L. Pichon et al., Analysis of the activation energy of the subthreshold current in laser- and solid-phase-crystallized polycrystalline silicon thin-film transistors, APPL PHYS L, 77(4), 2000, pp. 576-578
Analysis of the thermal and gate-voltage dependences of the current in the
subthreshold region is performed on both low-temperature laser-crystallized
and solid-phase-crystallized polycrystalline silicon (polysilicon) thin-fi
lm transistors (TFTs). Temperature measurements are made at first in order
to extract the variations of the activation energy E-A of the drain current
with the gate voltage. The plot of the subthreshold current versus the mea
sured activation energy leads to an apparent activation energy E-A/n, where
the n factor is extracted from the slope of this plot. The n factor is clo
se to 1 for laser-crystallized polysilicon TFTs while it is rather close to
2 for solid-phase-crystallized ones. These two values can be attributed to
a different defect distribution in the two differently crystallized TFTs p
olysilicon active layers. (C) 2000 American Institute of Physics. [S0003- 6
951(00)02830-8].