The Effects of Thermal Decomposition of Tetrakis-ethylmethylaminohafnium (TEMAHf) Precursors on HfO 2 Film Growth using Atomic Layer Deposition

Abstract

The ALD process is an adequate technique to meet the requirements that come with the downscaling of semiconductor devices. To obtain thin films of the desired standard, it is essential to understand the thermal decomposition properties of the precursors. As such, this study examined the thermal decomposition properties of TEMAHf precursors and its effect on the formation of HfO 2 thin films. FT-IR experiments were performed before deposition in order to analyze the thermal decomposition properties of the precursors. The measurements were taken in the range of 135 o C-350 o C. At temperatures higher than 300 o C, there was a rapid decrease in the absorption peaks arising from vibration of Sp 3 C-H stretching. This showed that the precursors experienced rapid decomposition at around 275 o C-300 o C. HfO 2 thin films were successfully deposited by Atomic Layer Deposition (ALD) at 50 o C intervals between 150 o C to 400 o C; the deposited films were characterized using a reflectometer, X-ray photoelectron spectroscopy (XPS), Grazing Incidence X-ray Diffraction (GIXRD), and atomic force microscopy (AFM). The results illustrate the relationship between the thermal decomposition temperature of TEMAHf and properties of thin films.