Effect of Mg and Zr co-doping on piezoelectric AlN thin films for bulk acoustic wave resonators

Yokoyama, Tsuyoshi; Iwazaki, Yoshiki; Onda, Yosuke; Nishihara, Tokihiro; Sasajima, Yuichi; Ueda, Masahiko

doi:10.1109/tuffc.2014.3039

Cited by 50 publications

(37 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because several of the here considered alloys have lower mixing enthalpies and driving force for phase separation than Sc x Al 1−x N, we envisage the possibility for their synthesis as metastable thin films. This is in line with the initial experimental work by Yokoyama et al [13] The Ti x/2 Zn x/2 Al 1−x N mixing enthalpies, Fig. 2(e), are distinctly different to the alloys with Mg.…”

Section: Resultssupporting

confidence: 92%

“…In TM Compared to previously reported piezoelectric coefficients e 33 , C 33 , and d 33,f by Yokoyama et al [11,13] and Iwazaki et al [12] there is a qualitative agreement that the quarternaries will be an improvement compared to pure AlN and a competitive alternative to ScAlN. There are, however, some quantitative differences, which is expected because of the different alloy models used.…”

Section: Resultsmentioning

confidence: 60%

“…Here, we investigate the piezoelectric and elastic properties of the nine different quarternary TM x/2 M x/2 Al 1−x N (TM = Ti, Zr, Hf; M = Mg, Ca, Zn) alloys. Of these quarternaries, TiMgAlN [11,12], ZrMgAlN [11][12][13][14], and HfMgAlN [11,12] have only recently begun to be studied theoretically, and only ZrMgAlN [11,13] and HfMgAlN [11] experimentally. Moreover, we investigate the thermodynamic stability of the alloys to determine the possibilities for equilibrium or the need for nonequilibrium synthesis routes.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles

et al. 2015

View full text Add to dashboard Cite

The potential of quarternary wurtzite TM x/2 M x/2 Al 1−x N (TM = Ti, Zr, Hf; M = Mg, Ca, Zn) alloys for piezoelectric applications is investigated using first-principles calculations. All considered alloys show increased piezoelectric response compared to pure AlN, and competing with the best ternary system proven to date: ScAlN. (Zr,Hf) x/2 (Mg,Ca) x/2 Al 1−x N alloys are particularly promising. Calculations reveal positive mixing enthalpies indicative for phase separating systems; their values are smaller compared to related nitride alloys, which still can be grown as metastable thin films. The wurtzite phase of the alloys is lowest in energy at least up to x = 0.5 and for Ti x/2 Zn x/2 Al 1−x N in the full composition range. Moreover, calculations reveal that wurtzite TM 0.5 Zn 0.5 N (TM = Ti, Zr, Hf) are piezoelectric alloys with d 33,f = 19.95, 29.89, and 24.65 pC/N respectively, up to six times that of AlN. Finally, we discuss the physical origin behind the increased piezoelectric response and show that the energy difference between tetrahedrally coordinated zinc-blende (B3) and the layered hexagonal (B k ) phases of the TM 0.5 M 0.5 N alloy can be used as a descriptor in a high-throughput search for complex wurtzite alloys with high piezoelectric response.

show abstract

Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles

et al. 2015

View full text Add to dashboard Cite

show abstract

“…So far there have been little experimental work on these quarternary alloys, limited to that of Yokoyama et al [80,81] and Minh et al [82,83], who have synthesized TM x/2 Mg x/2 Al 1−x N alloys and create devices with x ≤ 0.348.…”

Section: Tmmentioning

confidence: 99%

Piezoelectricity, Phase Stability, and Surface Diffusion in Multicomponent Nitrides

Tholander

2016

Linköping Studies in Science and Technology. Dissertations

View full text Add to dashboard Cite

The cover image is a compilation inspired by key results from my research.During the course of research underlying this thesis, Christopher Tholander was enrolled in Agora Materiae, a multidiciplinary doctoral program at Linköping University, Sweden.c Christopher Printed by LiU-Tryck 2016 Till min familj AbstractThe last hundred years have been full of scientific discoveries leading to technological advances, such as, computers, smart phones, etc. Most of the advances would not have been possible without new discoveries within the vast field of materials science. The specific area within materials science covered in this thesis is multicomponent nitride alloys, which are commonly used as thin films in industrial applications, e.g., as hard wear-resistant coatings for cutting-tools or as part of intricate electronic components in mobile telecommunication devices. The core of this thesis is towards the fundamental understanding of existing, and the discovery of new, nitride alloys using theoretical tools. Knowledge about the quantum mechanics of the alloys was gained using density functional theory (DFT), alloy theory, and thermodynamics investigating piezoelectricity, phase stability, and surface diffusion.The focus of the piezoelectricity research is on piezoelectric properties of both ordered and disordered nitrides. The exploration of disordered wurtzite nitrides revealed important aspects of the nitride alloying physics and the implications for their piezoelectric response, in addition to the discovery of interesting alloy candidates and their synthesis, e.g., Y x In 1−x N. For the ordered nitrides, novel TMZnN 2 (TM = Ti, Zr, Hf) structures with high piezoelectric responses have been predicted as stable.The thermodynamic stability of novel alloys with interesting properties is investigated in order to determine if equilibrium or non-equilibrium synthesis is feasible. The studies consist of ternary phase diagrams of TM-Zn-N, mixing enthalpies for disordered Y x Al 1−x N and Y x In 1−x N that can be used to predict possible synthesis routes and guide experiments. In addition, mixing enthalpies for strained Sc x Al 1−x N/In y Al 1−y N superlattices show that the stability of certain phases and, therefore, the crystalline quality can be improved by modifying in-plane lattice parameters through higher indium content in the InAlN layers.Surface diffusion is studied because it is an important factor during thin film growth with, for example, physical vapor deposition (PVD). It is the main atomic v vi transport mechanism and, thus, governs the structure development of thin films. Specifically, the research is focused on diffusion on the surfaces of disordered alloys, and in particular Ti, Al, and N adatom diffusion on TiN and TiAlN surfaces. The investigations revealed that Ti adatom mobilities are dramatically reduced in the presence of Al in the surface layer on the TiN and Ti 0.5 Al 0.5 N(0 0 1) surfaces, while Al adatoms are largely unaffected. Furthermore, the reverse effect is found on the TiN (1 1 1) surf...

show abstract

“…Recently, it was shown that the piezoelectric response and dielectric constant of AlN films are closely connected to the crystal structure, preferential orientation of c-axis, polar distribution of grains and defects in the AlN films [5,6]. Besides, substitution of Al by transition-metals has been reported to be one of the most effective ways to improve the materials performance including the piezoelectric response [7,8]. Research has demonstrated a 400% increase in piezoelectric modulus d 33 for Sc 0.43 Al 0.57 N alloys [9].…”

Section: Introductionmentioning

confidence: 99%

Influence of sputtering atmosphere on crystal quality and electrical properties of zirconium aluminum nitride thin film

Yuan

et al. 2016

Surface and Coatings Technology

View full text Add to dashboard Cite

Effect of Mg and Zr co-doping on piezoelectric AlN thin films for bulk acoustic wave resonators

Cited by 50 publications

References 26 publications

Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles

Large piezoelectric response of quarternary wurtzite nitride alloys and its physical origin from first principles

Piezoelectricity, Phase Stability, and Surface Diffusion in Multicomponent Nitrides

Influence of sputtering atmosphere on crystal quality and electrical properties of zirconium aluminum nitride thin film

Contact Info

Product

Resources

About