Specific Process Knowledge/Bonding

Choose bonding method

• Eutectic bonding
• Fusion bonding
• Anodic bonding

Comparing the three bonding methods in the EVG NIL

.	Eutectic bonding	Fusion bonding	Anodic bonding
General description	For bonding two substrates by use of an interphase that makes an eutecticum.	For bonding two identical materials.	For bonding Si and Glass.
Bonding temperature	Depending on the eutecticum 310$o^{}$C to 400$o^{}$C.	Depending on defects 50$o^{}$C to 400$o^{}$C.	Depending on the voltage 300$o^{}$C to 500$o^{}$C Standard is 400$o^{}$C.
Annnealing temperature	No annealing	1000$o^{}$C in the bond furnace C3	No annealing
Materials possible to bond	Bonding of substrates is done by use of the eutectica Au/Si, Au/Sn and Au/Sn/Ni	Si/Si, SiO${}_2$/SiO${}_2$	Si/Pyrex (glass)
Substrate size	Up to 6" (aligning only possible for 4" and 6")	Up to 6" (aligning only possible for 4" and 6")	Up to 6" (aligning only possible for 4" and 6")
Cleaning	Cleaning by N2.	Wet chemical cleaning, IMEC.	Cleaning by N2.
IR alignment	Double side polished wafers.	Double side polished wafers.	Not relevant.

Choose equipment

• EVG NIL
• C3 furnace anneal bond.