Oxide‐semiconductor interface roughness and electrical properties of polycrystalline silicon thin‐film transistors

Polycrystalline silicon thin‐film transistors (TFTs) have been fabricated with a smooth oxide‐semiconductor interface. Device characteristics are found to be improved with the interface smoothness. The channel mobility is especially improved to about 2 times larger than that of conventional poly‐Si TFTs. The topography of the oxide‐semiconductor interface was analyzed using nanometer resolution atomic force microscopy. The roughness of the oxide‐semiconductor interface and the electrical properties of poly‐Si TFTs are found to have a strong relationship.l