Local Doping of Semiconductor Crystals by Thermomigration

The article includes the analysis of the features related to local doping of silicon using electrically active doping agents by thermomigration of binary and ternary liquid zones as compared to doping by diffusion. The concentration range of doping by binary zone migration is found to be substantially narrower than that of doping by diffusion. Introduction of a third component to the liquid phase ena-bles expansion of the thermomigration doping range to the values exceeding the diffusion doping range by the same doping agent. For silicon crystals, this technological feature of thermomigration is produced by using GaxAl1-xSi and SnxAl1-xSi ternary zones. The crystal doping rate by thermomigration in techno-logically relevant situations was shown to exceed the rate of diffusion doping by orders of magnitude. The layers doped by thermomigration of stably moving liquid zones are structurally more perfect than diffusion layers.