Effects of Thermal Annealing on the Formation of Buried β-SiC by Ion Implantation

Abstract

A systematic study of the formation of buried b-SiC structures by carbon ion implantation into Si followed by high-temperature thermal annealing has been carried out. A high fluence of carbon ions (8 9 10 17 atoms/cm 2 ) was implanted at 65 keV energy. Formation of the crystalline b-SiC phase was monitored by Fourier-transform infrared (FTIR) spectroscopy, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) techniques. The implanted samples were annealed at 900°C and 1100°C to observe the effects of annealing temperature on the formation of crystalline b-SiC. Formation of crystalline b-SiC was clearly observed in the sample annealed at 1100°C in a flowing nitrogen environment for a period of 1 h. Graphitic carbon clusters were observed at the implanted carbon profile peak position by XPS depth profile measurements. Various structural defects such as grain boundaries were also visualized in the annealed sample by highresolution TEM.

Light-Emitting Diodes Fabricated From Carbon Ions Implanted Into p-Type Silicon

“…There is a clear enhancement in peak intensity after postannealing in both HT and AT targets. This is consistent with other reports of C:Si [8], [10], [11].…”

“…Diffraction peaks for β-SiC (111) at 38°, (200) at 44°, (220) at 65°, and (311) at 78°are also observed. These results are practically identical to those of previous studies [8], [10]. The G-XRD for the postannealed HT target shows diffraction peaks for β-SiC (111), (200), (220), and (311), and none for Si.…”

“…These high-temperature (HT) samples are treated with the same fluence as the ambient temperature targets (AT). The C:Si implanted samples are postannealed for 1 h at 1000°C in flowing nitrogen in a Barnstead Thermolyne 21 100 tube furnace [8].…”

“…Implantation recipes must be finely tuned for ion dose and implantation energy, because self-sputtering is a concern at low energy and high dose [10], [13]. Postimplantation treatments such as anodization [5], [6], and annealing [7], [8] must also be considered, since they repair nonradiative damage caused by the implantation process and enhance desired light emission. The target temperature during the implantation may also be considered to induce lattice healing and promote growth of imbedded SiC [7].…”