Implantation-induced defect passivation

A wide variety of process-induced defects in Si are passivated by reaction with atomic hydrogen. Examples of process steps in which electrically active defects may be introduced include reactive ion etching (RIE), sputter etching, laser annealing, ion implantation, thermal quenching and any form of irradiation with photons or particles wih energies above the threshold value for atomic displacement. In this section we will discuss the interaction of atomic hydrogen with the various defects introduced by these procedures. 

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]. 

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