Disconnected DPW Structures for Improving On-State Performance of MOS Devices

A semiconductor structure comprising:

• a semiconductor substrate;
• a high-voltage p-well (HVPW) region overlying the semiconductor substrate;
• a high-voltage n-well (HVNW) region overlying the semiconductor substrate, wherein the HVPW and the HVNW regions laterally contact each other and form an interface;
• an insulation region extending from a top surface of the HVNW region into the HVNW region;
• a gate dielectric extending from over the HVPW region to over the insulation region;
• a gate electrode on the gate dielectric;
• a source region in the HVPW region;
• a drain region in the HVNW region, wherein the source and the drain regions are heavily doped with an n-type impurity;
• and
• a deep p-well region comprising a first portion and a second portion horizontally spaced apart from each other, wherein the first and the second portions are both underlying the HVNW region.

A semiconductor structure comprising:

• a semiconductor substrate;
• a high-voltage p-well (HVPW) region overlying the semiconductor substrate;
• a high-voltage n-well (HVNW) region overlying the semiconductor substrate, wherein the HVPW and the HVNW regions are in contact with each other and form an interface therebetween;
• an insulation region extending from a top surface of the HVNW region into the HVNW region;
• a gate dielectric extending from over the HVPW region to over the insulation region;
• a gate electrode on the gate dielectric;
• a source region in the HVPW region;
• a drain region in the HVNW region, wherein the source and the drain regions are heavily doped n-type regions, and wherein the drain region has an inner edge adjoining the insulation region, and an outer edge away from the insulation region;
• and
• a deep p-well region underlying the HVNW region, wherein the deep p-well region has an inner edge and an outer edge, and wherein the inner edge and the outer edge of the deep p-well region are horizontally between the interface and the inner edge of the drain region.