Published online by Cambridge University Press: 15 February 2011
Patterns of sharp narrow vertical p-n junctions were produced by scanning a laser beam over the surface of a silicon wafer coated on the backsurface by either Au-Sb, Al or Ga. Formation of the junctions occurs by liquid zone migration along the thermal gradient induced by the laser beam. Nd-YAG as well as CO2 laser light was employed and the dependance of migration zone width, velocity, front stability and structure on the different laser wave lengths was studied. Structural investigations of the regrown layers included optical microscopy, SEM and TEM studies as well as spreading resistance measurements to ascertain the behaviour of the various p-n junctions produced. Annealing treatments of the migrated zones were performed to alleviate the stresses produced during the migration experiments.