Method of forming low capacitance esd device and structure therefor

A method of forming an ESD device comprising:

• providing a semiconductor substrate of a first conductivity type and having a first peak doping concentration;
• forming a first semiconductor region of a second conductivity type and at least approximately the first peak doping concentration wherein the first semiconductor region forms a first P-N junction with the semiconductor substrate;
• forming an epitaxial layer on the first semiconductor region and on a portion of the semiconductor substrate wherein the epitaxial layer has the second conductivity type and a second peak doping concentration;
• forming a first doped region of the first conductivity type and approximately the first peak doping concentration on the epitaxial layer and overlying the first semiconductor region;
• and
• forming a first isolation trench extending vertically from a top surface of the epitaxial layer through the first semiconductor region and into the semiconductor substrate wherein the first isolation trench extends laterally around an outside perimeter of the first doped region.

A method of forming a semiconductor device comprising:

• providing a semiconductor substrate of a first conductivity type and having a first peak doping concentration wherein the semiconductor substrate has first and second surfaces;
• forming a first semiconductor region of a second conductivity type and adjacent to a portion of dopants of the semiconductor substrate wherein the first semiconductor region forms a first P-N junction with the dopants of the semiconductor substrate and wherein the first P-N junction forms a zener diode;
• forming a second semiconductor region on the first semiconductor region and on a portion of the first surface of the semiconductor substrate wherein the second semiconductor region has the second conductivity type and a second peak doping concentration;
• forming a first P-N diode that includes a first doped region of the first conductivity type and approximately the first peak doping concentration on the second semiconductor region and overlying at least a portion of the first semiconductor region;
• and
• forming a first isolation trench extending vertically from a top surface of the second semiconductor region through the first semiconductor region and into the semiconductor substrate wherein the first isolation trench extends laterally around an outside perimeter of the first doped region.