| 摘要 |
PURPOSE:To reduce the effect of a level resulting from a gate insulating film, and to increase carrier mobility by forming a semiconductor layer in three layers and making a first layer adjacent to the gate insulating film smaller than an adjacent second layer and the second layer larger than an adjacent third layer in the Fermi level. CONSTITUTION:A gate 2 is formed on a transparent substrate 1 by a metal such as molybdenum, and three layers of a non-doped a-Si film 41 brought into contact with a gate insulating film 3 consisting of SiO2, etc., an n<-> a-Si film 42, which is brought into contact with the film 41 and to which a doner impurity is doped, and a non-doped a-Si film 43 brought into contact with the n<-> a-Si film 42 are shaped continuously. A source electrode 7 and a drain electrode 8 are formed by a metal such as Al in order to obtain electric connection to a-Si 43 through n<+> a-Si 5, 6. Conductive carriers flow in the deep section of a semiconductor film, currents between a drain and a source on the OFF of an MIS type FET are not increased, and the effect of localized potential is reduced and the mobility of carriers can be improved. |
