Chemical profiling and structural studies of ion-beam-mixed aluminum on silicon

The ion beam mixing technique has been applied to the production of AlSi thin alloy layers as an alternative method to thermal annealing. Both unimplanted deposited aluminum thin films on silicon substrates and films implanted with energetic xenon ions were studied by Rutherford backscattering, channeling, secondary ion mass spectroscopy, nuclear resonance profiling and scanning electron microscopy techniques. The results of these experiments indicate that (i) iintermixing between aluminum and silicon became observable when the implantation dose of energetic xenon through the interface surpassed 2 × 10¹⁶ ions cm^-2; (ii) intermixing is dependent on the dose but not on the dose rate of implantation; (iii) damage to the silicon substrate extended only to the region penetrated by implanted ions; (iv) the AlSi alloy layer region is uniform in texture and no segregation can be observed. Moreover, the integrity of the alloy layer is retained for a long period of room temperature annealing.