Annealing of a Vacancy-Type Defect and Diffusion of Implanted Boron in 6H-SiC

Abstract

We have investigated the annealing of vacancy-type defects and B diffusion in SiC using positron annihilation spectroscopy (PAS) and secondary ion mass spectroscopy (SIMS). Boron (B) and carbon (C) ions were implanted into 6H-SiC substrates, and the samples were annealed up to 1650 o C in Ar. In the PAS study, defective layer to a depth of 200 nm from the surface is observed after annealing between 800 and 1200 o C. This region disappears after annealing above 1500 o C. No significant difference in the annealing behavior of the vacancy-type defects is observed for only B-and C/B-implanted samples. In the SIMS study, the out-diffusion of B in 6H-SiC is observed after annealing above 1400 o C and a dip in the B concentration is created close to the surface. This outdiffusion of B is suppressed by C/B-implantation. This suppression tends to be enhanced by the temperature of the implantation and the concentration of the implanted C.

Vacancy-Boron Complexes in Plasma Immersion Ion-Implanted Si Probed by a Monoenergetic Positron Beam

“…This phenomenon was only observed after annealing at 1000 C for Si and at 1400 C for 6H-SiC, and disappeared after annealing at higher temperatures. 12,29) For P-or As implanted Si, and O-, N-, or P-implanted SiC, however, a small S value in the damaged region was not observed. [30][31][32][33] Thus, the results shown in Fig.…”

“…For B-implanted 6H-SiC, five fold implantation was used to form a box profile to a depth of 450 nm; the B concentration in the box profile was ð1{ 2Þ Â 10 18 cm À2 . 29) The annealing was performed in an Ar atmosphere for 30 min at 1000 C for Si and at 1400 C for 6H-SiC. For the annealed samples, the S values corresponding to the annihilation of positrons in the damaged region were smaller than 1.00 except near the surface.…”

Slow Positron Beam Investigations of Defects Caused by B⁺ Implantation into Epitaxial 6H-SiC

“…Although the implantation-induced damage in the case of B is lower than that of other group III elements, efforts are of strong need to avoid or reduce the damage of the implanted SiC. Recently, B + implantation into 6H-SiC was investigated [1], but no attention was paid to possibly evaluate the B distribution from the SPIS data. In this work, SPIS has been used to clear up the vacancy-type defect structure created by B + implantation into 6H-SiC and to prove the efficiency of damage reducing measures.…”