| 摘要 |
A method of forming field effect transistors (FETS) on a silicon wafer. A gate layer, polysilicon, is formed on a gate dielectric layer (oxide) on the silicon wafer. High voltage device locations are defined and blocked while normal NFETs and PFETs are formed. If the FET process is a gate predope process, the gate layer is blocked during predoping and patterned after the predoping is complete. Otherwise, the gate layer is patterned prior to doping. After gate definition, high voltage FETs are unblocked and implanted with a dopant, preferably boron (B) or (P), which dopes gates and source/drain regions such that they are depleted, resulting in a thicker effective gate dielectric than normal NFETs and PFETs.
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