Fabrication of epitaxial Si/SiO2 low dimensional structures using in situ multiple low energy oxygen implantation in combination with Si molecular beam epitaxy is described, highlighting its potential for the control of quantum confinement structures. Highly-oriented Si nanodots and Si quantum wires embedded in SiO2 are demonstrated as prominent examples and the formation mechanism of the epitaxial Si/SiO2 bilayer is described. Successful growth of epi-ready Si/SiO2 Bragg reflector is demonstrated in view of optoelectronic application.