Electrical properties of excimer-laser-crystallized lightly doped polycrystalline silicon films

The electrical properties of excimer-laser-crystallized lightly phosphorus-doped polycrystalline silicon films were investigated. The electrical conductivity of the films increased from 6.0 x 10(-7) to 2.3 x 10(-1) S/cm as the laser energy density increased from 235 to 436 mJ/cm(2) because the carrier concentration varied from 1.0 x 10(11) to 1.8 x 10(17) cm(-3). In contrast, the carrier mobility was 37.3 and 8.7 cm(2)/V.s at low- and high-laser-energy regimes, respectively, and showed a minimum value of 0.24 cm(2)/V.s at the intermediate laser energy density of 315 mJ/cm(2). These results can be well explained by a model featuring the localization of trap states at the grain boundary.