SOI low capacitance body contact

A method of making an FET device comprising:

• providing a first dielectric layer;
• depositing a substrate layer on the dielectric layer;
• forming a body contact region of a first conductivity type in the substrate layer, the body contact region having an edge;
• forming FET diffusion regions of a second conductivity type in the substrate layer, the FET diffusion regions, the edge of the body contact region abutting only first edges of the FET diffusion regions;
• forming a channel region of the first conductivity type in the substrate, the channel region abutting the edge of the body contact region and separating the FET diffusion regions along second edges of the FET diffusion regions;
• depositing a gate above the substrate layer over the channel region;
• and
• depositing a second dielectric layer on the body contact region.

A method of making an FET device comprising:

• providing a first dielectric layer;
• depositing a substrate layer on the dielectric layer;
• forming a body contact region of a first conductivity type in the substrate layer, the body contact region having an edge;
• forming source and drain FET diffusion regions of a second conductivity type in the substrate layer, the FET diffusion regions, the edge of the body contact region abutting only first edges of the FET diffusion regions;
• forming a channel region of the first conductivity type in the substrate having a thickness greater than that of the first conductivity type material in the body contact region, the channel region abutting the edge of the body contact region and separating the FET diffusion regions along second edges of the FET diffusion regions, the body contact region extending continuously from the channel region and abutting both said FET diffusion regions only on a portion of the first edges of the FET diffusion region;
• depositing a gate above the substrate layer over the channel region;
• and
• depositing a second dielectric layer on the body contact region.

An FET device comprising:

• a first dielectric layer;
• a substrate layer on the dielectric layer;
• a channel region of a first conductivity type formed in the substrate layer;
• a gate formed above the substrate layer over the channel region;
• FET diffusion regions of a second conductivity type formed in the substrate layer, the diffusion regions each edges, the edges of the FET diffusion regions being separated by the channel region;
• a body contact region of the first conductivity type extending continuously from the channel region, the first conductivity type material in said body contact region being thinner than the first conductivity type material in the channel region;
• and
• a second dielectric layer formed on the body contact region.

An FET device comprising:

• a first dielectric layer;
• a substrate layer on the dielectric layer;
• a channel region of a first conductivity type formed in the substrate layer;
• a gate formed above the substrate layer over the channel region;
• FET diffusion regions of a second conductivity type formed in the substrate layer, the diffusion regions each having first and second edges, the second edges of the FET diffusion regions being separated by the channel region;
• a body contact region of the first conductivity type extending continuously from the channel region and abutting both said FET diffusion regions only on at least a portion of the first edges of the FET diffusion regions;
• and
• a second dielectric layer formed on the body contact region.

An FET device comprising:

• a first dielectric layer;
• a substrate layer on the dielectric layer;
• a channel region of a first conductivity type formed in the substrate layer;
• a gate formed above the substrate layer over the channel region;
• source and drain FET diffusion regions of a second conductivity type formed in the substrate layer, the diffusion regions each having first and second edges, the second edges of the FET diffusion regions being separated by the channel region;
• a body contact region of the first conductivity type extending continuously from the channel region and abutting both said FET diffusion regions only on a portion of the first edges of the FET diffusion regions, the first conductivity type material in said body contact region being thinner than that in the channel region;
• and
• a second dielectric layer formed on the body contact region.