Patent ID: 6800924
Filing Date: 2004-10-05
Classification: H01L

Abstract:
A structure comprising:a substrate having a first dopant concentration of a first conductivity type; a layer formed on said substrate, said layer having a second dopant concentration of said first conductivity type; a surface well having a first dopant concentration of a second conductivity type formed in said layer; a first transistor having source and drain regions positioned within said layer and separated by a channel region, said source and drain regions having a second conductivity type, and a gate positioned over said channel region; a second transistor having source and drain regions positioned within said surface well and separated by a channel region, said source and drain regions having said first conductivity type, and a gate positioned over said channel region; a buried well having a second dopant concentration of said second conductivity type, said buried well being positioned between said substrate and said layer, paid buried well having a perforation; a first resistive path, said first resistive path being positioned in said layer and said substrate so as to couple a first location in said layer, below said channel region of said first transistor, to a second location in said layer, said first resistive path having a horizontal length in said substrate that is coupled to said first and second locations in said layer through said perforation in said buried well, wherein; said horizontal length of said first resistive path in said substrate is chosen to provide a resistance between said first location and said second location in said layer within a specific range of resistance values; and a second resistive path, said second resistive path being positioned so as to couple a first location in said surface well, below said channel region of said second transistor, to a second location in said surface well, said second resistive path having a horizontal, length in said buried well wherein; said horizontal length of said second resistance path in said buried well is chosen to provide a resistance between said first location and said second location in said surface well within a specific range of resistance values.