Optimization of sub-5-nm multiple-thickness gate oxide formed by oxygen implantation

A new method of growing multiple gate oxide thicknesses below 5 nm using masked oxygen implantation is presented. Multiple thicknesses can be achieved on the same wafer without degradation in the oxide properties. The oxygen implanted oxide quality is comparable to that of thermally grown oxides. Moreover, the effects of oxygen implant damage is minimized with higher implant energies, thicker sacrificial oxides, and low-temperature annealing.