Effects of deposition parameters on composition, structure, resistivity and step coverage of TiN thin films deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition

Abstract

TiN thin films of high quality-low impurity content, high crystallinity and low resistivity-were prepared by electron cyclotron resonance (ECR) plasma-enhanced chemical vapor deposition (PECVD) at low temperatures using TiCl4, N-2 and H-2. The effects of gas flow rate, microwave power and temperature on the composition, structure, resistivity and step coverage of the film were studied. Proper control of the H-2 flow rate was important in lowering the resistivity and impurity content of the films and enhancing the step conformality of the deposits. Increases in deposition temperature and in microwave power decreased the deposition rate, resistivity and impurity content of the film. Chlorine was below the detection limit of Auger electron spectroscopy (approximately 0.1 at.%), even at a deposition temperature of 30(310) degrees C. TiN film deposited at 250(400) degrees C showed a resistivity of 96 mu Omega cm and a bottom coverage of 47%. (C) 1997 Elsevier Science S.A.