In-situ etching of semiconductor with CBr4 in MOCVD reactor

In-situ etching of GaInAsP/InP and AlGaInAs/InP double-heterostructures in a MOCVD reactor was carried out with carbon tetrabromide (CBr₄). The InP layer was easily etched with proportion to the amount of CBr₄, and a smooth surface was obtained after etching. On the contrary, it was difficult to etch the GaInAsP layer and many residues were observed. The AlGaInAs layer was not etched at all and it was concluded that the AlGaInAs layer could be used as an etching-stop layer. When an epitaxial layer was successively grown after in-situ etching, a high-quality regrowth interface, such as reduced defects and oxygen concentration, was obtained