Study on Electric Field Modulation and Avalanche Enhancement of SiC/GaN IMPATT Diode

Abstract

This paper proposes a 6H-materials silicon carbide (SiC)/gallium nitride (GaN) heterogeneous p-n structure to replace the GaN homogenous p-n junction to manufacture an impact-ionization-avalanche-transit-time (IMPATT) diode, and the performance of this 6H-SiC/GaN heterojunction single-drift-region (SDR) IMPATT diode is simulated at frequencies above 100 GHz. The performance parameters of the studied device were simulated and compared with the conventional GaN p-n IMPATT diode. The results show that the p-SiC/n-GaN IMPATT performance is significantly improved, and this is reflected in the enhanced characteristics in terms of operating frequency, rf power, and dc-rf conversion efficiency by the two mechanisms. One such characteristic that the new structure has an excessive avalanche injection of electrons in the p-type SiC region owing to the ionization characteristics of the SiC material, while another is a lower electric field distribution in the drift region, which can induce a higher electron velocity and larger current in the structure. The work provides a reference to obtain a deeper understanding of the mechanism and design of IMPATT devices based on wide-bandgap semiconductor materials.

Thin SiC and Gan-Based Films and Structures: Production and Properties

“…Surface-barrier structures on (SiC)1-x (AlN)x, n-type solid solution films are obtained on 6H-SiC substrates by high-frequency (13.56 MHz) magnetron sputtering of composite targets [17,18]. The sputtering coefficients are estimated from the change in the target weight after spraying: (1) where m -change in target mass (mgk), Im -target current (μA),t -sputtering time (h), A -mass number of the target atom.…”