In this work the crucial role is established of the 'silane starving' plasma regime for the growth of a-Si1-xCx:H with chemical order similar to that of crystalline SiC as well as for the growth of carbon rich alloys with high optical gap. The a-Si1-xCx:H films were characterized by optical absorption, infrared spectroscopy, Anger electron spectroscopy, The samples were obtained by plasma enhanced chemical vapor deposition (PECVD) from silane (SiH4) and methane (CH4) mixtures. In order to analyze the effect of silane starving plasma conditions on the material properties, sets of samples were grown with identical methane concentrations but with different silane flows. The effect of varying methane concentration on the properties of samples grown under starving plasma conditions is also studied.