Low-temperature full wafer adhesive bonding

Abstract

We have systematically investigated the influence of different bonding parameters on void formation in a low-temperature adhesive bonding process. As a result of these studies we present guidelines for void free adhesive bonding of 10 cm diameter wafers. We have focused on polymer coatings with layer thicknesses between 1 µm and 18 µm. The tested polymer materials were benzocyclobutene (BCB) from Dow Chemical, a negative photoresist (ULTRA-i 300) and a positive photoresist (S1818) from Shipley, a polyimide (HTR3) from Arch Chemical and two different polyimides (PI2555 and PI2610) from DuPont. The polymer material, the bonding pressure and the pre-curing time and temperature for the polymer significantly influence void formation at the bond interface. High bonding pressure and optimum pre-curing times/temperatures counteract void formation. We present the process parameters to achieve void-free bonding with the BCB coating and with the ULTRA-i 300 photoresist coating as adhesive materials. Excellent void-free and strong bonds have been achieved by using BCB as the bonding material which requires a minimum bonding temperature of 180 • C.

Microfluidic channel fabrication by PDMS-interface bonding

“…Benzocyclobutene (BCB) [3] and Teflonlike amorphous fluorocarbon polymer [4] are used as the 0964-1726/06/010112+05$30.00 © 2006 IOP Publishing Ltd Printed in the UK S112 adhesive layers to bond different materials such as silicon and glass. However, their required bonding temperature is still over 100 • C. SU-8 is another polymer that requires a bonding temperature of ∼95 • C [5].…”

Low Temperature Wafer-Level Metal Thermo-Compression Bonding Technology for 3D Integration

“…Since a layer of polymer or inorganic adhesive is always spun before bonding, it is very suitable for non-uniform surfaces and for bonding at low temperature. Benzocyclobutene (BCB) and SU-8 are the most common materials used in 3D integration, since high bonding strength can be easily achieved with these two polymer materials (Niklaus et al, 2001;Pan et al, 2002).…”

Ultra-thin DVS-BCB adhesive bonding of III-V wafers, dies and multiple dies to a patterned silicon-on-insulator substrate

“…Both thermoplastic polymers, like SU-8 [11] and thermosetting polymers, such as spin-on glass [12], polyimide and DVS-BCB (divinylsiloxane-bis-benzocyclobutene), are used as adhesives [13]. DVS-BCB is a good candidate for hybrid bonding because of its excellent physical properties such as low dielectric constant, low moisture absorption, low curing temperature, high degree of planarization, low level of ionic contaminants, high optical clarity, good thermal stability, excellent chemical resistance, and good compatibility with various metallization systems [13,14].…”

“…DVS-BCB is a good candidate for hybrid bonding because of its excellent physical properties such as low dielectric constant, low moisture absorption, low curing temperature, high degree of planarization, low level of ionic contaminants, high optical clarity, good thermal stability, excellent chemical resistance, and good compatibility with various metallization systems [13,14]. Early work by Frank Niklaus investigated the influence of different bonding parameters on void formation in low-temperature full-wafer adhesive bonding using DVS-BCB as the intermediate bonding material, both on unpatterned and patterned substrates, using micrometer thick bonding layers [15].…”