# Fileset

[阿部さん　ICSCRM2026_abstract.docx](https://mdr.nims.go.jp/filesets/81093bdd-1073-48ba-a20f-49433ebf746b/download)

## Creator

Takehisa MINOWA, [Taichi ABE](https://orcid.org/0000-0002-5065-0939)

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[A New Understanding of the Growth Mechanism of Sublimation-Type SiC Single Crystals and Recommendations for New Manufacturing Equipment](https://mdr.nims.go.jp/datasets/e53e62df-cb36-4326-bca1-81622ce0e319)

## Fulltext

A New Understanding of the Growth Mechanism of Sublimation-Type SiC Single Crystals and Recommendations for New Manufacturing EquipmentT. Minowa1), T. Abe2) 1) Minowa Material Inspiring2-16-36 Komatsu, Echizen, Fukui, Japan2) National Institute for Materials Science (NIMS)1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, JapanE-mail: ttminowa@nx.ttn.ne.jpThe basic mechanism of the SiC sublimation method has conventionally been understood as follows [1]: SiC powder, placed in a sealed graphite crucible, decomposes into Si2C, SiC2, Si and C molecular species at temperatures above 2000°C [2]. Of these, the gaseous components Si2C, SiC2 and Si rise within the crucible and grow as SiC on the upper seed crystal surface in the lower-temperature region. At this time, C cannot evaporate and remain within the raw material powder. Because these carbon particles are extremely fine, they float and adhere to the growth surface, causing crystal defects. Furthermore, when the rising Si vapor component condenses, it forms droplets on the growth surface, causing micropipes and various crystal defects, and even eroding the crucible and graphite fixture.To further deepen our understanding of this sublimation method, we investigated the high-temperature reaction between Si and C at around 100 Torr. We performed the sublimation method under various conditions and analyzed the metallic structure of the raw material residue in the crucible using scanning electron microscopy and X-rays. As a result, a new Si-C phase diagram (Figure 1), different from conventionally considered phase diagrams [3] [4], was devised. This made it possible to explain various phenomena in conventionally known sublimation crucibles. Furthermore, a phase diagram (Figure 2) was created using thermodynamic calculations with Pandat, and the validity of the phase diagram in Figure 1 obtained experimentally was examined.According to the phase diagram in Figure 1, when SiC is heated, there is a temperature range in which only SiC gas of stoichiometric composition is produced, without the generation of C and Si gas. When this SiC gas phase is heated to an even higher temperature, it decomposes into Si and C. Also, the SiC gasification temperature and the SiC deposition temperature are directly adjacent. From this understanding, a new concept for a sublimation furnace apparatus and reaction vessel can be derived. The sublimation furnace proposed in this report has a flat plate heater installed at the bottom of the crucible so that the temperature is highest at the bottom of the crucible, while also having a structure in which the temperature is uniform in the radial direction. This allows the raw material SiC powder to be kept at a temperature above the temperature at which SiC gas is generated, while simultaneously being below the temperature at which Si and C decompose. This enables the sublimation and precipitation reactions to proceed while preventing the generation of Si gas and C fine powder. Furthermore, since the gasification temperature and precipitation temperature of SiC are close together, it is considered preferable to place the SiC raw material and seed crystal as close together as possible, as shown in Figure 4.These apparatuses, which consider the phase diagram in Figure 1, are expected to enable the stable and rapid growth of SiC single crystals with excellent crystallinity.[1] Jhon W. Palmour, Tutorial P14, ICSCRM in Giardini Naxos (2015)[2] J. Drowart, G. De Maria and Mark G. Inghram, J. Chem. Phys. 29, 1015 (1958)[3] E. Fromm and E. Gebhardt Gase and Kohlenstoff in Metallen, ⅡDaten Spring-Verlag (1976)[4] R.W. Olesinski and G.J. Abbaschian, Binary Alloy Diagrams, 2nd. ed. (1996)      Fig. 1.  Si-C phase diagram obtained in this experimennt                   Fig. 2. Si-C phase diagram obtained by thermodynamic calculationsFig. 3.  A new sublimation furnace proposed in this studyFig. 4. Internal structure of a graphite crucibleimage3.pngimage4.pngimage1.pngimage2.png