Low temperature direct bonding mechanisms of tetraethyl orthosilicate based silicon oxide films deposited by plasma enhanced chemical vapor deposition

Bonding behaviour and surface adhesion mechanisms of tetraethyl orthosilicate silicon oxide films are investigated. Prior to the bonding, infrared absorption spectroscopy was used to assess chemical composition of the bonding layers. The incorporation of −OH groups during the deposition process and the moisture absorption is shown and a specific effect of the applied RF power is highlighted. A strong correlation is found between trapped species and the evolution of the bonded layers during subsequent thermal annealing. The first observed phenomenon is an overall hardness reduction of the film deposited at low RF power which results in an increase of local adhesion area, hence an enhancement of the bonding energy. In the meantime, in this configuration water production is promoted in the volume of the film through silanol condensation and silicon oxidation occurs at the interface between the bonding layer and the silicon bulk. As a by-product of this reaction, hydrogen is released and it migrates towards t...

[1]  Luciana Capello,et al.  Rough Surface Adhesion Mechanisms for Wafer Bonding , 2006 .

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

[3]  D. Hamann,et al.  Physics and chemistry of silicon wafer bonding investigated by infrared absorption spectroscopy , 1996 .

[4]  D. Lafond,et al.  Mechanism of Thermal Silicon Oxide Direct Wafer Bonding , 2009 .

[5]  Young-soo Park,et al.  Evolution of residual stress in plasma-enhanced chemical-vapor-deposited silicon dioxide film exposed to room air , 1999 .

[6]  M. Reiche,et al.  Wafer bonding of silicon wafers covered with various surface layers , 2000 .

[7]  J. K. Srivastava,et al.  Low‐temperature growth of silicon dioxide films: A study of chemical bonding by ellipsometry and infrared spectroscopy , 1987 .

[8]  M. Rivoire,et al.  Physics of direct bonding: Applications to 3D heterogeneous or monolithic integration , 2010 .

[9]  Olivier Bonnaud,et al.  Tetraethylorthosilicate SiO2 films deposited at a low temperature , 2000 .

[10]  F. Fournel,et al.  Hydrophilic low-temperature direct wafer bonding , 2008 .

[11]  Didier Landru,et al.  Low temperature direct wafer to wafer bonding for 3D integration: Direct bonding, surface preparation, wafer-to-wafer alignment , 2010, 2010 IEEE International 3D Systems Integration Conference (3DIC).

[12]  J. Raskin,et al.  PECVD oxide as intermediate film for wafer bonding: Impact of residual stress , 2010 .

[13]  C. Vallée,et al.  Direct observation of water incorporation in PECVD SiO2 films by UV-Visible ellipsometry , 1997 .

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

[15]  Bernard Aspar,et al.  High-energy x-ray reflectivity of buried interfaces created by wafer bonding , 2001 .

[16]  N. Miki,et al.  Effect of nanoscale surface roughness on the bonding energy of direct-bonded silicon wafers , 2003 .

[17]  E. Amanatides,et al.  RF power effect on TEOS/O2 PECVD of silicon oxide thin films , 2005 .