Improving the horizontal current bipolar transistor breakdown voltage by floating field plates

A method for improvement of breakdown voltage of the Horizontal Current Bipolar Transistor (HCBT) by application of floating field plates (FFPs) is presented. The FFPs are used for shaping of the potential distribution and the electric field in the base-collector depletion region. The BV
_CEo
improvement from 13 V to 25 V by the addition of one FFP to a double-emitter HCBT is demonstrated by measurements of fabricated devices. The FFP is fabricated by the extrinsic base implantation and is aligned to the extrinsic base, allowing for ideal control of the electric field shaping. New structure is added to the HCBT BiCMOS process flow at zero-cost. Simulations show that multiple FFPs can be used for the increase of the BV
_ceo
in discrete steps. BV
_CEO
of 44 V is achieved by using 5 FFPs.