| 摘要 |
PURPOSE:To obtain an integrated circuit device whose density is made ultrahigh by a method wherein a channel formation region is formed in the longitudinal direction and a source and a drain are formed in the transverse direction. CONSTITUTION:A U-shaped single-crystal semiconductor region is formed in one main face of a semiconductor substrate 1; a source or a drain 4 on one side of a MISFET is constituted in its lower part; and in addition, side parts of the U-shaped region are used as longitudinal channel formation regions 6, 6'. The upper part of the substrate 1 is used as drains or sources 5, 5'; their impurity concentration is set to a low concentration at 10<18>; a drain breakdown strength is enhanced; and a parasitic capacity of the drains to a gate electrode is reduced. Rectangular or triangular gate electrodes 18, 18' are formed in corner parts of the U-shaped region. By this constitution, an electric current flows in the longitudinal direction in the channel formation regions under the gate electrodes, their channel length is made small, the size as viewed from the upper direction of one MISFET is made small and it is possible to obtain an element structure, for ultra-LSI use, which is capable of forming up to 16 Mbits to 16 Gbits. |
