The fabrication of photoresist gratings on reflecting surfaces is considered both theoretically and experimentally. We show that it is important to take into account the actual phase shift of the waves reflected from the surface. It is found that the intensity at the photoresist‐surface boundary may be significantly larger than that at the standing‐wave minimum. The theory is confirmed by the examination of the profiles of photoresist gratings made on PbSnTe, in comparison to GaAs. This phenomenon may have wider applications when the photolithographic fabrication of fine features on reflecting surfaces is considered.