Comparative study of electronically controlled motion of hydrogen around carbon and platinum atoms in silicon

We have studied the local motion of hydrogen in the neighborhood of carbon and platinum impurities by observing the stress-induced reorientation and subsequent recovery of two H-related (H-C and Pt-H₂) complexes in Si, using deep-level transient spectroscopy (DLTS) under uniaxial compressive stress. We notice two interesting differences in hydrogen motion around carbon and platinum atoms. The first one is a difference in the temperature where stress-induced reorientation occurs. That of the H-C complex occurs at high temperatures above 250 K, while it occurs at low temperatures around 80 K for the Pt-H₂ complex. The second difference is the effect of charge state of the complexes on their stress-induced reorientation and subsequent recovery. It occurs preferentially when an electron occupies the level of the H-C complex, but the Pt-H₂ complex has the reverse effect of level occupancy. These differences are discussed from viewpoint of different atomic configurations and electronic states of two H-related complexes.