InGaP/GaAs single quantum well(SQW) structure growth on GaAs facet wall is achieved by atomic layer epitaxy (ALE) using chloride source gases, such as InCl and GaCl. GaAs facets are formed on GaAs(100) surface openings by conventional hydride vapor phase epitaxy, which have {011} sidewalls perpendicular to the surface, {111}Band (100) faces. ALE growth of SQWs onto these faces results in a very smooth and uniform surface, as shown by scanning electron microscopy observation and cathodoluminescence measurements. The self‐limiting mechanism for ALE is also retained in such selective sidewall growth of heterostructures.