In this work we report on the development of the HfZrOx atomic layer deposition (ALD) process with tetrakisdiethylamino (TDEA) hafnium/zirconium (TDEAH/TDEAZ) and H2O. A nanolaminar structure approach is used to grow HfZrOx by alternating HfO2 and ZrO2 ALD reaction cycles at 250 degrees C. The HfZrOx film thickness increases linearly with the number of ALD cycles. Compared to the halide based process, the process with TDEA precursors and H2O yields a lower temperature window, an initial growth insensitive toward the starting surfaces, and a fast film closure on the hydrofluoric acid-last surface. The Zr content, measured by Rutherford backscattering increases linearly with the cycle ratio of Zr/(Zr + Hf). The as-deposited HfZrOx films are amorphous and crystallize after a 950 degrees C postdeposition anneal. Depending on the film composition a different crystalline phase is formed, ranging from monoclinic to tetragonal with increasing Zr content. Using H2O instead of O-3 not only reduces the interfacial oxide regrowth during deposition, which allows for a thinner interfacial layer and improves the interfacial oxide scalability, but also results in a lower C content in the deposited films. Finally, complementary metal oxide semiconductor transistor using HfZrOx as gate dielectric are fabricated for the evaluation of device performance. These results show that all considered splits with HfZrOx as gate dielectric yield a similar equivalent oxide thickness-gate leakage current performance and (low) gate current leakage level. The data reported in this paper demonstrates that ALD HfZrOx grown based on TDEAHf/Zr and H2O is a promising gate dielectric for subnanometer equivalent oxide thickness scaling. (c) 2010 The Electrochemical Society. [DOI: 10.1149/1.3516476] All rights reserved.