Deep levels by proton and electron irradiation in 4H–SiC

Abstract

The effects on 4H-silicon carbide epilayers of irradiation with protons and electrons having particle energies, respectively, of 6.5 and 8.2MeV were carefully studied and critically compared. In detail, the electronic levels associated with the irradiation-induced defects were analyzed by current-voltage characteristics and deep-level transient spectroscopy (DLTS) measurements up to 550K. In the same temperature range the apparent free-carrier concentration was measured by capacitance-voltage characteristics in order to monitor compensation effects due to the deep levels associated with the induced defects. Introduction rate, enthalpy, and capture cross section of such deep levels were compared. We found that a set of deep levels (at ET=0.39eV, ET=0.65eV, and ET=0.75eV) is the same in both cases of proton and electron irradiations, whereas two other pairs of levels (S1, ET=0.20eV and S1*, ET=0.23eV; S5, ET=1.09eV and S5*, ET=0.89eV) appearing in the same temperature range within the DLTS spectra should be associated with different defect complexes according to the irradiation type. Some conclusions regarding the microscopic nature of the defects related to the deep levels have been drawn.

Annealing behavior of the EB-centers and M-center in low-energy electron irradiated n-type 4H-SiC

“…14 After irradiation, the EH1 and EH3 (labeled ET1 and ET2, 14 S1 and S2, 5 or S2, S4 28,29 ) are observed. The bistable M-center with its two configurations A and B is detected.…”

DLTS study of deep level defects in Li-ion irradiated bipolar junction transistor

“…Introduction rate of defects in the semiconductor devices depends on carrier concentration, Fermi-level, recombination, impurities and electrical biasing [25]. Trap concentration N T and capture cross section are used to calculate the carrier life time corresponding to that defect level [5,26]. Table 1 also shows the atomic displacements estimated from TRIM.…”

“…It is useful to understand the radiation response of devices to find better design strategies before employing them for specific applications. Considerable amount of data are available on the irradiation effects of c-rays, fast neutrons, electrons and protons on semiconductor devices [1][2][3][4][5][6][7][8][9]. In the recent years, npn transistors have been studied for damage mechanisms by oxygen ion irradiation [10,11].…”

Electrical Characterization of High Energy Electron Irradiated Ni/4H-SiC Schottky Barrier Diodes

“…The effect of electron irradiation on defect formation and determination of carrier lifetimes has also been studied in SiC. [9][10][11][12] Study of defects induced by irradiation is very important as many of these defects have acceptor-like properties hence they reduce the semiconductor net donor concentration.…”

“…[8][9][10][11][12] Nava et al 8 performed high energy (8.2 MeV) electron irradiation in addition to proton and gamma ray irradiations on SiC diodes.…”