High-voltage termination-structure design using a test chip and two-dimensional simulation

The variation in breakdown voltage for high-voltage diodes with varying field-ring termination designs is examined using a junction-termination test chip. The experimental results are explained using two-dimensional simulation of the diode reverse I-V characteristics. A test chip is used to examine the performances of ten different floating-ring termination structures. Both three-ring and six-ring structures are included. For all substrate resistivities, the best termination structure is able to provide the nominal breakdown voltage, while less effective designs are insufficient. In general, the best performance is obtained from structures with closely spaced rings. The experimental results also point toward possible improvements in the termination structures (closer ring spacing)