| 摘要 |
PURPOSE:To increase the ON current and contrive the enhancement of mobility and the reduction of threshold voltage by a method wherein donor and acceptor impurities approximately in equal quantities are introduced into a polycrystalline semiconductor film constituting a channel region. CONSTITUTION:On an insulating substrate 101 made of quartz, glass or ceramics, a polycrystalline silicon thin film 102 is formed to be developed into a channel region. The polycrystalline silicon thin film 102 contains approximately equal quantities of such a donor impurity as phosphorus or arsenic and such an acceptor impurity as boron, which reduces the trap density attributable to crystal defects present in polycrystalline silicon. This lowers the threshold voltage, increases carrier mobility, and increases the available ON current. |
