Incomplete ionization and carrier mobility in compensated p-type and n-type silicon

In this paper, we show through both calculations and Hall effect measurements that incomplete ionization of dopants has a greater influence on the majority-carrier density in p-type and n-type compensated Si than in uncompensated Si with the same net doping. The factors influencing incomplete ionization at room temperature are shown to be the majority-dopant concentration, its ionization energy and type, and the compensation level. We show that both the majority- and the minority-carrier mobilities are lower in compensated Si than expected by Klaassen´s model and that the discrepancy increases with the compensation level at room temperature. The study of the temperature dependence of themajority-carrier mobility shows that there is no compensation-specific mechanism and that the reduction of the screening in compensated Si cannot explain alone the observed gap between experimental and theoretical mobility.