TY - JOUR
T1 - Influence of Hf precursor concentration on various properties of sol-gel based spin coated HfO2 thin films
AU - Sabhya,
AU - Kompa, Akshayakumar
AU - Kekuda, Dhananjaya
AU - Murari, M. S.
AU - Mohan Rao, K.
N1 - Funding Information:
Quantification of peaks corresponding to O1s and Hf 4f are presented in Table 5. On observing the quantified deconvoluted peaks of Hf 4f we can observe an increase in the percentage of Hf 4f 7/2 indicating the increase in formation of HfO2 with increasing sol-concentration. This supports our EDS observation. The samples are found to be oxygen rich. From calculations pertaining to the ratio O:Hf, slight increase in ratio from 2.64 to 2.7 was noted, with increase in sol-concentration. Films with similar O:Hf ratio was also observed by Zanders et al. [36]. The excess oxygen in the films could be attributed to incorporation of oxygen during air annealing. Moreover, the presence of hydroxides (which are not H bonded to water) arising from the active surface which is unreacted during film growth could also reflect in increment of O:Hf ratio [36,37]. Hence the increase in the precursor concentration had led to formation of oxygen excess HfO2 films. Hence from this study it can be specified that Hf precursor concentration plays vital role in the synthesis of HfO2 films.
Publisher Copyright:
© 2023 Elsevier B.V.
PY - 2023/2
Y1 - 2023/2
N2 - Rigorous studies on hafnium oxide (HfO2) thin films are crucial as it is regarded as the ideal insulating material, for the replacement of silicon dioxide (SiO2) dielectric material, widely used in electronic industry. HfO2 is also a promising material towards energy storage capabilities, as well as piezoelectric applications. In this direction we have studied HfO2 films synthesized from various precursor concentration using sol-gel processed spin coating method. Films were deposited on soda-lime glass substrates and were annealed at 500 °C. Subsequently optical, structural, morphological and chemical properties of the grown films were studied. XRD and Raman studies have confirmed the existence of monoclinic phase in all the films. Films with 0.1 M Hf sol-concentration exhibited comparatively higher grain size and better crystallinity compared to the films grown with other molarities. Optical studies have revealed the transparency of the films in the wavelength range of 300–1100 nm. The surface of the films exhibited low roughness values as observed from AFM studies. The film surface with fine spherical grains has been observed from the FESEM studies. Presence of desired elements such as Oxygen and Hafnium have been confirmed using EDS-elemental mapping. Cross-sectional morphology has been tried to check the thickness of the sample. From XPS studies hafnium and oxygen associated states has been extensively studied. The results of the aforementioned studies suggest that precursor concentration play a significant role in deciding the properties of the films.
AB - Rigorous studies on hafnium oxide (HfO2) thin films are crucial as it is regarded as the ideal insulating material, for the replacement of silicon dioxide (SiO2) dielectric material, widely used in electronic industry. HfO2 is also a promising material towards energy storage capabilities, as well as piezoelectric applications. In this direction we have studied HfO2 films synthesized from various precursor concentration using sol-gel processed spin coating method. Films were deposited on soda-lime glass substrates and were annealed at 500 °C. Subsequently optical, structural, morphological and chemical properties of the grown films were studied. XRD and Raman studies have confirmed the existence of monoclinic phase in all the films. Films with 0.1 M Hf sol-concentration exhibited comparatively higher grain size and better crystallinity compared to the films grown with other molarities. Optical studies have revealed the transparency of the films in the wavelength range of 300–1100 nm. The surface of the films exhibited low roughness values as observed from AFM studies. The film surface with fine spherical grains has been observed from the FESEM studies. Presence of desired elements such as Oxygen and Hafnium have been confirmed using EDS-elemental mapping. Cross-sectional morphology has been tried to check the thickness of the sample. From XPS studies hafnium and oxygen associated states has been extensively studied. The results of the aforementioned studies suggest that precursor concentration play a significant role in deciding the properties of the films.
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U2 - 10.1016/j.optmat.2022.113424
DO - 10.1016/j.optmat.2022.113424
M3 - Article
AN - SCOPUS:85146055946
SN - 0925-3467
VL - 136
JO - Optical Materials
JF - Optical Materials
M1 - 113424
ER -