Method of forming laser mesa by reactive ion etching followed by in situ etching in regrowth reactor

摘要

In a process for manufacturing a device having at least one active layer, semiconductor layers 11, 12, 17 are first etched by reactive ion etching to form a mesa having vertical sidewalls. A second in situ etch is performed within an epitaxial reactor to form undercuts on the mesa structures, and the substrate 12 is subsequently regrown by MOVPE, CBE, HVPE or MOMBE. The layers may comprise a multi quantum well (MQW) structure 11 including AlGaInAs, a first buffer layer 12 of InP and a cap layer 17 of Zn doped InP. The in situ etching step may include using a halogen based compound such as tertiarybutylchloride or CH2Cl2. The process is effective in obtaining smooth, planar and lateral surfaces for the regrowth step, and overcomes the problem of etching aluminium-containing materials. The method may be applied to MQW structures, bulk materials or a combination of bulk and MQW structures e.g. waveguides.