Effects of physical growth conditions on the structural and optical properties of sputtered grown thin HfO2 films

Reactive high-power impulse magnetron sputtering was used to deposit HfO 2 films on Si substrates using a voltage pulse duration, t 1 , from 100 to 200 µs and an deposition-averaged target power density, , from 7.2 to 54 Wcm-2. The effects of these processing parameters on the microstructure and properties of the films were studied by atomic force microscopy, nanoindentation, X-ray diffraction, electron diffraction and high-resolution transmission electron microscopy. Four HfO 2 films were prepared with (1) t 1 = 100 µs, = 7.2 Wcm-2 (T100S7), (2) t 1 = 200 µs, = 7.3 Wcm-2 (T200S7), (3) t 1 = 200 µs, = 18 Wcm-2 (T200S18) and (4) t 1 = 200 µs, = 54 Wcm-2 (T200S54). All films were found to be composed of an interlayer next to the Si interface followed by a nano-columnar structure layer. The interlayer structure of the films was found to contain a population of lower density nanoscale regions. A reduction in in films T200S54, T200S18, T200S7 and T100S7 caused an increase in the interlayer thickness and a decrease in the width of the nano-columnar structures from ~46 nm to ~21 nm. This microstructural change was accompanied by a concomitant change of the grain boundary

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~~“…Reactive dc magnetron sputtering is a suitable technique to deposit HfO 2 films [9,[11][12][13][14][15][16][17].…”~~

Section: Introductionmentioning
confidence: 99%

Microstructure of hard and optically transparent HfO2 films prepared by high-power impulse magnetron sputtering with a pulsed oxygen flow control
Pi
¹
,
Zhang
²
,
Jiang
³

et al. 2016
Thin Solid Films
27
2
12
0
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“…However, a common problem in all production methods is that an unavoidable interfacial layer formation occurs between the grown high-film and Si substrate [19]. Since many film properties like dielectric constant and refractive index depend on the thin film composition, various research groups have been trying different methods in order to prevent formation of this undesired interfacial layer [17].…”

Section: Introductionmentioning
confidence: 99%

Impact of incorporated oxygen quantity on optical, structural and dielectric properties of reactive magnetron sputter grown high-κ HfO2/Hf/Si thin film
Cantaş¹,
Aygün²,
Turan³
2014
Applied Surface Science
18
1
14
0
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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.

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“…3,[9][10][11][12][13] The group II oxides like SrO, etc., are not favored as they react with water, the metal oxides, such as Al 2 O 3 and Y 2 O 3 , are not preferred due to their relatively lower dielectric constant, and the oxides like La 2 O 3 , etc., are not entertained for being more hygroscopic.…”

Section: Introductionmentioning
confidence: 99%

In-situ spectroscopic ellipsometry and structural study of HfO2 thin films deposited by radio frequency magnetron sputtering
Cantaş
¹
,
Aygün
²
,
Basa
³

2014
Journal of Applied Physics
Self Cite
8
1
8
0
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We have investigated the reduction of unwanted interfacial SiO 2 layer at HfO 2 /Si interface brought about by the deposition of thin Hf metal buffer layer on Si substrate prior to the deposition of HfO 2 thin films for possible direct contact between HfO 2 thin film and Si substrate, necessary for the future generation devices based on high-j HfO 2 gate dielectrics. Reactive rf magnetron sputtering system along with the attached in-situ spectroscopic ellipsometry (SE) was used to predeposit Hf metal buffer layer as well as to grow HfO 2 thin films and also to undertake the in-situ characterization of the high-j HfO 2 thin films deposited on n-type h100i crystalline silicon substrate. The formation of the unwanted interfacial SiO 2 layer and its reduction due to the predeposited Hf metal buffer layer as well as the depth profiling and also structure of HfO 2 thin films were investigated by in-situ SE, Fourier Transform Infrared spectroscopy, and Grazing Incidence X-ray Diffraction. The study demonstrates that the predeposited Hf metal buffer layer has played a crucial role in eliminating the formation of unwanted interfacial layer and that the deposited high-j HfO 2 thin films are crystalline although they were deposited at room temperature. V C 2014 AIP Publishing LLC.

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Effects of physical growth conditions on the structural and optical properties of sputtered grown thin HfO2 films

Cited by 34 publications

References 23 publications

Microstructure of hard and optically transparent HfO2 films prepared by high-power impulse magnetron sputtering with a pulsed oxygen flow control

Microstructure of hard and optically transparent HfO2 films prepared by high-power impulse magnetron sputtering with a pulsed oxygen flow control

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

In-situ spectroscopic ellipsometry and structural study of HfO2 thin films deposited by radio frequency magnetron sputtering

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