An electronic device includes a substrate having a second conductivity type including a semiconductor surface layer with a buried layer (BL) having a first conductivity type. In the semiconductor surface layer is a first doped region (e.g., collector) and a second doped region (e.g., emitter) both having the first conductivity type, with a third doped region (e.g., a base) having the second conductivity type within the second doped region, wherein the first doped region extends below and lateral to the third doped region. At least one row of deep trench (DT) isolation islands are within the first doped region each including a dielectric liner extending along a trench sidewall from the semiconductor surface layer to the BL with an associated deep doped region extending from the semiconductor surface layer to the BL. The deep doped regions can merge forming a merged deep doped region that spans the DT islands.