Vertical GaN power MOSFET is a novel technology that offers great potential for power switching applications.Being still in an early development phase,vertical GaN devices are yet to be fully optimized and require car...Vertical GaN power MOSFET is a novel technology that offers great potential for power switching applications.Being still in an early development phase,vertical GaN devices are yet to be fully optimized and require careful studies to foster their development.In this work,we report on the physical insights into device performance improvements obtained during the development of vertical GaN-on-Si trench MOSFETs(TMOS’s)provided by TCAD simulations,enhancing the dependability of the adopted process optimization approaches.Specifically,two different TMOS devices are compared in terms of transfer-curve hysteresis(H)and subthreshold slope(SS),showing a≈75%H reduction along with a≈30%SS decrease.Simulations allow attributing the achieved improvements to a decrease in the border and interface traps,respectively.A sensitivity analysis is also carried out,allowing to quantify the additional trap density reduction required to minimize both figures of merit.展开更多
To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor(MOSFET) with a Schottky-drian(SD) and SD-connected semisuperjunctions(S...To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor(MOSFET) with a Schottky-drian(SD) and SD-connected semisuperjunctions(SDD-semi-SJ),named as SD-D-semi-SJ MOSFET is proposed and demonstrated by two-dimensional(2D) numerical simulations.The SD contacted with the n-pillar exhibits the Schottky-contact property,and that with the p-pillar the Ohmic-contact property.Based on these features,the SD-D-semi-SJ MOSFET could obviously overcome the great obstacle of the ineffectivity of the conventional superjunctions(SJ) or semisuperjunctions(semi-SJ) for the reverse applications and achieve a satisfactory trade-off between the reverse breakdown voltage(BV) and the specific on-resistance(R_(on)A).For a given pillar width and n-drift thickness,there exists a proper range of n-drift concentration(N),in which the SD-D-semi-SJ MOSFET could exhibit a better trade-off of R_(on)A-BV compared to the predication of SJ MOSFET in the forward applications.And what is much valuable,in this proper range of N,the desired BV and good trade-off could be achieved only by determining the pillar thickness,with the top assist layer thickness unchanged.Detailed analyses have been carried out to get physical insights into the intrinsic mechanism of R_(on)A-BV improvement in SD-D-semi-SJ MOSFET.These results demonstrate a great potential of SD-D-semi-SJ MOSFET in reverse applications.展开更多
基金funding from the Electronic Component Systems for European Leadership Joint Undertaking (ECSEL JU),under grant agreement No.101007229support from the European Union’s Horizon 2020 Research and Innovation Programme,Germany,France,Belgium,Austria,Sweden,Spain,and Italy
文摘Vertical GaN power MOSFET is a novel technology that offers great potential for power switching applications.Being still in an early development phase,vertical GaN devices are yet to be fully optimized and require careful studies to foster their development.In this work,we report on the physical insights into device performance improvements obtained during the development of vertical GaN-on-Si trench MOSFETs(TMOS’s)provided by TCAD simulations,enhancing the dependability of the adopted process optimization approaches.Specifically,two different TMOS devices are compared in terms of transfer-curve hysteresis(H)and subthreshold slope(SS),showing a≈75%H reduction along with a≈30%SS decrease.Simulations allow attributing the achieved improvements to a decrease in the border and interface traps,respectively.A sensitivity analysis is also carried out,allowing to quantify the additional trap density reduction required to minimize both figures of merit.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61574112,61334002,61306017,61474091,and 61574110)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.605119425012)
文摘To enhance the reverse blocking capability with low specific on-resistance,a novel vertical metal-oxidesemiconductor field-effect transistor(MOSFET) with a Schottky-drian(SD) and SD-connected semisuperjunctions(SDD-semi-SJ),named as SD-D-semi-SJ MOSFET is proposed and demonstrated by two-dimensional(2D) numerical simulations.The SD contacted with the n-pillar exhibits the Schottky-contact property,and that with the p-pillar the Ohmic-contact property.Based on these features,the SD-D-semi-SJ MOSFET could obviously overcome the great obstacle of the ineffectivity of the conventional superjunctions(SJ) or semisuperjunctions(semi-SJ) for the reverse applications and achieve a satisfactory trade-off between the reverse breakdown voltage(BV) and the specific on-resistance(R_(on)A).For a given pillar width and n-drift thickness,there exists a proper range of n-drift concentration(N),in which the SD-D-semi-SJ MOSFET could exhibit a better trade-off of R_(on)A-BV compared to the predication of SJ MOSFET in the forward applications.And what is much valuable,in this proper range of N,the desired BV and good trade-off could be achieved only by determining the pillar thickness,with the top assist layer thickness unchanged.Detailed analyses have been carried out to get physical insights into the intrinsic mechanism of R_(on)A-BV improvement in SD-D-semi-SJ MOSFET.These results demonstrate a great potential of SD-D-semi-SJ MOSFET in reverse applications.