Application of field-enhanced rapid thermal annealing to activation of doped polycrystalline Si thin films

Abstract

Activation of polycrystalline silicon (poly-Si) thin films doped as n-type using selective ion implantation of phosphorous was performed employing field-enhanced rapid thermal annealing where rapid thermal annealing of halogen lamps is combined with alternating magnetic fields. The ion activation was evaluated using Hall effect measurements incorporating the resistivity, the charge carrier concentration, and the mobility. Statistical design of experiments is attempted in order to clarify the effects and interactions of processes variables on field-enhanced rapid thermal annealing towards ion activation: the three processing variables are furnace temperature, power of halogen lamp, and the alternating magnetic field. Hall effect measurements indicate that the furnace temperature and RTA power are found to be dominant in activating the doped polycrystalline Si in dose. The activation process results from the competition between charge carrier concentration and mobility: the increase in mobility is larger than the decrease in charge carrier concentration.