Gate electrode comprising body centered cubic tantalum and tantalum nitride

A complementary semiconductor device, comprising:

• an N-channel insulated gate field effect transistor and a P-channel insulated gate field effect transistor,
• wherein each of the N-channel insulated gate field effect transistor and the P-channel insulated gate field effect transistor comprises:
• first and second impurity diffusion layers which are provided in a semiconductor layer and form a source region and a drain region;
• a channel region formed between the first and second impurity diffusion layers;
• a gate insulating layer formed on the channel region;
• and
• a gate electrode formed on the gate insulating layer,
• wherein the gate electrode includes:
• a tantalum nitride layer formed in a region which is in contact with at least the gate insulating layer, wherein the tantalum nitride layer has a thickness of 3 nm to 20 nm, and
• a body-centered cubic tantalum layer heteroepitaxially formed over the tantalum nitride layer by lattice matching.