Formation of SiC-surface layer by ion implantation

Abstract

A homogeneous SiC-surface layer is formed by implantation of 40 keV 13C carbon ions into single-crystalline silicon 〈100〉 with a fluence of 3.8×1017 ions/cm2 and subsequent electron beam rapid thermal annealing (EB-RTA). The carbon-depth distributions were analyzed with the resonant nuclear reaction 13C(p,γ)14N. In contrast to furnace annealing, EB-RTA (1150 °C for 15 min) leads to a carbon redistribution resulting in the formation of a homogeneous SiC-surface layer of about 50 nm in thickness. The carbon redistribution was investigated on silicon samples with an oxygen-depth marker using Rutherford backscattering spectroscopy. SiC bonds were detected by Fourier transform infrared spectroscopy measurements.

Ion Beam Synthesis and Characterization of Crystalline Si3N4 Surface Layers

“…In this article we report on the formation of a thin a-Si 3 N 4 surface layer after implantation of 60 keV nitrogen ions into silicon, when the implanted sample was thermally treated under high vacuum conditions. This work continues a former investigation, which demonstrated that thin b-SiC surface layers on silicon are formed by carbon implantation into silicon and subsequent thermal treatment under high vacuum conditions [18][19][20]. This formation process is caused by the process of active oxidation of silicon.…”

“…The alteration of the 15 N depth profile during the thermal treating, from a Gaussianlike nitrogen depth distribution into a rectangular one, was also observed on carbonimplanted silicon samples being subsequently thermally treated just as under high vacuum conditions with scanned 20 keV electron beam [18][19][20]. It was demonstrated, that the carbon redistribution was not the result of a diffusion process, but of silicon etching as shown by an experiment with a depth marker [18].…”

“…It was demonstrated, that the carbon redistribution was not the result of a diffusion process, but of silicon etching as shown by an experiment with a depth marker [18]. This etching process was caused by the process of ''active" oxidation [25] that takes place at low oxygen partial presphys.…”

Characterization of Crystallinity of SiC Surface Layers Produced by Ion Implantation

“…At the O 2 pressure of 3 Â 10 -7 mbar and sample temperature above 750 C the interaction of O 2 with Si results in forming volatile SiO molecules at the surface [15,16]. Therefore, silicon not bonded with carbon is selectively etched leading to the formation of a SiC surface layer [10]. A further increase of annealing temperature does not alter this rectangular carbon depth distribution, which represents a SiC surface layer with a thickness of about 70 nm taking into account the bulk density of SiC.…”

“…However, observations of Reeson et al [8] on high temperature implantations suggest the presence of 6H-SiC structure in implanted silicon, but the existence of this phase was not proven. There are also indications for the presence of the 6H-SiC modification in the thin SiC surface layer produced by low energy carbon implantation into silicon and post annealing under high vacuum conditions [10]. The aim of this work is to characterize the structure of this SiC surface layer in detail using XRD and HRTEM.…”