ITLDD transistor having a variable work function

An inverse-T gate electrode having a variable work function comprising:

• a semiconductor substrate having a surface;
• a monolithic semiconductor body overlying the surface having a relatively thick central portion and relatively thin lateral extensions projecting from the central portion along the surface;
• and
• a work function adjusting material overlying and in intimate contact with at least the extensions wherein the work function adjusting material changes the energy levels in the lateral extensions relative to the central portion of the semiconductor body.

An inverse-T, lightly-doped drain semiconductor device comprising:

• a P-type semiconductor substrate having a gate dielectric layer thereon;
• a monolithic, polysilicon inverse-T gate electrode overlying the dielectric layer having a relatively thick central portion and a relatively thin peripheral portion;
• a first vertical wall surface extending from the upper surface of the central portion to the upper surface of the peripheral portion;
• a second vertical wall surface extending from the upper surface of the peripheral portion to the gate dielectric layer;
• a work function adjusting material selected from the group consisting of P-type polycrystalline silicon, titanium, molybdenum, tungsten and cobalt overlying the first vertical wall surface and the upper surface of the peripheral portion;
• a spacer forming material selected from the group consisting of silicon dioxide and silicon nitride overlying the work function adjusting material;
• first and second lightly doped N-type regions in the substrate aligned to first vertical wall surface of the inverse-T gate electrode separated by a channel region underlying the central portion;
• and
• first and second heavily doped N-type regions in the substrate aligned to the second vertical wall surface of the inverse-T gate electrode and adjacent to the first and second lightly doped regions respectively.