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In this Letter, the robust ferroelectric properties of low-temperature (350 °C) Hf0.5Zr0.5O2 (HZO) films are investigated. We demonstrate that the lower crystallization temperature of HZO films originates from a densified film deposition with an anhydrous H2O2 oxidant in the atomic layer deposition process. As a consequence of this densification, H2O2-based HZO films showed completely crystallinity with fewer defects at a lower annealing temperature of 350 °C. This reduction in the crystallization temperature additionally suppresses the oxidation of TiN electrodes, thereby improving device reliability. The low-temperature crystallization process produces an H2O2-based HZO capacitor with a high remanent polarization (Pr), reduced leakage current, high breakdown voltage, and better endurance. Furthermore, while an O3-based HZO capacitor requires wake-up cycling to achieve stable Pr, the H2O2-based HZO capacitor demonstrates a significantly reduced wake-up nature. Anhydrous H2O2 oxidant enables the fabrication of a more reliable ferroelectric HZO device using a low process thermal budget (350 °C). [ABSTRACT FROM AUTHOR]

A novel precursor, 1,1,1-tris(dimethylamino)disilane {TADS, [(H3C)2N]3Si2H3}, is used to deposit silicon dioxide (SiO2) films in a temperature range of 115–480 °C by thermal atomic layer deposition (tALD) and plasma-enhanced atomic layer deposition (PEALD) techniques. Compared to tris(dimethylamino)silane (TDMAS), the additional Si-Si bond in TADS is expected to enhance the reactivity of the molecule due to the polarization of the bond. In the tALD process, TADS gives a growth rate of 0.06 nm/cycle, which is approximately 20% higher than that of TDMAS, and an excellent conformality (>95% step coverage) in high aspect ratio nanotrenches (6:1). In the case of the PEALD process, TADS leads to not only a higher or at least comparable growth rates (0.11 nm/cycle), but also a higher bulk film density (∼2.38 g/cm3). As a result, the PEALD SiO2 films of TADS show a wet-etch rate down to 1.6 nm/min in 200:1 HF, which is comparable to that of the thermal oxide. Analyzed with Fourier-Transform Infrared (FTIR), the SiO2 films contain predominant Si−O bonds and a low level of Si−H and O−H bonds, consistent with the observed high wet-etch resistance. Furthermore, the PEALD SiO2 films deposited at 310 °C have at least 75% step coverage in high aspect ratio nanotrenches, suggesting that TADS is applicable for forming high-quality SiO2 films on both planar and patterned surfaces. [ABSTRACT FROM AUTHOR]

In this Letter, a high-pressure annealing (HPA) process is proposed as a way to reduce the thermal budget of Hf0.5Zr0.5O2 (HZO) thin films with ferroelectric behaviors. The low-thermal-budget process is essential for integrating ferroelectric devices in the back-end-of-line to provide more functionalities and effective memory area. For the HZO film annealed at 300 °C using the HPA process, an orthorhombic phase responsible for ferroelectric behavior was formed with a decrease in film thickness, resulting in a remanent polarization (Pr) of ∼13 μC/cm2 (i.e., 2Pr of ∼26 μC/cm2). Meanwhile, when only the annealing time was increased at 300 °C without applying pressure, the HZO film did not crystallize and exhibited linear dielectric properties. Consequently, the HZO films (<10 nm) can be crystallized by applying pressure (15 atm) even at low temperatures of 300 °C, thereby obtaining ferroelectric properties. [ABSTRACT FROM AUTHOR]

Since HfO2‐based ferroelectric films were reported in 2011, several doping/alloying elements have been introduced to secure interesting ferroelectric/antiferroelectric properties of Hf‐based fluorite‐structured thin films. Using a conventional approach by atomic layer deposition (ALD), an enormous number of experiments would be required to reveal the compositional effects of doping/alloying components in ternary and quaternary systems. Therefore, for a comprehensive study of the ferroelectric properties of HfxZr1−xO2, a novel combinatorial ALD technique that enables the fabrication of multicomponent films with a different composition ratio and thickness via saturated/non‐saturated ALD without changing the supercycle of each material is reported. The gradient of the amount of HfO2 over a 100 mm substrate is achieved using a lower Hf‐precursor temperature that results in an insufficient Hf‐precursor dose for saturated deposition. Systematic study on the HfxZr1−xO2 combinatorial library is carried out by spectroscopic ellipsometry, X‐ray photoelectron spectroscopy, and X‐ray diffraction. Furthermore, TiN/HfxZr1−xO2/TiN capacitors are fabricated to measure the remnant polarization. The obtained results clearly show the ferroelectric–antiferroelectric transition according to continuous composition change instead of discrete research. Therefore, a highly productive method for studying ferroelectricity changes in terms of a doping and a composition of HfO2‐based ferroelectric thin films through a novel ALD combinatorial approach is proposed. [ABSTRACT FROM AUTHOR]

In recent times, the requirements have become extremely stringent for employing silicon nitride (SiNx) films in various types of applications. For instance, high etch resistance coating is required for a film to act as an etch stop layer and gate spacer for nanoscale patterning for next-generation semiconductor devices. In this study, a chlorodisilane precursor, 1,1,1-trichlorodisilane (3CDS, Si2H3Cl3), was used to deposit SiNx films using a hollow cathode plasma-enhanced atomic layer deposition system and compared with the SiNx films deposited using hexachlorodisilane (HCDS, Si2Cl6) as well as pentachlorodisilane (PCDS, Si2HCl5). In the process temperature range of 310–435 °C, a self-limiting surface reaction behavior with 4 × 103 L of 3CDS exposure and 2 × 106 L of NH3 plasma exposure was observed. 3CDS particularly gives ∼45 and ∼20% higher growth per cycle than HCDS and PCDS, respectively. In addition, the SiNx films deposited using 3CDS at 480 °C have improved the wet etch rate (0.4 nm/min in 200:1 HF) and density (2.88 g/cm3). Analyzed with time-of-flight secondary ion mass spectrometry, the 3CDS-derived SiNx films contain less hydrogen than the SiNx films formed using HCDS under identical process conditions. These superior film properties can be attributed to the unique structural characteristics of 3CDS, where the three chlorine and three hydrogen atoms are localized on each of the two silicon atoms. The SiNx films deposited on nanotrenches with a high aspect ratio (6:1) at 390 and 480 °C showed >85% and >65% conformality, respectively, and high etch resistance (1.9 and 0.8 nm/min, respectively, in 200:1 HF), suggesting that high-quality SiNx films can be formed from 3CDS on both planar and patterned surfaces. [ABSTRACT FROM AUTHOR]

In this paper, atomic layer deposition of SiO2 thin films was investigated with Si2Cl6 and O3/O2 (400 g m−3). O3/O2 is not preferred for high-temperature (>400 °C) processes due to its lower decomposition temperature, especially in a furnace-type chamber. However, with Si oxidation test using a cold-wall chamber, we have demonstrated the reactivity of O3/O2 up to 800 °C in comparison with O2 and H2O. The ALD of SiO2 films was examined at deposition temperatures from 500 °C to 700 °C. The growth rate at 600 °C was saturated to 0.03 nm/cycle with Si2Cl6 exposure over 1.2 × 105 L. O3/O2 also showed ALD-like saturation behaviors for exposures over 2.4 × 106 L. The ALD films deposited at 600 °C exhibited relatively smooth surface roughness (<0.18 nm) and low wet etch rate (1.6 nm min−1, 500:1 HF) that are comparable with PECVD SiO2 deposited at 250 °C and LPCVD SiO2 deposited at 450 °C. [ABSTRACT FROM AUTHOR]

The ferroelectric (FE) properties of 10-nm-thick Hf0.5Zr0.5O2 (HZO) films deposited by an atomic layer deposition technique were improved by adopting O3 as an oxygen source instead of H2O. All HZO films were annealed at 400 °C for 1 min in an N2 atmosphere after TiN top electrode deposition. Regardless of the oxygen source, the HZO films exhibited the formation of a noncentrosymmetric orthorhombic phase, which is responsible for FE behavior with the suppression of the monoclinic phase. However, compared to the O3-based HZO film, it was confirmed that the H2O-based HZO film was more incorporated with hydrogen derived from H2O, thereby degrading FE polarization and leakage behavior. The results indicate that the strategy of using O3 as the oxygen source is useful for the fabrication and integration of FE HZO films for next-generation memory applications. [ABSTRACT FROM AUTHOR]

Inductively coupled plasma reactive ion etching of Pd thin films with TiN hard masks was carried out in a CH 3 COOH/Ar gas mixture. The addition of CH 3 COOH to Ar gas decreased the etch rate but a good etch profile with a high degree of anisotropy was obtained at 50% CH 3 COOH/Ar. Variations in the etch parameters showed that high inductively coupled plasma power and dc-bias voltage improved the etch profile. X-ray photoelectron spectroscopy and optical emission spectroscopy results revealed that the Pd films in CH 3 COOH/Ar gas followed the sputtering etch mechanism assisted by the oxidation and sidewall protection provided by polymer films. [ABSTRACT FROM AUTHOR]