SiC trench MOSFET with integrated side-wall Schottky barrier diode having P⁺ electric field shield

Abstract

A new SiC trench MOSFET (T-MOSFET) integrated with a side-wall Schottky Barrier Diode (SBD) to form a compact power device is proposed. The proposed structure applies two trenches to form the n-channel and SBD in a single cell, respectively. A P + is implanted after etching the trenches to form a shield for both the gate oxide and the Schottky barrier. The breakdown voltage of the proposed one is about 363% larger than that of the conventional trench MOSFET (CT-MOSFET) with integrated SBD. The integrated SBD of the proposed T-MOSFET exhibits an ultra-low leakage current (1 µA/cm 2 ) and low forward voltage drop (V on_diode ≈ 0.9 V), as well as low reverse recovery charge (Q rr = 0.73 µC/cm 2 ).

An Investigation of Body Diode Reliability in Commercial 1.2 kV SiC Power MOSFETs with Planar and Trench Structures

“…Trench SiC power MOSFETs, due to their relatively complex process, may not have the cost advantage of planar SiC power MOSFETs [31]. Integrating an external Schottky diode may exacerbate this cost disadvantage, eroding the benefits provided by the smaller cell pitch of trench SiC power MOSFETs [32]. Furthermore, there are variations in the characteristics of P-type implants among different vendors and even different generations of trench SiC power MOSFETs from the same vendor, making the research on the reliability of the body diode in SiC power MOSFETs essential.…”

A novel SiC trench MOSFET with integrated Schottky barrier diode for improved reverse recovery charge and switching loss

“…In [8][9][10][11], it was reported that SBD was integrated by splitting the P-base or gate of power MOSFET, of which the performance degenerates resulting from the cell pitch increases. Yi et al [12] proposed a float P+-shield region (PSR) trench MOSFET with integrated SBD but the floating PSR will introduce reliability problems [13]. Kobayashi et al [14] proposed a SWITCH-MOS with integrated sidewall SBD.…”

“…In [8][9][10][11], it was reported that SBD was integrated by splitting the P-base or gate of power MOSFET, of which the performance degenerates resulting from the cell pitch increases. Yi et al [12] proposed a float P+-shield region (PSR) trench MOSFET with integrated SBD but the floating PSR will introduce reliability problems [13]. Kobayashi et al This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.…”

“…The simulation results show that, compared with Infineon's Cool-SiC™ trench MOSFET (CoolMOS), the proposed new structure can greatly improve the reverse recovery characteristics and decrease the switching energy loss without any degradation of other performance. The proposed MOSFET also provides a solvation to improve the device integration and reduce the specific resistance of SBD-integrated UMOSFET [12,14,15].…”

“…Yi et al. [12] proposed a float P+‐shield region (PSR) trench MOSFET with integrated SBD but the floating PSR will introduce reliability problems [13]. Kobayashi et al.…”