| AVS 55th International Symposium & Exhibition | |
| Nanomanufacturing Focus Topic | Thursday Sessions |
| Session NM+MS+NS+NC-ThA |
| Session: | Nanomanufacturing II: Nanostructures |
| Presenter: | J.F. Graham, University of Virginia |
| Authors: | J.F. Graham, University of Virginia C.D. Kell, University of Virginia J.L. Gray, University of Pittsburgh J.A. Floro, University of Virginia S.A. Wolf, University of Virginia L. Bischoff, Research Center Dresden-Rossendorf Inc., Germany R. Hull, University of Virginia and Rensselaer Polytechnic Institute |
| Correspondent: | Click to Email |
Self-assembled semiconductor quantum dots are a candidate for use in potential nanoelectronic device architectures such as quantum cellular automata and magnetic spin exchange switches. It is possible to grow quantum dots (QDs) with relatively uniform size-distributions using heteroepitaxial techniques, but in order to apply QDs in such nanoelectronic devices they must also be spatially ordered into patterns of varying complexity. In addition, the QDs must posses the magnetic or electronic properties required for device operation. We have previously demonstrated the use of Ga+ focused ion beam (FIB) templating of Si surfaces prior to growth in order to fabricate patterns of Ge(Si) QDs of any desired complexity. Our current work employs a mass-selecting FIB with liquid metal alloy ion sources, enabling the generation of a wide range of separated species in focused beams, to template QD structures and electrically or magnetically dope them at a dot-by-dot level for nanoelectronic device applications. Ions can be selected according to isotope mass and charge state by using a mass-selecting Wien filter. Suitable alloy sources then provide the ability to template a Si substrate with electrically non-invasive ions (i.e. Si or Ge) and implant dopant ions for electronic or magnetic activation (e.g. with B or Mn), with resolution of < 50nm and doses down to a few ions per dot. Key technical issues we are addressing include i) the attainable limits of spatial resolution and the dot-by-dot implantation dose, ii) comparisons between Ga and Si ion templated growth, iii) physical alignment between a templating ion beam and a dopant implantation ion beam and iv) procedures for eliminating unwanted exposure of adjacent areas of the sample to implantation ions.