| 摘要 |
PROBLEM TO BE SOLVED: To obtain a stabilized threshold level by forming the first region of a gate electrode of first and second group IV elements of different kind and forming a second region of the first group IV element thereby preventing impurities doped into the gate electrode from leaking to the channel region side. SOLUTION: A gate electrode 4P, 4N has a first underlying region 4g formed on the gate insulation film 3 side contiguously thereto, and an second overlying region 4p, 4n formed on the first region 4g while spaced apart from the gate insulation film 3. The first region 4g is formed of SiGe having a group IV element, i.e., Si, and a different group IV element, i.e., Ge. The second region 4p, 4n is formed of one kind of group IV element, i.e. Si. In a complementary MISFET of dual gate electrode structure, the threshold voltages can be stabilized respectively using identical gate electrodes 4P, 4N containing first and second group IV elements. |
