Experimental determination of electron-hole pair creation energy in 4H-SiC epitaxial layer: An absolute calibration approach

Abstract

Electron-hole pair creation energy (ε) has been determined from alpha spectroscopy using 4H-SiC epitaxial layer Schottky detectors and a pulser calibration technique. We report an experimentally obtained ε value of 7.28 eV in 4H-SiC. The obtained ε value and theoretical models were used to calculate a Fano factor of 0.128 for 5.48 MeV alpha particles. The contributions of different factors to the ultimate alpha peak broadening in pulse-height spectra were determined using the calculated ε value and Monte-Carlo simulations. The determined ε value was verified using a drift-diffusion model of variation of charge collection efficiency with applied bias.

Electron-hole pair generation in SiC high-temperature alpha particle detectors

“…This also suggests that for leakage currents smaller than ~10 -6 A, the FWHM for this detector is dominated by other mechanisms of resolution degradation, such as thermal (Johnson) noise originating in the preamplifier, as has been previously suggested for diode detector systems in general 2 , and/or alpha particle energy straggling in the Schottky metal contact.. A relatively large amount of alpha particle energy straggling is possible in this layer, since, to ensure mechanical robustness, the Schottky metal contact was grown to be relatively thick at 120 nm,. Because of this, and other temperatureinvariant contributions to FWHM, the room temperature FWHM is greater than the measurements by others 8,13 . …”

“…8. A conversion factor was measured that converted from channel in the DSA 2000 to number of charges input to the preamp.…”

Heavy Ion Induced Degradation in SiC Schottky Diodes: Incident Angle and Energy Deposition Dependence

“…Note that the range of the Xe ions at 1217 MeV in SiC is about . For the average electronhole pair creation energy in SiC, a value of was used, which is an average between the recently published experimental values of [17] and [18]. For modeling the avalanche multiplication, an anisotropic impact ionization model that is especially developed and calibrated for 4H-SiC power devices [19] has been implemented in Silvaco TCAD tools, and was used in this work.…”

Stability of Silicon Carbide Particle Detector Performance at Elevated Temperatures

“…In addition, 241 Am and pulser signal peaks were collected simultaneously by injecting signal form a 480 ORTEC pulser into the test input of the 142A ORTEC pre-amplifier. The broadening of the pulser peak recorded in this manner can be used to assess collectively the effect of detector leakage current and that of the noise form the front-end electronics to the overall resolution of the detector [33]. Further, stability of the signal was studied by fixing the values of temperature and bias voltage for longer periods up to 24 hours.…”