MOSFET using gate work function engineering for switching applications
AssigneeAlpha and Omega Semiconductor Incorporated
InventorsAnup Bhalla, Sik K. Lui
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Abstract
This invention discloses a new MOSFET device. The MOSFET device has an improved operation characteristic achieved by manufacturing a MOSFET with a higher gate work function by implementing a P-doped gate in an N-MOSFET device. The P-type gate increases the threshold voltage and shifts the C-Vds characteristics. The reduced Cgd thus achieves the purpose of suppressing the shoot through and resolve the difficulties discussed above. Unlike the conventional techniques, the reduction of the capacitance Cgd is achieved without requiring complicated fabrication processes and control of the recess electrode.
Claims25
A metal oxide semiconductor field effect transistor (MOSFET) device comprising:
- a trenched gate filled with a gate material doped with a dopant with a gradually decreasing dopant concentration along a channel formed in a body region along said trenched gate to adjust said work function for increasing a threshold voltage and creating a shift C-V characteristic of said MOSFET device from a MOSFET with an uniformly doped gate material.
A MOSFET device comprising:
- a trenched gate filled with a gate material constituting substantially a uniform single-deposition trenched gate having a work function higher than an N+ poly for a n-channel MOSFET or lower than a P+ poly for a P-channel MOSFET for increasing a threshold voltage and to create a shift C-V characteristic for said MOSFET device from a MOSFET with an uniformly doped polysilicon gate material.
A method for manufacturing a metal oxide semiconductor field effect transistor (MOSFET) device comprising:
- filling a trenched gate with a gate material having a work function higher than an N+ poly for a n-channel MOSFET and lower than a P+ poly for a P-channel MOSFET.
Dependencies are inferred from the claim text.