Microstructural Investigations of Hafnium Aluminum Oxide Films

Abstract

The crystalline structure, composition, chemical bonding and thermal stability of HfO 2 -Al 2 O 3 mixtures deposited on Si using a combinatorial pulsed laser deposition technique were investigated. After deposition some films were annealed at temperatures from 850 to 950 o C for 6 or 12 minutes. Grazing incidence x-ray diffraction investigations were performed to asses the crystallinity and thermal stability of the annealed layers. Measurements of the Al to Hf ratios were performed using energy dispersive x-ray spectroscopy and x-ray photoelectron spectroscopy. From simulations of the x-ray reflectivity and spectroscopic ellipsometry spectra the phase composition and thickness of the films was calculated and then the Al to Hf ratios. Al/Hf values of 1 and 8 were found to be necessary to block the crystallization of the films after anneals at 850 and 950 o C, respectively.

Structure versus Thermal Stability: The Periodic Structure of Atomic Layer Deposition-Grown Al-Incorporated HfO2 Films and Its Effects on Amorphous Stabilization

“…Elements forming CRN, MCRN, or RCP all show potential to stabilize the amorphous phase of high- k dielectric thin films; thus, the choice of incorporating elements involves an optimization/compromise between a stronger amorphizer and a higher dielectric constant. The film crystallization temperatures at a particular alloying element incorporation level are reported, ,,, but it is sometimes difficult to compare these temperatures because different film thicknesses are employed.…”

“…[27][28][29] According to Zallen's classification, there is a group of modified continuous random network (MCRN) materials between CRN and RCP, in which metal atom ionic bonds disrupt , or RCP all show potential to stabilize the amorphous phase of high-k dielectric thin films; thus, the choice of incorporating elements involves an optimization/compromise between a stronger amorphizer and a higher dielectric constant. The film crystallization temperatures at a particular alloying element incorporation level are reported, 13,18,30,31 but it is sometimes difficult to compare these temperatures because different film thicknesses are employed. Thermal stability is closely related to film thickness.…”

The Effect of the Deposition Method on the Structural and Optical Properties of ZnS Thin Films

“…The highest value of the average mass density (ρ m~2 θ TR , which allows us to determine the relative variation of mass density without knowing its absolute value) is obtained for the MSPLD thin films, both in the as-deposited state and after annealing. Considering that PLD is a punctual technique and the lateral thickness profiles are sharply falling [45,46] compared with the thickness variations of MS [47], the thickness difference can be explained this way. The highest value of the average mass density (ρ m~2 θ TR , which allows us to determine the relative variation of mass density without knowing its absolute value) is obtained for the MSPLD thin films, both in the as-deposited state and after annealing.…”