Accurate current sensor for lateral IGBT smart power integration

摘要

This paper describes research work on the design and fabrication of a current sensor suitable for smart power integration in lateral insulated-gate bipolar transistor (LIGBT) structure. In general, the proposed design can also be used for various types of MOS-controlled bipolar transistor structures. Both the electron and hole current sensor layers are integrated in a concise form within the device structure. The sensing performance was further refined with the proposed flat-top doping profile achievable through a double-implantation, single-anneal and post-anneal-oxidation approach. The integrated structure was fabricated on silicon wafer with laboratory measurements performed to verify its electrical performance. The sensing ratio is maintained at a relatively constant level with a variation of within ±0.46% and ±1.2% (as a switching device), and ±0.85% and ±1.73% (as an amplifier device), respectively, when anode current and gate voltage vary. For operating temperature range of 300 K to 400 K, the sensor is able to maintain a sensing ratio within ±5.2% variation.