Molybdenum film technology for power metal oxide semiconductor field effect transistor gate electrode applications

Molybdenum (Mo) film as a gate electrode for high-frequency power metal oxide semiconductor field effect transistor (MOSFET) has been investigated. The Mo films were deposited by sputtering in Ar ambient. The Mo films properties depend greatly on the substrate temperature. An accurate pattern was realized for Mo film. Stability and reliability of Mo gates for high-frequency power vertical double-diffused metal oxide semiconductor field effect transistors (VDMOSFETs) are as good as those of polysilicon gates. The shift of threshold voltage is below +/-35 mV and the change of gate-source leakage current is less than 5 nA under the stress condition of +/-5 MV/cm for 100 h at 250 degrees C. Power gain and drain efficiency improvement of Mo gates for VDMOSFETs have been obtained.