Fast growth of n-type 4H-SiC bulk crystal by gas-source method

Hoshino, Norihiro; Kamata, Isaho; Tokuda, Yasutaka; Makino, Emi; Kanda, Takahiro; Sugiyama, Naohiro; Kuno, Hironari; Kojima, Jun; Tsuchida, Hidekazu

doi:10.1016/j.jcrysgro.2017.08.004

Cited by 19 publications

(22 citation statements)

References 39 publications

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“…We have demonstrated that the high-temperature gassource method, also known as high-temperature chemical vapor deposition, 15) is capable of achieving high growth rates of up to >9 mm h −1 by increasing the partial pressure of source gases at a high temperature exceeding 2500 °C. 16) We also confirmed that the density of TSDs/TMDs was reduced during crystal growth at ∼3 mm h −1 based on this technique. Accordingly, the gas-source method has a potential to obtain a high growth rate while maintaining or reducing the dislocation density.…”

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confidence: 77%

“…An experimental configuration for the gas-source method is shown in our previous paper. 16) A 4°off-cut toward the á ñ 1120 ( ) 0001 C-face 4H-SiC seed crystal with a 2 inch diameter was prepared by the PVT method, and an H 2 -SiH 4 -C 3 H 8 -N 2 gas system was supplied to a growth reactor. The crystal growth was carried out by heating the hot-zone of the reactor, followed by forming an intermediate layer by gradually increasing the input partial pressure of source gases and growing the constant-growth layer for one hour by retaining a constant SiH 4 source gas partial pressure of 11 kPa, a C/Si ratio of 0.90 and a seed temperature of 2550 °C.…”

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confidence: 99%

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Reduction in dislocation densities in 4H-SiC bulk crystal grown at high growth rate by high-temperature gas-source method

Hoshino

Kamata

Kanda

et al. 2020

Appl. Phys. Express

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We performed fast growth of a 4H-SiC crystal using the gas-source method and investigated the crystal to reveal changes in dislocation densities along the growth direction. The remarkable reduction in densities of threading and basal plane dislocations to be less than 1/10 and 1/20, respectively, was confirmed in the crystal grown at ∼3 mm h−1. The change in radial distribution of threading dislocations indicates enhanced reduction in dislocation densities within an area containing high density dislocations. We discussed possible mechanisms which could explain declining densities of threading dislocations according to the results obtained by classifying threading dislocations into each Burgers vector.

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confidence: 77%

mentioning

confidence: 99%

Reduction in dislocation densities in 4H-SiC bulk crystal grown at high growth rate by high-temperature gas-source method

Hoshino

Kamata

Kanda

et al. 2020

Appl. Phys. Express

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“…3,16,17 Synchrotron X-ray topography (XRT) observations demonstrate that most TDs are generated at the initial stage of crystal growth as a result of growth condition discontinuities, such as temperature profile, C/Si ratio, and doping concentrations. 18,19 TDs are also found to replicate from TDs in the seed crystal. 3 Furthermore, the conversion from other kinds of defects to TDs is another important generation source of TDs during the single-crystal growth of 4H-SiC.…”

Section: Introductionmentioning

confidence: 80%

“…During the physical-vapor-transport (PVT) growth of 4H-SiC single crystals, TDs are formed under the thermal stress induced by the temperature gradient, as well as the misfit stress introduced by secondary precipitates, two-dimensional islands, polymorphs, and inclusions. ,, Synchrotron X-ray topography (XRT) observations demonstrate that most TDs are generated at the initial stage of crystal growth as a result of growth condition discontinuities, such as temperature profile, C/Si ratio, and doping concentrations. , TDs are also found to replicate from TDs in the seed crystal . Furthermore, the conversion from other kinds of defects to TDs is another important generation source of TDs during the single-crystal growth of 4H-SiC.…”

Section: Introductionmentioning

confidence: 99%

Nucleation of Threading Dislocations in 4H-SiC at Early Physical-Vapor-Transport Growth Stage

Shao

Chen³

et al. 2023

Crystal Growth & Design

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In this work, we identify the nucleation mechanism of threading dislocations (TDs) associated with stacking faults (SFs) and 15R-SiC at the early growth stage of 4H-SiC single crystals grown by the physical vapor transport (PVT) technology. By combining molten KOH etching and photochemical etching, we successfully reveal etch pits of TDs and linear etch patterns of SFs on the (112̅0) surface of 4H-SiC single crystals. Systematic investigations based on transmission electron microscopy (TEM) observations and Raman analysis indicate that the Si–C bilayer stacking sequence of SFs is (3, 2) in Zhdanov’s notation. The accumulation of SFs (3, 2) gives rise to the polymorph fluctuation and thus the formation of 15R-SiC at the early PVT growth stage of 4H-SiC single crystals. Quantitative stress analyses indicate that the strain field distributions along the SFs (3, 2) and the 15R-/4H-SiC interfaces are inhomogeneous, which give rise to the nucleation of TDs and low-angle grain boundaries (LAGBs), respectively. The nucleation of LAGBs releases the high stress at the 15R-/4H-SiC interface, which facilities the following 4H-SiC single-crystal growth. Our work indicates that the avoidance of polymorph fluctuation is important to the reduction of TDs at the early growth stage of PVT-grown 4H-SiC single crystals.

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“…However, unlike the solution method, the gas phase material preparation is faced with lots of difficulties, such as the inability to observe directly, the vast change of raw material state, the deterioration of thermal field conditions during processing and the difficulty in regulating [ 9 , 10 , 11 ]. Therefore, it is not easy to increase the thickness and maintain high quality simultaneously and the potential of lifting space is limited in a short period of time [ 12 ]. SiC crystal growth has a natural habit of diameter expansion, so the expansion of crystal size has been the main direction in its industrialization in the past 30 years, from the initial crystalline grain to a centimeter-sized single crystal.…”

Section: Introductionmentioning

confidence: 99%

Design and Optimization of Thermal Field for PVT Method 8-Inch SiC Crystal Growth

Zhang

Cai

et al. 2023

Materials

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As a wide bandgap semiconductor material, silicon carbide has promising prospects for application. However, its commercial production size is currently 6 inches, and the difficulty in preparing larger single crystals increases exponentially with size increasing. Large-size single crystal growth is faced with the enormous problem of radial growth conditions deteriorating. Based on simulation tools, the physical field of 8-inch crystal growth is modeled and studied. By introducing the design of the seed cavity, the radial temperature difference in the seed crystal surface is reduced by 88% from 93 K of a basic scheme to 11 K, and the thermal field conditions with uniform radial temperature and moderate temperature gradient are obtained. Meanwhile, the effects of different processing conditions and relative positions of key structures on the surface temperature and axial temperature gradients of the seed crystals are analyzed in terms of new thermal field design, including induction power, frequency, diameter and height of coils, the distance between raw materials and the seed crystal. Meanwhiles, better process conditions and relative positions under experimental conditions are obtained. Based on the optimized conditions, the thermal field verification under seedless conditions is carried out, discovering that the single crystal deposition rate is 90% of that of polycrystalline deposition under the experimental conditions. Meanwhile, an 8-inch polycrystalline with 9.6 mm uniform deposition was successfully obtained after 120 h crystal growth, whose convexity is reduced from 13 mm to 6.4 mm compared with the original scheme. The results indicate that the optimized conditions can be used for single-crystal growth.

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Fast growth of n-type 4H-SiC bulk crystal by gas-source method

Cited by 19 publications

References 39 publications

Reduction in dislocation densities in 4H-SiC bulk crystal grown at high growth rate by high-temperature gas-source method

Reduction in dislocation densities in 4H-SiC bulk crystal grown at high growth rate by high-temperature gas-source method

Nucleation of Threading Dislocations in 4H-SiC at Early Physical-Vapor-Transport Growth Stage

Design and Optimization of Thermal Field for PVT Method 8-Inch SiC Crystal Growth

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