Plasma and Directed Ion Beam Hydrogenation Methods

There are numerous literature reports (Bech-Nielsen and Andersen, 1988 Chevallier and Aucouturier, 1988 Heddleson et al., 1988a  

In contrast to the d.c. or microwave plasma apparatus, the sample environment produced by these directed beam sources has been reasonably well characterized. Studies of Kaufman source operation (Sharp et al., 1979) have established that H beams are typically composed of mixtures of H+ and H2+ ions and a roughly equal mixture of energetic neutrals. The ion energy spectrum of such a source is fairly sharply peaked at the maximum energy at low acceleration voltages (150-500 eV) but spreads out considerably if the source is operated at voltages above 1000V. 

SCREEN GRID (0-2000V) EXTRACTOR GRID (-200V) 

TARGET CURRENT MONITOR ttt CURRENT - DENSITY MONITOR 

There are several reports of the use of directed ion sources to hydrogen passivate both shallow impurities (Horn et al., 1987 Martinuzzi et al., 1985) and deep defect levels in silicon (Dube and Hanoka, 1984 Hanoka 

Although Sah etal. (1983) and Gale etal. (1983) have demonstrated that H can be introduced into Si by electron injection into the oxide layer of metal-oxide-silicon devices, there has been no report of hydrogen penetration with an applied bias of opposite polarity. This may suggest electric-field-induced proton migration through the oxide. 

In Chapter 3, Pankove deals with structural defects in crystalline silicon, the most obvious being the discontinuity of the crystal at the surface. Such a surface is covered with dangling bonds that can be terminated by 

In Chapter 4, Corbett deals with specific defect centers in semiconductors. He points out that H aids the motion of dislocations in Si, which can lead to enbrittlement. Throughout this chapter, Corbett raises many questions that need further exploration. For example Is oxygen involved in processes that are attributed to hydrogen Does H play a role in defect formation  

Electrical studies show that H neutralizes defects at relatively low temperatures, suggesting that H is very mobile at low temperatures. Corbett points out various defect centers in III-V materials that appear to be affected by H. 

From IR vibrational absorption experiments, there is a multitude of vibrational bands in Si that contain H, far more than the modes attributable to Si—H, Si—H2 and Si—H3. The presence of oxygen causes broadening and overlap of some of these modes, hindering their interpretation. Vibrational bands above 2000 cm-1 are attributed to vacancy- 

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