Interfacial reactions of ultrahigh vacuum deposited Er-Si multilayer thin films

Interfacial reactions of Er-Si multilayer thin films have been studied by conventional and high-resolution transmission electron microscopy as well as sheet resistance measurements. Completely amorphized Er-Si intermixing layers were found to form in all as-deposited multilayer samples. After low temperature annealing, the crystalline ErSi2-x was found to form in Si-rich amorphous alloys. On the other hand, both ErSi2-x and Er2O3 were found to form in Er-rich amorphous alloys. The ErSi2-x phase, which has the lowest activation energy to nucleate, is the preferred phase in the Er-Si interfacial reactions. The stability of amorphous alloys was found to increase with metal concentration.