Patent ID: 6417541
Filing Date: 2002-07-09
Classification: H01L

Abstract:
An electrostatic discharge protection structure comprising:a gate dielectric; source and drain contacts; and a semiconductor substrate of a first conductivy type having the gate dieletric disposed partlly therein on a surfce thereof, the semiconductor substrate having the source and drain contacts on the surface thereof separated by the gate dielectric, the semiconductor substrate having source and drain diffusion. regions having a second conductivity type and connected respectively to the source and drain contacts and separated by the gate dielectric, the semiconductor substrate having source and drain wells having the second conductivity type and respectively disposed under the source and drain diffusion regions, the semiconductor substrate having a channel region of the first conductivity type between the source and drain wells including a subsurface depletion region whereby the surface breakdown voltage is exceeded before the subsurface depletion region punch-through voltage is exceeded upon an electrostatic discharge at the drain contact and the semiconductor substrate including a subsurface conductivity region of the first conductivity type of a higher doping concentration than the doping concentration in the semiconductor substrate between the source and drain wells.