Atomic layer deposition of HfO2, Al2O3, and HfAlOx using O3 and metal(diethylamino) precursors

2007 ◽  
Vol 22 (12) ◽  
pp. 3455-3464 ◽  
Author(s):  
Rajesh Katamreddy ◽  
Ronald Inman ◽  
Gregory Jursich ◽  
Axel Soulet ◽  
Christos Takoudis

Tetrakis-diethylamino hafnium (TDEAH), tris-diethylamino aluminum (TDEAA), and ozone were used for the atomic layer deposition (ALD) of HfO2, Al2O3, and HfAlOx films. The ALD rates were measured to be 1.1 Å/cycle for HfO2 and 1.3 Å/cycle for Al2O3. The ALD temperature windows were found to be between 200 and 325 °C for TDEAA, and between 200 and 275 °C for TDEAH. The overlap of these ALD windows between 200 and 275 °C is critical for ALD of the composite film, HfAlOx. In addition to the overlapping ALD temperature windows, the two metal precursors have similar thermal characteristics, as shown by TGA and differential scanning calorimetry. As-deposited films and films postannealed at 600 and 800 °C films were analyzed using Fourier transformed infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy, and x-ray diffraction (XRD) techniques. FTIR spectra revealed interfacial oxide growth during deposition of both HfO2 and Al2O3 whose thickness increased with annealing temperature. The FTIR data also indicated hydroxyl and nitrate groups in the films; these species were removed after annealing in Ar at a temperature of ⩾600 °C. Both FTIR and XRD results indicated the crystallization of pure HfO2 after annealing at temperatures as low as 600 °C. On the other hand, pure Al2O3 remained amorphous after annealing at temperatures up to 800 °C. XRD data of the composite HfAlOx film show that films deposited by alternating five cycles of HfO2 and one cycle of Al2O3 remained amorphous after annealing at 600 °C. Rutherford backscattering analysis of HfAlOx deposited with a varied number of alternating HfO2 and Al2O3 cycles demonstrated a strong correlation between the cyclic dosage of TDEAA and TDEAH and the film composition.

2018 ◽  
Vol 32 (19) ◽  
pp. 1840074 ◽  
Author(s):  
Viral Barhate ◽  
Khushabu Agrawal ◽  
Vilas Patil ◽  
Sumit Patil ◽  
Ashok Mahajan

The spectroscopic study of La2O3 thin films deposited over Si and SiC at low RF power of 25 W by using indigenously developed plasma-enhanced atomic layer deposition (IDPEALD) system has been investigated. The tris (cyclopentadienyl) lanthanum (III) and O2 plasma were used as a source precursor of lanthanum and oxygen, respectively. The [Formula: see text]1.2 nm thick La2O3 over SiC and Si has been formed based on our recipe confirmed by means of cross-sectional transmission electron microscopy. The structural characterization of deposited films was performed by means of X-ray photoelectron Spectroscopy (XPS) and X-ray Diffraction (XRD). The XPS result confirms the formation of 3[Formula: see text] oxidation state of the lanthania. The XRD results reveals that, deposited La2O3 films deposited on SiC are amorphous in nature compare to that of films on Si. The AFM micrograph shows the lowest roughness of 0.26 nm for 30 cycles of La2O3 thin films.


2016 ◽  
Vol 316 ◽  
pp. 160-169 ◽  
Author(s):  
Nicholas David Schuppert ◽  
Santanu Mukherjee ◽  
Alex M. Bates ◽  
Eun-Jin Son ◽  
Moon Jong Choi ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5043
Author(s):  
Chia-Hsun Hsu ◽  
Xin-Peng Geng ◽  
Wan-Yu Wu ◽  
Ming-Jie Zhao ◽  
Xiao-Ying Zhang ◽  
...  

In this study, aluminum-doped zinc oxide (Al:ZnO) thin films were grown by high-speed atmospheric atomic layer deposition (AALD), and the effects of air annealing on film properties are investigated. The experimental results show that the thermal annealing can significantly reduce the amount of oxygen vacancies defects as evidenced by X-ray photoelectron spectroscopy spectra due to the in-diffusion of oxygen from air to the films. As shown by X-ray diffraction, the annealing repairs the crystalline structure and releases the stress. The absorption coefficient of the films increases with the annealing temperature due to the increased density. The annealing temperature reaching 600 °C leads to relatively significant changes in grain size and band gap. From the results of band gap and Hall-effect measurements, the annealing temperature lower than 600 °C reduces the oxygen vacancies defects acting as shallow donors, while it is suspected that the annealing temperature higher than 600 °C can further remove the oxygen defects introduced mid-gap states.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Majtyka ◽  
Anna Nowak ◽  
Benoît Marchand ◽  
Dariusz Chrobak ◽  
Mikko Ritala ◽  
...  

The present paper pertains to mechanical properties and structure of nanocrystalline multiferroic BeFiO3(BFO) thin films, grown by atomic layer deposition (ALD) on the Si/SiO2/Pt substrate. The usage of sharp-tip-nanoindentation and multiple techniques of structure examination, namely, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry, enabled us to detect changes in elastic properties(95 GPa≤E≤118 GPa)and hardness(4.50 GPa≤H≤7.96 GPa)of BFO after stages of annealing and observe their relation to the material’s structural evolution. Our experiments point towards an increase in structural homogeneity of the samples annealed for a longer time. To our best knowledge, the present report constitutes the first disclosure of nanoindentation mechanical characteristics of ALD-fabricated BeFiO3, providing a new insight into the phenomena that accompany structure formation and development of nanocrystalline multiferroics. We believe that our systematic characterization of the BFO layers carried out at consecutive stages of their deposition provides pertinent information which is needed to control and optimize its ALD fabrication.


Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1987 ◽  
Author(s):  
Mykola Pavlenko ◽  
Valerii Myndrul ◽  
Gloria Gottardi ◽  
Emerson Coy ◽  
Mariusz Jancelewicz ◽  
...  

In the current research, a porous silicon/zinc oxide (PSi/ZnO) nanocomposite produced by a combination of metal-assisted chemical etching (MACE) and atomic layer deposition (ALD) methods is presented. The applicability of the composite for biophotonics (optical biosensing) was investigated. To characterize the structural and optical properties of the produced PSi/ZnO nanocomposites, several studies were performed: scanning and transmission electron microscopy (SEM/TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), diffuse reflectance, and photoluminescence (PL). It was found that the ALD ZnO layer fully covers the PSi, and it possesses a polycrystalline wurtzite structure. The effect of the number of ALD cycles and the type of Si doping on the optical properties of nanocomposites was determined. PL measurements showed a “shoulder-shape” emission in the visible range. The mechanisms of the observed PL were discussed. It was demonstrated that the improved PL performance of the PSi/ZnO nanocomposites could be used for implementation in optical biosensor applications. Furthermore, the produced PSi/ZnO nanocomposite was tested for optical/PL biosensing towards mycotoxins (Aflatoxin B1) detection, confirming the applicability of the nanocomposites.


2018 ◽  
Vol 282 ◽  
pp. 232-237
Author(s):  
Adam Hinckley ◽  
Anthony Muscat

Atomic layer deposition (ALD) was used to grow titanium nitride (TiN) on SiO2with TiCl4and N2H4. X-ray photoelectron spectroscopy (XPS) and ellipsometry were used to characterize film growth. A hydrogen-terminated Si (Si-H) surface was used as a reference to understand the reaction steps on SPM cleaned SiO2. The growth rate of TiN at 573 K doubled on Si-H compared to SiO2because of the formation of Si-N bonds. When the temperature was raised to 623 K, O transferred from Ti to Si to form Si-N when exposed to N2H4. Oxygen and Ti could be removed at 623 K by TiCl4producing volatile species. The added surface reactions reduce the Cl in the film below detection limits.


2007 ◽  
Vol 990 ◽  
Author(s):  
Sung-Hoon Chung ◽  
Vladislav Vasilyev ◽  
Evgeni Gorokhov ◽  
Yong-Won Song ◽  
Hyuk-Kyoo Jang

ABSTRACTWe investigated effects of thermal annealing on Ru films deposited on the 8 inch Si substrates using a volatile liquid-phase Ru precursor, tricarbonyl-1,3-cyclohexadienyl ruthenium (Ru(CO)3(C6H8)) by an atomic layer deposition (ALD) technique. Structural and electrical properties of the films were characterized by scanning probe microscopy, X-ray diffractometry, sheet resistance. Grazing incidence X-ray diffraction (GIXRD) patterns show typical Ru hexagonal polycrystalline peaks as annealing temperature was increased. At the highest annealing temperature condition, Ta = 700 °C electrical resistivity become 6 times less than in as-deposited films.


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