Carbon nitride thin films synthesized at high temperature by using RF-plasma PLD

Carbon nitride (CN) thin films were synthesized at 600 degrees C. Despite t he high synthesis temperature, the nitrogen content of CN films was observe d to increase with the increase of negative DC bias voltage of Si substrate as determined by X-ray photoelectron spectroscopy. Transformation of CN bi nding states was found to proceed with the increase of bias voltage as indi cated by a series of Fourier transform infrared spectra. These films were d ominated by tetrahedral sp(3) C-N binding state at a substrate bias voltage above - 120 V. As observed from Raman spectroscopy, the carbon matrix was transformed from graphitic sp(2) into sp(3) carbon hybridization. Mechanism of tetrahedral CN phase formation at high temperature is proposed. (C) 199 9 Elsevier Science B.V. All rights reserved.