Neutral molecule mass spectrometry (NMMS), secondary ion mass spectrometry (SIMS) in combination with thermal desorption spectroscopy (TDS) study of deuterium trapping in a single crystalline silicon as a result of ion irradiation at fluences 1015-1017cm−2are presented. The subsequent formation of point defects ensembles containing one and two D-atoms (SiD- and SiD2-complexes) was revealed. Accumulation of these complexes starts not in the mean projected range of implanted ions but at the irradiated surface. Their profiles become wider into the bulk with increasing of the fluence