Comparison between the different implantation orders in H+ and He+ coimplantation

H+ and He+ were implanted into single crystals in different orders (H+ firs t or He+ first). Subsequently, the samples were annealed at different tempe ratures from 200 degreesC to 450 degreesC for 1 h. Cross sectional transmis sion electron microscopy, Rutherford backscattering spectrometry and channe lling, elastic: recoil detection were employed to characterize the defects and the distribution of H and He in the samples. Furthermore, the positron traps introduced by ion implantation and annealing were characterized by sl ow positron annihilation spectroscopy. Both orders in the coimplantation of H and He have the ability to decreases the total implantation dose after a nnealing. No bubbles or voids but cracks and platelets, were observed by cr oss sectional transmission electron microscopy. The different implantation orders affect the density of interstitial atoms and positron traps.