In situ defect studies on Si⁺implanted InP

Transmission electron microscopy (TEM) was used to investigate the structural evolution of InP during 50 keV Si ion implantation at room temperature (RT) and during further in situ annealing. The authors describe a new thinning method to obtain reproducible, easily handled and strong samples exhibiting very thin and large areas. In situ TEM studies were performed during implantation at 80 keV up to approximately 3*10 13 Si + /cm 2 . The defect density and size as a function of ion fluence is reported. Amorphisation sets in above a threshold fluence of approximately 2*10 13 Si + /cm 2 . Further studies on implanted samples at various total fluences show that the whole implanted layer ( approximately 70 nm) becomes amorphous at approximately 10 15 Si + /cm 2 . Below fluences of approximately 2*10 13 Si + /cm 2 in situ thermal annealing leads to complete recovery of induced defect clusters at T>or=500 K. The defect clusters induced by Si ion implantation anneal out during TEM observation at electron energies >or=100 keV, an effect which they ascribe to the low displacement energy of P atoms ( approximately 8 eV).