ALD of Ta(Si)N thin films using TDMAS as a reducing agent and as a Si precursor

Ta(Si) N thin films were deposited by atomic layer deposition (ALD) from tantalum chloride, ammonia, and tris(dimethylamino) silane (TDMAS). TDMAS was used as a reducing agent and as a silicon precursor. The pulsing order and the length of the TDMAS pulse were optimized. The deposition temperature was varied between 300 and 500 degreesC. The film properties were analyzed by time-of-flight elastic recoil detection analysis, energy dispersive X-ray spectroscopy, X-ray diffraction, and the standard four-point probe method. Additionally work function values were measured by depositing 50 nm thick Ta(Si)N films on different thicknesses of hafnium oxide layers on silicon. (C) 2004 The Electrochemical Society.