Temperature-dependent tunneling through thermally grown SiO2 on n-type 4H– and 6H–SiC

Abstract

The temperature dependence of field emission through thermally grown silicon dioxide (SiO2) on n-type 4H and 6H silicon carbide (SiC) substrates is reported. Room-temperature SiO2/SiC barrier heights, ΦB, of 1.92 and 2.12 V are extracted for the 4H– and 6H–SiC samples, respectively, using a Fowler–Nordheim analysis. Barrier heights of 2.2 and 2.4 V along with a linear temperature-dependent barrier height lowering, ΔΦB/ΔT, of 2.4 and 2.0 mV/K for 4H– and 6H–SiC are extracted using an alternative analytical expression for tunneling from semiconducting substrates derived previously. In both analyses, the temperature-dependent flatband voltage, using the measured room-temperature value, was included.

Transport mechanism in mica and SiO2 dielectrics

“…The dependence of an apparent variation of barrier height on temperature can naturally be clarified by taking into account tunnelling, as a temperature-related process, due to the interaction of electrons with the phonons of material. Therefore, the results of [23] cannot be interpreted as the F-N tunnelling but rather as a multiphonon-assisted tunnelling. For this purpose temperature-dependent I-V characteristics are compared with the dependence of the tunnelling rate of charge carriers on the field strength, which is calculated for different temperatures using Eq.…”

“…[29], a clearly expressed current dependence on temperature in the structures Аl-SiО 2 -Si was found and explained by the barrier height dependence on temperature. In a recently published work [23], the current dependence on temperature through the thin films SiО 2 (thickness 93 nm) was explained by the linear dependence of barrier height on temperature, considering that the current is caused by F-N tunnelling. According to [23], the barrier height temperature coefficient ∆Ф B /∆Т was found to be equal to −2.4 meV/K.…”

“…In a recently published work [23], the current dependence on temperature through the thin films SiО 2 (thickness 93 nm) was explained by the linear dependence of barrier height on temperature, considering that the current is caused by F-N tunnelling. According to [23], the barrier height temperature coefficient ∆Ф B /∆Т was found to be equal to −2.4 meV/K. However, the reason for barrier height diminishing with the temperature increase is not explained.…”

“…The comparison of the current dependence on the field strength, measured in a wide range of temperatures of the other widely used dielectric film, i.e. silicon dioxide extracted from [23] with the theory is also submitted.…”

“…It is shown that the experimental data better agree with the phonon-stimulated tunnelling theory than the Frenkel emission theory. Temperature-dependent I-V characteristics of М-SiO 2 -Si structures measured by Waters and Van Zeghbroeck [Appl. Phys.…”