The Effect of High Pressure Steam Oxidation on Phosphorus Diffusion in Sillicon

The effect of high pressure steam oxidation (7.5-10.7 atm.) on phosphorus extrinsic diffusion in (111)--and (100)--silicon ac 700° - 970°C has been examined by spreading resistance probes and ellipsometery. It has been found that the OED and ORD appear at the higher nd the lower temperature, respectively. The OED-ORD transition point is at about 880°C for 40´ in 7.5 atm. for (111)-silicon. The difference in effective diffusion coefficients between oxidation and non-oxidation regions (D) is proportional to (xO/t)ⁿ, the power figure n is related to the oxidation conditions. These results can be explained satisfactorily by considerations which take into account oxidation rate and concentration effect on phosphorus diffusion in silicon.