IN-SITU INVESTIGATION OF THE GROWING A-SI-D SURFACE BY INFRARED REFLECTION-ABSORPTION SPECTROSCOPY

The bonded deuterium atoms on the growing surface of a-Si:D films are investigated by use of polarization modulated infrared absorption reflection spectroscopy (PM-IR-RAS), which is capable of monolayer detection for surface deuterides. Similar to the hydride coverages on the growing a-Si:H surfaces, a shift in bonding configuration from higher to lower (SiD3-->SiD2-->SiD) is observed with an increase of the growth temperature. A clear splitting (1545 and 1570cm(-1)) in the stretching mode absorption is observed at the 25 degrees C growth and assigned to the SiD3 species on the top surface. At higher temperatures, the deuteride coverage is, when compared to the hydride counterpart, slightly more resistive to the thermal desorption judging from the remainder of the coverages observed after the film growth at 370 degrees C.