Size reduction and phosphorus doping of silicon nanocrystals prepared by a very high frequency plasma deposition system

In this paper, we describe the size reduction and phosphorus doping of silicon nanocrystals (SiNCs) fabricated using a very high frequency (VHF) plasma deposition system. The size reduction of SiNCs is achieved by changing the VHF plasma power. The size of SiNCs changes from 10 to 5 nm. We discuss the relationship between VHF plasma power and the size of SiNCs in terms of radicals in the VHF plasma, such as SiH₃, SiH₂, SiH, and H. On the other hand, we have fabricated phosphorus-doped SiNCs by adding PH₃ gas diluted with Ar gas. To confirm where phosphorus atoms are located, electrically detected magnetic resonance (EDMR) measurements are conducted. We have observed a hyperfine interaction between unpaired electrons and phosphorus atoms and enhanced hyperfine splitting owing to a quantum size effect. As a result, we can conclude that phosphorus atoms exist at substitutional sites of SiNCs and they act as donors.