Effect of interfacial hydrogen in CoSi2/Si(100) Schottky-barrier contacts

We have studied the effect of hydrogen in the CoSi2/Si(100) interface on the Schottky-barrier height of CoSi2 on n-type and p-type Si(100). It was found that hydrogenation results in an increase of 120 meV in the barrier height to n-type Si(100). Measurements of the hydrogen concentration in the interface, using quantitative ion-beam techniques, were used to establish the correlation between the change in barrier height and hydrogen concentration; other hydrogen effects such as passivation of shallow donor and acceptor impurities in silicon were ruled out. The results demonstrate that 8×1015 hydrogen atoms/cm2 can alter an interface layer and thereby change the pinning position of the Fermi level. © 1994 The American Physical Society.