Comparison between biased and floating guard rings used as junction termination technique

Passivation in High-Power Si Devices - An Overview

“…There are several works on the interaction of termination and passivation structures of high-power silicon devices published, see, for example Refs. [26][27][28][29]. Macary et al have modeled the avalanche breakdown for biased ring structures and floating rings [26].…”

“…[26][27][28][29]. Macary et al have modeled the avalanche breakdown for biased ring structures and floating rings [26]. They concluded that a Biased Ring structure needs a smaller area than a Floating Ring structure and is less sensitive to the inter-ring distances and interface charges.…”

Modeling of terminal ring structures for high-voltage power MOSFETs

“…Thus it is not viable to operate a VDMOS or other power MOS transistor for over a couple hundred volts. To operate a MOS transistor over a couple hundred volts with reasonable low R on value, extra voltage blocking structure has to be used in addition to the vertical layout of the MOS transistors [7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

“…This is because the device breakdown in a finite size MOSFET is mainly due to the field crowding at the junction edges and at silicon oxide interface. The adverse effect of the field crowding can be alleviated by field re-distribution, which can be achieved by various termination structures discussed in the literatures, such as the field ring termination (FLR) [8,10], the field plate (FP) [11], the semi-insulating polycrystalline silicon (SIPOS) [12], the junction termination extension (JTE) [13,14], the spiral junction termination (SJT) [15], reduced surface field (RES-URF) [16], the mesa or buried structure [17][18][19], and the variation lateral doping (VLD) [20], etc. Amongst all the possible termination techniques, the multiple floating field limiting rings (MFFLRs) is found to be the most popular structure to increase the voltage blocking capability of the power MOSFETs.…”

Passivation in High-Power Si Devices - An Overview

“…Charitat and co-workers published several works on the interaction of termination and passivation structures of high-power silicon devices, see, for example Refs. [12][13][14]. In conclusion of their works, termination and passivation areas cannot be strictly separated any longer, leading to complex three-dimensional structures for termination and passivation areas of high-power silicon devices.…”