| AVS 62nd International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Bodo Kalkofen, Otto von Guericke University Magdeburg, Germany |
| Authors: | B. Kalkofen, Otto von Guericke University Magdeburg, Germany A.A. Amusan, Otto von Guericke University, Magdeburg, Germany M. Lisker, IHP, Frankfurt (Oder), Germany Y.S. Kim, Lam Research Corporation E.P. Burte, Otto von Guericke University, Magdeburg, Germany |
| Correspondent: | Click to Email |
Plasma-assisted atomic layer deposition (PALD) was carried out for growing thin oxide films of silicon dopants onto flat and high-aspect ratio silicon substrates. The applicability of these films as dopant sources for shallow doping of silicon using various rapid thermal annealing methods, such as RTP, flash lamp anneal, and laser anneal, was investigated. Remote CCP and ICP sources were applied for generating oxygen radicals in the PALD processes. Tris(dimethylamido)borane was used as boron containing precursor for p type silicon doping, source layers for n type doping were grown using triethylphosphite and triethylantimony as phosphorus and antimony containing oxides, respectively.
The as-deposited films of boron oxide were highly unstable in ambient air and could be protected by capping with in-situ PALD grown antimony oxide films. Phosphorus containing films were stabilized by incorporating them into a silicon dioxide matrix by carrying out ALD processes with supercycles of phosphorus and silicon precursor reactions with oxygen radicals. Also capping of the phosphorus containing films was applied. Antimony oxide films were stable at ambient air conditions. Conformal growth of such films could be obtained on silicon trench structures of 6:1 to 10:1 aspect ratio with pitch below 50 nm.
Boron and phosphorus doping of silicon could be obtained using the respective oxide films as dopant sources. This was confirmed by SIMS and sheet resistance measurements. Diffusion of antimony into silicon from antimony oxide needs to be further improved by optimizing the annealing conditions. The influence of source layer thickness and different annealing conditions during rapid thermal annealing processes on the doping results was investigated. Controlled doping of 3-D nanostructured devices by pre-deposition with ALD source layers should be feasible by this method.