The extended defects induced by hydrogen diffusion in silicon during the process of (1) CF4/x% H2(0≤x≤100) reactive ion etching, or (2) hydrogenation in H2 plasma, or (3) passivation of boron acceptors in H2 plasma, are studied by high resolution electron microscopy and secondary ion mass spectrometry. In reactive ion etched Si, a higher density of {111} planar defects are produced as the concentration of H2 in the etching gas and/or the overetch time is increased. The Si surface appears rough after reactive ion etching. Similar {111} planar defects are also found in Si after a H2 plasma treatment at 200°C for 3 hours, while the Si surface remains smooth. Boron im-plantation (30keV, 1015 at/cm2) and furnace annealing (1000°C, 30 min) processes are found to introduce stacking faults and perfect dislocation loops into silicon wafers. After subsequent exposure of boron implanted Si to a H2 plasma (200°C, 3 hours), microprecipitates associated with dislocation loops are observed.

These results indicate that the apparent surface roughness (top 30 Å layer) in reac-tive ion etched Si is caused by energetic ion bombardment (∼500 eV). However, the {111} planar defects in CF4/x% H2(x>40%) reactive ion etched Si and the {111} planar defects and microprecipitates in H2 plasma treated Si are induced by the super-saturation of hydrogen diffused into Si during the plasma treatment process.