Novel hydrophilic SiO2 wafer bonding using combined surface-activated bonding technique

Low-temperature hydrophilic SiO2–SiO2 wafer bonding has been performed in vacuum by a new combined surface-activated bonding (SAB) technique. In this technique, wafers are irradiated by ion beam bombardment and simultaneously deposited with silicon by in situ silicon sputter deposition, and then terminated with Si–OH groups by water vapor exposure prior to bonding in vacuum. A surface energy of more than 1 J/m2 was achieved by 200 °C postbonding annealing. A void-free oxide intermediate layer with a thickness of about 15 nm was observed at the bonding interface by transmission electron microscopy (TEM). The increased bonding energy can be attributed to the greater number of Si–OH formed through hydroxylation of the silicon deposited on the SiO2 surfaces.

[1]  N St J Braithwaite,et al.  A Review of Hydrophilic Silicon Wafer Bonding , 2014 .

[2]  Modified diffusion bonding for both Cu and SiO2 at 150 °C in ambient air , 2010, 2010 Proceedings 60th Electronic Components and Technology Conference (ECTC).

[3]  U. Gösele,et al.  A Model of Low‐Temperature Wafer Bonding And Its Applications , 1996 .

[4]  F. Fournel,et al.  Measurement of bonding energy in an anhydrous nitrogen atmosphere and its application to silicon direct bonding technology , 2012 .

[5]  C. G. Armistead,et al.  Surface hydroxylation of silica , 1969 .

[6]  F. Fournel,et al.  Low temperature direct bonding: An attractive technique for heterostructures build-up , 2012, Microelectron. Reliab..

[7]  B. Hofflinger,et al.  Wafer fusion bonding and its application to silicon-on-insulator fabrication , 1991 .

[8]  Jian-Qiang Lu,et al.  Handbook of Wafer Bonding , 2012 .

[9]  Rajendra Singh,et al.  Wafer Direct Bonding: From Advanced Substrate Engineering to Future Applications in Micro/Nanoelectronics , 2006, Proceedings of the IEEE.

[10]  Ionut Radu,et al.  Study of the formation, evolution, and dissolution of interfacial defects in silicon wafer bonding , 2010 .

[11]  P. Lindner,et al.  Plasma Activated Wafer Bonding of Silicon: In Situ and Ex Situ Processes , 2006 .

[12]  Viorel Dragoi,et al.  Mechanisms for room temperature direct wafer bonding , 2013 .

[13]  P. Enquist,et al.  Room temperature SiO2∕SiO2 covalent bonding , 2006 .

[14]  Low-Temperature Direct CVD Oxides to Thermal Oxide Wafer Bonding in Silicon Layer Transfer , 2005 .

[15]  C. Tan,et al.  Effect of medium vacuum on low temperature wafer bonding , 2005 .

[16]  Chuan Seng Tan,et al.  PE-TEOS Wafer Bonding Enhancement at Low Temperature with a High- κ Dielectric Capping Layer of Al2O3 , 2011 .

[17]  Chuan Seng Tan,et al.  Microelectronics Thin Film Handling and Transfer Using Low-Temperature Wafer Bonding , 2005 .

[18]  J. Lasky.  Wafer bonding for silicon‐on‐insulator technologies , 1986 .

[19]  C. Tan,et al.  Mathematical model of low-temperature wafer bonding under medium vacuum and its application , 2005 .

[20]  T. Gessner,et al.  Plasma‐Activated Bonding , 2012 .

[21]  W. Maszara,et al.  Bonding of silicon wafers for silicon‐on‐insulator , 1988 .

[22]  C. Tan,et al.  Comparison of medium-vacuum and plasma-activated low-temperature wafer bonding , 2006 .

[23]  Kuan-Neng Chen,et al.  Low-temperature thermal oxide to plasma-enhanced chemical vapor deposition oxide wafer bonding for thin-film transfer application , 2003 .

[24]  Laurent Vandroux,et al.  Low temperature direct bonding mechanisms of tetraethyl orthosilicate based silicon oxide films deposited by plasma enhanced chemical vapor deposition , 2012 .

[25]  Laurent Vandroux,et al.  Treatments of Deposited SiOx Surfaces Enabling Low Temperature Direct Bonding , 2013 .

[26]  C. S. Tan,et al.  Low Temperature Wafer Bonding of Low-κ Carbon Doped Oxide (CDO) for High Performance 3D IC Application , 2011 .

[27]  T. Suni,et al.  Effects of Plasma Activation on Hydrophilic Bonding of Si and SiO2 , 2002 .

[28]  Q.-Y. Tong,et al.  Wafer Bonding and Layer Splitting for Microsystems , 1999 .

[29]  R. Maeda,et al.  Room-Temperature Bonding of Oxide Wafers by Ar-beam Surface Activation , 2008 .

[30]  U. Gösele,et al.  Formation of interface bubbles in bonded silicon wafers: A thermodynamic model , 1992 .

[31]  Tadatomo Suga,et al.  Investigation of fluorine containing plasma activation for room-temperature bonding of Si-based materials , 2012, Microelectron. Reliab..

[32]  Tadatomo Suga,et al.  Surface activation-based nanobonding and interconnection at room temperature , 2011 .