A Novel Agglomerated-Silicon Thin-Film Transistor

This letter discusses the fabrication and electrical characteristics of a novel thin-film transistor (TFT) architecture based on intentionally agglomerated silicon for the active (island) region. Although the agglomeration of irradiated semiconductor is undesirable during the laser crystallization of polycrystalline-silicon TFTs, it is shown that precisely controlled wirelike structures can be obtained for certain conditions. Their width and pitch are maintained over very long distances, and their crystal structure is almost single crystal. Fabricated n- and p-channel TFT characteristics with maximum effective mobility values of 360 and 70 $\hbox{cm}^{2}/\hbox{V} \cdot \hbox{s}$, respectively, are presented, with on/off current ratios exceeding ten decades.