A new power W-gated trench MOSFET (WMOSFET) with high switching performance

Recent technical trends and future prospects of IGBTs and power MOSFETs

“…9. Figure 9(a) shows a LV MOSFET with the breakdown voltage of 35 V which has reduced feedback capacitance by increasing the thickness of the oxide film in the trench bottom [7]. A 27% reduction from 762 pF to 207 pF at drain voltage of 0 V and a 55 % reduction from 163 pF to 89 pF at drain voltage of 30 V have been realized when compared with the conventional structure.…”

Modeling the Impact of the Trench Depth on the Gate–Drain Capacitance in Power MOSFETs

“…Since increasing the trench depth increases the gate-drain overlap, it is expected to cause higher C GD and has been demonstrated to do so by previous studies [2]. To mitigate this, concepts like the thick bottom oxide (TBO), the W-gated trench [3] and the split gate have been developed to reduce C GD without compromising on the conduction loss benefit of the trench structure. However, deeper trenches are known to reduce conduction losses because of increased modulation of the accumulation charge at the drain.…”

“…2. To understand this, we need to refer back to (1), where the C GD is expressed as a series combination of C GOX and the C D and to (3) where C GOX is expressed as a parallel combination of C OX and C BO (and the dependence of C GOX on the trench depth is taken into account). At low V D , the depletion width is small; hence C D is large meaning that C GD is dominated by C GOX .…”

Monolithic Integration of Trench Power JFET with Schottky Diode

“…For the SyncFET it's more important to reduce the specific on-resistance Rds,on in order to reduce the conduction loss. Trench MOSFETs have been the dominant devices for the SyncFET due to its extremely low Rds,on that can be achieved today [1][2][3]. However, due to the inherent body diode of conventional trench DMOSFET, a significant portion of the power loss is generated during the dead time; especially when the switching frequency is pushed higher in order to reduce the output capacitance.…”