Effect of SiC-JFET Structure on High Temperature and Noise Characteristics Used in Preamplifier

In specialized fields such as fusion energy, aerospace, and nuclear power, radiation detectors are often required to operate reliably at high temperatures. Wide-bandgap semiconductors offer a promising pathway for developing more compact, sensitive, and high-precision detection systems. However, conventional silicon-based preamplifiers suffer from performance degradation and increased noise under elevated temperatures, limiting the effectiveness of these advanced detectors. Silicon carbide (SiC) devices present a compelling alternative for realizing high-temperature, low-noise preamplifiers. This study investigates the electrical output characteristics and noise performance of SiC-based junction field-effect transistors (JFETs) at high temperatures. Due to the intrinsic properties of SiC—such as its wide bandgap and incomplete ionization—simply substituting silicon with SiC in an identical structure does not achieve optimal results. Building on prior research, this work systematically explores how JFET structural design influences device performance by comparing the electrical characteristics and output noise of devices with varying channel parameters across a range of temperatures. The results highlight the effects of channel doping concentration and channel height on transconductance and equivalent output noise under high-temperature conditions, offering valuable design guidance for low-noise, high-temperature SiC-JFETs. Furthermore, this paper presents the experimental fabrication and performance evaluation of SiC-JFETs specifically designed for front-end circuits in nuclear electronics. Key electrical parameters are analyzed as functions of temperature. These findings provide a foundation for advancing SiC-JFET-based front-end electronics in nuclear detection systems.