Effects of homogenous loading on silicon direct bonding

• Published in: Applied surface science 2011-06, Vol.257 (17), p.7693-7698
• Main Authors: Huang, Li-Yang, Ho, Kuan-Lin, Hu, Chen-Ti
• Format: Article
• Language: English
• Subjects: Anodic Bonder; Bonding; Bonding quality; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Dynamics; Exact sciences and technology; Homogenous load; Mechanical and acoustical properties; Nano-Imprint System; Nanocomposites; Nanomaterials; Nanostructure; Physical properties of thin films, nonelectronic; Physics; Silicon; Silicon direct Bonding; Stresses; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Wafers
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2011.04.011

► Applying a homogenous plane-stress using the Nano-Imprint System on the SDB process. ► Highly consistent interface energy of SDB pairs when applying a homogenous plane-stress. ► Improves bonding quality of point-stress bonded wafers by re-applying a plane-stress with Nano-Imprint System. The effect of a homogenous loaded stress on the bonding quality of silicon wafer pairs was investigated by employing a Nano-Imprint System and a homogenous plane-stress applied over the entire surface area of pre-cleaned wafers. In addition, the effects of variations in the applied homogenous stress (1, 10, 100, 500 psi) on the interface energy of the bonded pairs were examined using a dynamic blade insertion (DBI) method. Infrared imaging was used to evaluate the quality of the bonded interface of each bonded pair immediately after the bonding process and after allowing the bonded pairs to rest at room temperature for 80 h after bonding. The results indicated that the homogenous loading with the Nano-Imprint System further improved the bonding condition of wafer pairs that had been pre-bonded using an anodic bonder. Furthermore, the bonded pairs exhibited almost identical interfacial energies of about 0.2 Jm −2 when the homogenous stress was varied from 1 psi to 500 psi, which clearly indicates that the interfacial energy of bonded wafers is independent of the amount of stress applied by the homogenous loading process.