In0.53Ga0.47As lattice matched to InP substrate has been grown by chemical epitaxy (CBE). Epilayers with lattice‐mismatch &Dgr;a/a<1×10−3have been reproducibly obtained with extreme uniformity in both composition and layer thickness over a large area of 3.8 cm diameter (limited by the present substrate holder size) without the need of substrate rotation during growth. Surface morphologies were routinely featureless and mirrorlike as observed by Nomarski phase contrast microscope. Comparing with high‐quality In0.53Ga0.47As epilayers grown by molecular beam epitaxy (MBE), the CBE‐grown In0.53Ga0.47As epilayers have similar linewidths but can have substantially higher 300‐K photoluminescence intensities. The electron concentration and mobilities were found to be related to the source purity of the TMAs used. For epilayers grown with high‐purity TMAs source, room‐temperature electron mobility as high as 9000 cm2/V s and concentrations of ∼7×1015cm−3were produced. Such value represents the highest value obtained by using trimethylarsine as the arsenic source. In general, the electron mobilities were as good as those obtained from low‐pressure metalorganic chemical vapor deposition.