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The concentration profiles of deep energy levels(, and ) in platinum-diffused silicon have generally a sharp gradient in the vicinity of the surface of the silicon wafer. In this work two efficient methods are proposed to obtain the uniform concentration profiles throughout the silicon wafer. One is that the platinum diffusion is carried out at 1000 ℃ for 1h in oxygen atmosphere. In this case the values of obtained uniform concentration, 1×1015 cm-3 for the level, and 1×1014 cm-3 for the level, are very restricted, respectively. The other is two-step annealing process. The platinum diffusion is carried out at 850∼1100 ℃ in a nitrogen ambient for 1h and then·the annealing is performed at 1000 ℃ in oxygen ambient after removing platinum-source from the platinum diffused samples. The advantage of this method is that the uniform concentration of these levels required power devices can be controlled by setting the desired temperatures when the platinum diffusion is carried out in nitrogen ambient.