Lateral depletion-mode 4H-SiC n-channel junction field-effect transistors operational at 400 °C*

This paper presents the development of lateral depletion-mode n-channel 4H-SiC junction field-effect transistors (LJFETs) using double-mesa process toward high-temperature integrated circuit (IC) applications. At room temperature, the fabricated LJFETs show a drain-to-source saturation current of 23.03 mu A/mu m, which corresponds to a current density of 7678 A/cm(2). The gate-to-source parasitic resistance of 17.56 k omega . mu m is reduced to contribute only 13.49% of the on-resistance of 130.15 k omega . mu m, which helps to improve the transconductance up to 8.61 mu S/mu m. High temperature characteristics of LJFETs were performed from room temperature to 400 degrees C. At temperatures up to 400 degrees C in air, it is observed that the fabricated LJFETs still show normally-on operating characteristics. The drain-to-source saturation current, transconductance and intrinsic gain at 400 degrees C are 7.47 mu A/mu m, 2.35 mu S/mu m and 41.35, respectively. These results show significant improvement over state-of-the-art and make them attractive for high-temperature IC applications.