Impact of dislocation density on the ferroelectric properties of ScAlN grown by molecular beam epitaxy

We report on the effect of dislocation density on the ferroelectric properties of single-crystalline ScAlN thin films grown by molecular beam epitaxy. Wurtzite phase and atomically smooth ScAlN films have been grown on bulk GaN, GaN on sapphire, and GaN on Si substrates with dislocation densities ranging from ∼107 to 1010 cm−2. Despite the significant difference in dislocation density, ferroelectricity is observed in all three samples. The presence of high densities of dislocations, however, results in enhanced asymmetric P–E loops and overestimated remnant polarization values. Further measurements show that the leakage current and breakdown strength can be improved with decreasing dislocation density. Detailed studies suggest that trapping/detrapping assisted transport is the main leakage mechanism in epitaxial ferroelectric ScAlN films. This work sheds light on the essential material quality considerations for tuning the ferroelectric property of ScAlN toward integration with mainstream semiconductor platforms, e.g., Si, and paves the way for next-generation electronics, optoelectronics, and piezoelectronics.

[1]  Z. Mi,et al.  Ferroelectric N-polar ScAlN/GaN heterostructures grown by molecular beam epitaxy , 2022, Applied Physics Letters.

[2]  D. Jena,et al.  Epitaxial ScxAl1−xN on GaN exhibits attractive high-K dielectric properties , 2021, Applied Physics Letters.

[3]  Tengyu Ma,et al.  Interfacial Modulated Lattice-Polarity-Controlled Epitaxy of III-Nitride Heterostructures on Si(111). , 2022, ACS applied materials & interfaces.

[4]  Z. Mi,et al.  An Epitaxial Ferroelectric ScAlN/GaN Heterostructure Memory , 2022, Advanced Electronic Materials.

[5]  Md. Redwanul Islam,et al.  From Fully Strained to Relaxed: Epitaxial Ferroelectric Al1‐xScxN for III‐N Technology , 2022, Advanced Functional Materials.

[6]  Z. Mi,et al.  Quaternary alloy ScAlGaN: A promising strategy to improve the quality of ScAlN , 2022, Applied Physics Letters.

[7]  H. Funakubo,et al.  Demonstration of ferroelectricity in ScGaN thin film using sputtering method , 2021, Applied Physics Letters.

[8]  Z. Mi,et al.  Fully epitaxial ferroelectric ScGaN grown on GaN by molecular beam epitaxy , 2021, Applied Physics Letters.

[9]  D. Jena,et al.  Strong effect of scandium source purity on chemical and electronic properties of epitaxial ScxAl1−xN/GaN heterostructures , 2021, APL Materials.

[10]  Z. Mi,et al.  N-polar ScAlN and HEMTs grown by molecular beam epitaxy , 2021, Applied Physics Letters.

[11]  Kevin J. Chen,et al.  Gallium nitride-based complementary logic integrated circuits , 2021, Nature Electronics.

[12]  Z. Mi,et al.  Fully epitaxial ferroelectric ScAlN grown by molecular beam epitaxy , 2021 .

[13]  R. Olsson,et al.  Aluminum scandium nitride-based metal–ferroelectric–metal diode memory devices with high on/off ratios , 2021 .

[14]  O. Ambacher,et al.  On the exceptional temperature stability of ferroelectric Al1-xScxN thin films , 2021, Applied Physics Letters.

[15]  R. Tabrizian,et al.  A Segmented‐Target Sputtering Process for Growth of Sub‐50 nm Ferroelectric Scandium–Aluminum–Nitride Films with Composition and Stress Tuning , 2021, physica status solidi (RRL) – Rapid Research Letters.

[16]  F. Toma,et al.  Development of a photoelectrochemically self-improving Si/GaN photocathode for efficient and durable H2 production , 2021, Nature Materials.

[17]  Michael J. Hoffmann,et al.  Next generation ferroelectric materials for semiconductor process integration and their applications , 2021, Journal of Applied Physics.

[18]  H. Wakabayashi,et al.  Room-temperature deposition of a poling-free ferroelectric AlScN film by reactive sputtering , 2021 .

[19]  H. Wakabayashi,et al.  A possible origin of the large leakage current in ferroelectric Al1−x Sc x N films , 2021 .

[20]  Z. Mi,et al.  Oxygen defect dominated photoluminescence emission of ScxAl1−xN grown by molecular beam epitaxy , 2021 .

[21]  R. Olsson,et al.  Post-CMOS Compatible Aluminum Scandium Nitride/2D Channel Ferroelectric Field-Effect-Transistor Memory. , 2020, Nano letters.

[22]  H. Funakubo,et al.  Thickness scaling of (Al0.8Sc0.2)N films with remanent polarization beyond 100 μC cm−2 around 10 nm in thickness , 2021, Applied Physics Express.

[23]  Junjie Kang,et al.  Sec‐Eliminating the SARS‐CoV‐2 by AlGaN Based High Power Deep Ultraviolet Light Source , 2020, Advanced functional materials.

[24]  Suman Datta,et al.  The future of ferroelectric field-effect transistor technology , 2020, Nature Electronics.

[25]  H. Funakubo,et al.  Effects of deposition conditions on the ferroelectric properties of (Al1−xScx)N thin films , 2020 .

[26]  D. Muller,et al.  Structural and piezoelectric properties of ultra-thin ScxAl1−xN films grown on GaN by molecular beam epitaxy , 2020, Applied Physics Letters.

[27]  D. Katzer,et al.  Control of phase purity in high scandium fraction heteroepitaxial ScAlN grown by molecular beam epitaxy , 2020, Applied Physics Express.

[28]  O. Ambacher,et al.  Metalorganic chemical vapor phase deposition of AlScN/GaN heterostructures , 2020 .

[29]  Y. Tong,et al.  III-nitrides based resonant tunneling diodes , 2020, Journal of Physics D: Applied Physics.

[30]  Z. Mi,et al.  Molecular beam epitaxy and characterization of wurtzite ScxAl1−xN , 2020, Applied Physics Letters.

[31]  D. Jena,et al.  Oxygen Incorporation in the Molecular Beam Epitaxy Growth of ScxGa1−xN and ScxAl1−xN , 2019, physica status solidi (b).

[32]  K. Bertness,et al.  Eutectic Formation, V/III Ratio, and Controlled Polarity Inversion in Nitrides on Silicon , 2020, Physica status solidi. B, Basic solid state physics : PSS.

[33]  B. Wagner,et al.  AlScN: A III-V semiconductor based ferroelectric , 2018, Journal of Applied Physics.

[34]  Jian Zhang,et al.  Repeatable Room Temperature Negative Differential Resistance in AlN/GaN Resonant Tunneling Diodes Grown on Sapphire , 2018, Advanced Electronic Materials.

[35]  W. Hong,et al.  Grain‐size–dependent dielectric properties in nanograin ferroelectrics , 2018, Journal of the American Ceramic Society.

[36]  M. Islam,et al.  Ultrawide‐Bandgap Semiconductors: Research Opportunities and Challenges , 2017 .

[37]  Hong Zhou,et al.  Steep-slope hysteresis-free negative capacitance MoS2 transistors , 2017, Nature Nanotechnology.

[38]  D. Katzer,et al.  Epitaxial ScAlN grown by molecular beam epitaxy on GaN and SiC substrates , 2017 .

[39]  Hui Yang,et al.  GaN-on-Si blue/white LEDs: epitaxy, chip, and package , 2016 .

[40]  Xiaodong Wang,et al.  High mobility AlGaN/GaN heterostructures grown on Si substrates using a large lattice-mismatch induced stress control technology , 2015 .

[41]  Qian Sun,et al.  Strain relaxation and dislocation reduction in AlGaN step‐graded buffer for crack‐free GaN on Si (111) , 2014 .

[42]  Paul Muralt,et al.  Piezoelectric Al1−xScxN thin films: A semiconductor compatible solution for mechanical energy harvesting and sensors , 2013 .

[43]  C. Humphreys,et al.  Tunable optoelectronic and ferroelectric properties in Sc-based III-nitrides , 2013, 1303.3745.

[44]  U. Mishra,et al.  Growth of high quality N-polar AlN(0001¯) on Si(111) by plasma assisted molecular beam epitaxy , 2009 .

[45]  Y. Rosenwaks,et al.  Ferroelectric Domain Breakdown , 2007 .

[46]  Edward T. Yu,et al.  Analysis of leakage current mechanisms in Schottky contacts to GaN and Al0.25Ga0.75N∕GaN grown by molecular-beam epitaxy , 2006 .

[47]  James S. Speck,et al.  Dislocation mediated surface morphology of GaN , 1999 .