摘要 |
An Ta film for use in forming a source electrode and a drain electrode and an amorphous silicon film for use in forming an amorphous silicon semiconductor layer with impurity are continuously etched without setting an etching selectivity ratio. As a result, the source electrode, the drain electrode and the amorphous silicon semiconductor can be formed by a single etching process, and in the meantime, surface protrusions and recessions can be formed in a back channel region on the order of several hundreds of Å reflecting the crystal grain diameters of the Ta film for use in forming the source electrode and the drain electrode. The resulting protrusions and recessions offers an effect of suppressing an increase in OFF-state current value of the thin film transistor, and according to the foregoing method, the thin film transistor can be manufactured through a reduced number of steps at lower cost.
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