Experimental Demonstration of a 1.2-kV Trench Clustered Insulated Gate Bipolar Transistor in Field-Stop Technology

In this paper a 1.2 kV, 50 A trench clustered IGBT is experimentally demonstrated in field-stop technology for the first time. Due to the optimized field stop layer design, the off-state leakage current is lower than 1 mA at 175°C. A low on-state voltage drop of 1.6 V is achieved at 150°C. The saturation current levels are effectively controlled by the self-clamping feature. Moreover, experimental results confirm that the fabricated devices exhibit dynamic avalanche-free switching performance as well as high dV/dt controllability

Numerical Analysis of 3-Dimensional Scaling Rules on a 1.2-kV Trench Clustered IGBT

3-dimensional scaling rules for the cathode cells and threshold voltages of a 1.2-kV Trench Clustered IGBT (TCIGBT) are investigated using calibrated models in Synopsys Sentaurus TCAD tools. Scaling down results in an enhancement of current gain of the inherent thyristor action which reduces the forward voltage drop even more than that of a scaled Trench IGBT (TIGBT). For identical switching losses, at a scaling factor k=3, the forward voltage drop is reduced by 20% at 300K and 30% at 400K when compared to the conventional TCIGBT (k=1). Most importantly, despite its lower conduction losses than an equivalent TIGBT, a scaled TCIGBT structure can maintain its short circuit capability, due to the additional scaling principle applied to the n-well and p-well regions, maintaining the self-clamping feature. Thus, TCIGBT is a more efficient chip-for-chip, reliable replacement of a TIGBT for energy savings in applications

Evaluation of turn-off dV/dt controllability and switching characteristics of 1.2 kV GaN polarisation superjunction heterostructure field-effect transistors

Japanese Journal of Applied Physics The Japan Society of Applied Physics, find out more REGULAR PAPER • THE FOLLOWING ARTICLE ISOPEN ACCESS Evaluation of turn-off dV/dt controllability and switching characteristics of 1.2 kV GaN polarisation superjunction heterostructure field-effect transistors Alireza Sheikhan1, Sankara Narayanan Ekkanath Madathil1, Hiroji Kawai2, Shuichi Yagi2 and Hironobu Narui2 Published 5 July 2023 • © 2023 The Author(s). Published on behalf of The Japan Society of Applied Physics by IOP Publishing Ltd Japanese Journal of Applied Physics, Volume 62, Number 6 Citation Alireza Sheikhan et al 2023 Jpn. J. Appl. Phys. 62 064502 DOI 10.35848/1347-4065/acd975 DownloadArticle PDF Figures References Download PDF 290 Total downloads Turn on MathJax Share this article Share this content via email Share on Facebook (opens new window) Share on Twitter (opens new window) Share on Mendeley (opens new window) Hide article and author information Author e-mails [email protected] Author affiliations 1 Department of Electronic and Electrical Engineering, The University of Sheffield, Sheffield, United Kingdom 2 Powdec K.K. Oyama, Tochigi, Japan ORCID iDs Alireza Sheikhan https://orcid.org/0000-0002-2207-1593 Dates Received 16 April 2023 Revised 18 May 2023 Accepted 26 May 2023 Published 5 July 2023 Check for updates using Crossmark Buy this article in print Journal RSS Sign up for new issue notifications Create citation alert Abstract Gallium nitride (GaN) devices inherently offer many advantages over silicon power devices, including a higher operating frequency, lower on-state resistance and higher operating temperature capabilities, which can enable higher power density and more efficient power electronics. Turn-off dV/dt controllability plays a key role in determining common-mode voltage in electrical drives and traction inverter applications. The fast-switching edges of GaN can introduce challenges such as electromagnetic interference, premature insulation failure and high overshoot voltages. In this paper, the device working principle, characteristics and dV/dt controllability of 1.2 kV GaN polarisation superjunction (PSJ) heterostructure FETs (HFETs) are presented. The effect of gate driving parameters and load conditions on turn-off dV/dt are investigated. It is shown that in PSJ HFETs the dV/dt can be effectively controlled to as low as 1 kV μs−1 by controlling the gate, with a minimum increase in switching losses. These results are highly encouraging for the application of the devices in motor drives

Dynamic avalanche free super junction-TCIGBT for high power density operation

Dynamic Avalanche (DA) effects in the Super-Junction Trench IGBTs are analyzed through 3-D TCAD simulations for the first time. A DA free solution for high power density and low loss is proposed and demonstrated in detail. Furthermore, simulation results show that DA results in significant increase in turn-off losses in the Super-Junction Trench IGBTs at high current density operations, which poses a fundamental limit on the power density of IGBT applications. In contrast, the Super-Junction Trench Clustered IGBTs remain DA free at high current density and show low switching losses due to enhanced PMOS action. Therefore, the Super-Junction Trench IGBTs are well suitable for high power density operations with a potential to operate beyond the 1-D unipolar 4H-SiC limit

High dV/dt controllability of 1.2kV Si-TCIGBT for high flexibility design with ultra-low loss operation

High dV/dt controllability of IGBT is an important factor for flexible design as well as low switching loss in power electronics systems. However, Dynamic Avalanche (DA) phenomenon poses a fundamental limit on their dV/dt control range, operating current density, turn-off power loss as well as reliability. Overcoming this phenomenon is essential to ensure their safe operation and high robustness in emerging electric transport. In this work, detailed analysis of 1.2 kV trench gated IGBTs is undertaken through experiments and calibrated TCAD 3-dimensional simulations to show the fundamental cause of the low dV/dt controllability of conventional IGBTs and a method to achieve DA free design by Trench Clustered IGBT (TCIGBT). The potential of TCIGBT for ultra-high current density operation with high dV/dt controllability is also presented

Effect of SiO2 surface passivation on the performance of GaN polarization superjunction heterojunction field effect transistors

In this article, the effects of the SiO2 surface passivation layer are reported on normally-on 1.2 kV GaN polarization superjunction (PSJ) heterojunction field effect transistors (HFETs) by comparing the electrical performances of PSJ HFETs with and without SiO2 surface passivation. A slight recovery of the 2D electron gas sheet density is observed in the slight negative shift of Vth after SiO2 surface passivation. Passivation also increases the breakdown voltage. This improvement may result from removing positive surface charges in defects along the P-GaN gate sidewall and top u-GaN layer after the specifically designed SiO2 surface passivation. Furthermore, the SiO2 surface passivation can also effectively suppress the surface gate leakage currents in the PSJ HFETs by eliminating the conductive channel created by the positive surface charges in defects

Theoretical analysis of on-state performance limit of 4H-SiC IGBT in field-stop technology

In this paper, the on-state performance limits of 4H-SiC IGBTs are theoretically estimated for the first time and compared against silicon counterparts. The theoretical analysis is based on the static modelling of a high-current PiN diode and the calculation results are examined with TCAD simulations. Owing to conductivity modulation effect, the on-state losses of 4H-SiC IGBTs do not show any significant increase with the increase in breakdown voltage. However, the large built-in potential of SiC poses an inherent limit on the reduction of on-state voltage drop. Compared with 4H-SiC IGBTs, the silicon based IGBTs exhibit superior on-state performance limits within the breakdown voltage range considered, although their drift layer thicknesses are 10 times higher than that of 4H-SiC IGBTs. Therefore, silicon IGBTs remain as efficient technologies for enhancing high power conversion efficiency

3-D scaling rules for high voltage planar clustered IGBTs

In this paper, an approach for design optimization of high voltage (≥ 3300 V) planar Clustered IGBT (CIGBT) is proposed and investigated through TCAD simulations. New 3-D scaling rules are employed in this approach to improve the electrical characteristics and widen the safe operating area. As shown in the simulation results, a scaled 4.5 kV field-stop CIGBT can achieve an on-state voltage drop of 1.78 V at Tj = 300 K and Jc = 50 A/cm2, mainly due to the enhancement of inherent thyristor action. High levels of turn-off robustness are maintained by the scaled CIGBTs. In addition, the scaling rules also result in improved short-circuit robustness due to control of current saturation levels. Furthermore, by integrating the 3-D scaling rules with the trench CIGBTs, the on-state performance shows significant improvement compared to the state-of-the-art IGBT technologies. Therefore, scaling rules on CIGBTs is a highly promising approach for enhancing the converter efficiency in medium and high voltage applications