Surface and Interface Properties of Ion Implanted 4h-Silicon Carbide

Abstract

A series of ion-implanted 4H-SiC epilayers, Aluminum (Al) – Carbon (C) co-implanted and Al single implanted, have been studied by micro-Raman scattering, Fourier transform infrared (FTIR), and UV-Visible (200-1100 nm) optical transmission (OT) measurements. The damage and amorphization of SiC layer by ion-implantation, and the elimination or suppression of the implantation induced amorphous layer via high temperature annealing are evidenced. The recovery of the crystallinity and the activation of the implant acceptors are confirmed. Theoretical simulations on the spectroscopic features, for FTIR reflectance spectra, are performed based upon the structural model. The results from different ion implantation conditions are compared. This work also provides a non-destructive and convenient way to investigate the effects of ion implantation/annealing on SiC materials.

Raman Spectroscopy Characterization of Ion Implanted 4H-SiC

“…Other researchers particularly pay attention to the Fano interference effect between the folded transverse acoustic (FTA) modes and the continuum of electronic transitions [5]. As for ptype samples prepared by ion implantation, the implanted ions cause damage and amorphization of the silicon carbide layer [6]. However, high temperature annealing can restore the crystallinity, increase the activation ratio and result in silicon carbide samples with lower resistivity [6,7].…”

“…As for ptype samples prepared by ion implantation, the implanted ions cause damage and amorphization of the silicon carbide layer [6]. However, high temperature annealing can restore the crystallinity, increase the activation ratio and result in silicon carbide samples with lower resistivity [6,7]. Additionally, without a capping layer, the higher the annealing temperature, the rougher the surface of the silicon carbide sample will be [7].…”

Helium Ion‐Assisted Wet Etching of Silicon Carbide with Extremely Low Roughness for High‐Quality Nanofabrication

“…These bands were generated from amorphous Si bonds and a mixed phase of carbon sp2/sp3 vibrations, respectively. [ 57,58 ] The presence of these bands further confirmed the disruption of Si─C heteronuclear bonds and the formation of numerous Si─Si and C─C homonuclear bonds owing to replacements and interstitials created in cascade collisions.…”

“…This phenomenon is consistent with classical FTIR studies pertaining to large-scale ion-implanted SiC and can be attributed to the formation of a buried amorphous layer caused by ion damage. [61][62][63] Consequently, the nano-FTIR mapping image (Figure 2c right) shows that the ion-modificationinduced optical intensity was lower than that of pristine SiC and darkened as the dosing influence increased. The amorphous area (dark area) was well-confined within the irradiated regions, thus enabling localized selective etching with high spatial resolution.…”