A chemical reaction path design for the atomic layer deposition of tantalum nitride thin films

Abstract

The two-step atomic layer deposition of tantalum nitride (TaN) in which the deposition cycle involved two chemical reaction steps, the formation of elemental tantalum (Ta) by reducing tantalum-pentafluoride (TaF5) with hydrogen plasma and the subsequent nitridation of the preformed Ta with NH3, was performed at 350 degrees C. Cubic-TaN with a Ta/N ratio of 1:1 was achieved independently of the nitridation time, and the fluorine content of the films was below the detection limit using Auger electron spectroscopy. As a result, the electrical resistivity of the TaN film was reduced below 500 mu Omega cm by suppressing the formation of Ta3N5. (c) 2006 The Electrochemical Society.