Oxide nanodots and ultrathin layers fabricated on silicon using nonfocusedmulticharged ion beams

We have used slow multicharged argon ions in ultrahigh vacuum with a partia l pressure of oxygen to form ultrathin (subnanometer) oxide dots of a few t ens of nanometer diameter on a silicon surface. The main characteristic of this technique is that the incident multicharged ion does not penetrate bel ow the surface, so there is no implantation-induced modifications of the su bstrate. Thus, we utilized a unique possibility provided by the multicharge d ions interaction with surfaces of solids, the noncontact trampoline effec t, to open the bonds of hydrogenated silicon, and replace it with oxygen. T his article presents the fundamentals of slow multicharged ion interaction with a surface, the experimental multicharged ion beam line build at X-ion laboratory, and obtained results of oxide dot formation on silicon, using t hem as a mask in a reactive ion etching process to grow three-dimensional c rystalline silicon structures. Potential applications are in nanoflash-mult idot type nonvolatile memories. (C) 2000 American Vacuum Society. [S0734-21 1X(00)17706-6].