Diffusion barrier characteristics of TaSiN for Pt/TaSiN/Poly-Si electrode structure of semiconductor memory device

The TaSiN barrier layers for Pt/TaSiN/poly-Si structure were prepared by dc reactive magnetron sputtering. The resistivity of as-deposited films with an optimum composition of Ta0.23Si0.29N0.48 was about 1,277 mu Omega cm. Th e TaSiN films are amorphous over a wide range of annealing temperatures up to 900 degreesC and showed an abrupt increase of resistivity at annealing t emperatures of 700 and 750 degreesC because of the formation of TaSiNxOy am orphous phase onto TaSiN films. The I-V characteristics of Pt/TaSiN/poly-Si structure before and after annealing at various temperatures became linear , which is indicative of Ohmic characteristics, independent of annealing te mperature. The contact resistivities of Pt/TaSiN/poly-Si structures with in creasing annealing temperature up to 700 degreesC did not vary greatly comp ared with those of as-deposited electrode structures. The specific contact resistivities of as-deposited and annealed structures at 700 degreesC were about 2.5 x 10(-3) and 5.6 x 10(-3) Omega cm(2), respectively. (C) 2001 The Electrochemical Society.