Phase identification of micro and macro bubbles at the interface of directly bonded GaAs on sapphire

• Published in: Journal of materials science Vol. 33; no. 8; pp. 2073 - 2077
• Main Authors: SENZ, S, KOPPERSCHMIDT, P, KÄSTNER, G, HESSE, D
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01-04-1998; Springer Nature B.V
• Subjects: Applied sciences; Arsenic; Bond energy; Bonding agents; Bubbles; Chemical composition; Cleaning agents; Composition; defects and impurities; Condensed matter: structure, mechanical and thermal properties; Electron diffraction; Electron energy loss spectroscopy; Electronics; Energy dissipation; Energy measurement; Exact sciences and technology; Gallium oxides; Heating; Materials science; Metallization, contacts, interconnects; device isolation; Microelectronic fabrication (materials and surfaces technology); Organic chemistry; Photomicrographs; Physics; Sapphire; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Solid surfaces and solid-solid interfaces; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Van der Waals forces; X ray analysis; Crystal defects; Gallium arsenides; Inorganic compounds; Phase studies; Binary compounds; Solid-solid interfaces; Experimental study; Heat treatments; Substrates; Wafer bonding; Bubbles; Interface reaction; III-V semiconductors
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1023/A:1004310917627

Direct wafer bonding (DWB) of 3″ GaAs and R-cut sapphire was performed in a microcleanroom using ultra pure water as cleaning agent. The initial bonding is mediated by Van der Waals forces and hydrogen bridges. The bond energy is released by subsequent heating up to temperatures of 500°C. During heating the formation of macroscopic bubbles at the interface was observed. Details of the interface structure were investigated by cross-sectional as well as plan-view transmission electron microscope (TEM) micrographs. The chemical composition of the elements at the interface was measured by energy dispersive X-ray analysis (EDX) and electron energy loss spectroscopy (EELS). A high density of micro bubbles in bonded areas, a network of micro channels in the transition region and macro bubbles in debonded areas could be distinguished. The macro bubbles are filled with a porous oxide. X-ray diffraction (XRD) and selected area electron diffraction (SAED) revealed the growth of textured γ-Ga2O3 and elemental arsenic. © 1998 Chapman & Hall