Ind. Eng. Chem. Res. 2005, 44, 6387-6392
6387
Modeling of the Metalorganic Chemical Vapor Deposition of Tantalum Oxide from Tantalum Ethoxide and Oxygen Sukanya Murali,† Anand Deshpande, and Christos G. Takoudis* Department of Chemical Engineering, University of Illinois at Chicago, Chicago, Illinois 60607
This study focuses on modeling the chemical vapor deposition (CVD) of tantalum oxide, a high dielectric constant material, on silicon-based substrates. A three-dimensional model is developed and described for a CVD reactor in which tantalum ethoxide and oxygen precursors are used. The effect of pressure and substrate temperature on the deposition rate of thin films of tantalum oxide is studied at system pressures of 1-4 Torr and substrate temperatures in the range of 300-500 °C. Our model predictions and experimental data of a custom-made cold-wall CVD reactor are found to be in satisfactory agreement. The deposition rate is found to increase significantly with increasing substrate temperature; this suggests that the tantalum oxide CVD is surface-reaction-controlled. Introduction The rapid progress of the complementary metal-oxidesemiconductor integrated circuit technology has enabled the microelectronics industry to meet several technological requirements to fuel market expansion.1 The rapid shrinking of the transistor feature size has forced the channel length and gate dielectric thickness to also decrease rapidly.2 Devices made with present materials (SiO2, SiON, and Si3N4) require equivalent oxide thickness
