Lateral bipolar transistor with emitter and collector regions including portions within In-insulator layer cavities and method

A structure comprising:

• an insulator layer,
• a semiconductor layer on the insulator layer;
• an emitter region comprising:
• an emitter portion of the semiconductor layer;
• and an emitter semiconductor layer partially filling an emitter cavity in the insulator layer and adjacent to the emitter portion, the emitter semiconductor layer comprising an upper portion over a top surface of the emitter portion of the semiconductor layer;
• a collector region comprising:
• a collector portion of the semiconductor layer;
• and a collector semiconductor layer partially filling a collector cavity in the insulator layer and adjacent to the collector portion, the collector semiconductor layer comprising an upper portion over a top surface of the collector portion of the semiconductor layer;
• and
• a base region positioned laterally between the emitter region and the collector region wherein the emitter cavity and the collector cavity each extend laterally partially below the base region.

A method comprising:

• forming a base region;
• and
• forming an emitter region and a collector region,
• wherein the base region is positioned laterally between the emitter region and the collector region,
• wherein the emitter region comprises:
• an emitter portion of a semiconductor layer on an insulator layer;
• and an emitter semiconductor layer within an emitter cavity in the insulator layer and immediately adjacent to the emitter portion, the emitter semiconductor layer comprising an upper portion over a top surface of the emitter portion of the semiconductor layer,
• wherein the collector region comprising:
• a collector portion of the semiconductor layer;
• and a collector semiconductor layer within a collector cavity in the insulator layer and immediately adjacent to the collector portion, the collector semiconductor layer comprising an upper portion over a top surface of the collector portion of the semiconductor layer, and
• wherein the emitter cavity and the collector cavity each extend laterally partially below the base region.