In-situ growth mode control of AlN on SiC substrate by sublimation closed space technique

Dojima, Daichi; Ashida, Kiwamu; Kaneko, Tadaaki

doi:10.1016/j.jcrysgro.2017.11.032

Cited by 8 publications

(5 citation statements)

References 15 publications

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“…For the AlN sublimation growth, the temperature, ΔT, and N2 pressure were set at 1870°C, 6.7 K/mm, and 30 kPa. a high-temperature gradient environment of 6.7 K/mm is applied to suppress unintentional SiC surface decomposition at the initial phase of AlN growth [8]. High-purity AlN powder manufactured by Toyo Aluminum K. K. was used as the source material.…”

Section: Methodsmentioning

confidence: 99%

A Novel Approach of Utilizing Mechanically Flexible SiC Substrate to Grow Crack-Free AlN Bulk Crystal by Thermal Strain Relaxation Functionality

Dojima

Matsubara²,

Minamiyama³

et al. 2022

MSF

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The fabrication of novel semiconductor seed crystals using hetero-epitaxial growth on substrates such as Si, sapphire, and SiC, which have been successfully grown to large diameter and high quality, is very attractive as a breakthrough technology. However, a critical issue in heteroepitaxial growth is the formation of cracks due to thermal stress caused by the difference in the thermal expansion coefficient between the substrate and the growth layer during the cooling process after growth. In this study, we propose a method to reduce thermal stress by using a "Flexible substrate," which is a substrate with mechanical flexibility enhanced by removing more than 80% of its volume with periodic through holes. Using this method, we obtained an AlN hetero-epitaxial growth layer with absolutely no cracks observed. This method is applicable not only for AlN on SiC but also for the fabrication of various new semiconductor materials.

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Section: Methodsmentioning

confidence: 99%

A Novel Approach of Utilizing Mechanically Flexible SiC Substrate to Grow Crack-Free AlN Bulk Crystal by Thermal Strain Relaxation Functionality

Dojima

Matsubara²,

Minamiyama³

et al. 2022

MSF

Self Cite

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“…Therefore, many studies have been dedicated to analyzing the growth of AlN crystals on SiC seeds. Various features of AlN crystals or thick films were reported. − In these studies, the AlN crystals are critically influenced by the initial AlN growth modes, which can be simply divided into two main types. One is that AlN nucleates on a flat SiC seed surface, , followed by a layer-by-layer growth without voids at the heterointerface between the AlN and SiC seed.…”

Section: Introductionmentioning

confidence: 99%

“…Various features of AlN crystals or thick films were reported. − In these studies, the AlN crystals are critically influenced by the initial AlN growth modes, which can be simply divided into two main types. One is that AlN nucleates on a flat SiC seed surface, , followed by a layer-by-layer growth without voids at the heterointerface between the AlN and SiC seed. The other is that AlN flakes nucleate and grow on top of the isolated SiC pyramids, − which were formed due to the anisotropic decomposition of the SiC seed at some surface regions during the initial AlN growth.…”

Section: Introductionmentioning

confidence: 99%

Comparative Study of AlN Crystals Grown on SiC Seeds with/without Voids at the Heterointerface

Han,

Zhang,

et al. 2024

Crystal Growth & Design

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AlN crystal growth on SiC seeds is an alternative approach for obtaining wafer-sized AlN crystals and has been demonstrated in experiments. Various characteristics of AlN crystals grown on SiC seeds were reported by different researchers, leading to complications in designing a reliable growth process. Here, we used comprehensive and comparative methods to reveal key factors affecting the characteristics of the AlN crystal. These include the initial SiC seed morphology evolved at the beginning of AlN crystal growth; in short, two typical morphologies were formed in the heterointerface between the SiC seed and AlN. One is AlN grown on a flat heterointerface, and the other is the AlN crystal developed from SiC pyramid islands formed due to the decomposition of the SiC seed under an AlN atmosphere. Such dissimilar interfaces result in differences in aspects such as the incorporated Si impurity content, strain, and uniformity of the grown AlN crystal. Significantly, a nearlinear decrease in both the Si content (0.005%/μm) and the strain (represented by a Raman peak blue shift of 0.0084 cm −1 /μm) with increasing AlN crystal thickness is found and well verified in a 1.1 mm-thick AlN crystal, which shows a narrow 112 arcsec full width at half-maximum in its (0002) X-ray rocking curve. Our results suggest that the AlN crystal grown on a flat SiC seed possesses more uniform physical properties, which are suitable for the growth of wafer-sized AlN crystals. The characteristics of AlN crystals grown on SiC seeds with/without voids at the heterointerface are studied comparatively, including a quantitative variation of Si doping contents, shift rates of the Raman peak position, and an fwhm of (0002), with increasing AlN crystal thickness. These results are important to understand the various phenomena observed in AlN crystals grown on SiC seeds.

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“…In the heterogeneous growth of AlN on SiC, Dojima et al indicated that growth modes could be controlled by temperature and pressure, and then realized that the reduction of dislocations is a virtue of one of the modes. 17 However, the temperature range for heterogeneous growth is completely different from the one for homogeneous growth, and these growth modes are not directly applicable to quality improvement in homogeneous growth. As has been found in heterogeneous growth, it is possible that the growth conditions and their matching relations, such as temperature, pressure, temperature gradient, 18 transport structure, 19 and growth rate 20 studied in the fundamental theory [21][22][23][24] of PVT growth, will determine the growth modes.…”

Section: Introductionmentioning

confidence: 99%

Realizing overgrowth in the homo-PVT process for 2 inch AlN single crystals

et al. 2022

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In-situ growth mode control of AlN on SiC substrate by sublimation closed space technique

Cited by 8 publications

References 15 publications

A Novel Approach of Utilizing Mechanically Flexible SiC Substrate to Grow Crack-Free AlN Bulk Crystal by Thermal Strain Relaxation Functionality

A Novel Approach of Utilizing Mechanically Flexible SiC Substrate to Grow Crack-Free AlN Bulk Crystal by Thermal Strain Relaxation Functionality

Comparative Study of AlN Crystals Grown on SiC Seeds with/without Voids at the Heterointerface

Realizing overgrowth in the homo-PVT process for 2 inch AlN single crystals

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