Demonstration of lateral epitaxial growth of AlN on Si (1 1 1) at low temperatures by pulsed reactive sputter epitaxy

Hörich, Florian; Borgmann, Ralf; Bläsing, J.; Schmidt, Gordon; Veit, Peter; Bertram, F.; Christen, J.; Strittmatter, A.; Dadgar, A.

doi:10.1016/j.jcrysgro.2021.126250

Cited by 12 publications

(3 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These vanishing voids indicate a substantial lateral growth rate. [ 12 ] Now the crystallographic quality and surface morphology of this layer is an excellent starting point for the growth of further layers and complex device structures.…”

Section: Resultsmentioning

confidence: 99%

Sputter Epitaxy of AlN and GaN on Si(111)

Dadgar

Hörich

Borgmann

et al. 2022

Physica Status Solidi (a)

Self Cite

View full text Add to dashboard Cite

Sputter epitaxy is a low‐cost process suited for the deposition of group‐III‐nitride semiconductors and allowing the deposition on large substrate areas at lower growth temperatures than in metal–organic vapor phase epitaxy (MOVPE). High‐quality AlN, AlGaN, and GaN epitaxially grown on Si(111) substrates by reactive magnetron sputtering are demonstrated and details on process parameters are given. With an ammonia‐based reactive sputtering process in a high‐purity environment, AlN can be grown with high crystalline quality comparable to the best MOVPE‐grown samples regarding twist and tilt and with a very low surface roughness, free of the typical columnar structure of sputtered AlN and pits. Also AlGaN, typically required for strain engineering of GaN layers grown on Si, can be grown in the entire compositional range by co‐sputtering of Al and Ga. Thin undoped buffer layer samples show high breakdown field strengths well above 2.5 × 106 V cm−1 and demonstrate the possible use for field effect transistor (FET) buffer layers.

show abstract

Section: Resultsmentioning

confidence: 99%

Sputter Epitaxy of AlN and GaN on Si(111)

Dadgar

Hörich

Borgmann

et al. 2022

Physica Status Solidi (a)

Self Cite

View full text Add to dashboard Cite

show abstract

“…Dadgar et al . demonstrate good values of mosaicity, close to 0.3°, for 250 nm AlN films sputtered on Si(111) at 900 °C. For the fabrication of bulk acoustic-wave filters when a metallic electrode (Pt, Ir, or Ru) is inserted between the Si substrate and the sputtered AlN film, the strong texture of the sputtered metallic film is transmitted to the AlN film and the mosaicity reaches values close to 1° − for 2-μm-thick films.…”

Section: Introductionmentioning

confidence: 94%

Crack-Free AlN Film Grown on Sputtered-AlN/2D MoS₂ Seed Layers on a Si(100)-Based Wafer: Implications for Radio-Frequency Acoustic Filters

Hyot,

Dussaigne,

Patouillard

et al. 2024

ACS Appl. Nano Mater.

View full text Add to dashboard Cite

Aluminum nitride (AlN)-based acoustic filters are key devices of radio-frequency communications. However, the performance of electroacoustic resonators remains limited by the crystalline quality of the piezoelectric AlN material. An innovative material strategy that combines different types of materials (2D and 3D materials) and growth techniques is presented here to enhance the crystalline quality of thick AlN films grown on silicon-based substrates. Building upon previous works showing the efficacy of 2D MoS 2 in sputtered-AlN texturing, this paper demonstrates how an in situ thermochemical treatment of the sputtered-AlN/MoS 2 seed layers succeeded by a metal organic vapor phase epitaxy (MOVPE) AlN regrowth significantly enhances the crystalline quality of the AlN layer and avoids the detrimental stack delamination at the weak AlN/MoS 2 interface. This paper shows that a delicate balance in the thickness of the sputtered-AlN film should be found to facilitate species diffusion toward the underlying MoS 2 without compromising its texturizing properties for the subsequent MOVPE AlN regrowth. The sputtered-AlN/MoS 2 seed layers involve a nanometric AlN film of less than 5 nm deposited onto three monolayers of MoS 2 . The heat treatment induces an unexpected chemical and structural nanometric reorganization at the interface, converting the initial lamellar MoS 2 film into a discontinuous covalently bonded MoN x O y film, followed by the appearance of metallic Mo nanoparticles at an elevated temperature. Subsequent MOVPE AlN regrowth on the annealed seed layer stacks enables the growth of thick AlN films of up to 600 nm with a mosaicity of less than 0.3°without delamination or cracks. This approach not only facilitates the integration of thick AlN films on Si-based wafers but also opens avenues for growing III−N or other 3D materials on Si through the intercalation of 2D materials. KEYWORDS: highly oriented ALD MoS 2 , highly oriented AlN, sputtered AlN, MOVPE AlN growth, van der Waals interface, NH 3 heat treatments, RF acoustic filter

show abstract

“…High defect densities and cracking of films exceeding 1 μm in thickness are related issues that still need to be solved in the epitaxy process. , A process window for high-quality growth of GaN/AlN by MSE has already been demonstrated. − Careful design of buffer layers and strain management is necessary to successfully grow high-quality and crack-free GaN/AlN on Si. ,, The integration of an Al seed layer into the process flow has proven beneficial to improve the crystal quality of AlN-on-Si grown by various epitaxy technologies. Enhanced surface diffusion and avoiding the formation of SiN x layers promote the adhesion and subsequent growth of AlN layers. − However, a thorough investigation of the impact of this seed layer on the film morphology, structural quality, and film polarity of sputtered GaN/AlN/Si(111) stacks has rarely been reported. For wurtzite-type III-nitride-based electronic devices, such as high electron mobility transistors (HEMTs), the polarization direction along the c -axis is a key property that must be controlled reliably as it determines the direction of the internal electrical field and thus the device design.…”

Section: Introductionmentioning

confidence: 99%

III-Nitride Magnetron Sputter Epitaxy on Si: Controlling Morphology, Crystal Quality, and Polarity Using Al Seed Layers

Pingen,

Wolff,

Mohammadian

et al. 2024

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Group III-nitride semiconductors have been subject of intensive research, resulting in the maturing of the material system and adoption of III-nitrides in modern optoelectronics and power electronic devices. Defined film polarity is an important aspect of III-nitride epitaxy as the polarity affects the design of electronic devices. Magnetron sputtering is a novel approach for cost-effective epitaxy of IIInitrides nearing the technological maturity needed for device production; therefore, control of film polarity is an important technological milestone. In this study, we show the impact of Al seeding on the AlN/Si interface and resulting changes in crystal quality, film morphology, and polarity of GaN/AlN stacks grown by magnetron sputter epitaxy. X-ray diffraction measurements demonstrate the improvement of the crystal quality of the AlN and subsequently the GaN film by the Al seeding. Nanoscale structural and chemical investigations using scanning transmission electron microscopy reveal the inversion of the AlN film polarity. It is proposed that N-polar growth induced by Al seeding is related to the formation of a polycrystalline oxygen-rich AlN interlayer partially capped by an atomically thin Si-rich layer at the AlN/Si interface. Complementary aqueous KOH etch studies of GaN/AlN stacks demonstrate that purely metal-polar and N-polar layers can be grown on a macroscopic scale by controlling the amount of Al seeding.

show abstract

Demonstration of lateral epitaxial growth of AlN on Si (1 1 1) at low temperatures by pulsed reactive sputter epitaxy

Cited by 12 publications

References 22 publications

Sputter Epitaxy of AlN and GaN on Si(111)

Sputter Epitaxy of AlN and GaN on Si(111)

Crack-Free AlN Film Grown on Sputtered-AlN/2D MoS₂ Seed Layers on a Si(100)-Based Wafer: Implications for Radio-Frequency Acoustic Filters

III-Nitride Magnetron Sputter Epitaxy on Si: Controlling Morphology, Crystal Quality, and Polarity Using Al Seed Layers

Contact Info

Product

Resources

About

Demonstration of lateral epitaxial growth of AlN on Si (1 1 1) at low temperatures by pulsed reactive sputter epitaxy

Cited by 12 publications

References 22 publications

Sputter Epitaxy of AlN and GaN on Si(111)

Sputter Epitaxy of AlN and GaN on Si(111)

Crack-Free AlN Film Grown on Sputtered-AlN/2D MoS2 Seed Layers on a Si(100)-Based Wafer: Implications for Radio-Frequency Acoustic Filters

III-Nitride Magnetron Sputter Epitaxy on Si: Controlling Morphology, Crystal Quality, and Polarity Using Al Seed Layers

Contact Info

Product

Resources

About

Crack-Free AlN Film Grown on Sputtered-AlN/2D MoS₂ Seed Layers on a Si(100)-Based Wafer: Implications for Radio-Frequency Acoustic Filters