Solid Solubility of Nickel in Silicon Determined by Use of 63Ni as a Tracer

Abstract
The solid solubility of Ni in Si has been determined in the range of 900–1400°C by diffusing 63Ni as a tracer. The activity has been measured by the surface counting method. From the plateau in the distribution of the activity, the typical values of the solid solubility of 1.6×1017 and 5.8×1017 atoms/cm3 at 1000 and 1200°C are obtained. The distribution coefficient is deduced to be k=0.49exp (-27700/RT). k* at the melting point of silicon is 1.2×10-4. The differential heat of nickel in silicon at solid solution is 31.9 Kcal/mol. Retrograde solubility appears above 1200°C. The results of the solubility are fairly in good agreement with that determined by neutron activation analysis by Aalberts and Verheijke.