For TE or TM polarised optical signals. Produces tracks which are as smooth as possible.