We investigated etching of (100) InP by HCl gas inside on OMVPE reactor, at 76 Torr, and at temperatures of 580 at 625-degrees-C. Proper choice of etching parameters led to very good (at 625-degrees-C) or fair (at 580-degrees-C) morphologies for etched depths of up to 3-mu-m. With SiO2 stripes or stripe openings on the (100) surface, ridges or V grooves were obtained by etching, limited by very smooth (111)A or (111)B walls.