Ridge-waveguide production in III-V semiconductor layer structure

摘要

A process for producing a ridge-waveguide in III-V compound semiconductor layer structures involves (a) formation (especially by epitaxial growth), on a semiconductor substrate, of a basic structure with a first cladding layer, an active zone (4) of uniform material or alternating quantum wells and barriers, a second cladding layer (5) and a contact layer (6); (b) blanket deposition and structuring of a trench mask for defining a trench region of width which is a multiple of that of a ridge (7) to be formed within the trench region from the second cladding layer (5) and the contact layer (6); (c) formation of a strip-shaped ridge mask within the trench region; (d) selective etching of the contact layer (6) and the second cladding layer (5), using the masks as etching masks, for simultaneous ridge (7) and trench (8) production within the trench region; (e) edge conformal deposition of a passivation layer (9) of electrically insulating material; (f) lift-off of ridge mask and the overlying passivation material; and (g) deposition of a metallisation layer for electrical connection of the ridge (7). Also claimed is a semiconductor laser device with a ridge-waveguide, the ridge (7) of which is formed from the second cladding layer (5) and the contact layer (6) within a trench (8) of width which is a multiple of the ridge width.