Исследование примеси магния в кремнии

Abstract

Profiles of both electrically active and total concentration of magnesium impurity in silicon were measured. Diffusion was performed into the floating zone dislocation-free n-type silicon at the temperatures Tdiff = 1000, 1100◦C and duration from 0.5 to 22.5 h. The depth profiles of the electrically active interstitial magnesium concentration NMgi (x) were determined by differential conductivity method, while the total concentration profile Ntotal(x) — with secondary ion mass spectroscopy. The total concentration of magnesium was found to be almost two orders higher than the concentration NMgi . It turned out that the effective diffusion coefficient DMgi decreases with the diffusion time. Possible physical processes responsible for formation of the electrically inactive component of magnesium impurity and the dependence of effective diffusion coefficient on time are discussed.