Deep levels hydrogen induced

In addition to the generation of platelets, hydrogenation of silicon also induces electronic deep levels in the band gap. As in the case of platelet formation, these defects are considered to be unrelated to either plasma or radiation damage because they can be introduced with a remote hydrogen plasma. Comparison of depth distributions and annealing kinetics of the platelets and gap states has been used to a limited extent to probe the relationship among these manifestations of H-induced defects. 

The atomic hydrogen treatment removes the P line and enhances the overall PL intensity. This indicates a passivation of defect-induced deep levels that function as non-radiative recombination centers [7]. 

The passivation of two deep-level electron traps induced in n-type Ge by a Q-switched ruby laser anneal was found [141]. As with the corresponding case in Si, plasma exposures of 10 minutes at 100 C were sufficient to neutralize the electrical activity of such centers. In Ge most radiation damage or quenched-in centers that have been found are vacancy-related, and again the propensity of hydrogen to neutralize this type of defect is seen by the effectiveness of hydrogen plasma exposures in passivating Co-60 Y-induced hole traps [142], quenched-in acceptors [143], and ion-implanted oxygen-related deep levels [144]. 

---