PREPARATION OF CNX-PHASES USING PLASMA-ASSISTED AND HOT-FILAMENT CHEMICAL-VAPOR-DEPOSITION

Results are reported from a systematical investigation of deposition o f binary C-N-phases in a wide substrate temperature range. The experim ents are carried out in a r.f. assisted chemical vapour deposition (CV D)-apparatus. A hot filament is positioned between the electrodes to s upport the generation of activated species and a negative bias is appl ied to the substrate to increase their energy. The deposition temperat ure ranged from 200 degrees C without up to 1000 degrees C using hot f ilament. Different carbon-precursors and Ar/H-2 gas ratios were tested . The results can be summarized as follows. The films deposited at tem peratures up to 250 degrees C have mostly an amorphous polymer structu re. Paracyan-like coatings grow preferably in the temperature range 60 0-650 degrees C. At temperatures higher than 650 degrees C using a hot filament technique with r.f.-plasma and bias enhancement the depositi on rare decreased strongly. However, crystalline objects could be obse rved on the silicon substrate. Some of the X-ray diffraction peaks of those samples coincide with reflections of covalent C3N4 phases, but r eflections from alpha- or beta-Si3N4 are recorded additionally. Deposi tion experiments on inert substrates, for example nickel, but no CNx p hases could be produced until now. (C) 1998 Elsevier Science S.A. All rights reserved.