Method for forming a metal oxide semiconductor field effect transistor (MOSFET) having improved hot carrier immunity

A method for fabricating a Metal Oxide Semiconductor Field Effect Transistor (MOSFET) comprising:

• forming upon a semiconductor substrate a gate dielectric layer, the gate dielectric layer having a gate electrode formed thereupon, the gate dielectric layer extending beyond a pair of opposite edges of the gate electrode, the gate electrode layer being formed at least in part from a first doped polysilicon layer;
• forming into the semiconductor substrate directly adjoining the pair of opposite edges of the gate electrode a pair of low dose ion implants;
• forming upon the gate dielectric layer and contacting the pair of opposite edges of the gate electrode a pair of conductive spacers, the pair of conductive spacers partially overlapping the pair of low dose ion implants, the pair of conductive spacers being formed from a second doped polysilicon layer;
• and
• forming into the semiconductor substrate adjoining the pair of opposite edges of the gate electrode and further removed from the pair of conductive spacers a pair of source/drain electrodes, the pair of source/drain electrodes partially overlapping the pair of low dose ion implants, where at least either;
• the first doped polysilicon layer is employed in forming over the semiconductor substrate, simultaneously with the gate electrode, a first polysilicon capacitor electrode within a double layer polysilicon capacitor;
• or
• the second doped polysilicon layer is employed in forming over the semiconductor substrate, simultaneously with the pair of conductive spacers, a second polysilicon capacitor electrode within the double layer polysilicon capacitor.