Gate trench power semiconductor devices with deep jfet patterns

A semiconductor device, comprising:

• a semiconductor layer structure;
• and
• a plurality of gate trenches extending into the semiconductor layer structure,
• wherein the semiconductor layer structure comprises:
• a drift region having a first conductivity type;
• at least one well region having a second conductivity type on the drift region;
• a plurality of trench shields having the second conductivity type positioned below the respective gate trenches;
• a first junction field effect (“JFET”) pattern having the first conductivity type, the first JFET pattern comprising a plurality of spaced-apart first JFET regions that are positioned below and vertically overlaps the respective trench shields,
• wherein a first conductivity type dopant concentration of each first JFET region exceeds a first conductivity type dopant concentration of the drift region.

A semiconductor device, comprising:

• a semiconductor layer structure comprising:
• a drift region having a first conductivity type;
• a current spreading layer having the first conductivity type and a first conductivity dopant concentration that exceeds a first conductivity dopant concentration of the drift region on the drift region;
• a well region having a second conductivity type above the current spreading layer;
• and
• a first junction field effect (“JFET”) pattern having the first conductivity type that has a lower surface that extends deeper into the semiconductor layer structure than a lower surface of the current spreading layer, where the first JFET pattern includes a plurality of spaced apart first JFET regions, each of which has a first conductivity dopant concentration that exceeds a first conductivity dopant concentration of the current spreading layer;
• and
• a gate trench extending into the semiconductor layer structure.