Si surface orientation dependence of SiC-dot formation in bulk-Si using hot-C+-ion implantation technique

We experimentally investigated the Si surface orientation dependence of SiC-dot formation and photoluminescence (PL) properties in three (100)-, (110)-, and (111)-bulk-Si substrates (C+-Si) with different surface densities of Si atoms (N-S), where SiC-dots were fabricated by a hot-C+ ion implantation into bulk-Si and post-N-2 annealing processes. Transmission electron microscopy observation and x-ray photoelectron spectroscopy revealed the formation of SiC-dots in the (110)- and (111)-C+-Si, in addition to (100)-C+-Si. The diameter (phi) and surface density (N-D) of the SiC-dots depended on the Si surface orientation, and the average phi of the SiC-dots in three surface-oriented C+-Si decreased from approximately 5-3 nm with increasing N-S because the trapping value of C-ions at SiO2/Si interface increased with increasing N-S, which leads to the reduction of C-ions to convert SiC-dots in the SiC-dot formation area under higher N-S condition. However, the UV-Raman intensity of the TO mode of Si-C vibration was nearly independent of N-S. We experimentally confirmed the PL emissions from the (110)- and (111)-C+-Si in addition to the (100)-C+-Si. As a result, the PL spectrum and PL emission coefficient (eta) of the SiC-dots strongly depended on the Si surface orientation. The PL intensity I-PL of the SiC-dots strongly depended on the N-S because the eta of the SiC-dots significantly increased with decreasing phi, although SiC-dots in Si substrate are not quantum dots. Consequently, I-PL of SiC-dots can be improved in a Si substrate with higher N-S.

Automated summary

The experimental study investigates the influence of Si surface orientation on the formation and photoluminescence properties of SiC dots. The results show that the diameter and surface density of SiC dots depend on Si surface orientation, and the photoluminescence intensity of SiC dots is strongly influenced by Si surface orientation and Si atom surface density.