Regrowth uniformity in gan vertical devices

A method of fabricating a semiconductor device, comprising:

• providing a substrate structure comprising:
• a semiconductor substrate having a first conductivity type;
• a drift layer of the first conductivity type coupled to the semiconductor substrate;
• a fin array comprising a plurality of rows of fins on the drift layer, the plurality of rows of fins including a first row of fins and a second row of fins, the first row of fins comprising a plurality of first elongated fins arranged in parallel to each other along a first row direction and separated by a first distance, and the second row of fins comprising a plurality of second elongated fins arranged in parallel to each other along a second row direction and separated by a second distance, wherein each of the first distance and the second distance is non-uniform varying from a small distance in an edge region of the semiconductor substrate to a large distance in a center region of the semiconductor substrate;
• and
• a space between the first row of fins and the second row of fins;
• and
• providing a gate layer of a second conductivity type opposite the first conductivity type on the drift layer and adjacent to each of the plurality of first elongated fins and each of the plurality of second elongated fins.

A method of fabricating a semiconductor device, the method comprising:

• providing a substrate structure comprising:
• a semiconductor substrate of a first conductivity type,
• a drift layer coupled to the semiconductor substrate, and
• a fin array coupled to the drift layer and surrounded by a recess region,
• wherein:
• the fin array comprises a first row of fins and a second row of fins parallel to each other and separated from each other by a space;
• the first row of fins comprising a plurality of first elongated fins extending parallel to each other in a first direction and arranged with a first distance between each other;
• the second row of fins comprising a plurality of second elongated fins extending parallel to each other in a second direction parallel to the first direction;
• and
• the plurality of first elongated fins and the plurality of second elongated fins are arranged in a plurality of columns, a first portion of the plurality of first elongated fins and a first portion of the plurality of second elongated fins in a first column having a length different than a length of a second portion of the plurality of first elongated fins and a second portion of the plurality of second elongated fins in a second column adjacent to the first column;
• and
• providing a gate layer of a second conductivity type opposite to the first conductivity type adjacent to each fin in the first row of fins and the second row of fins.