Thin films of thulium and samarium doped AlN are deposited on silicon (111) substrates at 77 K by rf magnetron sputtering method. 200–400 nm thick films are grown at 100–200 watts RF power and 5–8 mtorr nitrogen, using a metal target of Al with Tm and Sm separately. X-rays diffraction results show that films are amorphous. Cathodoluminescence studies are performed at room temperature and two dominant peaks are observed in Tm at 467 nm from $^{1}{\rm D}_{2}$ $\to$ $^{3}{\rm F}_{4}$ transition and 480 nm from 1G4 to the ground state 3H6 transition. Other peaks in the visible region are obtained at 650 nm and 685 nm due to $^{1}{\rm G}_{4}$ $\to$ $^{3}{\rm F}_{4}$ and $^{1}{\rm D}_{2}$ $\to$ $^{3}{\rm H}_{4}$ transitions. Peaks in the ultraviolet and infrared region are also obtained at 371 nm, and 802 nm as a result from $^{1}{\rm D}_{2}$ $\to$ $^{3}{\rm H}_{6}$ and $^{3}{\rm H}_{4}$ $\to$ $^{3}{\rm H}_{6}$ transition respectively. Sm gives four peaks at 564 nm, 600 nm, 648 nm and 707 nm as a result of $^{4}{\rm G}_{5/2}$ $\to$ $^{6}{\rm H}_{5/2}$ , $^{4}{\rm G}_{5/2}$ $\to$ $^{6}{\rm H}_{7/2}$ , $^{4}{\rm G}_{5/2}$ $\to$ $^{6}{\rm H}_{9/2}$ and $^{4}{\rm G}_{5/2}$ $\to$ $^{6}{\rm H}_{11/2}$ transitions. Films are thermally activated at 1200 K for half an hour in a nitrogen atmosphere. Thermal activation enhances the intensity of luminescence.