Structures to avoid floating resurf layer in high voltage lateral devices

A semiconductor device, comprising:

• a semiconductor substrate comprising p-type material;
• a lateral extended drain n-channel metal oxide semiconductor (LDNMOS) transistor, comprising:
• a body of p-type semiconductor material disposed in the semiconductor substrate;
• and
• a drain drift region of n-type semiconductor material disposed in the semiconductor substrate, the drain drift region extending laterally to the body;
• a doped layer of p-type semiconductor material disposed in the semiconductor substrate over at least a portion of the drain drift region, the doped layer extending from the drain drift region to a top surface of the semiconductor substrate;
• and
• a vertical shunt of p-type semiconductor material disposed in the semiconductor substrate, the vertical shunt extending vertically through an opening in the drain drift region, between the doped layer and a p-type portion of the semiconductor substrate below the drain drift region.

A semiconductor device, comprising:

• a semiconductor substrate comprising p-type material;
• a lateral extended drain n-channel metal oxide semiconductor (LDNMOS) transistor, comprising:
• a body of p-type semiconductor material disposed in the semiconductor substrate;
• a source region within the body;
• a drain drift region of n-type semiconductor material disposed in the semiconductor substrate, the drain drift region extending laterally to the body;
• and
• a gate extending over a portion of the body region and a portion of the drain drift region;
• an oxide region at a portion of a top surface of the semiconductor substrate;
• a doped layer of p-type semiconductor material disposed in the semiconductor substrate over at least a portion of the drain drift region, the doped layer extending from the drain drift region to the top surface of the semiconductor substrate under the oxide region;
• a vertical shunt of p-type semiconductor material disposed in the semiconductor substrate, the vertical shunt extending vertically through an opening in the drain drift region, between the doped layer and a p-type portion of the semiconductor substrate below the drain drift region;
• an n-type buried layer in the semiconductor substrate below the body;
• and
• an n-type sinker in the semiconductor substrate, the n-type buried layer extending from the drain drift region to the n-type sinker, the n-type buried layer and n-type sinker isolating the body from a portion of the semiconductor substrate below the n-type buried layer.