Lattice Location of As and Sb Implanted in Silicon after Annealing with a Pulsed Ruby Laser

摘要

The lattice location of implanted arsenic and antimony in single crystal silicon ((100) orientation) after pulsed laser annealing was studied using positive ion channeling-backscattering. The samples were implanted with 100 keV exp 75 As or exp 121 Sb to doses in the range 1 x 10 exp 15 to 3 x 10 exp 16 /cm exp 2 and subsequently annealed using the Q-switched output of a pulsed ruby laser (1.5 to 1.7 J/cm exp 2 , approx. 50 x 10 exp -9 sec pulse duration). Channeling measurements (2.5 MeV He exp + ions) along major axial directions ((100), (110), and (111)) and detailed scans across the axes were used to determine the lattice location of the implanted dopants after annealing. In the dose range investigated, 98 to 99% of the As occupy substitutional sites. Antimony doses less than 1.5 x 10 exp 16 /cm exp 2 yield similar results. Electrical measurements of the number of electrically active dopants support the high substitutional fractions observed by the ion channeling-backscattering measurements. Also reported are channeling results for exp 75 As implanted (approx. 1 x 10 exp 16 As/cm exp 2 ) samples that were annealed with an electron beam generator. Substitutional fractions (97 to 99%) comparable to laser annealing were obtained, but some nonuniformities across the samples were observed that were not present in the laser annealed samples. (ERA citation 04:030789)