Impact of incorporated oxygen quantity on optical, structural and dielectric properties of reactive magnetron sputter grown high-κ HfO2/Hf/Si thin film

Abstract

a b s t r a c tHigh-hafnium-oxide thin films have been fabricated by radio frequency (rf) reactive magnetron sputtering technique. To avoid formation of an undesired interfacial suboxide layer between Si and highfilm, prior to HfO 2 deposition, a thin Hf buffer layer was deposited on p-type (1 0 0) Si substrate at room temperature. Effect of oxygen gas quantity in the O 2 /Ar gas mixture was studied for the optical and structural properties of grown HfO 2 high-thin films. The grown thin oxide films were characterized optically using spectroscopic ellipsometer (SE) in detail. Crystal structure was studied by grazing incidence X-ray diffractometer (GIXRD) technique, while bonding structure was obtained by Fourier transform infrared spectroscopy (FTIR) analyses. In agreement with GIXRD and FTIR analyses, SE results show that any increment above ideal quantity of oxygen content in the gas mixture resulted in decrements in the refractive index and thickness of HfO 2 dielectric film, while increments in SiO 2 thickness. It is apparent from experimental results that oxygen to argon gas ratio needs to be smaller than 0.2 for a good film quality. The superior structural and optical properties for grown oxide film were obtained for O 2 /Ar gas ratio of about 0.05-0.1 combined with ∼30 W constant rf sputtering power.

Impact of post deposition annealing in O2 ambient on structural properties of nanocrystalline hafnium oxide thin film

“…The weak peak detected at 610 cm -1 for the film annealed at 800 and 1000 °C is related to absorption of a Si phonon [24]. Also, the wide peak lying at 748 cm -1 corresponds to HfO 2 [3,24]. The other main peaks around 512, 412 cm -1 are due to Hf-O chemical bonds [3,23,[29][30][31].…”

“…films have been identified in the 1200-400 cm -1 spectral region. FTIR spectrum of hafnium oxide film shows broad absorption band between 1100 and 1000 cm -1 which corresponds to transverse optical component of asymmetrical stretch of SiO 4 [3,[23][24].…”

“…The miniaturization of electronic devices viz., metal-insulator-semiconductor, RF (radio frequency) micro-electromechanical systems (MEMS) capacitive switch, RF MEMS phase shifter, dynamic random access memory, electro luminescent devices etc., along with improved performance ( high speed, reduce size and low power consumption ) have been demonstrated by replacing low-k dielectrics such as SiO 2, Si 3 N 4 or its oxynitrides by high-k dielectrics [1,3,4].…”

Investigation of structural, optical and micro-mechanical properties of (NdyTi1−y)Ox thin films deposited by magnetron sputtering

“…Such behaviour was observed for (Nd 0. 13 The comparison of hardness and elastic modulus determined by traditional and CSM indentation testing for the as-prepared thin films is presented in Fig. 17.…”

“…Typically in optical thin film design, layers with high and low refractive indexes such as SiO 2 , ZrO 2 , HfO 2 , Nb 2 O 5 , Ta 2 O 5 or Al 2 O 3 are used [9][10][11][12][13][14]. A well known material with high refractive index often used in the deposition of optical coatings is TiO 2 (titanium dioxide, titania).…”