SiC VJFET with edge termination for dual tilted gate implants

A semiconductor device, comprising:

• a substrate;
• an epitaxial layer on the substrate, the epitaxial layer having a first conductivity type;
• an active region comprising a plurality of alternating trenches and mesas in the epitaxial layer, the plurality of alternating trenches and mesas extending in a first direction;
• an edge termination region adjacent the active region and comprising a first edge termination region and a second edge termination region, wherein the edge termination region comprises first and second guard ring trenches adjacent the active region, wherein the first and second guard ring trenches are separated by a termination mesa that extends in the first direction in the first edge termination region and extends in a second direction, perpendicular to the first direction, in the second edge termination region;
• and
• first and second implanted guard rings in the first and second guard ring trenches respectively, wherein a distance between the first and second guard rings in the first edge termination region is substantially the same as a distance between the first and second guard rings in the second edge termination region.

A method of forming a semiconductor device, comprising:

• providing an epitaxial layer on a substrate, the epitaxial layer having a first conductivity type;
• providing an active region comprising a plurality of alternating trenches and mesas in the epitaxial layer, the plurality of alternating trenches and mesas extending in a first direction;
• and
• providing an edge termination region adjacent the active region, the edge termination region having a first edge termination region and a second edge termination region, wherein the edge termination region comprises first and second guard ring trenches adjacent the active region that are separated by a termination mesa that extends in the first direction in the first edge termination region and extends in a second direction, perpendicular to the first direction, in the second edge termination region;
• wherein the termination mesa has a first width in the first edge termination region and a second width in the second edge termination region that is different from the first width.

A method of forming a semiconductor device, comprising:

• providing an epitaxial layer on a substrate, the epitaxial layer having a first conductivity type;
• providing an active region comprising a plurality of alternating trenches and mesas in the epitaxial layer, the plurality of alternating trenches and mesas extending in a first direction;
• providing an edge termination region adjacent the active region, wherein the edge termination region comprises first and second guard ring trenches adjacent the active region, wherein the first and second guard ring trenches are separated by a termination mesa, wherein the termination mesa comprises a first mesa region extending in the first direction and a second mesa region extending in a second direction;
• and
• providing first and second implanted guard rings in the first and second guard ring trenches respectively, wherein a distance between the first and second guard rings in the first mesa region is substantially the same as a distance between the first and second guard rings in the second mesa region.

A method of forming a semiconductor device, comprising:

• providing an epitaxial layer on a substrate, the epitaxial layer having a first conductivity type;
• providing an active region comprising a plurality of alternating trenches and mesas in the epitaxial layer, the plurality of alternating trenches and mesas extending in a first direction;
• and
• providing an edge termination region adjacent the active region, wherein the edge termination region comprises first and second guard ring trenches adjacent the active region, wherein the first and second guard ring trenches are separated by a termination mesa, wherein the termination mesa comprises a first mesa region extending in the first direction and a second mesa region extending in a second direction;
• and
• implanting second conductivity ions at an angle into the plurality of mesas in the active region and the termination mesa to form sidewall implanted regions in sidewalls of the plurality of mesas in the active region and the termination mesa, the sidewall implanted regions having the second conductivity type;
• wherein the second conductivity ions are implanted into the plurality of mesas in the active region and the termination mesa at more than four twist directions.