Defect introduction during E-beam metal deposition on bulk n-type 6H-SiC

摘要

Deep level transient spectroscopy is employed in order to assess whether E-beam metal deposition on bulk n-type 6H-SiC effects any changes to the underlying material. Near-surface E-beam-related damage is shown to be device specific. The EB1-related defect at E_c ― (0.346+- 0.007) eV with σ_(na) = (5.4_(-1.2)~(+1.5)) x 10~(-16) cm~2 and the EB2-related defect at E_c ― (0.47 +-0.01) eV with σ_(na) = (2.2_(-1.7)~(+0.5)) x 10~(-15) cm~2 are detected in several devices, independently of the metal used for deposition. It is shown that the broad EB3 peak, detected in a set of E-beam fabricated devices, corresponds to the p5-related band of interface states also detected in thermally metallized devices. It is shown that neither the EB3 nor the p5 peak can be detected in environmentally aged E-beam fabricated devices. This is attributed to interface state passivation via in-diffusion of atmospheric oxygen.