High energy proton irradiation effects on SiC Schottky rectifiers

Abstract

4H-SiC Schottky rectifiers with dielectric overlap edge termination were exposed to 40 MeV protons at fluences from 5×107–5×109 cm−2. The reverse breakdown voltage decreased from ∼500 V in unirradiated devices to ∼−450 V after the highest proton dose. The reverse leakage current at −250 V was approximately doubled under these conditions. The forward current at −2 V decreased by ∼1% (fluence of 5×107 cm−2) to ∼42% (fluence of 5×109 cm−2), while the current at lower biases was increased due to the introduction of defect centers. The ideality factor, on-state resistance, and forward turn-on voltage showed modest increases for fluences of ⩽5×108 cm−2, but were more strongly affected (increase of 40%–75%) at the highest dose employed.

Effects of swift heavy ion irradiation on the electrical characteristics of Au/n-GaAs Schottky diodes

“…Any mechanism that modifies the properties of the interface such as the introduction of an interfacial layer [1][2][3][4], annealing [5,6], irradiation with gamma rays [7,8], protons [9][10][11][12][13][14] and neutrons [14][15][16], ion implantation, [17][18][19] and high-energy ion beam irradiation [20][21][22][23][24][25][26] are found to alter the characteristics of the barrier. The Schottky barrier height (SBH) forms a very important parameter of the diode as it controls the electrical transport across the barrier.…”

“…In order to avoid any sample-to-sample variation [27] in diode properties, an in situ current-voltage (I-V) characterization technique has been used. The diode characteristics have been studied over a large range of ion irradiation fluencies from 5 Â 10 9 to 8 Â 10 13 close intervals for systematic and detailed analysis of ion beam induced modification on diode performance. The modifications observed in device characteristics are explained on the basis of interaction mechanism of SHI with solid.…”

Radiation effects on ohmic and Schottky contacts based on 4H and 6H-SiC

“…The effects of high-energy proton irradiation and highdose gamma ray irradiation on 4H-SiC Schottky rectifiers have been investigated by Nigam et al and Kim et al respectively, [17,18]. Although both Ni ohmic and SC properties for 4H-SiC have been reported by Perez et al [11], there is no information for the performance of Ni both for ohmic and SC for 6H-SiC and also its performance under electron irradiation has not been reported for 4H and 6H-SiC samples.…”

Proton irradiation of ZnO schottky diodes

“…These changes on a percentage basis are approximately a factor of 2 less than we have observed for proton irradiation of both SiC and GaN rectifiers under the same conditions. 18,19 It is likely that the creation of generation-recombination centers related to atomic displacements created by the incoming protons that can act as carrier traps is the main mechanism for the changes in leakage current. Our past work with lower-energy proton implantation showed that it led to a decrease of the carrier concentration in the near-surface region, but at the end of the proton range, shallow donors are observed whose concentration tracks the implant dose and that we attribute to hydrogen donors.…”