HYDROGENATED AMORPHOUS SILICON-NITROGEN ALLOYS, A-SINX-H-Y - A WIDE-BAND GAP MATERIAL FOR OPTOELECTRONIC DEVICES

Amorphous silicon-nitrogen, a-SiNx:H-y, thin films with optical gap in the range 2.0-5.2 eV have been deposited by 13.56 MHz ultra-high-vacu um plasma enhanced chemical vapor deposition system in SiH4+NH3 gas mi xtures. Compositional, optical, dark and photoelectrical and defect ch aracterizations have been performed in order to show that a-SiNx:H-y f ilms can be applied in optoelectronic technology as wide band-gap semi conductor. A comparison between electronic properties of a-SiNx:H-y sa mples and device quality a-Si1-xCx:H films, already applied in electro nic devices, has been carried out. Amorphous silicon-nitrogen films sh ow high deposition rates, good controllability of optical gap, and ele ctronic properties similar to high-quality silicon-carbon films. No do ping effect of nitrogen atoms in tetrahedral configuration has been ev idenced and spin density below 7x10(17) cm(-3) have been measured in a -SiNx:H-y films with optical gap as high as 5.2 eV. (C) 1996 American Institute of Physics.