摘要 |
There is provided a semiconductor device in which gate electrodes of both an n-channel field effect transistor and a p-channel field effect transistor constituting a complementary field effect transistor are made of the same material and threshold voltages of both are sufficiently lowered. In the semiconductor device including an n-channel MOSFET and a p-channel MOSFET which constitute a CMOS structure, the gate electrode of the n-channel MOSFET and the gate electrode of the p-channel MOSFET are made of the same material, at least a part of a channel region of the n-channel MOSFET is formed in a strained Si layer, at least a part of a channel region of the p-channel MOSFET is formed in an SiGe layer, the work function of the material making the gate electrodes is higher than an energy difference between the conduction band edge of the strained Si layer and the vacuum level, and is lower than an energy difference between the valence band edge of the SiGe layer and the vacuum level.
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