Limitations during Vapor Phase Growth of Bulk (100) 3C-SiC Using 3C-SiC-on-SiC Seeding Stacks

Abstract

The growth of 3C-SiC shows technological challenges, such as high supersaturation, a silicon-rich gas phase and a high vertical temperature gradient. We have developed a transfer method creating high-quality 3C-SiC-on-SiC (100) seeding stacks, suitable for use in sublimation “sandwich” epitaxy (SE). This work presents simulation data on the change of supersaturation and the temperature gradient between source and seed for the bulk growth. A series of growth runs on increased source to seed distances was characterized by XRD and Raman spectroscopy. Results show a decrease in quality in terms of single-crystallinity with a decrease in supersaturation. Morphology analysis of as-grown material indicates an increasing protrusion dimension with increasing thickness. This effect limits the achievable maximal thickness. Additional polytype inclusions were observed, which began to occur with low supersaturation (S ≤ 0.06) and prolonged growth (increase of carbon gas-species).

Overgrowth of Protrusion Defects during Sublimation Growth of Cubic Silicon Carbide Using Free-Standing Cubic Silicon Carbide Substrates

“…While the surface morphology shows no changes, the dimension of the pyramidal protrusion defects increases. The lateral expansion of these defects with increasing layer thickness is related to the structure of this defect and has been described in previous studies. , …”

“…The lateral expansion of these defects with increasing layer thickness is related to the structure of this defect and has been described in previous studies. 24,25 Protrusion defects represent one of the major challenges in exploiting the 3C-SiC material system. The origin of these defects is due to the fabrication of the seed layers for sublimation growth.…”

New Approaches and Understandings in the Growth of Cubic Silicon Carbide

“…They found that for the heteroepitaxial growth of 3C-SiC on (0001)-oriented 6H—SiC, a supersaturation as high as s = 0.4 is necessary to achieve a high yield. Based on the development regarding the carbon materials databases, this value was revised to s = 0.24 [ 32 ]. In the case of homoepitaxial sublimation growth on seeds already containing the cubic polytype, a supersaturation higher than s = 0.1 was found to be suitable to ensure stable growth.…”

“…Using a transfer process developed at FAU Erlangen-Nurnberg [ 31 ], growth of the bulk 3C-SiC with reasonable dimensions and thicknesses was demonstrated using such seeding material and the approach of closed space PVT (CSPVT), [ 26 , 32 ], in its original concept also known as Sublimation epitaxy (SE), was utilized.…”

“…( b ) Schematic of the seed manufacturing process. Starting from 3C grown by CVD on a silicon substrate, the silicon is removed by chemical wet etching and subsequently the thin freestanding 3C layer is merged to a polycrystalline SiC carrier for mechanical stabilization and backside protection (see Reference [ 32 ]).…”