Silicon Carbide Junction Field‐Effect Transistors (SiCJFETs)

Abstract

Wide bandgap semiconductors like silicon carbide (SiC) are currently being developed for high‐power/high‐temperature applications. Silicon carbide (SiC) is ideally suited for power switching because of its high saturated drift velocity, its high critical field strength, its excellent thermal conductivity, and its mechanical strength. For power devices, the 10‐fold increase in critical field strength of SiC relative to Si allows high‐voltage blocking layers to be fabricated significantly thinner than those of comparable Si devices. This reduces device ON‐state resistance and the associated conduction and switching losses, while maintaining the same high‐voltage blocking capability. The specific ON‐state resistance of 4H‐SiC is approximately 400 times lower than that of Si at a given breakdown voltage. This allows for high current operation at relatively low forward voltage drop. In addition, the wide bandgap of SiC allows operation at high temperatures where conventional Si devices fail. In this article, we will review the SiC single‐implant no epitaxial regrowth vertical channel junction field‐effect transistor (JFET). The feasibility of efficient 1200 V normally OFF JFET operation will be investigated. The all‐SiC JFET‐based cascode switch will be introduced and aspects of its operation evaluated. High‐temperature direct‐current (dc) characteristics of JFETs and 1200 V normally OFF cascode switches will be discussed. Large‐area high‐current JFETs and their current sharing and switching performances will be presented. Aspects of JFET fabrication, including their edge termination, will be provided. JFET wafer yields and parameter uniformities will be presented. Hard and unclamped inductive JFET switching evaluations will be introduced. Finally, a 9‐kV JFET will be introduced and its reliability under bipolar stress will be examined.

A Monolithically Integrated SiC Circuit Breaker

“…To realise the proposed "thyristor dual" concept depicted in Fig. 1a using an existing 4H-SiC JFET process technology [27], [28], the topology shown in Fig. 1b is employed.…”

Applications, Prospects and Challenges of Silicon Carbide Junction Field Effect Transistor (SIC JFET)

“…Moreover, the on-state resistance of 4H-SiC JFET may be up to 400 times lower than that of Si at a specific breakdown voltage. Thereby permitting its use in high current circuits with a comparatively lesser forward voltage drop [3]. The N-OFF SiC JFETs are more recent and desirable than N-ON SiC JFET [17].…”

“…In this context, SiC offers great potential for the realization of high power devices owing to its attractive properties. When compared with Si materials they have ten times higher breakdown electric field; three times wider band gap -about 3 eV at 27 0 C and higher thermal conductivity; and two times higher saturation velocity [2], [3]. In addition, intrinsic charge carrier concentration of SiC material is lower than the corresponding value for Si which is principally attributed to the wide band-gap of SiC [4]- [9].…”

Temperature Dependent Analytical Model for the Threshold Voltage of the SiC VJFET with a Lateral Asymmetric Channel

“…Compared with the SiC MOSFET, SiC VJFET received a lot of attention because of its threshold voltage (V th ) stability for different temperature values, since no reliability issues appear with gate oxide on contrary to SiC MOSFETs [5][6][7]. Different structures of the SiC VJFET device have been developed and studied [16][17][18][19][20][21][22][23][24][25]. Among of them, in this paper, the SiC LC-VJFET of Figure 1 [16,20] is investigated under a physical model of the threshold voltage.…”