A semiconductor device has a deep trench in a semiconductor substrate of the semiconductor device, with linear trench segments extending to a trench intersection. Adjacent linear trench segments are connected by connector trench segments that surround a substrate pillar in the trench intersection. Each connector trench segment has a width at least as great as widths of the linear trench segments connected by the connector trench segment. The deep trench includes a trench filler material. The deep trench may have three linear trench segments extending to the trench intersection, connected by three connector trench segments, or may have four linear trench segments extending to the trench intersection, connected by four connector trench segments.