Deep submicron MOS transistor with increased threshold voltage

A method of using a MOS transistor formed in a semiconductor material of a first conductivity type,

• the transistor having:
• spaced-apart source and drain regions of a second conductivity type formed in the semiconductor material,
• the source region includes:
• a first lightly-doped region,
• a first heavily-doped region that is formed in the first lightly-doped region, and
• a second heavily-doped region that adjoins the first lightly-doped region and is spaced apart from the first heavily-doped region;
• and
• the drain region includes:
• a second lightly-doped region,
• a third heavily-doped region that is formed in the second lightly-doped region, and
• a fourth heavily-doped region that adjoins the second lightly-doped region and is spaced apart from the third heavily-doped region;
• a channel region located between the source and drain regions;
• a gate oxide layer formed over the channel region, and
• a channel gate formed on the gate oxide layer over the channel region, the channel gate having side walls;
• ground applied to the second heavily-doped region;
• a first positive voltage applied to the fourth heavily-doped region;
• and
• a second positive voltage applied to the channel gate, the second positive voltage being equal to or greater than a voltage required to invert the channel region of the MOS transistor;
• the transistor being biased off by:
• inducing a first potential in the first heavily-doped region that is substantially equal to ground, and
• inducing a second potential in the third heavily-doped region that is substantially equal to ground.

A method of forming a MOS transistor in a semiconductor material of a first conductivity type, the transistor having a layer of gate oxide formed over the semiconductor material, and a gate formed on the layer of gate oxide over a region of the semiconductor material, the method comprising the steps of:

• implanting the semiconductor material with a dopant of the second conductivity type to form a lightly-doped source region and a lightly-doped drain region;
• forming a side wall spacer that adjoins the side walls of the gate;
• and
• forming an outer gate on the layer of gate oxide to adjoin the side wall spacer over the lightly-doped source region and the lightly-doped drain region.

A transistor formed in a semiconductor material of a first conductivity type, the transistor comprising:

• spaced-apart diffusion regions of a second conductivity type formed in the semiconductor material,
• a diffusion region of the spaced-apart diffusion regions having:
• a first lightly-doped region,
• a first heavily-doped region that is formed in the first lightly-doped region, and
• a second heavily-doped region that adjoins the first lightly-doped region and is spaced apart from the first heavily-doped region;
• a channel region located between the source and drain regions;
• a gate oxide layer formed over the channel region;
• and
• a center gate formed on the gate oxide layer over the channel region, the center gate having side walls.