A new evaluation method of silicon wafer bonding interfaces and bonding strength by KOH etching

• Published in: Japanese Journal of Applied Physics Vol. 31; no. 4; pp. 969 - 974
• Main Authors: MITANI, K, FEIJOO, D, CHA, G, GÖSELE, U. M
• Format: Journal Article
• Language: English
• Published: Tokyo Japanese journal of applied physics 01-04-1992
• Subjects: Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Physics; Solid surfaces and solid-solid interfaces; Surface structure and topography; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Semiconductor materials; Crystal orientation; Chemical bond; Solid solid interface; Silicon Oxides; Defect; Selective etching; Silicon; Chemical etching; Experimental study; Wafer; Inorganic compound
• ISSN: 0021-4922; 1347-4065
• DOI: 10.1143/jjap.31.969

KOH anisotropic etching is used to study the interfaces of bonded silicon wafers. This method has been developed to detect the presence of bubbles or unbonded areas with a gap of less than 0.27 µm, which is the detection limit of an IR camera. Because of the anisotropic etching properties of KOH and the presence of interfacial oxide layers, the etching surface morphology is dependent on the crystallographic orientation of the cross section. Correlation of etching results to the bonding strength of silicon wafers with and without a thermally oxidized silicon layer is also discussed.