Electro-optice device comprising a ridge waveguide and a PN junction and method of manufacturing said device

摘要

An electro-optic device (10), comprising an insulating layer (14) and a layer (16, 18a, 18b, 20a, 20b) of light-carrying material adjacent the insulating layer. The layer of light-carrying material, such as silicon, comprises a first doped region (18a, 18b) of a first type and a second doped region (20a, 20b) of a second, different type abutting the first doped region to form a pn junction. The first doped region has a first thickness at the junction, and the second doped region has a second thickness at the junction, the first thickness being greater than the second thickness the two regions thereby, defining a waveguide rib (21) in the first doped region for propagating optical signals. Since the position of the junction coincides with the sidewall of the waveguide rib (21) a self-aligned process can be used in order to simplify the fabrication process and increase yield.