Papers by Author: P. Martin

Abstract: In this work we have demonstrated the high-temperature operations of 600 V/50 A 4HSiC vertical-channel junction field-effect transistors (VJFETs) with an active area of 3 mm2. Specific-on resistance (RONSP) in the linear region of a single die is less than 2.6 mW.cm2 while the drain-source current is over 50 A under a gate bias (VGS) of 3 V. A reverse blocking gain of 54 is obtained at gate bias ranging from -13 V to -23 V and drain-source leakage current (IRDS) of 200 μA. To demonstrate the use of SiC VJFETs for high-power applications, eight 3 mm2 SiC VJFETs are bonded in a high current 600-V module. RONSP in the linear region of these eight-paralleled SiC VJFETs is 2.8 mW.cm2 at room temperature and increased to 5.35 mW.cm2 at an ambient temperature of 175 °C in air, corresponding to a shift of 0.61%/°C from room temperature to 175 °C. Meanwhile, the forward current is over 360 A at room temperature and reduces to 188 A at 175 °C at drain-source bias (VDS) of 5.25 V and VGS of 3 V.

Abstract: In this work we report the most recent high-temperature long-term reliability results of the 600 V/14 A, 4H-SiC vertical-channel junction field-effect transistors (VJFETs). Two groups (A and B) devices were subjected to different thermal and electrical stresses. One device (Group A) reached 12,000 hours of continuous switching without a single failure. Four devices in Group A were thermally stressed at 250 °C over 4,670 hours in air, for which standard deviation of the specific on-resistance (RONSP) in linear region at gate bias (VGS) of 3 V were < 4.1% throughout the entire duration time. The off-state characteristics were evaluated by high temperature reverse bias (HTRB) tests. Three devices (Group A) were biased at 50% rated BVDS at 250 °C for 2,278 hours. A higher reverse bias at 80 % rated BVDS was then applied to 14 devices (group B) at 200 °C for 1,000 hours. Variations of the leakage current were negligible throughout the entire HTRB test for all tested devices.