Shanghai, China, November 12, 2024- Toshiba Electronic Components and Storage Devices Co., Ltd. ("Toshiba") announced today that it has developed a new bare chip [2] 1200 V silicon carbide (SiC) MOSFET "X5M007E120" for automotive traction inverters [1]. Its innovative structure enables low on resistance and high reliability. X5M007E120 has now started providing test samples for customer evaluation.

When the body diode of a typical SiC MOSFET is bipolar energized during reverse conduction operation [3], its reliability decreases due to an increase in on resistance. Toshiba SiC MOSFET alleviates the above problems by embedding SBD (Schottky barrier diode) in MOSFET to weaken the device structure of body diode operation. However, if SBD is arranged on the chip, it will reduce the board area provided for channels. The board area not only determines the resistance of MOSFET conduction operation, but also increases the conduction resistance of the chip.

The SBD embedded in X5M007E120 adopts a grid pattern arrangement instead of the commonly used bar pattern. This arrangement can efficiently suppress the bipolar conduction of the diode body, and even if it occupies the same SBD mounting area, it can increase the upper limit of unipolar operation to about twice the current area. In addition, channel density can also be increased for strip arrays, and the on resistance per unit area is very low, reducing it by approximately 20% to 30% [5]. This improved performance, low on resistance, and reliability for reverse conduction operation can save energy for inverters used in motor control, such as traction inverters.

Reducing the on resistance of SiC MOSFET can lead to excessive current flowing through the MOSFET during short circuit [6], thereby reducing the durability of the short circuit. In addition, enhancing the conduction of embedded SBDs and improving the reliability of reverse conduction operation will also increase the leakage current during short circuits, thereby further reducing the durability of short circuits. The latest bare chip has a deep barrier structure design [7], which can suppress the excessive current of MOSFET and the leakage current of SBD in short-circuit state. This can improve its durability while maintaining extremely high reliability for reverse conduction operation.

Users can customize bare chips according to their specific design requirements to achieve solutions tailored to their applications.

Toshiba expects to provide engineering samples of X5M007E120 in 2025 and put it into mass production in 2026, while further exploring improvements in device features.

Toshiba will provide customers with more user-friendly and high-performance power semiconductor products, fully meeting the application needs of energy efficient fields such as motor control inverters and electric vehicle power control systems, thus contributing to the realization of a decarbonized society.

Application:

-Vehicle mounted traction inverter

characteristic:

-Low on resistance and high reliability

-Vehicle mounted bare chip

-Passed AEC-Q100 certification

-Rated drain source voltage: VDSS=1200 V

-Rated value of drain current (DC): ID=(229) A [8]

-Low on resistance:

RDS (ON)=7.2 m Ω (typical value) (VGS=+18 V, Ta=25 ° C)

RDS (ON)=12.1 m Ω (typical value) (VGS=+18 V, Ta=175 ° C)

Main specifications:

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Note:

[1] A device that can convert battery powered DC power into AC power and control electric vehicle (EV) or hybrid electric vehicle (HEV) motors.

[2] Unpackaged chip products.

[3] The operation in which current flows from the source to the drain due to current backflow in a circuit.

[4] Bipolar operation when a forward voltage is applied to the pn diode between the drain and source.

[5] Compared to products that use bar shapes.

[6] Compared with the short-term conduction during normal switch operation, the phenomenon of long-term conduction in abnormal modes such as control circuit faults requires a strength that will not cause faults for a certain duration of short-circuit operation.

[7] The device structural components provided to control the high electric field generated by high voltage can have a significant impact on device performance.

[8] Provisional value.