Potential performance of SiC and GaN based metal semiconductor field effect transistors

Abstract

A Monte Carlo simulation has been used to model steady-state electron transport in SiC and GaN field effect transistor. The simulated device geometries and doping are matched to the nominal parameters described for the experimental structures as closely as possible. Simulations of SiC MESFETs of lengths 2, 2.6 and 3.2 µm have been carried out and compared these results with those on GaN MESFETs of the same dimensions. The direct current IV characteristics of the two materials were found to be similar, though the GaN characteristics were on the whole superior, reaching their operating point at higher drain voltages and possessing higher gains. However, oscillations in the drain current caused by changes in drain voltage in the GaN devices were not present to the same degree in the SiC devices. This difference is caused partially by the onset of the negative differential regime in SiC at a higher electric field than in GaN but the primary cause is the longer ballistic transport times in SiC. This suggests that GaN MESFETs may prove to have superior frequency response characteristics than SiC MESFETs.

Review of using gallium nitride for ionizing radiation detection

“…4 GaN can also be used for detecting ionizing radiation under extreme radiation conditions due to its properties such as a wide band-gap (3.39 eV), large displacement energy (theoretical values averaging 109 6 2 eV for N and 45 eV for Ga), 5 and high thermal stability (melting point: 2500 C). 6 Compared to narrower band-gap semiconductors such as silicon, GaN can operate at higher temperatures; while a comparison with other wide band-gap semiconductors, such as silicon carbide, demonstrates GaN's higher electron mobility 7 and potential for better carrier transport properties. In addition, the high Z-value and density of GaN makes it a suitable material for X-ray detection in medical imaging.…”

A novel symmetric GaN MESFET by dual extra layers of Si3N4

“…The GaN is a wide band gap semiconductor with high breakdown field and low thermal generation rate. These properties combined with good thermal conductivity and stability make it as an attractive material for high power, high temperature, and high electron mobility devices including MESFETs [11][12]. The fabricated device from these materials are predicted to have over superior DC and RF performances compared to the conventional devices fabricated based on Si and GaAs [13].…”

Study of transient response characteristics of electrons in GaN by Monte Carlo method

“…Monte Carlo methods have been widely used to study carrier transport in GaN because they provide a nearly exact solution of the Boltzmann transport equation by treating accurately the hot-electron effects in GaN. This cannot be accomplished by the drift diffusion models [3]. The transferred-electron (TE) effect at high electric fields due to inter-valley scattering gives rise to a negative differential resistance (NDR) in GaN [4].…”