Variation in atomistic structure due to annealing at diamond/silicon heterointerfaces fabricated by surface activated bonding

Abstract

Chemical composition around diamond/silicon heterointerfaces fabricated by surface activated bonding at room temperature is examined by energy dispersive X-ray spectroscopy under scanning transmission electron microscopy. Iron impurities segregate just on the bonding interfaces, while oxygen impurities segregate off the bonding interfaces in the silicon side by 3-4 nm. Oxygen atoms would segregate so as to avoid the amorphous compound with silicon and carbon atoms, self-organized at the bonding interfaces in the surface activated bonding process. When the bonding interfaces are annealed at 1000 oC, the amorphous compound converts into cubic silicon carbide (c-SiC), and nano-voids 5-15 nm in size are formed at the region between silicon and c-SiC, at which the oxygen density is high before annealing. The nano-voids can act as the gettering sites in which metal impurities are preferentially agglomerated, and the impurity gettering would help to improve the electronic properties of the bonding interfaces by annealing.

High Thermal Stability and Low Thermal Resistance of Large Area GaN/3C‐SiC/Diamond Junctions for Practical Device Processes

“…Previous studies have reported the transformation of the amorphous carbon and amorphous Si layers at the interface fabricated using the SAB method into a SiC layer after a high-temperature annealing process. [54][55][56] The carbon atoms involved in this reaction originated from the amorphous carbon layer formed on the diamond surface due to Ar plasma irradiation. The formation of the amorphous carbon layer on the diamond surface following plasma irradiation has been reported in the literature.…”

Heterojunctions fabricated by surface activated bonding–dependence of their nanostructural and electrical characteristics on thermal process

“…18(c)]. 103) We also performed micro-Raman spectroscopy measurements of diamond//Si junctions using a × 100 objective lens and a 488 nm laser. The diameter of the laser spot on the sample surface was ≈2 μm.…”

“…(Color online) C 1s and Si2p spectra of diamond surfaces exposed by dissolving Si wafers of (a) an as-bonded and (b) a 1000 °C annealed diamond// Si junction. 101) (c) A HAADF-STEM image of a 1000 °C annealed diamond (100) //Si (100) junction 103).…”

Surface-activated direct bonding of diamond (100) and c-plane sapphire with high transparency for quantum applications

“…Alternatively, dry process-based bonding is a possible choice for bonding diamond (100) to mother substrates. Atomic diffusion bonding (ADB) [10][11][12][13][14][15][16][17] and surface activation bonding (SAB) 7,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] have been reported for various material combinations. ADB is a promising technique for some applications and can ensure chemical bond formation by atom diffusion.…”