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 500DGC. 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. [Applications: CMOS devices].