Erbium is of particular interest in telecommunication systems because of its sharp and intense photoemission at 1.54 μm. However, erbium is difficult to incorporate at high concentrations in the semiconductor matrix and presents a tendency to segregate in the material. A better solution would be to use the erbium impurity as an element of the matrix rather than as a dopant. Such a structure can be obtained with a garnet‐like layer realized on a semiconductor substrate. Evaporation, implantation, and annealing techniques were combined to obtain a new ternary material Al‐Er‐O. These garnet‐like layers were developed on silicon. The layer composition as well as the interaction of the different elements with the substrate were studied by Rutherford backscattering, secondary ion mass spectroscopy, and X analyses. The surface aspect variations were observed by scanning electron microscopy. According to the annealing conditions, a photoluminescence at about 1.54 μm corresponding to erbium emission was observed at 77 K. This luminescence is due to insulating microparticles composed of aluminum, erbium, oxygen, and possibly silicon.